Market validation of a strategy of compensatory … 186...Market validation of a strategy of compensatory gain for feeder pigs Final Report June 30, 2011 Marie-Josée Turgeon, M. Sc.,

Market validation of a strategy of

compensatory gain for feeder pigs

Final Report

June 30, 2011

Marie-Josée Turgeon, M. Sc., agr., CDPQ

in collaboration with

Dr. Frédéric Guay, Scientific Director, Université Laval

PRODUCTION TEAM Collaborators

Frédéric Guay, Ph. D., agr., Université Laval (scientific lead) Yan Martel-Kennes and Marquis Roy, La Coop fédérée Francis Simard, Nutreco Canada/Shur-Gain Nicolas Lafond, Aliments Breton Donald and Alain Lefebvre, Ferme Aldo (Gestion Lido) Michel Mercier Consultants Attending veterinarians for each farm Consultants or research professionals

Antoine St-Cyr, La Coop fédérée Mélanie Leduc, Nutreco Canada/Shur-Gain Johanie Fournier, Aliments Breton Isabelle Bélanger and Michel Mercier, Ferme Aldo Participating farms

Ferme Rosanges (La Coop fédérée) Ferme Laflamme et Gauthier (Nutreco Canada/Shur-Gain) Ferme Rémi Ouellet (Aliments Breton) Ferme Aldo (Gestion Lido) Financial partners

Porcima inc. Aliments Breton Nutreco Canada/Shur-Gain La Coop fédérée Ferme Aldo (Gestion Lido) Agriculture and Agri-food Canada through the Canadian Agricultural Adaptation Program

(CAAP). In Québec, the portion directed to the agricultural sector is managed by the Conseil pour le développement de l’agriculture du Québec. As well, part of the financing for the project was supplied by sectorial councils in Quebec, Ontario, Alberta and Saskatchewan who manage the Canadian Agricultural Adaptation Program (CAAP) on behalf of Agriculture and Agri-food Canada.

Project lead and writer

Marie-Josée Turgeon, CDPQ Collaborators at CDPQ

Sonia Goulet Joël Rivest Staff in the administrative department

ACKNOWLEDGMENTS This project could not have been carried out without financial backing from our partners whom we thank warmly. As well, we wish to thank Dr. Frédéric Guay of Université Laval for his role as scientific lead for the project along with all those who worked on the farms gathering data and following the project protocol. Their collaboration was irreplaceable and has allowed us to present the present report. As well, we wish to draw attention to the collaboration extended to us by the various feed mills involved in the project.

A portion of the financing for this project was underwritten by Agriculture and Agri-Food Canada through the Canadian Agricultural Adaptation Program (CAAP). In Quebec the portion directed to the agricultural sector is managed by the Conseil pour le développement de l’agriculture du Québec. Part of the financing for this project was supplied by sectorial councils in Quebec, Ontario, Alberta and Saskatchewan who manage the Canadian Agricultural Adaptation Program (CAAP) on behalf of Agriculture and Agri-food Canada.

© Centre de développement du porc du Québec inc. Legal deposit 2011 Bibliothèque et Archives nationales du Québec Library and Archives Canada ISBN 978-2-92227876-52-7

Market validation of a strategy of compensatory gain for feeder pigs i

TABLE OF CONTENTS

INTRODUCTION ....................................................................................................................... 1

Context................................................................................................................................. 1

Project goals ........................................................................................................................ 2

1ST PART – GENERAL METHODOLOGY AND RESULTS FOR EACH FARM .......................... 3

General methodology ........................................................................................................... 3

Farm 1.................................................................................................................................. 5

Description of operations specific to this farm and results............................................... 5

Farm 2.................................................................................................................................. 9

Description of operations specific to this farm and results............................................... 9

Farm 3.................................................................................................................................12

Description of operations specific to this farm and results..............................................12

Farm 4.................................................................................................................................17

Description of operations specific to this farm and results..............................................17

2ND PART – GENERAL DISCUSSION OF RESULTS OBTAINED ON THE FOUR FARMS .....21

Hog performance during the various growth phases............................................................21

Phase 1 .........................................................................................................................21

Phase 2 .........................................................................................................................21

Phase 3 .........................................................................................................................21

Phase 4 .........................................................................................................................21

Overall swine performance from entry to first shipment .......................................................21

Economic impact of using compensatory gain strategy on four farms .................................22

RECOMMENDATIONS .............................................................................................................23

APPENDIX 1 – FEED SPECIFICATIONS FOR THE FOUR FARMS ........................................25

ii Market validation of a strategy of compensatory gain for feeder pigs

TABLES Table 1 Hog performance over the various feeding phases prior to shipping (Farm 1) .......... 5

Table 2 Comparison of observed slaughter data for gilts and barrows in both experimental diets (Farm 1) ...................................................................................... 7

Table 3 Hog performance for the various feeding phases prior to shipping (Farm 2) ............. 9

Table 4 Comparison of slaughter data for gilts and barrows in both feed groups (Farm 2) .. 11

Table 5 Performance of hogs for the various feeding phases prior to shipping (Farm 3) ...... 13

Table 6 Comparison of slaughter data for gilts and barrows from both diets (Farm 3) ......... 15

Table 7 Hog performance over the various feeding phases prior to shipping (Farm 4) ........ 17

Table 8 Comparison of slaughter data for gilts and barrows in both diets ............................ 19

CHARTS

Chart 1 Differentials between groups: carcass revenue less feed cost (Farm 1) .................... 8

Chart 2 Differentials between the groups: carcass revenue less feed costs (Farm 2) .......... 12

Chart 3 Differentials between groups: carcass revenue less feed cost (Farm 3) .................. 16

Chart 4 Differentials between groups: carcass revenue less feed cost (Farm 4) .................. 20

Market validation of a strategy of compensatory gain for feeder pigs 1

INTRODUCTION Context In 2010, a team led by Dr. Frédéric Guay of Université Laval (Maude Richer-Lanciault, Jean-François Bernier, Robert Fillion, Marie-Josée Turgeon and Martin Lessard) published a report on the project “La restriction alimentaire chez le porc en engraissement : les impacts de la période et de la durée sur les performances techniques et sur le bilan alimentaire“ (Feed restriction on grower pigs: impact of period and duration on technical performance and on the food balance sheet). This project aimed at evaluating the effects of the period and the duration of a qualitative restriction of amino acids/phosphorus/calcium on the compensatory gain of grower pigs. The site for the project was a research station belonging to the Centre de recherche en sciences animales de Deschambault (Deschambault animal science research centre) in Deschambault, Quebec. The project aimed at comparing the performance of barrows fed with a conventional feeding program (control: start, growth, finishing 1 and finishing 2) versus a program restricted to three different periods (from 0 to 21 days: R0-21; from 21 to 49 days: R21-49 or from 0 to 49 days: R0-49). All of the pigs ate the same food, in unlimited supply, but in a different sequence depending on the process to be evaluated. The feed restriction was therefore qualitative only. During the restricted periods, the amounts of digestible lysine, available phosphorus and total calcium were restricted by about 30% compared to the nutritional requirements for the targeted period. The feed contained maze, wheat and soybean meal with no by-products. For this project, the average daily gain (ADG) and the feed conversion (FC) of the restricted pigs were less than those of the control group during the periods of restriction. At the end of the growing period, we observed no significant difference in overall performance measurements over the whole fattening period (ADG, FC) and the slaughter data from the various groups of hogs. Moreover, all of the pigs from the restricted groups rejected less nitrogen and phosphorus than the control pigs at the end of the growth period. By varying the prices of corn and soybean meal, we were able to carry out a simulation in order to determine the economic impact of the restriction on feed cost. The 21 to 49-day process is the one which allowed us to get the best feed cost in all of the pricing contexts used. Savings varied from $2.61 to $4.45 per pig. Taken as a whole, the results demonstrated that the overall performance was not affected by the restriction on digestible lysine, on available phosphorus and on calcium, and that the pigs were able to make up the growth delay caused by this qualitative restriction. Related to these results, the strategy which used compensatory gain also had a positive impact on the nitrogen and phosphorus environmental footprint and on the economic performance during fattening. In the current economic context, reducing the cost of production in the pork industry is probably the most important factor to ensure business viability for the future. Among the elements that make up the cost of production, livestock feed is the most important. Since reducing feeding costs by using food restriction between days 21 and 49 of the fattening process was a promising option according to the results presented in 2010, the research corporation Porcima expressed interest in validating the results on commercial farms. The present project was designed and carried out with this in mind.

2 Market validation of a strategy of compensatory gain for feeder pigs

Project goals The overall aim of the project was to corroborate commercially the results that had been obtained as part of the project “La restriction alimentaire chez le porc en engraissement : les impacts de la période et de la durée sur les performances techniques et sur le bilan alimentaire” More specifically, we wished to measure the following: overall hog performance (entry to slaughter) in two dietary programs (normal feeding

sequence compared to a restricted diet in the 40-65 kg phase) the impact of these two dietary programs on the margins of swine food costs at the end of

the period Our aim in carrying out this commercial corroboration in four barns simultaneously was to accelerate the validation of possible savings based on a dietary strategy and, thus, allow producers to have quick access to the results.


1ST PART – GENERAL METHODOLOGY AND RESULTS FOR EACH FARM General methodology This project was carried out on four commercial farms: Ferme Aldo, Aliments Breton - Ferme Rémi Ouellet, La Coop fédérée - Ferme Rosanges and Nutreco Canada/Shur-Gain - Ferme Laflamme et Gauthier. The feed mix was prepared by each of the nutritional specialists, working from the specifications predetermined by the scientific lead. The choice of ingredients that could be used in the recipes was also limited, given that the project had to validate the previous trial. Three of the four farms used customized pellets made in commercial feed mills. One farm manufactured its own mash feeds. The directives for feed and ingredients are set out in appendix 1. The feed served was mixed according to our specifications and therefore does not correspond to the usual feed provided by each farm. For this reason, the resulting performances cannot be linked to the usual performances from these growers.

The general protocol for this in-the-field validation trial was prepared by the scientific lead and the CDPQ project leader who then presented it to each farm. Regular follow-up on each farm was carried out along with occasional visits when the hogs were weighed. The data were compiled in a file prepared by the CDPQ based on information gathered on each farm.

The project involved two diets: control and restricted. The barrows and gilts were separated in the pens in order to verify the feeding scenarios on each of the sexes.

The hogs in the “control” scenario followed a four-phase feeding program: start (25 to 40 kg weight), growing (40 to 65 kg), finishing 1 (65 – 90 kg) and finishing 2 (90 kg to end). The hogs in the “restricted” scenario also followed a program with the same four feeds but allocated as follows: start (25 to 40 kg), finishing 2 (40 to 65 kg), finishing 1 (65 to 90 kg) and finishing 2 (90 kg to end). In order to change phases at the right weight on all farms, the feed quantities were calculated by nutrition specialists on each farm. Feed served to the pigs was weighed out each day, as were the quantities remaining at the end of the fattening period. The weanlings arrived at the various farms between the 16th of December and the 15th of February (a single entry date per farm). Average animal performances for pigs from each combination of gender by diet were calculated for each phase.

To calculate the animal performance, the results were separated into two periods. Under commercial conditions, many livestock farmers group the animals in pens during the shipping period in order to avoid leaving only a few pigs in their pens or in a room and to allow them to speed up preparation of the rooms for the next group. This practice was allowed to continue, among pigs from the same diet group. This adaptation obliged to separate the results into two periods in order to take into account the integrity of the experimental units. Statistical comparisons were carried out for the period from weanling entry to first shipping to slaughter based on data from all of the experimental units (experimental units or integrated pens). During the final weeks of shipping, the pigs in the same group had to be brought together on three of the four farms. Thus, only the descriptive statistics for the four combinations of gender by program are included from the start of shipping. The weight of dead pigs and number of days present were tallied in the calculations of animal performance and the average length of the period. Hogs were shipped to each farm’s usual abattoir. They were classified using the existing grids and agreements for each farm. If required, we used the data from the slaughterhouse files to reclassify hogs on the same grid, in order to make it easier to compare results (keeping in mind that selection of hogs for shipping was done based on the grower’s grid). We used the regular


Porc Qualité Québec grid number 225. This grid allows for maximum indices in the weight range from 90.0 to 104.9 kg. For the classification indices, the fat and muscle thickness and the meat yield, only data from carcasses that had really been tested were compiled. In order to measure the impact of our two dietary strategies, we calculated the margin on feed cost (income from carcasses minus feed cost). The income was calculated as follows, based on real weight paid for each farm: Carcass revenue = average carcass weight (in kg) x PQQ average index/100 x $1.6552 (price per kg of pork, week of 5 to 11 June 2011). The cost of feed was calculated based on the kilograms of feed distributed per pig in each phase and on the price of feed for each grower in the week of June 6, 2011. To carry out this calculation, we considered the total amount of feed consumed right up until the very end of shipping. This is not the same as the calculations of animal production performance which were carried out between weanling entry and the start of shipping. We purposely chose not to use adjusted and standardized animal production performance for specific weights so as to present the results exactly as we received them from each farm. Given this decision, it is unadvisable to compare animal performance among the farms. The results obtained from Ferme Aldo and from Ferme Rosanges were analyzed as a “random” arrangement using the “Mixed” procedure from SAS statistical software. The model was as follows: Yijk = µ + Bi + Cj +Dk + eijk where Yijk is the dependent variable, µ is the average of the variable, Bi is the gender, Cj is the dietary program, Dk is the pen and eij is the residual effect. Interactions between gender and the feeding program were also evaluated. In the case of grower Nutreco Canada/Shur-Gain, the effect of the pen was excluded since their pens were divided by gender. Significant differences and tendencies were determined to a value of P <0.05 and <0.10, respectively. For these farms, the experimental unit was the pen which was composed of 19 to 24 animals. The results obtained from Aliments Breton were analyzed as a “split-plot” arrangement using the SAS statistical software “Mixed“procedure. The model was as follows: Yijk = µ + Bi + Cj + eijk where Yijk is the dependent variable, µ is the average of the variable, Bi is the feeding program, Cj is the gender and eij is the residual effect. In this model, the main effect was the diet and the split-plot effect was the gender. For this farm, the experimental unit was the hog in the pen where the same diet was given. As for the other farms, the significant differences and the tendencies were determined by a value of P <0.05 and <0.10, respectively.


Farm 1 Description of operations specific to this farm and results In this trial, 494 pigs were separated into 26 pens located in two fattening rooms (19 pigs per pen, 7.4 sq.ft./pig). The barrows were separated from the gilts in 24 of the 26 pens. Thus, there were two mixed pens. These mixed pens were removed from the statistical analyses. Each pen on the farm was equipped with its own wet feeder. Feed was formulated in conformity to specifications set out in the Appendix. Because of the rate of animal growth, the second feeding phase, during which the feed restriction for pigs in the restricted group was carried out, lasted 18 days. The length of the period was similar for the control pigs (96.6 days) and for the restricted pigs (95.5 days). There was a problem with tail-biting in two pens during the last feeding phase (phase 4) and the farm managers had to intervene. Blocks of salt were placed in the affected pens. The problem decreased slightly but returned with a vengeance once the blocks were consumed. A few animals had physical after effects that required transfer to a hospital pen or euthanasia. The problem does not seem to be related to the feed restriction; it showed up at the end of the fattening period when the hogs had recovered from the restriction imposed during phase 2 and, more important, in both affected pens the animals were part of the control program (barrow control) and the restricted program (mixed restricted). Over the course of the growth period, 13 pigs died or were euthanized and 3 were removed from the trial and sent to the sick pen. The date and weight of the animals at the moment of death or of transfer were recorded and we took the kg of gain and the days of presence of these animals into account when we calculated the performance. The growth performances of the males and females based on the two dietary strategies were calculated for the period from the entry of weanlings up to the first shipping. The results are set out in table 1. Table 1 Hog performance over the various feeding phases prior to shipping (Farm 1)

Gilts Barrows Standard

deviation Control Restricted Control Restricted

Phase 1

Weanling weight at entry, kg 34.8 34.7 34.8 35.3 0.5

ADGa, kg/d 0.943 1.010 1.046 1.047 0.032

ADFI, kg/d 1.96 1.99 2.18 2.05 0.09

FCb 2.10 1.98 2.08 1.96 0.08

Weight at end of phasec, kg 48.0 48.8 49.5 49.9 0.7




Phase 2

ADGa, kg/d 0.903 0.884 1.008 0.979 0.023

ADFIa, kg/d 2.28 2.31 2.66 2.53 0.08

FC 2.52 2.62 2.65 2.62 0.06

Weight at end of phasea, kg 64.3 64.7 67.7 67.7 1.1

Phase 3

ADGa,d, kg/d 0.904 0.971 1.054 1.064 0.022

ADFIa, kg/d 2.46 2.57 3.02 2.94 0.05

FCc 2.74 2.65 2.88 2.77 0.09


Phase 4

ADG, kg/d 0.793 0.799 0.795 0.831 0.025

ADFIa, b, kg/d 2.51 2.38 2.81 2.64 0.06

FCa, b 3.18 2.99 3.54 3.19 0.07


Entry to 1st shipmente

ADGa, kg/d 0.869 0.896 0.947 0.957 0.014

ADFIa, kg/d 2.36 2.36 2.74 2.61 0.05

FCa, b 2.73 2.64 2.90 2.73 0.05 a Gender effect, P<0.05

b Diet effect, P<0.05

c Gender effect, P<0.10

d Diet effect, P<0.10

e These values were evaluated from entry of weanlings to first shipping.

If we look at the growth period from entry of the weanlings up until the first shipping of hogs, the feed restriction improved the feed conversion (FC) by 3% for the gilts (2.64 vs. 2.73) and by 6% for the barrows (2.73 vs. 2.90). The control hogs and the restricted hogs showed statistically similar average daily gains (ADG) and average daily feed intake (ADFI). As was to be expected, there were significant differences between the genders. The barrows consumed 320 g/d more feed than the gilts, had a superior weight gain (70 g/d) and their feed conversion was also greater than that of the gilts by 5%. These differences between genders can be observed through all phases of fattening. The animals on the restricted diet ate the finisher 2 feed instead of the grower feed during the second fattening phase. During the first phase, all pigs ate exactly the same feed. It is intriguing to see a significant diet-related difference in conversion show up at the end of the 1st phase given that entry weights for weanlings in the different groups were similar. A close examination of the farm data led to note that performances obtained from some pens in room 2 were not as good as others in the same room and in room 1. Because of this, a room effect was added into the statistical analysis model of the data. It is possible that a ventilation problem in the corner of


the barn may explain the differences. Nonetheless, this data is very interesting for the producer and his or her technical consultant who work on correcting the situation. During the restriction phase itself, even though there was no difference between the control and restricted groups, the ADG for gilts and restricted males was numerically less than that for the control group. Even if, on this farm, the length of this phase was only 18 days, it would have been expected to note a slowdown in growth or deterioration in feed conversion given that finishing feed 2 is not adapted to the needs of hogs of this weight. As well, it is interesting to note that the differences in feed conversion related to the restriction noted in the 1st phase had disappeared by the end of the 2nd phase. The examination of the data leads to confirm that the pigs attempted to compensate for the restriction in subsequent phases. In phase 3, the restricted gilts had a tendency (p<0.10) to have a better ADG than the control gilts (971 g/d vs. 904). The effect on the barrows was less apparent (1,064 g/d vs. 1,054). Feed conversion was not significantly different during the 3rd phase but, numerically, the restricted animals showed a conversion improvement of around 0.1, for both gilts and barrows. On the other hand, a significant increase in food efficiency related to the restriction was observed at the end of the 4th phase (gilts 6% and barrows 10%). Table 2 sets out the slaughter data for hogs in the four experimental groups. Since we had only one tattoo number per group, it was not possible to make statistical comparisons based on these parameters. The averages and standard deviations are set out. Just as for the animal performances, differences were also observed between the gilts and the barrows on every criterion. However, where carcass weight and classification index are concerned, the results are relatively similar between the control hogs and the restricted hogs. It would thus appear that the restriction imposed during the 2nd feeding phase affected the carcass characteristics only slightly. Table 2 Comparison of observed slaughter data for gilts and barrows in both

experimental diets (Farm 1)



Carcass weight, kg 101.3 101.5 103.2 103.4 4.99

Back fat, mm 15.22 15.17 18.54 19.88 3.01

Muscle, mm 70.29 69.57 68.28 68.18 5.33

Meat yield 62.68 62.67 61.04 60.44 1.50

PQQ classification index 109.7 109.8 111.0 110.8 5.83

PQQ classification index in the weight range 90.0 to 104.9 kg

92 hogs

111.0

91 hogs

111.1

81 hogs

113.0

86 hogs

113.2

Although statistical comparisons were not produced for these results, feed consumption data were compiled right up to the end of the growth period so that the differences in feed cost between the groups could be calculated. The results are set out in Chart 1. Over the course of the period, the female control group consumed a total of 244.5 kg of feed compared to 239.6 kg for the restricted group. For the control barrows, the total consumption was 262.9 kg of feed compared to 256.3 kg for the restricted barrows. Using the feeding strategy based on compensatory gain resulted in an improvement in margin on feed costs (carcass revenue minus


feed costs) averaging $2.96 ($2.83/hog for gilts and $3.09/hog for barrows). As well, the results demonstrate that feed costs are lower for gilts, leading to an improvement in margin on feeding costs of $0.55 per pig in favour of gilts compared to barrows.

2,83 $

3,09 $

2,96 $

0,55 $

0,00 $

0,50 $

1,00 $

1,50 $

2,00 $

2,50 $

3,00 $

3,50 $

femelles restreintes vs

femelles témoins

castrats restreints vs

castrat témoins

restreint vs témoin femelles vs castrats

Chart 1 Differentials between groups: carcass revenue less feed cost (Farm 1)

$3.09

$2.83 $2.96

$0.55

Restricted females

vs. control females

Restricted animals

vs. control animals

Restricted barrows

vs. control barrows

Females

vs. barrows


Farm 2 Description of operations specific to this farm and results A total of 853 pigs entered the barn. 156 of them were put in two rooms and divided among 12 pens (13 pigs per pen, 7.8 sq ft/pig). Weight and feed consumption were noted for each of the 156 pigs.

Feed was formulated in accordance with the specifications set out in Appendix 1. The 2nd feeding phase, where the feed restriction for the pigs in the restricted group was applied, lasted for 28 days.

It should be noted that, for this farm, all of the hogs were shipped on the same day. Thus, the length was the same for all of them: 92 days.

Throughout the period, there were no health or tail-biting problems. However, five pigs were removed from the trial and sent to the sick pen. The transfer dates were recorded but not the animal weight at the time of transfer. They were completely removed from the calculations. As well, four other pigs (all barrows) were not included in the statistical analyses in order to balance the average weights at the entry of pigs for each group.

The growth performances of males and gilts for both diets were calculated for the period of weanling entry until shipping. The results are set out in Table 3. Table 3 Hog performance for the various feeding phases prior to shipping (Farm 2)



Phase 1

Entry weighta, kg 33.7 33.3 36.1 35.2 0.4

ADGa, kg/d 0.804 0.829 0.959 0.935 0.031

ADFIa, kg/d 1.37 1.33 1.66 1.59 0.04

FC 1.76 1.94 1.78 1.72 0.15

Final weighta, kg 40.1 40.0 43.8 42.7 0.4

Phase 2

ADGa, kg/d 0.882 0.805 0.954 0.941 0.024

ADFIa, kg/d 1.86 1.77 2.23 2.13 0.05

FC 2.12 2.22 2.50 2.28 0.08

Final weighta, kg 64.8 62.5 70.6 68.9 0.8

Phase 3

ADGa, kg/d 0.897 0.916 1.013 1.026 0.025

ADFIa, kg/d 2.34 2.28 2.89 2.83 0.06

FC 2.66 2.48 2.90 2.83 0.11

Final weighta, kg 89.9 88.1 98.9 97.8 1.2




Phase 4

ADGa, kg/d 0.856 0.969 0.917 0.909 0.035

ADFIa, kg/d 2.52 2.61 3.06 3.04 0.07

FC 2.99 2.71 3.91 3.62 0.31

Final weighta, kg 114.0 115.3 124.5 123.1 1.4

Overall

ADGa, kg/d 0.873 0.890 0.959 0.955 0.015

ADFIa, kg/d 2.17 2.14 2.63 2.58 0.05

FC 2.48 2.39 2.75 2.71 0.06 a Gender effect, P<0.05

b Effect of feed program, P<0.05

c Effect of X gender interaction program, P<0.05

Overall, for the whole length of the growth period, the feed restriction had no significant effect on the feed conversion or on the ADG or on the average daily feed intake. Feed conversion was not significantly different between control pigs and restricted pigs at the end of the trial, but numerically the restricted animals showed an improvement in conversion of 0.1 for gilts and 0.05 for barrows. There were, however, significant differences between the genders. The barrows consumed 450 g/d more feed than the gilts, gained more weight (75 g/d) and their feed conversion was also greater by 11% than that of the gilts. These differences by gender were generally evident throughout all fattening phases. The results obtained for each feeding phase do not reveal any important differences. However, at the end of the feed restriction phase (phase 2), the restricted animals weighed significantly less (2.3 kg for the gilts and 1.7 kg for the barrows). On the other hand, the ADGs were not statistically different, although the gilts seem to have been affected more than the barrows. The animals made up for lost time in phase 3. Thus, at the end of this period, there was no weight difference at all between the restricted animals and the control group. However, during phase 4, the restricted gilts continued to compensate (significant gender x feed program interaction for the ADG) leading to a final weight slightly greater. Since all animals were shipped on the same day, the final weight of hogs was down 9.1 kg for the gilts. Table 4 sets out the slaughter data for the four trial groups. Since we had only one tattoo number per group, it was not possible to make statistical comparisons. Averages and standard deviations are presented. As with animal performance, we can see differences between gilts and barrows for all of the observed criteria. On the other hand, where carcass weight and classification index are concerned, the results for the control and restricted groups are very similar. It would thus appear that the restriction imposed during the 2nd feeding phase affected carcass characteristics only slightly.


Table 4 Comparison of slaughter data for gilts and barrows in both feed groups (Farm 2)




Back fat, mm 12.54 13.32 18.36 17.22 1.42

Muscle, mm 68.21 67.32 68.96 68.33 5.23

Meat yield 63.93 63.49 61.15 61.62 1.50


PQQ classification index for the weight range 90.0 to 104.9 kg

29 pigs

110.2

26 pigs

110.4

21 pigs

111.3

18 pigs

112.4

Feed intake right up to the end of the period was compiled. This allowed to calculating the differences in feeding costs between the groups. The results are set out in Chart 2. The gilt control group consumed, in total, 199.3 kg of feed over the period compared to 196.8 kg for the gilts in the restricted group. For the barrow control group, total consumption per hog was 242.3 kg of feed as against 237.1 kg for the restricted barrows. Using the feeding strategy based on compensatory gain made for an improvement in the margin on feed cost (carcass revenue less feed cost) of an average of $2.66/hog, broken down to $4.51/hog for gilts and $0.81/hog for barrows. The results demonstrate that, in spite of the fact that feed costs were lower for gilts, the fact that they were shipped the same day as the barrows that weighed less (8.4 kg average) led to a decrease in the margin on the costs of feed by $6.18/hog compared to the barrows.


4,51 $

0,81 $

2,66 $

-6,18 $

-8,00 $

-6,00 $

-4,00 $

-2,00 $

0,00 $

2,00 $

4,00 $

6,00 $


femelles témoins


castrat témoins


Chart 2 Differentials between the groups: carcass revenue less feed costs (Farm 2)

Farm 3 Description of operations specific to this farm and results The barn used for this project contained two sections with two rooms each. For purposes of the project, only one section was used. Each room in the section included pens that were part of the project and pens that were not. At entry, the 504 weanlings were divided up among the 24 pens equipped with a double wet feeder (7.2 sq. ft/pig). The barrows were placed in different pens than the gilts. Feed was formulated according to specifications set out in Appendix 1. For the hogs in the restricted group, the restriction phase (2nd phase of feeding) lasted 23 days. The length of the trial was 95.3 days for the control group and 97.5 days for the restricted group. An episode of violent coughing (pneumonia) occurred in the groups just as we were moving from phase one to phase two. The pathogen was not formally identified but the hogs responded to the drug treatment administered by the farm staff. According to the person in charge, given that the situation broke out two days before the change of phase, there is no apparent connection to the feed. The total number of dead animals and animals removed from the trial (transferred to sick pens) was very high for the lot (80 dead, 8 removed) and several hogs died suddenly when they were weighed for the second time. Date and weight of the animals were

Restricted females

vs. control females

Restricted animals

vs. control animals

Restricted barrows

vs. control barrows

$4.51

$0.81

$2.66

- $6.18

Females

vs. barrows


recorded at the moment of death or of transfer and we took into account the kg of gain and the number of days that the animals were present when we calculated the performances. There was a tail-biting problem in several pens during phase 1 (obviously unrelated to diet). Plastic tubes were added to the pens to mitigate the problem. When the growth period was completely over, 48 hogs that remained in the barn for the project were mistakenly mixed in with other hogs from the farm. We thus lost track of them, but we figured that these animals would have been shipped 15 days later. In our calculations of performance, we considered the feed consumed up until the date when we lost track of the hogs and not until the end of shipping as we would normally have done. Feed consumption for the 4th phase and thus for the whole growing period is therefore under-estimated. It should be noted, however, that this quantity is minimal since it only represents the quantity of feed consumed by 48 hogs over 15 days out of the 504 hogs from the start of the trial. Where carcass data was concerned, we treated these 48 hogs as missing data. Since the number was not the same in our various groups (14 control gilts, 20 restricted gilts, 4 control barrows and 10 restricted barrows), it may have an effect on the estimation of feed quantity in the various groups. With one exception, all hogs shipped were in the weight range 90.0 to 104.9 kg. The data for the 48 hogs we lost track of were neither included nor estimated in the analyses. Interpretation of the results must therefore be done taking into account the fact that we do not have data from the hogs that left last. This corresponds to around 10% of the hogs (the lightest of the group). The growth performance of the males and gilts with relation to the two diets was calculated for the period from weanling entry up to the first shipping. The results are set out in Table 5. Table 5 Performance of hogs for the various feeding phases prior to shipping (Farm 3)



Phase 1

Start weight, kg 29.6 29.3 30.8 29.3 0.6

ADGc, kg/d 0.900 0.993 1.058 0.994 0.045

ADFIc, e, kg/d 1.93 1.82 1.81 1.88 0.01

F.C. 2.01 1.90 1.84 1.83 0.10

Final weighta,e, kg 40.5 41.2 43.8 41.3 0.6

Phase 2

ADGa, kg/d 0.940 0.915 1.048 1.016 0.029

ADFIa,d,e, kg/d 2.07 2.31 2.56 2.49 0.04

F.C.a, b, e 2.21 2.52 2.49 2.47 0.04

Final weighta,d,f, kg 62.5 62.6 68.6 65.2 0.9




Phase 3

ADGb, e , kg/d 1.027 1.010 0.938 1.121 0.036

ADFIa, kg/d 2.68 2.73 3.20 3.21 0.06

F.C.a, c, e 2.64 2.70 3.43 2.86 0.09

Final weighta, kg 89.0 90.1 98.3 95.9 1.2

Phase 4g

ADG, kg/d 0.793 0.799 0.795 0.831 0.025

ADFIa, kg/d 2.69 2.93 3.66 3.19 0.22

F.C. 3.60 3.92 4.75 3.93 0.79

Final weighta, kg 94.2 94.8 103.3 100.8 1.3

Entry to 1st shippingg

ADGa, kg/d 0.951 0.952 0.984 1.036 0.021

ADFIa, kg/d 2.33 2.45 2.81 2.72 0.06

F.C.a, e 2.45 2.58 2.86 2.63 0.06 a Gender effect, P<0.05

b Feed program effect, P<0.05

c Gender effect, P<0.10

d Feed program effect, P<0.10

e Program X interaction gender effect, P<0.05

f Program X interaction gender effect, P<0.10

g These values were calculated up to weighing for first shipping

If we look at the growth period from weanling entry up to first shipping of hogs, the feed restriction decreased the feed conversion (F.C.) by 5% for the gilts (2.58 vs. 2.45) and improved that of the barrows by 8% (2.63 vs. 2.86). For the gilts, the decrease in conversion seems to have started in phase 2 and even though the difference shrank over the following phases, the effect remained significant overall between entry and first shipping. The control hogs and the restricted hogs had average daily gains (ADG) and daily feed intake (ADFI) statistically comparable. As expected, significant differences were also obtained between genders. The barrows consumed 380 g/d more feed that the gilts, had a higher weight gain by 59 g/d and their feed conversion was also higher than that of the gilts by 8%. Even taking into account the episode of sickness at the outset of the growth period, the hogs performed quite well. If we look at the performances obtained during each of the feeding phases, it is surprising to note the significant gender x feed program interactions (p<0.05) for the first phase, given that all of the hogs consumed the same feed (restriction was carried out in the 2nd phase) and that the entry weights of the hogs were similar. These interactions were recorded for the average daily feed consumption and for the weight at the end of the phase. Moreover, they are contradictory: the restricted gilts consumed less feed than the control and they weighed more. However, the restricted barrows ate more and were lighter than the control group. The animals went through the pneumonia-related coughing episode at the end of this period. There were major losses. Perhaps that would explain the differences we noted considering that the losses were not spread evenly over the groups. The death rates were 5.9% and 12.5% respectively for control and restricted gilts, and 26.7% and 16.1% for the control and restricted barrows. Indeed, it is possible that the animals that ate the least in each group died and, thus, the lower rate of consumption by the restricted gilts and the control barrows are linked to the high mortality rate.


The differences in phase 1 disappeared in the restriction phase and the average weights of hogs at the end of phase 2 were not different for the control animals and the restricted animals for each gender. As we expected, the animals attempted to compensate for the restriction by eating more feed in phase 2. However, we observed this phenomenon only for the gilts. This had repercussions on their feed conversion (restricted 2.52 vs. control 2.21 – a decrease of 14%) During the 3rd phase, the gilts seem to have continued feeling the effects of the restriction and the feed conversion of the restricted hogs was worse than that of the control (2.70 vs. 2.64 – a decrease of 2%) However, for the barrows, the restriction brought on an improvement in the conversion (2.86 vs. 3.43) showing the expected improvement in feed efficiency during the catch-up period. Table 6 sets out the slaughter details for hogs in the four experimental groups. Since we had only one tattoo number per group, it was not possible to make statistical comparisons. The averages and the standard deviations are given without data from the 48 lost hogs. As with all animal performances, we noticed differences between gilts and barrows, especially where back fat and muscle thickness is concerned. However, where carcass weight and classification index are concerned, the results are fairly similar between control hogs and restricted hogs. It would thus appear that the effect of the second-phase feed restriction only marginally affects the carcass characteristics. Table 6 Comparison of slaughter data for gilts and barrows from both diets (Farm 3)




Back fat, mm 17.6 17.5 20.8 20.1 2.7

Muscle, mm 65.7 66.1 63.5 62.8 5.4

Meat yield 61.3 61.5 59.8 60.1 1.5

PQQ classification index* 112.3 112.3 112.8 113.1 2

* All carcasses except one were in the weight range from 90.0 to 104.9 kg.

Although we did not produce a statistical comparison of the results, we nevertheless compiled the food consumption data right to the end of the process in order to measure the differences in feed cost between groups. The results are set out in Chart 1. The control gilts consumed a total of 242.5 kg of feed over the course of the period compared to 248.6 for the restricted gilts. For the control barrows, consumption per hog was 256.2 kg of feed as compared to 262.3 kg for the restricted barrows. Using a feed strategy based on compensatory gain led to a decrease in feed cost margin (carcass revenue less feed costs) of an average of $1.27/hog, ($1.83/hog for gilts and $0.72 /hog for barrows). Our results show, as well, that feeding costs are lower for gilts, leading to an improvement in feed cost margin of $3.86/hog in favour of gilts compared to barrows. The margin decrease on feed cost for gilts and restricted barrows compared to control appears to be a direct consequence of their poorer feed conversion. As well, it is difficult to interpret these results given that the mortalities were not uniformly distributed among the groups and that there are missing data on the carcasses.


-1,83 $

-0,72 $

-1,27 $

3,86 $

-3,00 $

-2,00 $

-1,00 $

0,00 $

1,00 $

2,00 $

3,00 $

4,00 $

5,00 $


femelles témoins


castrat témoins



Restricted females

vs. control females

Restricted animals

vs. control animals

Restricted barrows

vs. control barrows

$3.86

Females

vs. barrows

- $1.27

- $0.72

- $1.83


Farm 4 Description of operations specific to this farm and results

For this project, 768 market barrows and gilts were divided up, as is usual practice on this farm, into 32 pens located in three fattening rooms (24 pigs per pen, 7.4 sq.ft./pig). The barrows were kept in different pens than the gilts. However, one of the rooms had gilts only, another had barrows only and a third had pens for both barrows and gilts. Other pigs were present on site. Each pen on this farm had its own wet feeder.

Feed was formulated in accordance with the specifications set out in the appendix. The 2nd feeding phase, during which the restricted diet was put in place for the restricted group, lasted for 20 days. The growth period was similar for the control group (97.7 days) and for the restricted group (98.8 days).

This growth session proceeded with no major problems: only two or three cases of tail-biting. During the period, 19 pigs died and 12 were removed from the trial because they had to be taken out of their initial pens. We recorded the date and the weight of the pigs at time of death or time of transfer and we included the kg of gain and the number of days present in our performance calculations. At final shipping, 19 project pigs were sent by mistake along with another group of non-project pigs from the same farm and we were unable to recuperate the carcass data (10 control gilts, 7 restricted gilts, 2 restricted barrows). However, since we had the live weight of these animals before loading, we estimated the carcass weight using a yield of 81%. Given the way the barrows and gilts were separated in experimental units, we did not include the room effect in the model for statistical analysis.

The growth performance of barrows and gilts according to the two diets was calculated for the period from weanling entry to first shipping. The results are set out in Table 7. Table 7 Hog performance over the various feeding phases prior to shipping (Farm 4)



Phase 1

Start weight, kg 29.8 29.9 29.9 29.9 0.3

ADGb, kg/d 0.918 0.876 0.914 0.875 0.015

ADFIa, kg/d 1.97 1.99 2.05 2.02 0.02

F.C.c,b 2.15 2.28 2.25 2.31 0.04

Final weightb, kg 50.1 49.2 50.1 49.3 0.4

Phase 2

ADGa,b, kg/d 1.025 0.970 1.126 1.052 0.015

ADFIa, f, kg/d 2.55 2.59 2.85 2.75 0.04

F.C. b 2.47 2.67 2.53 2.63 0.04

Final weighta,b, kg 71.4 70.1 73.3 71.7 0.4




Phase 3

ADGa, kg/d 1.028 1.015 1.067 1.078 0.017

ADFIa, kg/d 2.94 2.86 3.25 3.23 0.04

F.C.a 2.87 2.82 3.05 2.99 0.04

Final weighta,b, kg 93.1 91.5 95.8 94.3 0.4

Phase 4g

ADG, kg/d 0.802 0.813 0.830 0.859 0.024

ADFIa, kg/d 2.60 2.51 2.82 2.82 0.05

F.C.a,b 3.27 3.09 3.40 3.28 0.07

Final weighta,d, kg 109.4 107.9 112.6 111.5 0.6

Entry to 1st shippingg

ADGa, kg/d 0.939 0.924 0.980 0.972 0.008

ADFIa, kg/d 2.51 2.49 2.74 2.70 0.02

F.C.a 2.68 2.69 2.78 2.77 0.02 a Gender effect, P<0.05

b Feeding program effect, P<0.05

c Gender effect, P<0,10

d Feeding program effect, P<0.10

e Programme X gender interaction effect, P<0.05

f Programme X gender interaction effect, P<0.10

g These values were calculated up until weighing for first shipping.

If we look closely at the growth period from weanling entry up until first shipping, the feed restriction had no significant effect on feed conversion, ADG or daily food intake. The only result that stands out is a significant tendency to lower the live weight of the hogs. The restricted gilts weighed 1.5 kg less than the control gilts whereas this difference was 1.1 kg for the barrows. Between weanling entry and the first shipment of hogs, the only significant differences we observed were gender related. The barrows consumed 220 g/d more feed than the gilts, had a weight gain of over 45 g/d and their food conversion was also more than that of the gilts, but by barely 3%. The restriction phase began with the second feed mix and lasted for 20 days. It is surprising to see significant effects of the feed program in the first fattening phase, before the restriction, on the weight of the hogs at the end of the phase, on the ADG and on the conversion. Where weight at the end of phase 1 is concerned, the differences observed were slight between restricted animals and control animals (0.9 kg for gilts and 0.8 kg for barrows), but are nevertheless significant. After the restriction during the 2nd phase, the difference changed to 1.3 kg for gilts and 1.6 for the barrows. After the 3rd phase, there was still a difference: restricted gilts -1.6 kg and restricted barrows -1.5 kg. However, just prior to the first shipment to the abattoir, as we mentioned earlier, the observed differences were only tendencies. The ADG of the restricted animals was slightly less in phase 2, during the restriction, but not after. During the restriction phase, the F.C. of the restricted animals dropped compared to the


control group: two index points for the gilts and one point for the barrows. During the 4th phase, the differences were reversed. These results are hard to interpret considering that the feed conversion was significant from the outset, prior to the restriction, and that it was no longer significant at the end of the period, before the first shipments. If there had been no difference at the beginning, it would have been interesting to see if the animals subject to the compensatory gain strategy would have benefited. It should be remembered that in spite of the fact that the conversions were poorer from the outset, the restricted animals nevertheless finished the growth period with conversions similar to those of the control animals. Table 8 sets out the slaughter data for the four groups of hogs. Since there was only one tattoo number for each group, it was impossible to carry out statistical comparisons. The results show differences in back fat, muscle thickness and in meat yield for gilts and barrows. The average classification index was slightly lower for the restricted animals compared to the control (gilts -0.8 and barrows -0.7). However, if we look only at the pork index values in the right weight range, these differences are no longer observable. Table 8 Comparison of slaughter data for gilts and barrows in both diets




Back fat, mm 17.7 17.8 19.9 20.2 3.5

Muscle, mm 65.3 64.7 63.7 62.9 6.7

Meat yield 61.2 61.1 59.8 59.7 2.7


PQQ classification index in the weight range 90.0 to 104.9 kg

158 hogs

110.2

153 hogs

110.4

164 hogs

112.2

149 hogs

113.0

Although a statistical comparison of results was not produced, the feed consumption was compiled right up to the end of the period so as to be able to calculate the differences in feeding costs among the groups. The results are set out in Chart 4. The control gilts consumed a total of 248.9 kg of feed over the period compared to 250.8 for the restricted gilts. For all intents and purposes, this is the same quantity. For the control barrows, the total consumption per hog was 264.7 kg of feed compared to 269.1 kg for restricted barrows. Using the strategy of compensatory gain did not result in any savings on this farm. The margin on feed cost was less by $3.68/hog for the gilts and by $1.72/hog for the barrows, giving an average of $2.70 per pig. However, when all were taken together, the margins over feed cost were $6.23/hog higher for gilts than for barrows. Since the feed quantities are similar, these results seem to be caused by the carcass weight and the weaker average indexes for the hogs that underwent the restriction, leading to poorer revenue for carcasses, which effectively cancelled out any cost savings related to feed during phase 2. For this report, we chose to report the results as they were obtained on the farms, but considering that there was no real difference where classification indexes for control and restricted hogs in the proper weight range were concerned, we would perhaps have ended up with positive results had we used the same indexes for calculating the carcass revenue. As well, if the grower had shipped his restricted animals at the same weight as the control animals, the results might have been different.


-3,68 $

-1,72 $

-2,70 $

6,23 $

-6,00 $

-4,00 $

-2,00 $

0,00 $

2,00 $

4,00 $

6,00 $

8,00 $


femelles témoins


castrat témoins



Restricted females

vs. control females

Restricted animals

vs. control animals

Restricted barrows

vs. control barrows

Females

vs. barrows

- $3.68

- $2.70

- $1.72

$6.23


2ND PART – GENERAL DISCUSSION OF RESULTS OBTAINED ON THE FOUR FARMS Hog performance during the various growth phases Phase 1

During phase 1, all of the animals in the various groups received the same feed according to the various farms. In spite of random distribution to pens according to the various groups in the barns, we noted weight differences at the end of phase 1 on farms 3 and 4. For farm 4, this difference was observed for barrows and gilts, whereas on farm 3, the difference was noticed only for barrows. After analysis of the way the processes were done in the barns, we are unable to explain these differences. However, these differences probably had an effect on the ability of the animals to recover during phases 3 and 4. In the earlier experiment presented in the report “La restriction alimentaire chez le porc en engraissement : les impacts de la période et de la durée sur les performances techniques et sur le bilan alimentaire” (Feed restriction in grower pigs: impact of period and duration on technical performance and on food balance sheet), we noted that restriction on the two initial growth phases (20 to 60 kg weight) could numerically compromise the pig’s capacity for compensatory gain. Phase 2

At the end of phase 2, all the farms noticed a reduction in final weight for hogs in the restricted groups, with the exception of farm 1. Related to this weight loss, a decrease in the feed conversion was also observed for the majority of them. Phase 3

During this phase, the ADG improved for hogs on farm 1 and for the barrows in the group on farm 3. A numerical increase in gain was also noted for hogs on farm 2. Overall, the animals seemed to partially compensate during this phase between 65 and 90 kg. Weights for restricted animals and control animals were the same for groups 1, 2 and 3. For farm 4, compensation did not take place and the weight of the restricted animals remained less at the end of the phase. Phase 4

During this phase, the ADG stayed the same for the restricted and control groups on all farms, except for the restricted gilts on farm 2. The final weight at the end of this phase was not reduced for the restricted animals except for farm 4. However, the restricted animals on farms 1 and 4 had a better feed conversion during this phase, suggesting a better feed use. Overall swine performance from entry to first shipment In general, animals that undergo qualitative feed restriction (in our case, a reduction in the concentration of nutrients including lysine, phosphorus and calcium) at the beginning of their growth (between 40 and 65 kg) compensated for the slowdown in growth without any weight difference from the animals in the first shipment to slaughter. No differences were noticed in overall ADG or ADFI. These results confirm the initial hypothesis suggesting that compensatory gain for pigs is possible under market conditions. For farm 1, an improvement in overall feed conversion was even observed, suggesting a more effective use of feed during fattening. For farm 3, an improvement in feed conversion was also noticed, but only for barrows. It should be noted that for this farm we observed a compensatory gain in spite of an episode of sickness and a death rate of 17%.


In general, the restricted animals between 40 and 65 kg compensated for the slowdown in growth and attained similar weights at the end of phase 4, except for the group of animals on farm 4. It is difficult to explain the differences since each group had a specific environment and the feed, although formulated to the same specifications, had a different composition and different ingredients. As mentioned earlier, although the feed was formulated to the same specifications, the makeup of the ingredients varied from one group to another. Among other things, this included the percentage of ingredients, with the exception of corn and soybean meal in finishing 2 (restricted feed) varied from 12 to 32% and for finishing 1 (growth feed), the percentage varied as well from 13 to 39%. It is well-known that certain by-products can affect consumption and therefore affect gain. In a context of compensatory gain, the presence of by-products may possibly affect the animal’s response and thus, its ability to compensate for certain slowness in growth. This aspect remains to be investigated.

If we look at the various farm environments, we see that the square footage per pig is comparable in all four groups. The barn temperatures adhered to the standard curve and the time of year was not conducive to spikes in temperature. As far as feed distribution is concerned, farms 1 and 2 used dry feeders while farms 3 and 4 were outfitted with wet feeders. It is unlikely that this difference lies behind the differences in results. As regards to animals, farms 1 and 2 worked with a genetic identity made up of Duroc and Pietrain, while farms 3 and 4 worked with terminal cross breeds based on Duroc. The impact of the animal’s genotype on compensatory gain has never really been studied and remains to be better defined with a view to applying this feed strategy on the farm.

Finally, the timing of the restriction is known to affect the hog’s ability to compensate. For all groups, except farm 4, the restriction period took place between 40 and 65 kg. For farm 4, the period was from 50 to 70 kg. In spite of this difference, it is unlikely that this slight offset of the restriction period underlies the differences in compensation obtained in this farm. Economic impact of using compensatory gain strategy on four farms In order to evaluate the economic impact of compensatory gain, the margin over the feed cost was calculated. This value gives a good idea of the effect of our strategy since feed represents between 50 and 60% of the cost of pork production. For two groups, the margin on the cost of feed was positive: $2.96 and $2.66 respectively. The restricted pigs during the second feeding phase consumed finishing feed 2 instead of the growth feed given to the control group. Part of the savings is thus explained by the price difference between the two feeds. This varies from $10 to $25 a ton depending on the farm and on the additives used. As well as this cost difference in the 2nd phase, an overall improvement in conversion was noted for the two farms, particularly for farm 1. This improvement reduces the quantity of feed by around 2%. For the two other farms, the margin was negative: $1.27 and $2.70 respectively. For farm 3, the restricted gilts consumed more feed in the 2nd phase (5.48 kg/pig) probably to compensate for the restriction in nutrients. However, they did not improve their food efficiency in the following phases and this led to a greater overall consumption of feed (+2.5%). For the barrows in this group, a slowdown in growth was noticed during phase 1 for reasons unknown (-2.5 kg). This slowdown in growth in phase 1 brought on an increase in the length of the fattening, in spite of a partial renewed gain in phase 3. Thus, there was an increase in the quantity of feed in phase 4 (+8 kg/pig), raising the amount of feed per hog. For farm 4, the same inexplicable phenomenon of growth reduction during phase 1 was observed. On average, reduction by almost 1 kg in final weight was noted in the restricted animals. This difference was not entirely compensated for in the gilts, leading to a slight reduction in carcass weight and, by extension, in revenue. For the restricted barrows, they ate more in phase 4 (+7.53 kg), increasing the total amount of feed by 1.7%.


The results that were obtained for the gilts and the barrows lead to believe that the two genders react differently to a compensatory gain strategy. It would be interesting to continue the work in order to get a better grasp on the response of these animals. If we set aside the diets and only look at the effect of gender, the gilts had margins over feed cost above those of the barrows in three of the four farms (+$0.55, +$3.86, +$6.23, -$6.18 per hog). Feeding the genders separately has long been well known as a strategy that allows the grower to better respond to the hogs’ needs. The results we have obtained will allow the industry to ask more questions about this practice, which nevertheless has major implications in livestock management. RECOMMENDATIONS As the results demonstrate, hogs raised under market conditions can show a compensatory gain following a qualitative dietary restriction at the outset of growth. Moreover, this strategy can be profitable, but the growth conditions for optimization still need to be better defined: type of ingredients and genetic type among others. The results in some groups may give rise to the belief that a reduction in growth at the beginning of the growth period (between 20 and 40 kg) may reduce the hog’s ability to compensate totally after the restriction with consequences for the weight at slaughter or on the length of the fattening. An extended period of fattening may also increase the total quantity of feed leading to increased costs for feed. The possible effects of sickness on compensatory gain need to be better understood. Although the group that had health problems during the trial had good performance and a recovery after the restriction, the possible impact on the health status of the group on the ability to recover must be better defined in order to recommend or discourage this dietary strategy depending on the health level of the group.

To conclude, before applying a feeding strategy using compensatory gain on a large scale, several questions still need to be answered. Among them, we draw special attention to the effect of the ingredients making up the feed, the genetic type, the group density and the ambient temperature. However, with single rations based on corn or soybean meal, compensatory gain offers a good opportunity to reduce cost for hog farms. However, its application goes beyond a simple restriction-recovery.


APPENDIX 1 – FEED SPECIFICATIONS FOR THE FOUR FARMS

Feed specifications for market validation project

Start Growth Finishing 1 Finishing 2

Hog weight (kg) 25-40 40-65 65-90 90-120

Net energy (MJ/kg) 10.25 10.25 10.15 10.15

Digestible AA (%)

Lysine 1.05 0.90 0.80 0.70

Methionine 0.30 0.27 0.23 0.20

Cysteine + Methionine 0.58 0.52 0.48 0.40

Tryptophan 0.18 0.16 0.14 0.13

Threonine 0.63 0.57 0.50 0.42

Available phosphorus (%) 0.30 0.28 0.24 0.22

Calcium (%) 0.75 0.70 0.54 0.50

Maximum levels per metric ton

Start Growth Finishing 1 Finishing 2

Corn DDGS 100 100 100 80

Wheat shorts 50 75 100 100

Bread/bakery meal 100 100 100 100

Corn 1 000 1 000 1 000 1 000

Soybean meal 1 000 1 000 1 000 1 000

Canola meal 50 50 50 50

Wheat 150 150 150 150

Vomitoxin, ppm 1 1 1 1

Meat meal 0 0 0 0

Fat ok ok ok ok

Corn Gluten feed 0 0 0 0

Medication usual usual usual usual

Additives usual usual usual usual

Phytase Yes Yes Yes Yes

Microminerals and vitamins premix

usual usual usual usual

Ractopamine (PayleanMD, Elanco)

No No No No

Documents

Market validation of a strategy of compensatory … 186...Market validation of a strategy of compensatory gain for feeder pigs Final Report June 30, 2011 Marie-Josée Turgeon, M. Sc.,