Timing of maternal supplementation of dried distillers grains during late gestation influences postnatal growth, immunocompetence, and carcass characteristics ofBos indicus-influenced beef calves

Abstract

This 2-yr study investigated the timing of dried distillers grains (DDG) supplementation during the third trimester of gestation of Bos indicus-influenced beef cows and its impact on offspring performance. On day 0 of each year (84 d before calving), Brangus cows (n = 84/yr; cow age = 8 ± 3 yr) were stratified by initial body weight (BW; 482 ± 75 kg) and body condition score (BCS; 5.3 ± 0.8) and assigned randomly to 1 of 6 bahiagrass (Paspalum notatum) pastures (experimental units; 14 cows/pasture). Treatments were assigned randomly to pasture (2 pastures/treatment/yr) and consisted of no prepartum supplementation (CON), 2 kg/d of DDG from day 0 to 42 (LATE42), or 1 kg/d of DDG from day 0 to 84 (LATE84). Following calving (day 84), cow-calf pairs remained in their respective pastures and cows were offered sugarcane molasses + urea (1.82 kg of DM/cow/d) from day 85 until the end of the breeding season (day 224). On day 347, steer calves (n = 38/yr; 11 to 15 steers/treatment/yr) were weaned and transported to the feedlot (1193 km). Steers were penned according to cow prepartum pasture and managed similarly until time of harvest. Body condition score at calving was greater (P < 0.01) for LATE42 and LATE84 vs. CON cows but did not differ (P = 0.16) between LATE42 and LATE84 cows. Calving date, calving percentage, and birth BW of first offspring did not differ (P ≥ 0.22) among treatments. However, LATE42 cows calved their second offspring 8 days earlier (P = 0.04) compared to CON and LATE84 cows. At weaning (1 st offspring), LATE84 calves were the heaviest (P ≤ 0.05), CON calves the lightest, and LATE42 calves had intermediate BW (P ≤ 0.05). Steer plasma concentrations of cortisol and haptoglobin and serum BVDV-1 titers did not differ (P ≥ 0.21) between treatments. Steer serum PI3 titers were greater (P = 0.03) for LATE42 vs. CON steers, tended to be greater (P = 0.10) for LATE84 compared with CON steers, and did not differ (P = 0.38) between LATE42 and LATE84 steers. Steer feedlot BW, average daily gain, dry matter intake, and hot carcass weight did not differ (P ≥ 0.36) between treatments. Marbling and the percentage of steers grading choice were greater (P ≤ 0.04) for LATE42 vs. CON steers, whereas LATE84 steers were intermediate. In summary, different timing of DDG supplementation during the third trimester of gestation could be explored to optimize cow body condition score and offspring preweaning growth and carcass quality.

Frequency of maternal supplementation of energy and protein during late gestation modulates preweaning growth of their beef offspring

“…Forage CP concentrations from day 0 to 77 were greater than the CP requirement of late-gestating beef cows (8.1% CP of DM; NASEM, 2016 ), whereas forage IVDOM concentrations from day 0 to 77 were below the TDN requirements of pregnant beef cows (53% TDN of DM; NASEM, 2016 ), explaining the BCS loss experienced by NOSUP cows from day 35 to 77. These responses were expected and in agreement with previous studies conducted in the same location and similar animals ( Moriel et al, 2020b ; Palmer et al, 2020 , 2022a , b ; Vedovatto et al, 2022 ).…”

“…Prepartum supplementation of protein and energy supplementation increased prepartum BCS of beef cows ( Winterholler et al, 2012 ; Bohnert et al, 2013 ; Kennedy et al, 2019 ; Moriel et al, 2020b ; Palmer et al, 2020 , 2022a , b ; Vedovatto et al, 2022 ), did not impact the percentage of pregnant beef cows in the subsequent breeding season ( Stalker et al, 2007 ; Larson et al, 2009 ; Bohnert et al, 2013 ) but resulted in earlier calving compared to no prepartum supplementation of protein and energy ( Palmer et al, 2020 ). Likewise, prepartum supplementation of DDG at 77 kg/cow from day 0 to 77, regardless of supplementation frequency, was sufficient to prevent or minimize prepartum BCS loss, leading to greater BCS during the first 30 d of the breeding season compared to NOSUP cows.…”

“…Treatments were randomly assigned to pastures (5 pastures/treatment) and consisted of cows offered no precalving supplementation of DDG from day 0 to 77 (NOSUP) or precalving supplementation of DDG dry matter (DM) at 1 kg/cow daily (7×), 2.33 kg/cow every Monday, Wednesday, and Friday (3×), or 7 kg/cow every Monday (1×) from day 0 to 77. All cows assigned to DDG supplementation received the same total amount of DDG dry matter (77 kg/cow) to gain at least 0.5 unit of BCS (1 to 9 scale) from day 0 to 77 ( Palmer et al, 2022a ). Each respective DDG supplement amount was offered in open plastic feed bunks at 0800 h from day 0 to 77.…”

“…From day 110 to 231, each group was offered stargrass ( Cynodon nlemfuensis ) hay ad libitum and provided a commercial sugarcane molasses and urea supplement at 12.4 kg of DM per cow weekly (82.4% DM; 22% CP and 75% TDN; Westway Feed Products LLC, Clewiston, FL). Molasses and urea supplement was provided at 0800 h every Monday and Thursday in open plastic tanks placed 1 m above the ground to avoid calf consumption of supplement ( Palmer et al, 2020 , 2022a ). All groups were checked daily for calving starting on day 77.…”

“…Nutritional status during third trimester of gestation of beef cows modulates placental environment, fetal development ( Funston et al, 2012 ), and offspring postnatal performance ( Palmer et al, 2020 , 2022a , b ). Reducing the frequency of concentrate supplementation during third trimester of gestation did not impact offspring birth BW ( Klein et al, 2014 ) but was detrimental to offspring physiological stress following birth ( Moriel et al, 2016a ).…”