427Reprod. Nutr. Dev. 45 (2005) 427440 INRA, EDP Sciences, 2005DOI: 10.1051/rnd:2005040

Original article

Effect of feeding live yeast products to calves with failure of passive transfer on performance

and patterns of antibiotic resistance in fecal Escherichia coli

Klibs N. GALVO, Jos E.P. SANTOS*, Anelis COSCIONI, Marcos VILLASEOR, William M. SISCHO, Anna Catharina B. BERGE

Veterinary Medicine Teaching and Research Center, University of California Davis, 18830 road 112, Tulare, CA 93274, USA

(Received 20 January 2005; accepted 8 March 2005)

Abstract Fifty-two newborn Holstein calves with serum IgG concentrations less than 0.73 gdL1were randomly assigned to one of four treatments: no added live yeast (control), 0.5 g of live yeastadded to the grain for 84 d (SC; Saccharomyces cerevisiae), 0.5 g of live yeast added to the milk for42 d (SB; S. cerevisiae, spp. boulardii), and 0.5 g of live yeast added to the grain for 84 d and to themilk for 42 d (SCSB). Calves were offered 440 g of milk replacer DM for the first 42 d and grainfor ad libitum intake throughout the study. Plasma was analyzed weekly for concentrations of glucoseand -hydroxybutyrate. Escherichia coli isolated from fecal samples collected every 2 weeks wereused for determination of antibiotic resistance patterns. Calves receiving SC consumed more grainDM, had increased weight gain prior to weaning, and increased plasma glucose concentrationscompared to controls. Days with diarrhea were reduced by feeding live yeast to calves. Antibioticresistance in fecal E. coli was associated with the age of calves with highest levels of resistanceobserved in the 3 d calves. While calves receiving SCSB had higher levels of antibiotic resistancethan controls, this effect was not associated with any of the other treatments. Improvements inperformance of calves with failure of passive transfer were observed when live yeast was added onlyto the grain.

Saccharomyces cerevisia / yeast / failure of passive transfer

1. INTRODUCTION

During the last decades, microbial addi-tives (probiotics) such as yeasts (Saccharo-myces cerevisiae), or fungi (Aspergilusoryzae) have been widely used in ruminantnutrition to improve growth, lactation, andhealth because of their effects on dry matter

(DM) intake, rumen pH, and nutrientdigestibility [1]. However, few studies haveevaluated the effects of feeding yeast prod-ucts to the diet of young calves.

Passive immunity in calves is providedwhen maternal colostrum antibodies are fedwithin the first few hours of life to assureadequate absorption, which results in

* Corresponding author: Jsantos@vmtrc.ucdavis.edu

Article published by EDP Sciences and available at http://www.edpsciences.org/rnd or http://dx.doi.org/10.1051/rnd:2005040

428 K.N. Galvo et al.

increased concentrations of serum IgG andtotal protein [2]. Inadequate supply of goodquality colostrum to newborns puts them atgreater risk for diseases, especially bacterialinfections of the digestive tract [3]. Immune-suppressed calves or those at increased riskfor infections are often fed sub-therapeuticdoses of antimicrobials in the diet to mini-mize prevalence of infections early in life.However, addition of penicillin to milk fedto calves increased resistance to antibioticsby gut bacteria [4], and sub-therapeutic useof antibiotics in food animals can potentiallyincrease the risks for human infectionscaused by antibiotic-resistant bacteria [5].

An alternative method to improve ani-mal performance is to provide non-antimi-crobial feed additives that minimize patho-genic bacteria colonization of the digestivetract. A subspecies of Saccharomyces cer-evisiae, S. cerevisiae boulardii, has beenextensively used as both a preventive andtherapeutic agent for the treatment of a vari-ety of intestinal diseases in humans and othermonogastrics [6]. Gedek [7] found thatS. cerevisiae boulardii can be irreversiblybound to pathogenic bacteria such as somestrains of entero-hemorrhagic Escherichiacoli and the multiple antibiotic-resistantSalmonella typhimurium DT 104 due to thepresence of lectin sites for mannose-sensi-tive adhesion in the outer membrane of theyeast cell.

A functional microflora must be estab-lished in the developing rumen prior to wean-ing as it controls the animals intake poten-tial, and therefore production performance[3, 8]. Feeding of a yeast culture fromS. cerevisiae to newborn calves improvedgrain intake and slightly influenced rumendevelopment [9]. Furthermore, when adried live yeast was fed to young lambs,establishment of cellulolytic bacteria [8,10] ciliate protozoa [11], which might par-tially explain the improved DM intake andweight gain in young calves fed S. cerevi-siae [9, 12, 13].

Although some studies have indicatedpositive effects of yeast products on calf

performance, no study has evaluated theeffect of feeding a live yeast product incor-porated into the grain or milk replacer onperformance and patterns of antibiotic resist-ance in bacteria from gut of calves with fail-ure of passive transfer. We hypothesizethat: feeding S. cerevisiae incorporated tothe grain of Holstein calves with failure ofpassive transfer would enhance productionperformance by improving DM intake andbody weight gain; feeding S. cerevisiaeboulardii added to the milk replacer wouldimprove performance of calves by reducingdiarrhea; and feeding S. cerevisiae incorpo-rated to the grain and S. cerevisiae boulardiito the milk replacer would have additiveeffects on calf performance. We alsohypothesized that the addition of live yeastcontaining S. cerevisiae boulardii couldreduce the level of antibiotic resistance incommensal intestinal bacteria. Therefore,the objectives of this study were to deter-mine the effects of a live yeast productadded to the grain (SC; S. cerevisiae), milkreplacer (SB; S. cerevisiae, spp. boulardii),or both (SCSB) on performance, somehealth parameters, and patterns of antibioticresistance in calves with failure of passivetransfer.

2. MATERIALS AND METHODS

2.1. Animals, housing, and feeding

All procedures involving animals wereapproved by the University of CaliforniaDavis Institutional Animal Care and UseCommittee. Fifty-two Holstein bull calvesin the first week of age (5 2 d of age) wererandomly assigned to one of the four treat-ments (13/treatment). All calves originatedfrom a single dairy and were transported tothe study site by truck. All calves received4 L of a solution containing electrolytes andwere only offered milk replacer and grain12 h later. Milk replacer was fed in bottlesfor the first week, and then offered in buck-ets afterwards. In the morning followingarrival, a blood sample was collected and

Yeast for calves with failure of passive transfer 429

serum separated and analyzed for concen-trations of total protein using a refractome-ter, and total IgG using a single radialimmunodiffusion assay according to themanufacturer guidelines (Veterinary Med-ical Research and Development, Pullman,WA, USA). All calves had serum IgG 0.10) onfecal scores either prior to or after weaningand fecal scores were generally low (Tab. III).However, calves receiving SC and SB hadfewer (P < 0.05) days with diarrhea prior toweaning than control calves. Similarly,

Table II. Effect of live yeast products added to the grain or milk replacer on performance of Holsteindairy calves.

Treatment1

Item2 Control SC SB SCSB SEM

Serum TP at 5 d of age, gdL1 5.15 5.08 4.91 5.04 0.13Serum IgG at 5 d of age, gdL1 0.57 0.62 0.52 0.64 0.06Grain DM intake, gd1

Prior to weaning 438.3b 682.3a 611.4ab 500.0ab 73.8After weaning 2193.9c 2575.5d 2379.2cd 2400.0cd 150.0

DM intake, % body weightPrior to weaning 1.53b 1.72a 1.69ab 1.58ab 0.07After weaning 2.58 2.66 2.60 2.70 0.09

Body weight gain, gd1Prior to weaning 298.0a 464.7b 416.7ab 379.3ab 52.7After weaning 907.1 1037.2 975.1 975.9 68.7

Mean body weight, kg 64.0a 73.2b 67.4ab 69.4ab 3.06Feed efficiency

Prior to weaning 0.276c 0.401d 0.331cd 0.331cd 0.050After weaning 0.431 0.429 0.425 0.417 0.014

Plasma glucose, mgdL1Prior to weaning 74.0b 78.1a 74.5ab 77.3ab 1.49After weaning 74.5b 83.4a 79.7ab 80.0ab 2.44

Plasma BHBA, ML1 Prior to weaning 77.5 91.9 79.3 86.4 8.0After weaning 272.8 275.7 269.8 251.7 15.0

a,b Different superscripts in the same row differ (P 0.05).c,d Different superscripts in the same row tend to differ (P 0.10).1 Control = no live yeast; SC = live yeast as S. cerevisiae added to the grain; SB = live yeast as S. cerevisiaeboulardii added to the milk replacer; and SCSB = the respective live yeasts added to the grain and milk replacer.2 TP = total protein; IgG = immunoglobulin G; DM = dry matter; Feed efficiency = daily body weight gain/daily DM intake; BHBA = -hydroxybutyrate.

434 K.N. Galvo et al.

calves fed SC, and SCSB had fewer (P 1.0 gdL1) [2, 3]. In fact, calves withconcentration of serum IgG < 1.0 gdL1were less likely to survive than those withserum IgG greater than 1.0 gdL1 [3].

Figure 3. Temporal chan-ges in plasma glucose incontrol calves (---x---), incalves fed live yeast in thegrain (SC; z), in themilk replacer (SB; ),and in the grain and milkreplacer (SCSB; c).

Figure 4. Temporal changesin plasma BHBA in controlcalves (---x---), in calves fedlive yeast in the grain (SC;z), in the milk replacer(SB; ), and in thegrain and milk replacer(SCSB; c).

436 K.N. Galvo et al.

Few studies have evaluated the effects ofadding live yeast to the grain or milk replaceron performance of young calves. Prelimi-nary reports [12, 13] indicated that feedingS. cerevisiae to young calves increased DMintake and weight gain. When newborn

calves were fed 0, 1, or 2% of the grain asa culture of S. cerevisiae [9], grain intake inthe first 6 weeks of life increased with the 2%yeast culture treatment. However, Quigleyet al. [25] did not find any effect of yeastculture on DM intake and weight gain in

Table III. Effect of live yeast products added to the grain or milk replacer on fecal score, days withdiarrhea, and costs associated with treatment of diarrhea in Holstein calves.

Treatment1

Item Control SC SB SCSB SEMFecal score, 13

Prior to wean 1.19 1.14 1.12 1.20 0.03After wean 1.04 1.02 1.03 1.01 0.01

Days with diarrheaPrior to wean 5.83a 4.00b 4.00b 5.50ab After wean 2.08a 1.46b 2.83a 0.92b

Treatment cost, US$/calf 3.03 1.49 1.43 1.96 0.92a,b Different superscripts in the same row differ (P 0.05).1 Control = no live yeast; SC = live yeast as S. cerevisiae added to the grain; SB = live yeast as S. cerevisiaeboulardii added to the milk replacer; and SCSB = the respective live yeasts added to the grain and milkreplacer.

Table IV. The distribution of E. coli isolates within antibiotic resistance clusters. The data are strat-ified by treatment group and calf age. The clusters are ranked from most susceptible (cluster 1) to mostresistant (cluster 12) with the rankings based on the sum of the mean zone sizes for the 12 antibioticstested in each cluster.

Treatments1 Age of calves, daysCluster Freq2 CON SC SB SCSB 13 25 38 59 741 68 21 19 14 14 14 6 26 14 82 26 13 2 3 8 1 9 12 2 23 13 1 6 2 4 1 2 9 0 14 96 21 23 33 19 7 28 12 23 265 8 7 0 1 0 0 0 2 3 36 88 8 23 32 25 0 3 14 33 387 21 7 6 2 6 4 5 2 3 78 25 10 5 10 0 9 9 2 0 59 17 4 3 7 3 9 7 2 0 010 29 7 9 4 9 26 0 0 2 111 22 7 2 1 12 7 5 4 4 212 32 8 5 5 14 14 4 7 4 3Sum3 445 114 103 114 114 92 78 92 88 961 Control = no live yeast; SC = live yeast as S. cerevisiae added to the grain; SB = live yeast as S. cerevisiaeboulardii added to the milk replacer; and SCSB = the respective live yeasts added to the grain and milkreplacer.2 Freq = Number of Escherichia coli isolates that fall in each cluster category.3 Sum = Sum of the number of E. coli isolates for the 12 clusters in each column.

Yeast for calves with failure of passive transfer 437

young Jersey calves in the first 12 weeks oflife, and suggested that the numerous healthproblems experienced by those calvesmight have masked response to treatments.

Chaucheyras-Durand and Fonty [8]observed that S. cerevisiae increased activ-ity of fibrolytic enzymes, decreased rumenammonia and increased VFA concentra-tions in the rumen of gnotobiotic lambs.Their data suggested that daily consump-tion of live yeast influenced microbial col-onization of the rumen, which could poten-tially influence digestive processes. Thesame group observed that S. cerevisiaeinfluenced establishment of ciliate proto-zoa in the rumen [11]. Furthermore, incu-bating a strain of S. cerevisiae with Strep-tococcus bovis and Megasphaera elsdeniireduced availability of glucose for lactatesynthesis by S. bovis and enhanced utiliza-tion of L-lactate by M. elsdenii [26], whichsuggest that live S. cerevisiae can poten-tially minimize fluctuation in rumen pH andreduce the risk for acidosis. In fact, rumen

pH was increased when live S. cerevisiaewas incubated in vitro with mixed ruminalmicroorganisms [27].

It is possible that inclusion of S. cerevi-siae in the grain for calves in SC might haveenhanced colonization of the rumen andenzymatic activities responsible for diges-tion of carbohydrates, which would stimu-late DM intake. Furthermore, a more stableruminal environment when yeast is fedwould also favor performance of calves [1].However, most of these mechanisms havebeen demonstrated in vitro or in lambs withcontrolled rumen flora, and limited data areavailable to determine mechanistic aspectsof the effects of live yeast and yeast cultureon young calves. Intriguing was lack of pos-itive effects on performance of calves whenfed SCSB, which was not expected.

Early after birth, calves usually maintainor even lose weight in spite of consumptionof milk, which can result in negative effi-ciency of feed utilization [3]. We observeda period of low and even negative feed effi-ciency in the first 2 weeks of the study,which was associated with the low weightgain in calves. However, efficiency of feedconversion into body weight increased from0.4 to 0.6 after 32 d in the study. This is atypical pattern for calves in the first weeksof life [3, 9]. In spite of the changes in feedefficiency over time, yeast only had minoreffects on efficiency of feed conversion intobody weight. These are similar to resultsobtained with yeast culture by others [9, 25].

The greater concentrations of glucose incalves receiving live yeast were probablythe result of greater energy intake [28].When Jersey calves were fed a culture of S.cerevisiae incorporated into the grain frombirth to 12 weeks of age, plasma glucoseconcentrations remained unaffected by treat-ment when measured immediately prior tofeeding and at 4 h postfeeding [25]. Thelack of effect of yeast culture on plasma glu-cose in that study was probably associatedwith the lack of effects of treatment on DMintake.

Table V. Results of cumulative multinomiallogistic regression predicting the odds of isolat-ing increasing multi-drug resistant commensalEscherichia coli from experimental calves.

Comparisons Odds ratio 95% Walds CI P