Effects of stocking rate on perinatal cows and subsequent growth and performance of calves from birth to carcass: A long-term epigenetic analysis

Objective

Our objective was to analyze long-term cow-calf records to document effects of perinatal stocking rates on subsequent cow and calf performance from birth to slaughter.

Materials and Methods

Over 1,900 cattle records from F-1 (Hereford or Angus × Brahman) cows calving in the fall or winter and stocked on bermudagrass at 3 distinct stocking rates (i.e., low [LO; 2.4 cow-calf pairs {CC} per hectare], moderate [MOD; 3.8 CC per hectare], or high [HI; 5.8 CC per hectare]) were analyzed. At termination of the stocker period, calves were shipped to a commercial feedlot. When most of the cattle in a pen reached a visual backfat of 1.25 cm, they were weighed and shipped 50 km to an abattoir for slaughtering and carcass grading. Carcass traits included hot carcass weight, DP, backfat, marbling score, predicted YG, longissimus muscle area, and KPH percentage.

Results and Discussion

Calving season, cow age, calf sex, gestation stocking rate (for a given CC and for the cow’s previous calf), and lactation stocking rate had various effects on cow, suckling calf, feedlot yearling, and carcass measures. High stocking rate generally decreased calf performance, yearling feedlot performance, and carcass parameters.

Implications and Applications

Stocking rate during gestation had substantial implications for cow, fetus, and calf nutrition and, thus, subsequent offspring performance from birth to slaughter. Stocking rate, particularly during the calf rearing period, was a critical component of grazing management within the context of weather, site production potential, and operational strategy.