The performance of two breeds given different amounts and sources of protein in a high-molasses diet

Abstract

On a fattening diet in which final molasses supplied from 68 to 76 % of the metabolizable energy and napier grass some 10 %, the treatments in a 2 x 2 x 3 factorial design were breed (Brahman or Brown Swiss x Brahman), source of supplementary protein (fish meal or poultry waste) and protein level (low, medium or high-replacing urea). Mean daily gains to 404 kg live weight were better for the crossbreds (0-89 compared with 0-77 kg), as was conversion rate in terms of Meal ME per kg gain (25-6 compared with 29-5); fish meal improved gains by 44 % and conversion rate by 39 % as compared with poultry waste when the two supplements were fed at levels designed to equate N intakes from this source. The superiority of the crossbreds was only apparent on the fish meal diets where they averaged 1*19 compared with 0-94 kg/day for the Brahmans. Daily N x 6-25 intakes decreased from 3-8 g/kg live weight on the low level of poultry waste to 2-9 on the high level due to low palatability of this material. On this treatment (poultry waste), daily gain (kg) was significantly related (6 = 0-119+0-031; P<0-01) to N X 6 -2 5 intake (g) per unit live weight (kg). Commercial half carcass dissection showed the crossbreds to have significantly more edible meat, more bone and less excess fat than Brahmans. Protein source had no effect on carcass composition.

Effects of Selenium and Vitamin E, and Copper Administrations on Weight Gains of Beef Cattle Raised in a Selenium-Deficient Area

“…Shorthorn yearling steers, were conducted to determine the effects ofselenium ( than untreated cattle (Powell 1966 Shirley et al 1966) or added to the mineral supplement (Preston et al 1970 . In northern Ontario, cattle frequently receive inadequate dietary copper (Cu) (Lessard et al 1970).…”