188 Voluntary individual intake and performance of mature cows compared to primiparous heifers consuming a low quality forage. (28th November 2020)

• Record Type: Journal Article
• Authors: Holder, Amanda; Andresen, Claire; Gross, Megan A; Moehlenpah, Alexi; Lalman, David L
• Is Part Of: Journal of animal science. Volume 98(2020)Supplement 2
• Page Start: 56
• Page End: 56
• Publication Date: 2020-11-28
• Subjects: Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.1093/jas/skz397.127
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: This study investigated production and efficiency of Angus first-calf heifers and mature cows. During late lactation (January through April), cow/calf pairs were provided abundant bermudagrass hay and 2.5 kg of dried distiller's grains with solubles daily. Milk yield and composition was determined monthly using a milking machine. After weaning, forty-three Angus 2-yr-old heifers (n = 22) and cows (n = 21) were assigned to one of five pens according to their dry matter intake EPD. Each pen was equipped with two SmartFeed individual intake units adapted with a hay basket. Cows had ad libitum access to long stem prairie hay (CP = 5.7%, NDF = 66.4, TDN = 54%). Cows were provided 1 kg corn and 1 kg cotton seed meal daily. Performance variables were analyzed with a mixed model including pen as a random variable and age the fixed variable. Following a 14-day adaptation period, individual cow forage intake was measured for 45 days. There was a positive phenotypic correlation (r = 0.40, P < .01) between residual average daily gain EPD and average study-period BCS on trial. Mature cows consumed 1.9 kg more forage daily (P = 0.05) than heifers although there was no difference when expressed as a percent of BW (2.0%; P > .78). There was no difference in the amount of time spent in feeders between heifers and cows (4.6 hrs, P > 0.59) nor average body condition score (5.1, P > .86). Cows produced more milk per unit of body weight (P < .01) and had greater residual feed intake and calf weaning weight (kg) compared to heifers (0.63 and 211.6 vs -0.45 and 189.3; P < 0.04). Heifers consumed similar amount of forage per unit of BW, spent the same amount of time in feeders and were more efficient in weight gain while consuming low quality forage.