Arpijaza,Lekezhi and Zhangmu cattle discovered in cooled region of Tibet are Bos populations which have close blood relationship with zebu. Besides studying their distribution, nature environment and ecological condit...Arpijaza,Lekezhi and Zhangmu cattle discovered in cooled region of Tibet are Bos populations which have close blood relationship with zebu. Besides studying their distribution, nature environment and ecological conditions, the multivariate statistics analysis of three sides (i. e. , body measurement, morphology and ecology characters) were carried out on three zebu populations from cooled region of Tibet and other three reference populations. The results indicated that there were various ecology types within Tibet zebu populations. Fore two character values were selected as the principal components (occupied 88.15% of total information amount). The cluster analysis according to two principal component values of each sample displayed that three zebu populations from Tibet and two zebu populations from Yunnan emerged in clustering figure alternately, Lhasa yellow cattle was independent from the five zebu populations. The study has proved that there were zebu populations in Tibet cooled region and there was a possibility of blood relationship between the zebu populations from Tibet and Yunnan.展开更多
A comparative of two induction methods of estrus induction and fertility has been carried out on 28 females Azawak zebu in Niger. This study mains chiefly and identifying the most effective method for better inseminat...A comparative of two induction methods of estrus induction and fertility has been carried out on 28 females Azawak zebu in Niger. This study mains chiefly and identifying the most effective method for better inseminations. The females have been divided into two sets following two intra-vaginal devices used. Two sub-sets of 7 females have been formed according to the PMSG dose associated with the treatment. Two inseminations have been carried out. The results are as follows： response to the induction： PRIDe, 57.14%; CIDR-B, 61.53%. Fertility rate： PRIDe, 28.57%; CIDR-B, 38.46%. There has been no significant difference to the estrus induction and fertility, between the PRIDe and the CIDR-B synchronization. Since the two methods virtually lead to the same response rate, the stock breeder can choose one of the methods depending on the cost and by paying attention to the feeding and less stressful factors.展开更多
Improving Malagasy zebu production in the face of booming Malagasy population and regression of the animal number, this study was initiated to put forth some Malagasy zebu carcass weight performance and dressing perce...Improving Malagasy zebu production in the face of booming Malagasy population and regression of the animal number, this study was initiated to put forth some Malagasy zebu carcass weight performance and dressing percentages following slaughter. Measurements concerned live weight before slaughtering, carcass weights, quarters and carcass halves, left and right and the fiffla quarter （blood, leather, intestine, lung, heart, liver, kidneys, spleen and rumen with its content） weights on 544 individuals without distinction （age nor sex）. Descriptive statistical analysis was undertaken to qualify and compare the various weights. It results high proportion females （66%）, smaller size （live weight less than 250 kg, 60%） and 5 live weight classes. Live weight was different in the 2 sexes starting class 3 （live weight 〉 250 kg） （p = 0.0027）. Males fore quarters were heavier than females （p 〈 1‰）. Carcass dressing percentage increased according to live weight class, whereas, 5th quarter yield presented a regressive reduction with increasing weight class. Survey shows an average dressing percentage of 46.20% with an average 5th quarter yield of 37.43%. Malagasy zebus are light weighted animals compared to the African zebus. Precocious slaughtering （before 250 kg live weight） doesn＇t allow a good meat yield.展开更多
Determination of nutritional requirements is the basis for diet formulation. The objectives of this study were to determine the net energy requirements for maintenance （NEro） and weight gain （NEg） in Nellore bulls...Determination of nutritional requirements is the basis for diet formulation. The objectives of this study were to determine the net energy requirements for maintenance （NEro） and weight gain （NEg） in Nellore bulls during the growing and finishing phases, and to estimate efficiency of metabolizable energy （ME） utilization for maintenance and gain （km, kg）. Five Nellore bulls were housed in individual pens at the Universidade Federal de Minas Gerais （Belo Horizonte, Brazil） and evaluated over four experimental periods at 210, 315,378 and 454 kg shrunk body weight （SBW）, approximately. During each period, heat production （HP） was quantified by open circuit indirect calorimetry for three feeding levels： ad libitum, restricted and fasting. The NEm requirement was determined by linear regression between the Log of HP andthe ME intake （MEI） for the ad libitum and restricted levels. This requirement was also determined by quantifying fasting heat production （FHP）. The NEQ requirement was calculated by the difference between MEI and HP during ad libitum feeding. The k and kg were calculated by the relationship between net energy （NE） and ME requirements for maintenance and weight gain （MEm, MEp）, respectively. The NEm requirements per kg of metabolic empty body weight （EBW0.75） fluctuated between 348 and 517 kJ d-1, showing a decreasing trend with age, and were higher than the values reported in the literature. The NEg requirements ranged between 48.3 and 164 kJ kg-1 EBW0.75 d-1, and varied according to age and weight gain. The k values varied between 58.6 and 69.7%, while kg varied between 23.4 and 40.2%. We concluded that NEm and NEg requirements were influenced by age and possibly by the level of stress, nervousness and activity of animals into the respirometry chamber. Further studies should quantify HP with records of positional changes （time spent standing vs. lying down）. Additionally, HP quantification should be repeatedly performed in the same experimental period to obtain a representative value of NEg requirements.展开更多
Early pregnancy diagnosis is a very important routine management to identify non-pregnant cows in order to keep an optimum reproductive efficiency both for dairy and beef cows. Ultrasound equipment allows estimating t...Early pregnancy diagnosis is a very important routine management to identify non-pregnant cows in order to keep an optimum reproductive efficiency both for dairy and beef cows. Ultrasound equipment allows estimating the viability and size of the embryo during early gestation. With the aim of assessing age and viability of Bos indicus embryos between 24 and 35 days of gestation, 55 cows were divided into 4 clusters. These clusters were conformed according to the first day that an echogenic structure was seen inside the embryonic vesicle (Group 1: day 24, Group 2: day 26, Group 3: day 27 and Group 4: day 28). The age of the embryos was estimated from the date of AI. Three progressive serial measurements of their length were made within 2 to 5 days. With a model GEE (Generalized Estimating Equations), the effect of days was evaluated to compare the second measurement with the first one and the former with the third observation. No differences in the size of the embryos were observed between the first evaluation (24 days) and the second (28 days) (P = 0.387). Also, simple linear regression analysis found a positive linear association between the size of the embryo and gestation days (R2 = 0.593) with an average growth of 0.078 cm per day (P = 0.001). In conclusion, the variation between measurements at a given time does not allow estimating with precision the exact day of gestation. Nonetheless, serial measurements are useful to estimate the healthy growth of the embryo from day 26 of gestation.展开更多
A comparison between two distinct levels of back fat thickness in open cows, females not becoming pregnant during the previous breeding season, was carried out in order to evaluate their reproductive performance prior...A comparison between two distinct levels of back fat thickness in open cows, females not becoming pregnant during the previous breeding season, was carried out in order to evaluate their reproductive performance prior to the next natural mating in a seasonal breeding program. Thirty open cows from the previous breeding season were divided evenly by age and back fat thickness (BFT) in two groups. HBFT (high back fat thickness ≥ 70 mm) and LBFT (low back fat thickness ≤ 70 mm), values statistically different between groups (P < 0.05). The study was divided into three phases in which the formation of CL and follicular dynamics were recorded by ultrasound and progesterone. Also, serial monitoring of glucose, urea and triglycerides and back fat thickness were studied. A fertile bull previously approved from a breeding soundness evaluation was introduced after the third phase and remained with the herd for 90 days. No differences were found in the follicular dynamics;the number of animals cycling in the two groups and fertility were also similar (80%). Differences in urea and triglycerides were found in cows with high scores of BFT. In conclusion, the decision of keeping open cows to the next breeding season must be based on an economical advantage to the farmer.展开更多
基金This study was supported by the National Natural Science Foundation of China(39670530)the Key Program of Agricultural Department of China.
文摘Arpijaza,Lekezhi and Zhangmu cattle discovered in cooled region of Tibet are Bos populations which have close blood relationship with zebu. Besides studying their distribution, nature environment and ecological conditions, the multivariate statistics analysis of three sides (i. e. , body measurement, morphology and ecology characters) were carried out on three zebu populations from cooled region of Tibet and other three reference populations. The results indicated that there were various ecology types within Tibet zebu populations. Fore two character values were selected as the principal components (occupied 88.15% of total information amount). The cluster analysis according to two principal component values of each sample displayed that three zebu populations from Tibet and two zebu populations from Yunnan emerged in clustering figure alternately, Lhasa yellow cattle was independent from the five zebu populations. The study has proved that there were zebu populations in Tibet cooled region and there was a possibility of blood relationship between the zebu populations from Tibet and Yunnan.
文摘A comparative of two induction methods of estrus induction and fertility has been carried out on 28 females Azawak zebu in Niger. This study mains chiefly and identifying the most effective method for better inseminations. The females have been divided into two sets following two intra-vaginal devices used. Two sub-sets of 7 females have been formed according to the PMSG dose associated with the treatment. Two inseminations have been carried out. The results are as follows： response to the induction： PRIDe, 57.14%; CIDR-B, 61.53%. Fertility rate： PRIDe, 28.57%; CIDR-B, 38.46%. There has been no significant difference to the estrus induction and fertility, between the PRIDe and the CIDR-B synchronization. Since the two methods virtually lead to the same response rate, the stock breeder can choose one of the methods depending on the cost and by paying attention to the feeding and less stressful factors.
文摘Improving Malagasy zebu production in the face of booming Malagasy population and regression of the animal number, this study was initiated to put forth some Malagasy zebu carcass weight performance and dressing percentages following slaughter. Measurements concerned live weight before slaughtering, carcass weights, quarters and carcass halves, left and right and the fiffla quarter （blood, leather, intestine, lung, heart, liver, kidneys, spleen and rumen with its content） weights on 544 individuals without distinction （age nor sex）. Descriptive statistical analysis was undertaken to qualify and compare the various weights. It results high proportion females （66%）, smaller size （live weight less than 250 kg, 60%） and 5 live weight classes. Live weight was different in the 2 sexes starting class 3 （live weight 〉 250 kg） （p = 0.0027）. Males fore quarters were heavier than females （p 〈 1‰）. Carcass dressing percentage increased according to live weight class, whereas, 5th quarter yield presented a regressive reduction with increasing weight class. Survey shows an average dressing percentage of 46.20% with an average 5th quarter yield of 37.43%. Malagasy zebus are light weighted animals compared to the African zebus. Precocious slaughtering （before 250 kg live weight） doesn＇t allow a good meat yield.
文摘Determination of nutritional requirements is the basis for diet formulation. The objectives of this study were to determine the net energy requirements for maintenance （NEro） and weight gain （NEg） in Nellore bulls during the growing and finishing phases, and to estimate efficiency of metabolizable energy （ME） utilization for maintenance and gain （km, kg）. Five Nellore bulls were housed in individual pens at the Universidade Federal de Minas Gerais （Belo Horizonte, Brazil） and evaluated over four experimental periods at 210, 315,378 and 454 kg shrunk body weight （SBW）, approximately. During each period, heat production （HP） was quantified by open circuit indirect calorimetry for three feeding levels： ad libitum, restricted and fasting. The NEm requirement was determined by linear regression between the Log of HP andthe ME intake （MEI） for the ad libitum and restricted levels. This requirement was also determined by quantifying fasting heat production （FHP）. The NEQ requirement was calculated by the difference between MEI and HP during ad libitum feeding. The k and kg were calculated by the relationship between net energy （NE） and ME requirements for maintenance and weight gain （MEm, MEp）, respectively. The NEm requirements per kg of metabolic empty body weight （EBW0.75） fluctuated between 348 and 517 kJ d-1, showing a decreasing trend with age, and were higher than the values reported in the literature. The NEg requirements ranged between 48.3 and 164 kJ kg-1 EBW0.75 d-1, and varied according to age and weight gain. The k values varied between 58.6 and 69.7%, while kg varied between 23.4 and 40.2%. We concluded that NEm and NEg requirements were influenced by age and possibly by the level of stress, nervousness and activity of animals into the respirometry chamber. Further studies should quantify HP with records of positional changes （time spent standing vs. lying down）. Additionally, HP quantification should be repeatedly performed in the same experimental period to obtain a representative value of NEg requirements.
文摘Early pregnancy diagnosis is a very important routine management to identify non-pregnant cows in order to keep an optimum reproductive efficiency both for dairy and beef cows. Ultrasound equipment allows estimating the viability and size of the embryo during early gestation. With the aim of assessing age and viability of Bos indicus embryos between 24 and 35 days of gestation, 55 cows were divided into 4 clusters. These clusters were conformed according to the first day that an echogenic structure was seen inside the embryonic vesicle (Group 1: day 24, Group 2: day 26, Group 3: day 27 and Group 4: day 28). The age of the embryos was estimated from the date of AI. Three progressive serial measurements of their length were made within 2 to 5 days. With a model GEE (Generalized Estimating Equations), the effect of days was evaluated to compare the second measurement with the first one and the former with the third observation. No differences in the size of the embryos were observed between the first evaluation (24 days) and the second (28 days) (P = 0.387). Also, simple linear regression analysis found a positive linear association between the size of the embryo and gestation days (R2 = 0.593) with an average growth of 0.078 cm per day (P = 0.001). In conclusion, the variation between measurements at a given time does not allow estimating with precision the exact day of gestation. Nonetheless, serial measurements are useful to estimate the healthy growth of the embryo from day 26 of gestation.
文摘A comparison between two distinct levels of back fat thickness in open cows, females not becoming pregnant during the previous breeding season, was carried out in order to evaluate their reproductive performance prior to the next natural mating in a seasonal breeding program. Thirty open cows from the previous breeding season were divided evenly by age and back fat thickness (BFT) in two groups. HBFT (high back fat thickness ≥ 70 mm) and LBFT (low back fat thickness ≤ 70 mm), values statistically different between groups (P < 0.05). The study was divided into three phases in which the formation of CL and follicular dynamics were recorded by ultrasound and progesterone. Also, serial monitoring of glucose, urea and triglycerides and back fat thickness were studied. A fertile bull previously approved from a breeding soundness evaluation was introduced after the third phase and remained with the herd for 90 days. No differences were found in the follicular dynamics;the number of animals cycling in the two groups and fertility were also similar (80%). Differences in urea and triglycerides were found in cows with high scores of BFT. In conclusion, the decision of keeping open cows to the next breeding season must be based on an economical advantage to the farmer.
