51 Influence of maternal energy status during mid-gestation on pre-weaning and early post-weaning performance of beef calves

Summary

Cows bred to calve within a similar calving interval (n = 46) were stratified into two groups by fetal sex, cow age, initial body weight (BW) and body condition score (BCS: 1 = extremely emaciated, 9 = very obese) to evaluate the influence of maternal nutrient restriction during mid-gestation on calf performance. Groups were randomly assigned to one of two treatments based on global nutrient intake: 1) fed to achieve and/or maintain a BCS of 5 or 6 (Positive Energy Status [PES]; n = 24) or 2) fed to lose one BCS during midgestation (Negative Energy Status [NES]; n = 22). After the treatment period, cows were managed to be in a positive energy status throughout the final trimester and achieve a BCS > 5.0 by parturition. At birth, calf birth weight, date of birth, and sex were recorded, an