Two experiments were conducted to in- vestigate the effects of net energy （NE） level on the performance and carcass traits of finishing pigs fed low crude protein （CP） diets supplemented with crystalline amino aci...Two experiments were conducted to in- vestigate the effects of net energy （NE） level on the performance and carcass traits of finishing pigs fed low crude protein （CP） diets supplemented with crystalline amino acids （CAA）. A total of 216 （Exp. 1） and 360 （Exp. 2 ） barrows （ Yorkshire × Landrace× Duroc ） were allotted to one of six treatments （n =6）. The experimental diets were based on corn and soybean meal, and consisted of a high-CP diet that contained approximately 16% CP and 2.50 Mcal/kg of NE as well as five low-CP diets in which the CP level of the diet was reduced by approximately four percentage units but was supplemented with crystalline lysine, methionine, threonine, and tryptophan. The low CP diets provided 2.64, 2.58, 2.50, 2.42, or 2.36 Mcal/kg in Exp. 1 as well as 2.45, 2.40, 2.35, 2.30, or 2.25 Mcai/kg in Exp.2. In Exp. 1, a linear （P=0.03） increase in weight gain was observed with decreasing NE level while the ratio of gain to feed was unaffect- ed （P 〉 0.05） by NE level. There was a linear in-crease （P = 0.01 ） in the percentage of fat-free lean and a linear decrease （ P = 0.03 ） in the percentage of total fat with decreasing NE levels. In Exp. 2, a sig- nificant quadratic （ P = 0.03 ） effect of NE level was observed for weight gain. The ratio of gain to feed demonstrated a significant （P 〈0.01 ） quadratic effect with pigs fed 2.35 and 2.40 Mcal/kg of NE, Pigs fed the diet containing 2.40 Mcal/kg of NE had the lowest percentage of total fat （36. 95% ） and the highest percentage of fat-free lean （49.36%）. The overall results of these experiments indicate that feed- ing either a surplus or a deficiency of NE is detrimen- tal to both pig performance and carcass composition when low CP diets supplemented with CAA are fed. Our results indicate that when the CP content of the diet is reduced by four percentage units and the diet is properly supplemented with CAA, maximum per- formance and carcass quality will be obtained if the diet provides approximately 2.42 Mcal/kg of NE.展开更多
This experiment was conducted to determine whether the performance of broilers fed diets based on corn and soybean meal could be enhanced with enzymes or probiotics. A total of 120 male broilers, three days of age, we...This experiment was conducted to determine whether the performance of broilers fed diets based on corn and soybean meal could be enhanced with enzymes or probiotics. A total of 120 male broilers, three days of age, were assigned to one of four treatments in a completely randomized design, and housed in groups of five with six cages per treatment. The control diet was based on corn and soybean meal while the three experimental diets consisted of the basal diet supplemented with 0.1% of enzyme I, enzyme II, or probiotic. Enzyme I provided α-galactosidase and fl-mannanase, while enzyme II provided protease, amylase, α-galactosidase, xylanase, and cellulase. The probiotic was composed of Bacillus coagulance, Bacillus lichenformis , Bacillus subtilis , and Clostridium butyricum. Over the 28 day experiment, the weight gain of birds fed the probiotic treatment was superior （P = 0.03 ） to the control, while gains for the enzyme treatments were intermediate to those of the control and probiotic. Feed intake and feed conversion did not differ among treatments （P 〉 0.05 ）. Ammonia production was significantly （ P 〈 0.01 ） higher in the control compared with either of the enzyme or probiotic treatments. Compared with the control, supplementation with enzyme H significantly reduced the digestibility of arginine, isoleucine, and lysine （P 〈 0.05 ）. In contrast, the digestibility of energy was higher （P 〈 0.01 ） for birds supplemented with enzyme II than the control. Digestibility coeffi- cients did not differ for any other parameter with the exception of energy which was significantly higher for birds fed the probiotic treatment than the control （P 〈 0.01 ）. In summary, the performance of broilers was significantly enhanced by the addition of a probiotic to the diet. However, under the conditions of this experi- ment, supplementation with a multi-enzyme complex containing either α-galactosidase and fl-mannanase or the combination of protease, amylase, galactosidase, xylanase, and cellulase failed to improve broiler performance.展开更多
基金supported by the National Natural Science Foundation of P.R.China (No.NSFC30525029)
文摘Two experiments were conducted to in- vestigate the effects of net energy （NE） level on the performance and carcass traits of finishing pigs fed low crude protein （CP） diets supplemented with crystalline amino acids （CAA）. A total of 216 （Exp. 1） and 360 （Exp. 2 ） barrows （ Yorkshire × Landrace× Duroc ） were allotted to one of six treatments （n =6）. The experimental diets were based on corn and soybean meal, and consisted of a high-CP diet that contained approximately 16% CP and 2.50 Mcal/kg of NE as well as five low-CP diets in which the CP level of the diet was reduced by approximately four percentage units but was supplemented with crystalline lysine, methionine, threonine, and tryptophan. The low CP diets provided 2.64, 2.58, 2.50, 2.42, or 2.36 Mcal/kg in Exp. 1 as well as 2.45, 2.40, 2.35, 2.30, or 2.25 Mcai/kg in Exp.2. In Exp. 1, a linear （P=0.03） increase in weight gain was observed with decreasing NE level while the ratio of gain to feed was unaffect- ed （P 〉 0.05） by NE level. There was a linear in-crease （P = 0.01 ） in the percentage of fat-free lean and a linear decrease （ P = 0.03 ） in the percentage of total fat with decreasing NE levels. In Exp. 2, a sig- nificant quadratic （ P = 0.03 ） effect of NE level was observed for weight gain. The ratio of gain to feed demonstrated a significant （P 〈0.01 ） quadratic effect with pigs fed 2.35 and 2.40 Mcal/kg of NE, Pigs fed the diet containing 2.40 Mcal/kg of NE had the lowest percentage of total fat （36. 95% ） and the highest percentage of fat-free lean （49.36%）. The overall results of these experiments indicate that feed- ing either a surplus or a deficiency of NE is detrimen- tal to both pig performance and carcass composition when low CP diets supplemented with CAA are fed. Our results indicate that when the CP content of the diet is reduced by four percentage units and the diet is properly supplemented with CAA, maximum per- formance and carcass quality will be obtained if the diet provides approximately 2.42 Mcal/kg of NE.
文摘This experiment was conducted to determine whether the performance of broilers fed diets based on corn and soybean meal could be enhanced with enzymes or probiotics. A total of 120 male broilers, three days of age, were assigned to one of four treatments in a completely randomized design, and housed in groups of five with six cages per treatment. The control diet was based on corn and soybean meal while the three experimental diets consisted of the basal diet supplemented with 0.1% of enzyme I, enzyme II, or probiotic. Enzyme I provided α-galactosidase and fl-mannanase, while enzyme II provided protease, amylase, α-galactosidase, xylanase, and cellulase. The probiotic was composed of Bacillus coagulance, Bacillus lichenformis , Bacillus subtilis , and Clostridium butyricum. Over the 28 day experiment, the weight gain of birds fed the probiotic treatment was superior （P = 0.03 ） to the control, while gains for the enzyme treatments were intermediate to those of the control and probiotic. Feed intake and feed conversion did not differ among treatments （P 〉 0.05 ）. Ammonia production was significantly （ P 〈 0.01 ） higher in the control compared with either of the enzyme or probiotic treatments. Compared with the control, supplementation with enzyme H significantly reduced the digestibility of arginine, isoleucine, and lysine （P 〈 0.05 ）. In contrast, the digestibility of energy was higher （P 〈 0.01 ） for birds supplemented with enzyme II than the control. Digestibility coeffi- cients did not differ for any other parameter with the exception of energy which was significantly higher for birds fed the probiotic treatment than the control （P 〈 0.01 ）. In summary, the performance of broilers was significantly enhanced by the addition of a probiotic to the diet. However, under the conditions of this experi- ment, supplementation with a multi-enzyme complex containing either α-galactosidase and fl-mannanase or the combination of protease, amylase, galactosidase, xylanase, and cellulase failed to improve broiler performance.
