برآورد فراسنجه‌هاي ژنتيكي زنده‌ماني در بزغاله‌هاي كركي رايني با استفاده از دو مدل خطي و ويبال

Estimating genetic parameters of kid survival in Raini Cashmere goat using linear and Weibul models

در اﻳﻦ ﭘﮋوﻫﺶ از رﻛﻮرد­ﻫﺎي زﻧﺪه­ﻣﺎﻧﻲ شمار 3055 رأس بزغاله، ﻣﺮﺑﻮط ﺑﻪ ﮔﻠۀ اﻳﺴﺘﮕﺎه ﭘﺮورش و اﺻﻼح نژاد بز كركي رايني واﻗﻊ در شهرستان بافت، گردآوري‌شده ﻃﻲ سال‌هاي 1386-1372 استفاده شد.داده‌ها ﺑﺎ ﻣﺪل­ﻫﺎي ﺧﻄﻲ و ﻧﺴﺒﺖ ﺧﻄﺮ ﺑﺎ ﺗﺎﺑﻊ وﻳﺒﺎل ﺗﺠﺰﻳﻪ ﺷﺪﻧﺪ. اﻳﻦ ﻣﺪل­ﻫﺎ ﺷﺎﻣﻞ اﺛﺮگذاري‌هاي عامل‌هاي ﺛﺎﺑﺖ ﺳﺎل، ﻣﺎه ﺗﻮﻟﺪ، ﺟﻨﺲ، ﻧﻮع ﺗﻮﻟﺪ، ﺳﻦ ﻣﺎدر و ﻣﺘﻐﻴﺮ كمكي وزن ﺗﻮﻟﺪ به‌صورت درﺟﻪ دوم و اﺛﺮگذاري‌هاي ﺗﺼﺎدﻓﻲ ژﻧﺘﻴﻜﻲ اﻓﺰاﻳﺸﻲ ﻣﺴﺘﻘﻴﻢ، ژﻧﺘﻴﻜﻲ اﻓﺰاﻳﺸﻲ ﻣﺎدري، ﻣﺤﻴﻂ دائمي ﻣﺎدري و باقي‌مانده ﺑﻮدند. فراسنجه‌‌ﻫﺎي ژﻧﺘﻴﻜﻲ از روش بيشينه درستنمايي محدودشده ﺑﺎ و ﺑﺪون اﺛﺮگذاري‌هاي ﻣﺎدري و ﻣﺪل ﭘﺪري ﺑﺮ­آورد شد. وراﺛﺖ­ﭘﺬﻳﺮي ﻣﺴﺘﻘﻴﻢ ﻣﻴﺰان زﻧﺪه­ﻣﺎﻧﻲ ناشي از ﻣﺪل­ﻫﺎي ﻣﺨﺘﻠﻒ ﺧﻄﻲ در ﺣﺪ ﭘﺎﻳﻴﻦ (0/01 تا 0/06) ﺑﺮ­آورد شد. وراﺛﺖ­ﭘﺬﻳﺮي­ﻫﺎي ﻣﺴﺘﻘﻴﻢ در ﻣﻘﻴﺎس ﻟﮕﺎرﻳﺘﻤﻲ، ﻣﻘﻴـﺎس اوﻟﻴﻪ و وراﺛﺖ­ﭘﺬﻳﺮي مؤثر ﻧﺴﺒﺖ ﺧﻄﺮ به‌دست‌آمده از ﻣﺪل ﭘﺪري و داراي ﺗﺎﺑﻊ وﻳﺒﺎل در ﻣﻘﺎﻳﺴﻪ ﺑﺎ مدل خطي، ﺑﻴﺸﺘﺮ و در ﺣﺪ ﻣﺘﻮﺳﻂ ﺗﺎ ﺑﺎﻻ (0/17 تا 0/70) ﺑﻮدﻧﺪ. ﺑﺮآوردﻫﺎي ﻣيانگين ﺑﯿﺎﻧﮕﺮ اﯾﻦ اﺳﺖ ﮐﻪ عامل‌هاي ﻣﺨﺘﻠﻒ ژﻧﺘﯿﮑﯽ و ﻏﯿﺮ ژﻧﺘﯿﮑﯽ ﺑﺮ زنده‌ماني تأثيرگذار اﺳﺖ. ﻟﺬا، ﺑﺮاي ﺑﻬﺒﻮد اﯾﻦ ﺻﻔﺎت مي‌بايست در ﮐﻨﺎر ﺷﺮاﯾﻂ ﻣﺪﯾﺮﯾﺘﯽ مطلوب، اﺻﻼح ژﻧﺘﯿﮑﯽ نيز اﻧﺠﺎم ﮔﯿﺮد.

In this study, the records of survival of 3056 kids related to the breeding station of Raini Cashmere goat were used during years 1993-2004. These records were collected in Raein Breeding station located in the Baft city, Kerman province, Iran. The data were analyzed using linear and hazard ratio models with Weibul function. These models included fixed factors such as year and month of birth, sex, type, age of dam and birth weight as quadratic covariate, and direct additive genetic, maternal additive genetic, maternal permanent environmental and residual random effects. Genetic parameters were estimated using restricted maximum likelihood procedure and different animal models contained with and without maternal and common environmental effects and sire model. The direct heritability of length of life and survival rate estimated from different linear models was low (0.01 to 0.06). The estimates of heritability in logarithmic scale, original scale and effective heritability obtained from sire and animal models with Weibull function were medium to high (0.17 to 0.70) and higher than analogous values estimated by different linear models. Medium estimates show that genetic and non-genetic factors affect survival. Hence, to improve these traits, selecting beside suitable management are necessary.