title: Linear model analysis of the influencing factors of boar longevity in Southern China.
abstract: This study aimed to investigate the factors influencing the boar herd life month (BHLM) in Southern China. A total of 1630 records of culling boars from nine artificial insemination centers were collected from January 2013 to May 2016. A logistic regression model and two linear models were used to analyze the effects of breed, housing type, age at herd entry, and seed stock herd on boar removal reason and BHLM, respectively. Boar breed and the age at herd entry had significant effects on the removal reasons (P < 0.001). Results of the two linear models (with or without removal reason including) showed boars raised individually in stalls exhibited shorter BHLM than those raised in pens (P < 0.001). Boars aged 5 and 6 months at herd entry (44.6%) showed shorter BHLM than those aged 8 and 9 months at herd entry (P < 0.05). Approximately 95% boars were culled for different reasons other than old age, and the BHLM of these boars was at least 12.3 months longer than that of boars culled for other reasons (P < 0.001). In conclusion, abnormal elimination in boars is serious and it had a negative effect on boar BHLM. Boar removal reason and BHLM can be affected by breed, housing type, and seed stock herd. Importantly, 8 months is suggested as the most suitable age for boar introduction.
authors.affiliation: Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, PR China; YangXiang Joint Stock Company, Guigang 53700, PR China.
authors.forename: Jia-Lian
authors.initials: JL
authors.lastname: Li
authors.affiliation: Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Hong-Kui
authors.initials: HK
authors.lastname: Wei
authors.affiliation: Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Yuan-Fei
authors.initials: YF
authors.lastname: Zhou
authors.affiliation: Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture, Huazhong Agricultural University, Wuhan 430070, PR China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, PR China. Electronic address: jiangsiwen@mail.hzau.edu.cn.
authors.forename: Si-Wen
authors.initials: SW
authors.lastname: Jiang
authors.affiliation: Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, PR China. Electronic address: pengjian@mail.hzau.edu.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Peng
mesh_terms: D000375:Aging; D000818:Animals; D001947:Breeding / Q000379:methods; D002681:China; D006799:Housing, Animal; D016014:Linear Models; D008136:Longevity / Q000502:physiology*; D008297:Male; D013045:Species Specificity; D034421:Sus scrofa / Q000502:physiology*
keywords: Boar; Influencing factor; Linear model; Longevity; Removal reason