The objective of this study was to determine whether nutrient digestibility and reproductive performance of pregnant mink(Neovison vison) were affected by different dietary protein levels. One hundred and twenty femal...The objective of this study was to determine whether nutrient digestibility and reproductive performance of pregnant mink(Neovison vison) were affected by different dietary protein levels. One hundred and twenty female mink were randomly assigned to four groups, receiving diets of fresh material with different protein levels. The dietary protein levels,expressed as percentage of dry matter(DM),were 32,36, 40 and 44% respectively. These values corresponded to average 320, 360, 400 and 440 g protein/kg DM, respectively. Results were as follows. All of crude protein digestibility, nitrogen(N) intake, N retention increased along with dietary protein level increasing. Low protein level(32%) significantly reduced the above indicators(P < 0.05). DM digestibility and ether extract digestibility were not affected by dietary protein level. Results of mated females, barren females, kids per litter, live born kids per mated female, birth survival rate, and birth weight showed that mink achieved optimal reproductive performance when dietary protein level was 36%. In conclusion, dietary protein was anticipated to significantly influence some nutrients' utilization. Adopting the appropriate dietary protein level allow better reproduction performance. The most preferable reproductive performance was achieved when diet contained 275.5 g digestible protein per kg DM for female mink in gestation.展开更多
The experiment was to study the nutrient digestibility and metabolism performance of male minks,which were fed different protein level diets during growth period. Effects of protein quantity on growth and development ...The experiment was to study the nutrient digestibility and metabolism performance of male minks,which were fed different protein level diets during growth period. Effects of protein quantity on growth and development of minks and feed conversion ratio(FCR) were also investigated. Sixty healthy male minks of 45 d were randomly allocated into six groups with ten replicates, which was one sable for each replicate. The minks in six groups were fed diets in which protein levels were 28, 30,32, 34, 36 and 38%,respectively. The six groups were denoted as P28, P30, P32, P34, P36 and P38. After 2 wk, all minks were weighed, average daily gains(ADG) were calculated, and the digestibility values of nutrients were determined. The results indicated that digestibility of calcium, nitrogen of fence, nitrogen deposition, net protein utilization(NPU), and biological value of protein(BV) were similar(P > 0.05), however, nitrogen intake greatly varied among groups(P < 0.01). Compared with group P28, groups of P34, P36 and P38 showed significant difference(P < 0.01) in ADG and FCR. In conclusion, it was recommended that adding34% protein to mink diet would optimize production parameters including ADG, digestibility of nutrition,and FCR, and negative result was observed when diet protein was lower than 28%.展开更多
The objective of the present study was to investigate the effects of methionine(Met) supplementation on growth performance of cubs, nutrient digestibility, nitrogen metabolism and serum biochemical parameters of femal...The objective of the present study was to investigate the effects of methionine(Met) supplementation on growth performance of cubs, nutrient digestibility, nitrogen metabolism and serum biochemical parameters of female blue foxes. One hundred primiparous female blue foxes that were similar in breeding date, pedigree, age, and weight were selected for the trial. The foxes were randomly assigned to four groups(n = 25 each group) and fed diets supplemented with Met at 2(Met2), 4(Met4), 6(Met6)and 8 g/kg(Met8), respectively, for 40 days. Our data showed that body weights at 20 and 40 d were significantly higher in the Met4 group than in the Met2 group(P < 0.05). The Met4 group also had the highest apparent digestibility of dry matter and crude protein compared with either the Met2, Met6, or Met8 group(P< 0.05). The serum Met and isoleucine(Ile) concentrations were significantly higher in the Met4 group than in the Met6 or Met8 group(P < 0.05). In summary, these data indicate that supplementary Met improves growth performance of cubs likely due to increased crude protein and dry matter and increased nitrogen retention of female blue foxes. The optimal amount of Met supplementation is10 g/kg basal diet.展开更多
基金The financial support is from Special Fund for Public Welfare Technology Research of Agricultural Industry(200903014)Supporting Plan for Scientific and Technological Research of Jilin Province(20090238)
文摘The objective of this study was to determine whether nutrient digestibility and reproductive performance of pregnant mink(Neovison vison) were affected by different dietary protein levels. One hundred and twenty female mink were randomly assigned to four groups, receiving diets of fresh material with different protein levels. The dietary protein levels,expressed as percentage of dry matter(DM),were 32,36, 40 and 44% respectively. These values corresponded to average 320, 360, 400 and 440 g protein/kg DM, respectively. Results were as follows. All of crude protein digestibility, nitrogen(N) intake, N retention increased along with dietary protein level increasing. Low protein level(32%) significantly reduced the above indicators(P < 0.05). DM digestibility and ether extract digestibility were not affected by dietary protein level. Results of mated females, barren females, kids per litter, live born kids per mated female, birth survival rate, and birth weight showed that mink achieved optimal reproductive performance when dietary protein level was 36%. In conclusion, dietary protein was anticipated to significantly influence some nutrients' utilization. Adopting the appropriate dietary protein level allow better reproduction performance. The most preferable reproductive performance was achieved when diet contained 275.5 g digestible protein per kg DM for female mink in gestation.
基金financially supported by the Special Fund for Public Welfare Technology Research Agricultural Industry of P.R.China(No.200903014)
文摘The experiment was to study the nutrient digestibility and metabolism performance of male minks,which were fed different protein level diets during growth period. Effects of protein quantity on growth and development of minks and feed conversion ratio(FCR) were also investigated. Sixty healthy male minks of 45 d were randomly allocated into six groups with ten replicates, which was one sable for each replicate. The minks in six groups were fed diets in which protein levels were 28, 30,32, 34, 36 and 38%,respectively. The six groups were denoted as P28, P30, P32, P34, P36 and P38. After 2 wk, all minks were weighed, average daily gains(ADG) were calculated, and the digestibility values of nutrients were determined. The results indicated that digestibility of calcium, nitrogen of fence, nitrogen deposition, net protein utilization(NPU), and biological value of protein(BV) were similar(P > 0.05), however, nitrogen intake greatly varied among groups(P < 0.01). Compared with group P28, groups of P34, P36 and P38 showed significant difference(P < 0.01) in ADG and FCR. In conclusion, it was recommended that adding34% protein to mink diet would optimize production parameters including ADG, digestibility of nutrition,and FCR, and negative result was observed when diet protein was lower than 28%.
文摘The objective of the present study was to investigate the effects of methionine(Met) supplementation on growth performance of cubs, nutrient digestibility, nitrogen metabolism and serum biochemical parameters of female blue foxes. One hundred primiparous female blue foxes that were similar in breeding date, pedigree, age, and weight were selected for the trial. The foxes were randomly assigned to four groups(n = 25 each group) and fed diets supplemented with Met at 2(Met2), 4(Met4), 6(Met6)and 8 g/kg(Met8), respectively, for 40 days. Our data showed that body weights at 20 and 40 d were significantly higher in the Met4 group than in the Met2 group(P < 0.05). The Met4 group also had the highest apparent digestibility of dry matter and crude protein compared with either the Met2, Met6, or Met8 group(P< 0.05). The serum Met and isoleucine(Ile) concentrations were significantly higher in the Met4 group than in the Met6 or Met8 group(P < 0.05). In summary, these data indicate that supplementary Met improves growth performance of cubs likely due to increased crude protein and dry matter and increased nitrogen retention of female blue foxes. The optimal amount of Met supplementation is10 g/kg basal diet.
