The aim of this study was to evaluate the use of melengestrol acetate （MGA） as a strategy to improve the production efficiency in ewes of rural areas in Mexico. Twenty ewes of breeds （Dorper and Dorper with Pelibue...The aim of this study was to evaluate the use of melengestrol acetate （MGA） as a strategy to improve the production efficiency in ewes of rural areas in Mexico. Twenty ewes of breeds （Dorper and Dorper with Pelibuey） non-pregnant and with ovarica activity were used. The treatment consisted of the administration of 0.22 mg MGA/ewe/d for 17 d. The MGA efficiency was measured once the treatment finalized, and the producer was responsible for the registration of the estrus presentation and prolificacy rate. 95% of the sheep presented estrus in a period of 14 d after stopping treatment. The prolificacy percentage was of 1.2 lambs born by ewe during a period of six months （including treatment and period of gestation）. In conclusion, the use of MGA represents an alternative to improve the efficiency of sheep production in rural areas in Mexico, since it can increase the number of lambs by 30% in a period of 12 months.展开更多
In this study, the data of Macoei sheep from 1994 to 2008 were collected in Affair Animal Breeding Unit, Agriculture Organization of West Azerbijan province of Iran for recognition of reproductive and morphological ch...In this study, the data of Macoei sheep from 1994 to 2008 were collected in Affair Animal Breeding Unit, Agriculture Organization of West Azerbijan province of Iran for recognition of reproductive and morphological characteristics. The trait in this research include birth weight （BW）, 3 （W3）, 6 （W6）, 9 （W9）, 12 （W12） months weight, fleece weight （WF） （as production traits）, body length（BL）, size of femur（F）, thorax（TX）, testis（TS）, height of lumber（L） and shoulder（SH） （as morphological traits）. Variance components, least square means and standard error of production and morphological traits were estimated and environmental factors （including effects of year of birth, season, sex, type of birth and age of dam） were studied with GLM procedure of SAS 9.1 software. The results showed that the all environmental factors have significant effect, male lambs weight more than females, and twins were more performance than single. Production and apparent performance characteristics of phenotypic traits was different in year of birth, maternal age, season. This study shows that Macoie sheep breed at the various management environment have suitable performance and genetic potential.展开更多
In Mexico the predominant sheep production system is the semi-extensive with grazing during the day and stanchion afternoon and night. Sheep herd are usually small, approximately 10 to 75 heads. The objectives of thes...In Mexico the predominant sheep production system is the semi-extensive with grazing during the day and stanchion afternoon and night. Sheep herd are usually small, approximately 10 to 75 heads. The objectives of these systems are savings and marketing of lambs. Meat is the main economic product of this kind, the breeding is long, which do not control the delivery dates and ages of the sheep are not uniform, affecting the demand for the local market （for the months of June and December）. Therefore the aim of this work was implement a technology that allows the grouping of the estrus and therefore group deliveries for batches of uniform lambs. This technology was designed to suppress the estrus and heifers growth promoter of feedlots, this technology is melengestrol acetate （MGA） which is a synthetic progesterone oral administration that it is easy to manage in the food or alone, economic that it does not represent any risk for sheep females of abortive type, evaluating the effect of the MGA on rate of estrus and gestation in sheep. Work developed in the municipality of Charo from Michoac^in State, M6xico, 20 hair sheep divided in two groups of 10 female, group one treated with MGA and group tow was the whitens. 100% of the sheep treated with a dose of 0.45 mg MGA/head/day for 17 days orally, presented estrus grouped in 5-10 days; however only 50% of the sheep of the witness group presented estrus. In the experimental group there was a rate of 70% with a gestation difference time of no more than ten days gestation and witness group 50%. The MGA is an efficient alternative for the producer of sheep when administered 0.45 mg MGA/head/day for 17 days because inhibits the estrus and once withdrawn treatment manifests estrus synch with which get a rate of gestation elevated by natural riding.展开更多
文摘The aim of this study was to evaluate the use of melengestrol acetate （MGA） as a strategy to improve the production efficiency in ewes of rural areas in Mexico. Twenty ewes of breeds （Dorper and Dorper with Pelibuey） non-pregnant and with ovarica activity were used. The treatment consisted of the administration of 0.22 mg MGA/ewe/d for 17 d. The MGA efficiency was measured once the treatment finalized, and the producer was responsible for the registration of the estrus presentation and prolificacy rate. 95% of the sheep presented estrus in a period of 14 d after stopping treatment. The prolificacy percentage was of 1.2 lambs born by ewe during a period of six months （including treatment and period of gestation）. In conclusion, the use of MGA represents an alternative to improve the efficiency of sheep production in rural areas in Mexico, since it can increase the number of lambs by 30% in a period of 12 months.
文摘In this study, the data of Macoei sheep from 1994 to 2008 were collected in Affair Animal Breeding Unit, Agriculture Organization of West Azerbijan province of Iran for recognition of reproductive and morphological characteristics. The trait in this research include birth weight （BW）, 3 （W3）, 6 （W6）, 9 （W9）, 12 （W12） months weight, fleece weight （WF） （as production traits）, body length（BL）, size of femur（F）, thorax（TX）, testis（TS）, height of lumber（L） and shoulder（SH） （as morphological traits）. Variance components, least square means and standard error of production and morphological traits were estimated and environmental factors （including effects of year of birth, season, sex, type of birth and age of dam） were studied with GLM procedure of SAS 9.1 software. The results showed that the all environmental factors have significant effect, male lambs weight more than females, and twins were more performance than single. Production and apparent performance characteristics of phenotypic traits was different in year of birth, maternal age, season. This study shows that Macoie sheep breed at the various management environment have suitable performance and genetic potential.
文摘In Mexico the predominant sheep production system is the semi-extensive with grazing during the day and stanchion afternoon and night. Sheep herd are usually small, approximately 10 to 75 heads. The objectives of these systems are savings and marketing of lambs. Meat is the main economic product of this kind, the breeding is long, which do not control the delivery dates and ages of the sheep are not uniform, affecting the demand for the local market （for the months of June and December）. Therefore the aim of this work was implement a technology that allows the grouping of the estrus and therefore group deliveries for batches of uniform lambs. This technology was designed to suppress the estrus and heifers growth promoter of feedlots, this technology is melengestrol acetate （MGA） which is a synthetic progesterone oral administration that it is easy to manage in the food or alone, economic that it does not represent any risk for sheep females of abortive type, evaluating the effect of the MGA on rate of estrus and gestation in sheep. Work developed in the municipality of Charo from Michoac^in State, M6xico, 20 hair sheep divided in two groups of 10 female, group one treated with MGA and group tow was the whitens. 100% of the sheep treated with a dose of 0.45 mg MGA/head/day for 17 days orally, presented estrus grouped in 5-10 days; however only 50% of the sheep of the witness group presented estrus. In the experimental group there was a rate of 70% with a gestation difference time of no more than ten days gestation and witness group 50%. The MGA is an efficient alternative for the producer of sheep when administered 0.45 mg MGA/head/day for 17 days because inhibits the estrus and once withdrawn treatment manifests estrus synch with which get a rate of gestation elevated by natural riding.
