9/3/11. Joplin/newsroom.html. Implications of nutritional management for beef cow/calf systems

Transcription

1 Implications of nutritional management for beef cow/calf systems Rick Funston Reproductive Physiologist Crude protein in cattle diets on Sandhills range UNL Beef Research and Extension BBR NEREC ARDC KCWL WEC Lincoln NCTA Crude Protein, % OM GSL PHREC Dalbey APR Instantaneous growth rate of the bovine fetus MAY JUN JUL AUG SEP Month OCT NOV DEC JAN FEB Weaning and Supplement Treatments for March Calving Cows 0.4 August weaning Kg/day No protein supplement during winter grazing Protein supplement during winter grazing November weaning No protein supplement during winter grazing Protein supplement during winter grazing Day of gestation Joplin/newsroom.html 1

2 Effect of Weaning Date on Cow Body Condition Score Winter Supplementation Pregnancy 95.1% Calve 3 5 Wean 9 11 Months After Calving P< NRC (1996) 94.2% Crude protein in cattle diets on Sandhills range 20 Protein, %OM NE (Mcal/day) Net Energy (NE) Requirement for a 1200 Lb March Calving Cow With 23 Lbs/day Peak Milk Production APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB Month No Protein Supplement Effect of Protein Supplementation on Cow BCS Pregnancy 93.8% November Wean August Wean 95.5% P<.0001 November Wean, with Winter Supplement Protein Supplement November Wean, No Winter Supplement August 432 November Wean, with Winter Supplement November 518 November Wean, No Winter Supplement Calf Weaning Weight, lb Joplin/newsroom.html 2

3 Protein No Protein Calf Weaning Weight, lb Feedlot Performance Weaning Protein Supp. Early Late Supp. No Supp. In wt, lb Days on feed Interactions ES ENS LS LNS Out wt, lb Daily gain, lb HCW, lb Costs and Net Revenues After Finishing August Wean November Wean Supp. No Supp. Supp. No Supp. Costs, $/hd Calf Feed Yardage Trucking Processing Total Cost Revenue, $/hd Steer Net/cow exp Winter No Protein Supplement Protein Supplement Spring Meadow Hay Introduction Systems Late-gestation supplementation of spring-calving cows in the Sandhills No difference cow pregnancy rate No difference calf birth weight Increased calf weight at weaning Greater economic return Increased weaning percentage Numerical advantage in carcass weight Stalker et al., 2006 Effect of Winter Protein Supplement on Pregnancy Rate P = 0.46 Joplin/newsroom.html 3

4 Effect of Winter Protein Supplement on Percentage of Live Calves Weaned P = 0.01 Calf weight (lbs) Effect of Winter Protein Supplement on Feedlot Weight P = P = Sup No Sup In Out Heifer data Protein supplementation of spring-calving cows grazing dormant Sandhills range: Increases adj. 205 d wt Differences maintained through 2 yr of age Increased first service conception rate, overall pregnancy rate, and greater proportion calved in initial 21 d of calving No difference age at puberty, cycling before breeding season No difference in gain:feed Interaction for RFI Martin et al., 2007 Effect of Prepartum Nutrition on Heifer Development 3-yr No Supplement Supplement BW WW ADJ 205d Wt Preg Check Wt Pregnancy and Calving Data 3- yr No Supplement Supplement Age at Puberty Cycling (%) Calved 1 st 21 d (%) Final Preg, % Calving Date Effects of winter grazing system and supplementation on beef cow and progeny performance R. N. Funston, J. L. Martin, D. C. Adams, and D.M. Larson Joplin/newsroom.html 4

5 Corn crop residue provides a reasonably priced alternative to grazing dormant winter range Objectives Determine if supplementing beef cows grazing range or corn residue during the last third of gestation affects cow or progeny performance. Materials & Methods Completely randomized design 2 x 2 Factorial treatment arrangement Treatments applied only to dam Winter grazing mid-nov. to mid-feb: winter range corn crop residue Last trimester of gestation: PS kg/d of 28% CP cake NS - No supplement Materials & Methods Cow Management Gudmundsen Sandhills Laboratory, Whitman, NE (GSL) n = 342, 3 rd yr in progress 5/8 Red Angus, 3/8 Simmental cows 3 to 5 yr of age at beginning of trial Within age group, stratified by previous calf WW Remain on treatment throughout experiment Numbers maintained by adding 3 yr old cows each fall Natural service breeding Calving season begins March 1 Supplement Composition DM Basis Dried distillers grains 62.0 Wheat middlings 10.6 Cottonseed meal 9.0 Dried corn gluten feed 5.0 Cane molasses 3.0 Calcium Carbonate 3.0 Urea 2.1 VTM, binder, etc. 5.4 n = 172 Materials & Methods Steer Progeny Weaned at GSL Transported to West Central Research & Extension Center, North Platte, NE (WEC) feedlot 10 d later 221 DOF Monensin, mg/kg 178 Joplin/newsroom.html 5

6 Materials & Methods Heifer Progeny Cow Performance n = yr reproductive data 3 yr growth, FE data Weaned at GSL Transported to WEC 10 d later Wintered in drylot Heifers from cows individually fed Heifers from cows pen fed Age and weight at puberty determined Transported back to GSL Cow Body Weight Cow BCS Cow Performance Treatment RS RNS SS SNS WT BCS PG Joplin/newsroom.html Cow Weaning BW, lb P-value Sys Sup S*S < Cow Weaning BCS Pregnancy Rate, % Calved 1st 21 d 83a 62b 78a 80a

7 Steer Feedlot Performance Final Live Weight and ADG RS RNS SS SNS Quality Grade (% Choice) RS RNS SS SNS Heifer Performance 43 PS NS Heifer Pregnancy Diagnosis and Weights Heifer Performance Treatment P-value Sys Sup S*S Pubertal prior to breeding, % 91b 74a 79ab 84ab Age at puberty, d Pregnancy rate, % Treatment BW Range S Range NS Stalks S Stalks NS Pregnancy (%) day breeding season Joplin/newsroom.html 7

8 Heifer Performance Treatment P-value Sys Sup S*S ADG 1.85 a 1.81 a 1.54 b 1.79 a DMI Gain:Feed a a 0.09 b a < RFI, kg/d CGC Composite 50% Red Angus, 25% Charolais, 25% Tarentaise Lifetime Productivity Study (Feed inputs and Reproduction) CGC Heifer calves Experiment Design 64% Corn silage, 23% alfalfa, 13% supp. Fed to appetite 140 d development (80 % of control) Puberty Graze native pasture 52 d breeding Winter Suppl. Wean On test Off test AI BW Date: 10/2 12/5 4/24 6/8 11/ kg hay/d 1.1 kg/d What about offspring? 100% Retention of CGC heifers COW Daughter Retention 90% 80% 70% 60% C Cdam C Rdam R Cdam R Rdam 50% 40% Epigenetic Effect? 30% Breeding year Joplin/newsroom.html 8

9 What about calf Birth Wt What about calf Wean Wt Dam Cow 35 kg Dam Cow 225 kg 35 kg 222 kg 35 kg 223 kg 34 kg 216 kg Fetal Programming Stimuli experienced during fetal development may impact postnatal growth and physiology Barker et al., 1993 Restriction of primiparous heifers during the final 100 d of gestation resulted in tendency for increased age at puberty in female progeny Corah et al., 1975 Late gestation nutrient restriction of ewes alters adult female progeny endocrine functionindependent of birth weight Bloomfield et al., 2003 Undernutrition Placental insufficiency Related to restricted supply May result from limited uterine blood flow protein limited arginine = low NO Important for vasodilation and increased blood flow Exhibit similar postnatal symptoms as overnutrition Undernutrition Offspring predisposed to: Neonatal morbidity/mortality Cardiovascular disease Thrifty phenotype Aberrant fat development/deposition Diabetes Reproductive deficiencies Depends on timing of restriction May depend on type of nutrient restricted Nutrient Restriction Consequences of nutrient restriction must be considered not only on individual animal performance but also the developing fetus. Joplin/newsroom.html 9

10 BEEF SYSTEMS RESEARCH beef.unl.edu Questions??? beef.unl.edu ; Joplin/newsroom.html 10