Effects of different energy and protein levels on growth performance and beef quality in the bull
The experiment was conducted to study the effect of different levels of energy and protein on growth performance and blood biochemical index by using a single factorial design and 40 heads of bulls with similar weight and health were selected.These bulls were randomly divided into four groups that were relatively fed low,medium and high energy-protein levels dairy ration.The results showed that the daily gain of cows was improved as increases of diet energy-protein levels.The average day gain (ADG) was relatively increased about 21.88％ (P＜0.05) from 959 g/d to 1 181 g/d.The slaughter rate and pure meat percentage were found significantly different among groups (P＜0.05),and the highest was in group Ⅳ,their value were 60.84％ and 49.21％.Back fat thickness were highest in group Ⅲ and reached to 106.5 mm (P＜0.05).The shear force has no significantly different (P＞0.05).The saturated fatty acid and monounsaturated fatty acid contents of beef in four groups were not significantly different (P＞0.05),but the polyunsaturated fatty acid was different significantly (P＜0.05).The lowest monounsaturated fatty acid contents were in group Ⅰ of 5.31％ and the highest were in group Ⅳ of 6.70％,relative reduced by 26.18％ (P＜0.05).The highest income of everyday each cow was 6.91 RMB but the lowest was 3.14 RMB,increased 3.77 RMB.Together,our finding suggested that the energy and protein level in group Ⅲ was appropriate and economic benefit was the highest in the BMY finishing process during 200 ～ 350 kg weight under this experimental condition.
国家科技期刊平台
NSTL
万方数据
维普
