Evaluation of Growth Performance of Local and Dorper × Local Crossbred Sheep in Eastern Amhara Region, Ethiopia
محورهای موضوعی : CamelM. Lakew 1 , M. Haile-Melekot 2 , G. Mekuriaw 3
1 - Sirinka Agricultural Research Center, North Wollo, EthiopiaCollege of Agriculture and Environmental Science, Bahir Dar University, Ethiopia
2 - College of Agriculture and Environmental Science, Bahir Dar University, Ethiopia
3 - College of Agriculture and Environmental Science, Bahir Dar University, Ethiopia
کلید واژه: growth, Dorper crossbred, local sheep, Sirinka,
چکیده مقاله :
The present study was performed to evaluate the on-station growth performance of local and Dorper × local crossbred sheep in eastern Amhara region, Ethiopia. Data on 302 lambs collected over a 4-year period (2009 to 2012) on local and Dorper × local crossbred sheep at Sirinka breeding, evaluation and distribution site were used in this study. Fixed effects considered were breed, lamb sex, birth season, birth type and birth year. Results revealed that breed was a significant source of variation that crossbred lambs consistently weighed more than the local sheep lambs at all ages. The mean birth weights of local and crossbred lambs were 2.36 ± 0.05 and 3.24 ± 0.04 kg, respectively. Sex was an important source of variation at weaning, six months and yearling of ages in which male lambs were superior over their female contemporaries. Lambs born in dry season were heavier than lambs born in wet season at six months (20.51±0.34 kg vs. 16.74±0.59 kg) and at yearling (31.12±0.38 kg vs. 27.72±0.82 kg). Single-born lambs were heavier (P<0.0001) than their multiple-born contemporaries. There was also significant (P<0.0001) difference on average daily gain of lambs between the crossbred (129.97±2.23 g/day) and local sheep (67.78±1.60 g/day) lambs from birth to weaning age. Males had higher pre-weaning average daily gain than females (125.83±3.38 vs. 116.93±3.13 g/day, P<0.05). Single-born lambs grew faster than their multiple contemporaries between birth to 30 days (179.85±3.15 vs. 127.27±6.82 g/day, P<0.0001) and birth to weaning (123.96±2.55 vs. 107.49±5.04 g/day, P<0.0001) of age. The crossbred lambs also gained higher (64.69±1.74 g/day) than the local sheep lambs (37.94±1.19 g/day) after weaning. Breed was found to have significant (P<0.0001) effect on overall growth rate, where crossbred lambs had higher growth rate than the local sheep lambs. There were generally crossbred lambs had better growth performance and higher growth rates than the local sheep lambs.
هدف این مطالعه ارزیابی عملکرد رشد خارج ایستگاهی گوسفندان بومی و آمیختههای بومی و دروپِر در منطقه اَمهارا شرقی اتیوپی بود. در این مطالعه از دادههای جمعآوری شده از 302 گوسفند بومی و آمیختههای بومی و دروپِر در یک دوره 4 ساله (2009 تا 2012) توسط سایت اصلاح نژاد، ارزیابی و توزیع سیرینکا استفاده شد. نژاد، جنسیت گوساله، فصل تولد، تیپ تولد، و سال تولد به عنوان اثرات ثابت در نظر گرفته شدند. نتایج نشان داد که نژاد یک منبع اصلی تنوع بوده و در تمامی سنین، برههای آمیخته در مقایسه با برههای بومی، سنگینتر بودند. میانگین وزن تولد برههای بومی و آمیخته، به ترتیب برابر با 05/0±36/2 کیلوگرم و 04/0±24/3 بود. جنسیت یک منبع مهم تنوع در وزنهای از شیرگیری، ششماهگی و یکسالگی بود. طوری که همواره نرها از مادهها سنگینتر بودند. برههای متولد شده در فصل خشک در مقایسه با برههای متولد شده در فصل مرطوب، هم از نظر وزن شش ماهگی (34/0±51/20 در مقایسه با 59/0±74/16) و هم از نظر وزن یکسالگی (38/0±12/31 در مقایسه با 82/0±72/27) سنگینتر بودند. برههای تکقلو نیز سنگینتر از برههای چندقلو بودند (0001/0>P). تفاوت بین متوسط افزایش روزانه وزن برههای بومی (60/1±78/67 گرم در هر روز) و برههای آمیخته (23/2±97/129 گرم در روز) از تولد تا شیرگیری معنیدار بوده است (0001/0>P). متوسط افزایش وزن پیش از شیرگیری نرها بیشتر از مادهها بوده است (83/3±83/125 در مقایسه با 13/3±93/116 گرم در روز (05/0>P). برههای تکقلو سریعتر از برههای چندقلو در فاصله تولد تا 30 روزگی (82/63±27/127 در مقایسه با 15/3±85/179 گرم در روز (0001/0>P) و در فاصله تولد تا شیرگیری (04/5±49/107 در مقایسه با 55/2±96/123 گرم در روز (0001/0>P) رشد کردهاند. علاوه بر این برههای آمیخته (74/ 1±69/64 گرم در روز) در مقایسه با برههای بومی (19/1±94/37 گرم در روز) پس از شیرگیری افزایش وزن بیشتری داشتند. همچنین مشخص شد که نژاد اثر معنیداری بر نرخ رشد کلی داشته و برههای آمیخته در مقایسه با برههای بومی از نرخ رشد بالاتری برخوردار بودند (0001/0>P). به طور کلی میتوان نتیجه گرفت که برههای آمیخته در مقایسه با برههای بومی عملکرد رشد بهتر و نرخ رشد بالاتری داشتند.
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