Nutrition and Reproduction in Beef Cows Cattlemens College
Nutrition and Reproduction in Beef Cows Cattlemen’s College January 29, 2003 David Lalman Oklahoma State University
The Big Picture Genetics and yesterday’s nutritional environment determines today’s body condition. Adaptation and body condition at calving influence tomorrow’s reproductive success.
Body Condition Score at Calving and Pregnancy Rate Body Condition of Cows and Heifers at Calving
Predicted number of days from calving to first heat Condition score at calving 3 66 Condition score change after calving to day 90 -1 189 4 161 5 133 5. 5 -0. 5 0 173 160 145 131 116 103 93 118 102 0. 5 150 121 86 89 Difference = 28 days Lalman et al. , 1997 1 143 115 83 79 1. 5 139 111 82 72 2 139 111 69
Predicted number of days from calving to first heat Condition score at calving 3 4 5 5. 5 Condition score change after calving to day 90 -1 189 161 133 118 -0. 5 173 145 116 102 0 160 131 103 89 0. 5 150 121 93 79 Difference = 16 days Lalman et al. , 1997 1 143 115 86 72 1. 5 139 111 83 69 2 139 111 82 66
Heifer Weights at and After Calving and Pregnancy Rate 94% 66% 91% 36% Weeks after Calving
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 Supplementation and Beef Cow Reproduction • Limited research including performance data. • Considerable work currently being conducted on this topic. • There are MANY factors to consider.
Fat Supplementation Factors 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 Author Cow Sup Age (No. ) Timing Amount Fat Fed (lb) Source Lammoglia Hfr (52) Bellows Hfr (52) -53 to Clv -65 to Clv Bellows Johnson Alexander Espinoza Graham -68 to Clv 1. 1 -64 to Clv. 78 -59 to Clv. 25 -61 to 44. 28 -45 to Clv. 56 Hfr (41) Cow (67) Cow (48) Cow (67) Cow (? ? ) Trt VS Con Pregnancy . 7 Safflower *75 vs 57. 55 Saf, Soy, Sun *94 vs 79 Sunflower Sun & Soy Megalac Soybeans * Indicates a significant difference at P < 0. 1 80 vs 90 95 vs 95 91 vs 88 91 vs 84 93 vs 86
Effects of Fat Supplementation on Pregnancy in Beef Females Author Cow Sup Age (No. ) Timing Amount Fat Fed (lb) Source Trt VS Con Pregnancy De Fries Cow (20) Clv to Est. 33 Rice Bran *94 vs 71 Filley Hfr (19) Burns Johnson Graham Beckmeir Burns Hfr (41) Cow (67) Cow (? ? ) Cow (96) Hfr (25) Clv to 30 . 5 Megalac 72 vs 68 61 to 176 Clv to AI Clv to 125 50 to 120 . 1. 78. 56 ? ? . 18 Fishmeal Sunflower Soybeans Soy oil Fishmeal 85 vs 90 95 vs 95 87 vs 86 83 vs 83 No diff * Indicates a significant difference at P < 0. 1
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 1 st service conception
Program Feeding Concentrates to Replace Hay Corn 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 22. 25% of body weight • No hay or pasture • ADG = 2. 0 -2. 5 • Requires intensive management, equipment and facilities
Program Feeding • • Mc. Cullum 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 Feeding Results Dry W. 96 ADG Avg DM intake Feed/Gain Feed $/Gainaa. Feed Wintering Regimen 1. 0 1. 53 2. 01 2. 0 2. 54 7. 41 4. 9 $. 27 10. 7 4. 3 $. 24 cost = $110 per ton Gill et al. , 1991, OSU An. Sci. Res. Report 9. 0 4. 5 $. 25
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 Cows Item Cracked Corn Whole Corn ADG BCS change Calf ADG -. 50 -. 55 2. 4 -. 38 -. 51 2. 5 From Tjardes, 1998, J. Anim. Sci. , 76: 8
Program Feeding Bred Heifers Hay Sup Feed Total Hay 19 2 21 Corn 3. 5 2 7 12. 5 WMSH 3. 5 10. 5 14 BMS 3. 5 1 10. 6 15. 1 TDN CP 9. 7 1. 5 9. 2 1. 5 8. 9 1. 5 9. 0 1. 9
Program Feeding Bred Heifers ADG $/Day $/lb gain Hay 1. 1. 76. 67 Corn 1. 4. 75. 54 WMSH 1. 4. 83. 60 Hay = $60/ton, Sup = $190/ton, Corn = $2. 40/bu, WMSH = $137/ton, BMS = $90/ton BMS 1. 4. 70. 51
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