PSXV-26 Late-Breaking: Effects of feeding haylage on the reproductive performance of 2-year-old beef cattle raised in a sustainable production system at Berea college farm

Abstract

Abstract Effects of winter feeding haylage on the growth and reproductive performance of late weaned, summer breeding, rotationally grazed, selectively bred mixed breed cattle (n =90) raised at Berea College Farm during 2015 to 2021 were evaluated. Cattle were grouped based on the year in which they turned 2 years old (2017, 2018, 2019, 2020 and 2021). The 2017 group alone was not fed haylage. Initial data indicated that maintenance of a pre-ruminant gastrointestinal tract during the early developmental years under our management is the main factor impacting cattle performance. Indeed, despite similar birth weights, weaning and yearling weights were numerically higher in 2018 and 2019 compared to 2017 cattle. Significantly higher weaning and yearling weights (264.47 vs 229.37kg and 306.60 vs 253.03kg; P < 0.05) were observed in 2020 versus 2017 cattle, respectively. Additionally, 2018 (426.83kg) but not 2019 (387.38kg) cattle had higher (P < 0.05) liveweights than 2017 (398.93kg) cattle at yearling pregnancy check. At the 2nd breeding, 2018 cattle maintained numerically higher weights than 2019. However, the higher liveweights observed for 2018 cattle compared to that of 2017 cattle at the yearling pregnancy check, was reversed in the following year at the 2-year-old pregnancy check. Consequently, pregnancy rates at the yearling pregnancy check did not differ (89.47 vs 91.67%) but numerically lower retention (31.8 vs 50%) and pregnancy rates (50 vs 75%) were observed for 2018 cattle than 2017 cattle by the 2-year-old pregnancy check, respectively. Additionally, 55% the 2018 cattle displayed ovarian activity and 50% of the 2019 cattle displayed estrus prior bull introduction. In 2019 cattle, 92% were cyclic before introduction of the bull and a 91% estrus response was detected during the breeding season. Feeding haylage promoted growth and reproductive performance of cattle but apparently did not alleviate 2019 drought induced dystocia occurrences during 2020 and 2021 calving seasons.