Grass hay as a supplement for grazing cattle. I. Animal performance.

Abstract

Regrowth grass hay produced on subirrigated meadows in the Nebraska Sandhills was evaluated as a supplement for gestating beef cows grazing winter range. Ninety-six crossbred spring calving, gestating beef cows were used in a winter supplementation study on upland Sandhills range from 5 November to 27 February in 1990 and again in 1991. Cows were divided into 4 treatments (24 cows/treatment): 1) control (range forage only, no supplement); 2) range forage and 2.2 kg cow-l day-1 of meadow regrowth hay (15.5% crude protein); 3) range forage and 1.2 kg cow-1 day-1 of a 30% wheat grain and 70% soybean meal:30% wheat supplement (36.0% crude protein); and 4) range forage with supplements in treatments 2 and 3 fed on alternate days. Meadow hay and soybean meal:wheat supplements provided 0.32 kg of crude protein/cow daily. Supplemented cows gained 3 to 53 kg body weight/year and maintained body condition, while control cows lost an average of 24.5 kg body weight/year and lost body condition. Intake of range forage was less (P < 0.05) by cows fed meadow hay and soybean meal:wheat supplements on alternate days than by cows on other treatments. Digestibility of range forage was lower (P < 0.05) for supplemented cows than control cows, but differences were small (avg. = 2%). Calving date, birth and weaning weights, and pregnancy rate were similar (P > 0.05) for all treatments. We concluded that subirrigated meadow regrowth grass hay was an effective alternative to traditional soybean meal-based supplements for maintaining body weight and body condition of gestating beef cows grazing winter range.