Nutrition and Reproductionin Beef Cows

Cattlemen’s College

January 29, 2003

David Lalman

Oklahoma State University

The Big PictureGenetics and

yesterday’s nutritional environment determines today’s body condition.Adaptation and body condition at calving influence tomorrow’s reproductive success.

Body Condition Score atCalving and Pregnancy Rate

6081

92

0

20

40

60

80

100

<4 5 6>

Body Condition of Cows and Heifers at Calving

Predicted number of days from calving to first heat

Condition score at calving Condition score change after calving to day 90

-1 -0.5 0 0.5 1 1.5 2 3 189 173 160 150 143 139139 4 161 145 131 121 115 111111 5 133 116 103 93 86 83 82 5.5 118 102 89 79 72 69 66 Difference = 28 days

Lalman et al., 1997

Predicted number of days from calving to first heat

Condition score at calving Condition score change after calving to day 90

-1 -0.5 0 0.5 1 1.5 2 3 189 173 160 150 143 139139 4 161 145 131 121 115 111111 5 133 116 103 93 86 83 82 5.5 118 102 89 79 72 69 66 Difference = 16 days

Lalman et al., 1997

Heifer Weights at and After

Calving and Pregnancy Rate

640

690

740

790

840

890

Calving 4 Weeks 8 Weeks 12 Weeks

>5 Gain

>5Maintain

<5 Gain

<5 Maintain

Weeks after Calving

36%

66%91%

94%

Moral of the BCS Story

•Achieving moderate body condition at calving is more effective than making up body condition after calving.

•Playing “catch up” is almost always expensive and usually not practical.

Achieving Moderate BC•Genetics

•Grazing conditions•Early (or earlier) weaning•Limit feeding concentrates•Protein and (or) energy

supplementation during fall and winter…prior to calving

Fat Supplementationand Beef Cow Reproduction•Limited research including

performance data.•Considerable work currently

being conducted on this topic.

•There are MANY factors to consider.

Fat SupplementationFactors to Consider•Timing of supplementation

•Fat source•Amount to supplement•Cow age•Cow condition•Historical reproductive rates•Cost effectiveness

Effects of Fat Supplementation

on Pregnancy in Beef Females Cow Sup Amount Fat Trt VS Con

Author Age (No.) Timing Fed (lb) Source Pregnancy

Espinoza Cow (67) -61 to 44 .28 Megalac 91 vs 84

* Indicates a significant difference at P < 0.1

Lammoglia Hfr (52) -53 to Clv .7 Safflower *75 vs 57

Bellows Hfr (52) -65 to Clv .55 Saf, Soy, Sun *94 vs 79

Bellows Hfr (41) -68 to Clv 1.1 Sunflower 80 vs 90

Johnson Cow (67) -64 to Clv .78 Sunflower 95 vs 95

Alexander Cow (48) -59 to Clv .25 Sun & Soy 91 vs 88

Graham Cow (??) -45 to Clv .56 Soybeans 93 vs 86

Effects of Fat Supplementationon Pregnancy in Beef Females

Cow Sup Amount Fat Trt VS ConAuthor Age (No.) Timing Fed (lb) Source Pregnancy

De Fries Cow (20) Clv to Est .33 Rice Bran *94 vs 71

* Indicates a significant difference at P < 0.1

Filley Hfr (19) Clv to 30 .5 Megalac 72 vs 68

Burns Hfr (41) 61 to 176 .1 Fishmeal 85 vs 90Johnson Cow (67) Clv to 76 .78 Sunflower 95 vs 95

Graham Cow (??) Clv to AI .56 Soybeans 87 vs 86

Beckmeir Cow (96) Clv to 125 ?? Soy oil 83 vs 83

Burns Hfr (25) 50 to 120 .18 Fishmeal No diff

Fat Supplementation

Summary• Fat supplementation has improved pregnancy rates in 3 out of 14 studies reviewed.

• Marginal responses may be due to adequate body energy stores or adequate basal diet nutrient availability

• Expect greater response with thin cows or when nutrient availability is low (drought, late-winter calving)?

• Response seems to be greater when overall pregnancy rates are low.

• Potential for improvement in 1st service conception

Program Feeding Concentrates

to Replace HayCorn may be the lowest cost energy source for cattle in some drought

areas.

Program Feeding for Calves

• 80% whole shelled corn • 20% commercial supplement (38 to

44% protein) including high calcium and ionophore

• Feed 80/20 mix at approximately 2-2.25% of body weight

• No hay or pasture• ADG = 2.0-2.5• Requires intensive management,

equipment and facilities

Program Feeding

• McCullum and Gill, 1991• Steers, initial weight = 463

lbs• 84 d wintering study• Treatments

• Dry wintered with 2 lb supplement• Target gain of 1.0• Target gain of 1.5• Target gain of 2.0

Program FeedingResults

Wintering RegimenDry W 1.0 1.5 2.0

ADG .96 1.53 2.01 2.54Avg DM intake - 7.41 9.0 10.7Feed/Gain - 4.9 4.5 4.3Feed $/Gaina- $.27 $.25 $.24

aFeed cost = $110 per tonGill et al., 1991, OSU An. Sci. Res. Report

Program Feeding, Cont’d• In adequate volume most

Oklahoma Feed Manufacturers can make these supplements for you

•Supplements should be pelleted

•Not an easy fix• Takes much more labor• Requires more intensive management

It can work for cows too!

• Goal is usually maintenance• Include small amount of hay

for safety• Example diet:

Corn 9 lbs.Grass hay 3 - 7 lbs.Supplement 2 lbs

Cow Example

• Cost of free choice avg quality hay ($65 per ton) + 2 lb. protein = $1.04

• Cost of limit fed corn program at current costs = $.80

• Does require more labor and management skill

Whole VS Cracked Corn

for Limit Fed CowsItem Cracked Whole Corn Corn

ADG -.50 -.38BCS change -.55 -.51Calf ADG 2.4 2.5From Tjardes, 1998, J. Anim. Sci., 76:8

Program Feeding

Bred HeifersHay Corn WMSH BMS

Hay 19 3.5 3.5 3.5Sup 2 2 - 1Feed - 7 10.5 10.6Total 21 12.5 14 15.1

TDN 9.7 9.2 8.9 9.0CP 1.5 1.5 1.5 1.9

Program Feeding Program Feeding Bred HeifersBred Heifers

Hay Corn WMSH BMSADG 1.1 1.4 1.4 1.4$/Day .76 .75 .83 .70$/lb gain .67 .54 .60 .51

Hay = $60/ton, Sup = $190/ton, Corn = $2.40/bu, WMSH = $137/ton, BMS = $90/ton