排序方式： 共有23条查询结果，搜索用时 46 毫秒
21.
An experiment was conducted to evaluate the performance of crossbred growing chickens (Rhode Island Red × indigenous Burkina
Faso hens) from 6 to 17 weeks of age, under five feeding/management regimes: (1) CMx(+), confined and given a mixed feed containing
cracked maize and cowpea and a vitamin–mineral premix ad libitum; (2) CS(+), confined and offered ad libitum a choice of cracked maize and cowpea with the premix; (3) ScS(+), scavenging from 09:00 to 16:00 with the diet in treatment
(2) available from 16:00 to 09:00; (4) ScS(−), treatment (3) but without the premix; and (5) ScO, scavenging only, with no
supplements provided. Daily dry matter (DM) intake was highest for CS(+) (43.5 g), and lowest for CMx(+) (33.6 g) (p < 0.05), with intermediate intakes for ScS(+) and Sc(−) of 36.7 g and 36.2 g, respectively. The ratios of intakes of cowpea
to maize were 50:50, 21:79, 27:73 and 22:78 for CMx(+), CS(+), ScS(+) and ScS(−), respectively (p < 0.05). Dietary concentrations of crude protein (CP) were 15.7%, 11.5%, 12.3% and 11.6% of DM for CMx(+), CS(+), ScS(+)
and ScS(−), respectively. Average daily gains (ADG) were 8.15 g, 5.24 g, 6.03 g, 5.36 g and 4.45 g for CMx(+), CS(+), ScS(+),
ScS(−) and ScO, respectively, and were significantly higher for CMx(+) (p < 0.05). Feed conversion ratio was highest for CS(+) and lowest for CMx(+). ADG of the males (6.44 g) was significantly (p < 0.05) higher than that of the females (5.86 g). Breast and thigh muscle weights were highest for ScS(+) (p < 0.05). 相似文献
22.
Total tract digestibility and nitrogen retention of three diets containing different levels of fibre [200, 260 and 320 g/kg neutral detergent fibre (NDF) in dry matter] were determined in three breeds of growing pig at an initial age of approximately 3.5 months. The breeds were local (Mong Cai, MC), F1 crossbred (MC x Yorkshire) and exotic (Landrace x Yorkshire, LY), allocated at random within breed (block) to double 3 x 3 Latin squares. The main fibrous ingredients of the experimental diets were rice bran, cassava residue meal and non-dehulled groundnut cake meal. Digestibility of organic matter (OM), crude protein (CP), NDF, crude fibre, gross energy (GE) and ether extract (EE) decreased as the level of dietary NDF increased (p < 0.001). The r(2) values for the relationship between NDF level and digestibility of OM, CP, GE and EE were 83%, 83%, 80% and 82% respectively. On average, an increase in NDF content of 1% unit resulted in a decrease in OM, CP, GE and EE digestibility of 0.67%, 0.75%, 0.50% and 0.42% units respectively. Digestibility of energy and nutrients was the highest for MC and the lowest for LY (p < 0.01), with intermediate values for F1. There was a negative effect of NDF level on nitrogen (N) retained as a proportion of intake (p < 0.05). Nitrogen retention and utilization were significantly higher (p < 0.001) for LY than for MC and F1 pigs. 相似文献
23.
An experiment was carried out to determine the effect of feeding brewery waste that replaced different levels of concentrate in diets for growing crossbred common ducks. A total of 300 ducks at 3 weeks of age were allocated in a 2 x 5 factorial experiment. Two feeding systems were compared, with the brewery waste provided separately (S) or mixed (M) with a concentrate. For the first feeding system the concentrate was fed alone (C100M), or replaced successively by brewery waste at ratios of concentrate to brewery waste: 75:25 (C75M), 50:50 (C50M) and 25:75 (C25M) on a dry matter basis, and fed ad libitum. For the second system concentrate and brewery waste were fed separately, with the same levels as in the first system. Total feed intakes for both feeding systems and intakes of brewery waste, total dry matter, crude protein, calcium and phosphorus increased significantly as concentrate was reduced (p <0.05). Daily weight gains were not significantly different between the two feeding systems, but were significantly lower for the C25 and C0 diets (p <0.05). Replacement of 50% of the concentrate by brewery waste resulted in the best growth performance. The highest net profits were from the separate feeding system, and for ducks fed brewery waste only (C0). It is concluded that brewery waste can replace traditional diets for crossbred common ducks based on concentrate. 相似文献