208 Nutrient Restriction During Late Gestation Alters Beef Heifer Colostrum Composition. (12th April 2022)

• Record Type: Journal Article
• Authors: Meyer, Allison M; Redifer, Colby A; Wichman, Lindsey G; Rathert-Williams, Abigail R
• Is Part Of: Journal of animal science. Volume 100(2022)Supplement 2
• Page Start: 97
• Page End: 98
• Publication Date: 2022-04-12
• Subjects: developmental programming -- lactation -- pregnancy; Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.1093/jas/skac064.162
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: We hypothesized that late gestational nutrient restriction of beef heifers would decrease nutrient partitioning to the mammary gland, resulting in less colostrum nutrient availability for neonatal calves. Fall-calving Hereford-SimAngus heifers (single-sired; BW: 451 ± 28 [SD] kg; BCS: 5.4 ± 0.7) bred to a single sire were individually fed 100% (control; n = 12) or 70% (nutrient restricted; NR; n = 13) of NASEM net energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to calving. Diets were based on chopped sorghum sudan hay (1.74 Mcal ME, 6.66% CP, 72.0% NDF; DM basis) supplemented to meet targeted nutritional planes. Calving was observed for all females, and total colostrum from one rear quarter was collected pre-suckling (50.5 ± 17 min [SD] postpartum). Colostrum nutrient composition was determined by colorimetric assays run on a UV-visible light microplate reader. Data were analyzed with treatment, calving date, and calf sex (when P < 0.25) as fixed effects. We have previously reported that single-quarter colostrum weight and volume were 40% less ( P = 0.04) in NR compared with control heifers. Colostrum lactose concentration was not affected ( P = 0.32) by treatment, but yield differences resulted in 46% less ( P = 0.03) total single-quarter colostrum lactose in NR than control. Colostrum from NR heifers had 36% greater ( P = 0.004) protein concentration than control, but greater colostrum yield of control heifers allowed for total protein to be unaffected ( P = 0.57) by treatment. Nutrient restricted heifers had 23% less ( P = 0.04) colostrum urea N concentration and 60% less ( P = 0.01) total colostrum urea N than control. Late gestational nutrient restriction ( P ≥ 0.59) did not affect colostrum triglyceride concentration or total. In summary, energy and protein restriction had disparate effects on nutrient partitioning to colostrum in primiparous beef females.