[Objective] The ovary microstructure and the changes of the follicle during the development period of blue fox during the estrous period were studied.[Method] Ten left ovaries were collected from 10 female blue foxes ...[Objective] The ovary microstructure and the changes of the follicle during the development period of blue fox during the estrous period were studied.[Method] Ten left ovaries were collected from 10 female blue foxes during the estrous period. The histological structure of the ovary and follicular development process were observed by using optical microscope. And 30 primordial follicles, 30 primary follicles, 15 growing follicles, 15 vesicular follicle, 15 mature follicles and the oocytes in the follicles of different developing stages were measured and photographed by eyepiece micrometer and photomicrographic technique respectively. [Result] The ovary of blue fox consisted of germinal epithelium, tunica albuginea, cortex and medulla. The cor- tex, which was located at the periphery of the ovary, contained many interstitial cells and follicles at different developing stages. Medulla was located below the cortex, with a lot of blood vessels. The diameters of follicles at different developmental stages and oocytes had greater differences during the developmental period of follicle. The diameter of follicles was 45.45-974.55 μm and the diameter of oocytes was 30.23-147.27 μm. The zona pellucida appeared at the primary follicle stage. The atresia of follicles occurred at all the developmental stages of follicle and the main manifestations were the shrunk oocyte and karyon, and loose and degraded granular cells. [Conclusion] The research provided histological basis for revealing the reproductive mechanism of female blue fox.展开更多
This study evaluated the effects of dietary fat levels on the growth, nutrient digestibility, nitrogen balance and pelt characteristics of the blue fox(Alopex lagopus). Age-matched blue foxes(12 weeks old) with simila...This study evaluated the effects of dietary fat levels on the growth, nutrient digestibility, nitrogen balance and pelt characteristics of the blue fox(Alopex lagopus). Age-matched blue foxes(12 weeks old) with similar body weights were randomly divided into six dietary groups over 98 days, during the growing-furring period. Blue foxes in the six groups were fed with experimental diets containing 10%(groupⅠ), 12%(groupⅡ), 14%(group Ⅲ), 16%(group Ⅳ), 18%(groupⅤ) and 20%(group Ⅵ) fat during the growing period(from 13 weeks to 18 weeks of age);foxes were fed with diets containing 12%(groupⅠ), 14%(groupⅡ), 16%(group Ⅲ), 18%(group Ⅳ), 20%(groupⅤ) and 22%(group Ⅵ) fat during the furring period(from 18 weeks to 26 weeks of age). The results indicated that 16%-18% dietary fat, during the growing period significantly improved nutrient utilization, and as a main energy source, significantly reduced the feed/gain ratio. A dietary fat level of 18%, during the furring period not only improved the growth and development and decreased the feed/gain ratio, but also increased nutrient digestibility and fur quality. These data, combined with data from a conic regression model, showed that dietary fat levels between 16.29% and 18.40%, during the growing period and between 17.72% and 18.72%, during the furring period enhanced the growth performance and fur quality of blue foxes.展开更多
The aim was to compare radiographic X-ray data to foreleg bending, moving difficulties and body size in juvenile blue foxes. Experimental groups were: 1) restricted feeding, Ca:P ratio 1.5:1 (R 1);2) restricted feedin...The aim was to compare radiographic X-ray data to foreleg bending, moving difficulties and body size in juvenile blue foxes. Experimental groups were: 1) restricted feeding, Ca:P ratio 1.5:1 (R 1);2) restricted feeding, Ca:P ratio 2.9:1 (R 2);3) restricted feeding Ca:P ratio 2.0:1 control level (R 3);4) ad libitum feeding, Ca:P ratio 1.5:1 (AL 1);5) ad libitum feeding, Ca:P ratio 2.9:1 (AL 2);6) ad libitum feeding Ca:P ratio 2.0:1 control level (AL 3). Moving difficulties and foreleg bending were evaluated in live animals. At pelting, left foreleg was removed. X-ray pictures were taken from lateral views. Dimensions of ulna and radius were measured from the X-ray pictures. Conditions of carpal joint and elbow joint were visually evaluated. The results showed that final body weight was affected by feeding intensity (P = 0.001). Ad libitum fed animals had more moving difficulties compared to restricted ones (P = 0.001). The Ca:P ratio tended (P = 0.06) to have an effect on feet bending. Bending was greatest in low Ca:P ratio (1.5:1) and, correspondingly, least in high Ca:P ratio (2.9:1). Moving difficulties were most common in heaviest animals. The moving difficulties tended (P = 0.07) to be positively related to feet bending. Maximum width of ulna was lowest in low Ca:P ratio diet (1.5:1). Bending was negatively correlated with maximum width of ulna. It can be concluded that low Ca:P ratio in the diet (1.5:1) increases foreleg bending in juveniles. Moving difficulties are related to foreleg bending and high body weight.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
Several statistic indexes including pelt weight, pelt area, skin thickness, length of hair, fineness of hair and hair density, were adopted in the evaluation of winter pelt quality of blue frost fox and their parents....Several statistic indexes including pelt weight, pelt area, skin thickness, length of hair, fineness of hair and hair density, were adopted in the evaluation of winter pelt quality of blue frost fox and their parents.Results showed that some indexes of qualitative characters of blue frost fox were the medium between blue fox and silver fox, and some were superior to them.展开更多
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(200903014)~~
文摘[Objective] The ovary microstructure and the changes of the follicle during the development period of blue fox during the estrous period were studied.[Method] Ten left ovaries were collected from 10 female blue foxes during the estrous period. The histological structure of the ovary and follicular development process were observed by using optical microscope. And 30 primordial follicles, 30 primary follicles, 15 growing follicles, 15 vesicular follicle, 15 mature follicles and the oocytes in the follicles of different developing stages were measured and photographed by eyepiece micrometer and photomicrographic technique respectively. [Result] The ovary of blue fox consisted of germinal epithelium, tunica albuginea, cortex and medulla. The cor- tex, which was located at the periphery of the ovary, contained many interstitial cells and follicles at different developing stages. Medulla was located below the cortex, with a lot of blood vessels. The diameters of follicles at different developmental stages and oocytes had greater differences during the developmental period of follicle. The diameter of follicles was 45.45-974.55 μm and the diameter of oocytes was 30.23-147.27 μm. The zona pellucida appeared at the primary follicle stage. The atresia of follicles occurred at all the developmental stages of follicle and the main manifestations were the shrunk oocyte and karyon, and loose and degraded granular cells. [Conclusion] The research provided histological basis for revealing the reproductive mechanism of female blue fox.
基金Supported by the Harbin Applied Technology Research and Development Project(2016RAXXJ015)
文摘This study evaluated the effects of dietary fat levels on the growth, nutrient digestibility, nitrogen balance and pelt characteristics of the blue fox(Alopex lagopus). Age-matched blue foxes(12 weeks old) with similar body weights were randomly divided into six dietary groups over 98 days, during the growing-furring period. Blue foxes in the six groups were fed with experimental diets containing 10%(groupⅠ), 12%(groupⅡ), 14%(group Ⅲ), 16%(group Ⅳ), 18%(groupⅤ) and 20%(group Ⅵ) fat during the growing period(from 13 weeks to 18 weeks of age);foxes were fed with diets containing 12%(groupⅠ), 14%(groupⅡ), 16%(group Ⅲ), 18%(group Ⅳ), 20%(groupⅤ) and 22%(group Ⅵ) fat during the furring period(from 18 weeks to 26 weeks of age). The results indicated that 16%-18% dietary fat, during the growing period significantly improved nutrient utilization, and as a main energy source, significantly reduced the feed/gain ratio. A dietary fat level of 18%, during the furring period not only improved the growth and development and decreased the feed/gain ratio, but also increased nutrient digestibility and fur quality. These data, combined with data from a conic regression model, showed that dietary fat levels between 16.29% and 18.40%, during the growing period and between 17.72% and 18.72%, during the furring period enhanced the growth performance and fur quality of blue foxes.
文摘The aim was to compare radiographic X-ray data to foreleg bending, moving difficulties and body size in juvenile blue foxes. Experimental groups were: 1) restricted feeding, Ca:P ratio 1.5:1 (R 1);2) restricted feeding, Ca:P ratio 2.9:1 (R 2);3) restricted feeding Ca:P ratio 2.0:1 control level (R 3);4) ad libitum feeding, Ca:P ratio 1.5:1 (AL 1);5) ad libitum feeding, Ca:P ratio 2.9:1 (AL 2);6) ad libitum feeding Ca:P ratio 2.0:1 control level (AL 3). Moving difficulties and foreleg bending were evaluated in live animals. At pelting, left foreleg was removed. X-ray pictures were taken from lateral views. Dimensions of ulna and radius were measured from the X-ray pictures. Conditions of carpal joint and elbow joint were visually evaluated. The results showed that final body weight was affected by feeding intensity (P = 0.001). Ad libitum fed animals had more moving difficulties compared to restricted ones (P = 0.001). The Ca:P ratio tended (P = 0.06) to have an effect on feet bending. Bending was greatest in low Ca:P ratio (1.5:1) and, correspondingly, least in high Ca:P ratio (2.9:1). Moving difficulties were most common in heaviest animals. The moving difficulties tended (P = 0.07) to be positively related to feet bending. Maximum width of ulna was lowest in low Ca:P ratio diet (1.5:1). Bending was negatively correlated with maximum width of ulna. It can be concluded that low Ca:P ratio in the diet (1.5:1) increases foreleg bending in juveniles. Moving difficulties are related to foreleg bending and high body weight.
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.
文摘Several statistic indexes including pelt weight, pelt area, skin thickness, length of hair, fineness of hair and hair density, were adopted in the evaluation of winter pelt quality of blue frost fox and their parents.Results showed that some indexes of qualitative characters of blue frost fox were the medium between blue fox and silver fox, and some were superior to them.
