Effects of breed of cattle on energy requirements for growth

Abstract

SUMMARYWith the object of comparing the energy requirements of cattle of different breeds a total of 108 animals, representing three maturity types, were individually fed at two levels of intake over three 12-week periods commencing at 250, 375 and 500 kg live weight in a co-ordinated experiment. The three breeds compared were Aberdeen Angus cross, Hereford × British Friesian and British Friesian. Animals were offered a 50:50 hay: concentrate ration at two levels of feeding; one level was designed to give 0·7 kg gain daily and the other 75 to 80% of this intake.Though the relative performance of breeds differed at the three centres, overall average live-weight gain did not differ significantly between breeds. Feed conversion efficiency dropped from 8·55 kg dry matter per kg gain in the first period to 16·95 kg in the third period, but differences in conversion ratio between breeds were not significant.Carcass measurements taken at slaughter immediately after the third test period indicated higher killing-out percentages and higher fat percentages in the Angus cross than in the British Friesian with Hereford × Friesian intermediate. Differences in energy needs for gain among the three breeds, predicted by apportioning ME intake to maintenance and gain using a multiple regression technique, were greater than differences calculated from carcass composition and published energy requirements for fat and protein deposition. The limitations of the use of the multiple regression technique for this purpose are discussed.

Effects of variations in energy and protein intake on digestibility, nitrogen balance and carcass composition in British Friesian castrate male cattle

“…Although carcass protein deposition was related both to ME and CP intake, energy deposition in the CMFT (CED) was related to ME intake only: CED = 0-15 (±0-017) ME-3-78 (MJ) R2 = 0-83 The following equation, similar to that obtained by Chestnutt, Marsh, Wilson, Stewart, McCullough and McCallion (1975), was found for the relationship between ME intake, M and LW gain: ME = 0-57 M +18-5 LW gain (residual s.d. ± 6-10) (MJ) (LWO-75) (kg/day) For LW of 150 to 350 kg and LW gain of 0-5 and 0-75 kg/day this equation estimated ME requirements similar to recent recommended values (Ministry of Agriculture, Fisheries and Food, Department of Agriculture and Fisheries for Scotland and Department of Agriculture for Northern Ireland, 1975) but the partition between maintenance and tissue requirements differed.…”

Fat deposition in Hereford and Friesian steers: 1. Body composition and partitioning of fat between depots

“…1977;Wyatt et al 1977;Blakely et al 1979). This difference may be due to a higher maintenance requirement in dairy-types (Garrett, 1971;Chestnutt et al 1975). Alternatively, major differences in fat partitioning between carcass and non-carcass depots in beef and dairy-types may bias the interpretation of food utilization; i.e.…”

Rice bran as a supplement to elephant grass for cattle and buffalo in Indonesia: 1. Feed intake, utilization and growth rates

“…The inclusion of live weight and growth rate in a multiple regression accounted for 86 % of the varia-tion in intake of ME (equation 4) as long as there is a sufficiently wide range in growth rates, this multiple regression approach has been shown to be valid for partitioning ME into requirements for maintenance and for growth (Chestnutt et al 1975;Moran, 1976). In the present study, individual growth rates ranged from 0-15 to 0-68 in Ongoles and from 0-20 to 0-76 kg/head/day in buffaloes.…”