University of Tehran Press Journal of Animal Production, Print ISSN: 2008-6776., Online ISSN: 2382-994X 2008-6776 23 4 2021 12 22 The effect of successful phenotypic selection against ascites syndrome on different traits in a commercial broiler line The effect of successful phenotypic selection against ascites syndrome on different traits in a commercial broiler line 501 514 84710 10.22059/jap.2021.318204.623591 FA Maryam Karami Department of Animal Science , Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, Ahvaz, Iran. Karim Hasanpur Department of Animal Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran 0000-0001-8936-684X Jamal Fayazi Department, of Animal Science. Agricultural Sciences and Natural Resources University of Khuzestan, Mollasani, Ahvaz, Iran. 0000-0002-3459-7736 Arash Javanmard Department of Animal Science, Faculty of Agriculture, University of Tabriz,, Tabriz,, Iran Hamid Varnaseri Nahadehay Dami Jahed (NDJ) company, Tehran, Iran Journal Article 2021 04 27 The aim of present study was to investigate the effect of selection against ascites syndrome on different traits body growth, internal organs, and blood parameters in a broiler line. Therefore, by classifying different families based on the frequency of ascites under intense ascites inducing condition (AIC), 10 susceptible families (SUS) and 10 resistant families (RES) to ascites were selected and another set of offspring from the same families were bred under normal commercial condition (NCC). This process of selection and cross validation was carried out twice in the two distinct generations. The genetic relationship of different traits, the difference in the frequency of ascites between AIC and NCC, and the difference between different traits in SUS and RES were performed by correlation statistics, Chi-square test, and GLM procedure of SAS software (version 9.1), respectively. The correlation between ascites susceptibility in different families indicated that families that showed more ascites under AIC also had more ascites under NCC. Comparative study of different traits in susceptible and resistant groups showed that in SUS, body weight, growth rate and respiratory capacity were significantly lower and blood partial pressure of carbon dioxide was significantly higher than RES (P<0.05). In the present study it was shown that selection against this syndrome not only does not reduce growth rate in the investigated broiler line, but also improves growth traits and resistance to this syndrome in the mentioned line. The aim of present study was to investigate the effect of selection against ascites syndrome on different traits body growth, internal organs, and blood parameters in a broiler line. Therefore, by classifying different families based on the frequency of ascites under intense ascites inducing condition (AIC), 10 susceptible families (SUS) and 10 resistant families (RES) to ascites were selected and another set of offspring from the same families were bred under normal commercial condition (NCC). This process of selection and cross validation was carried out twice in the two distinct generations. The genetic relationship of different traits, the difference in the frequency of ascites between AIC and NCC, and the difference between different traits in SUS and RES were performed by correlation statistics, Chi-square test, and GLM procedure of SAS software (version 9.1), respectively. The correlation between ascites susceptibility in different families indicated that families that showed more ascites under AIC also had more ascites under NCC. Comparative study of different traits in susceptible and resistant groups showed that in SUS, body weight, growth rate and respiratory capacity were significantly lower and blood partial pressure of carbon dioxide was significantly higher than RES (P<0.05). In the present study it was shown that selection against this syndrome not only does not reduce growth rate in the investigated broiler line, but also improves growth traits and resistance to this syndrome in the mentioned line. https://jap.ut.ac.ir/article_84710_0a4c60e3eaaae2e7d088a99296fa61d5.pdf