Tao Duan;Ziyuan Wu;Huan Zhang;Ying Liu;Yan Li;Wei Zhan

State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, People’s Republic of China;Beijing Sunlon Livestock Development Company, Beijing, People’s Republic of China;1State key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, 100193 People's Republic of China.;College of Animal Science, Zhejiang University, Hangzhou, People’s Republic of China;State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, People’s Republic of Chin

Carcass characteristics;Cashmere goat;Meat quality;Melatoni

Background Implantation of goats with melatonin can induce cashmere growth and significantly increase cashmere production performance. However, the impact of melatonin implantation on the carcass characteristics, meat quality and related hormone levels in muscle and viscera of cashmere goats has not been studied. This experiment was conducted to determine the effects of melatonin implantation of cashmere goats during the non-growing period on meat quality and related hormone levels in the tissues. It aimed to provide a theoretical basis for the practical application of melatonin in cashmere goat production systems. Results Melatonin implantation (2 mg/kg live weight) had no influence (P > 0.05) on daily weight gain, carcass weight, dressing percentage, loin muscle area, or the pH, moisture level, crude fat (except for Gluteus muscle) and amino acid content of muscles of cashmere goats. After implantation for 1 month, shear force of Longissimus dorsi and water loss rate of Longissimus dorsi and Biceps femoris of cashmere goats were increased (P < 0.05), whereas the cooking yield of Gluteus muscle was reduced (P < 0.05). The melatonin treatment decreased (P < 0.05) muscle crude protein, Gluteus muscle crude fat and n-ary sumation n-3PUFA content and decreased (P < 0.05) n-ary sumation n-6PUFA content. However, after 2 months of implantation most of these effects had resolved. Melatonin implantation had no effect (P > 0.05) on the melatonin or prolactin contents of kidney, heart, spleen, liver, Longissimus dorsi, Biceps femoris and Gluteus muscles. Melatonin content of lung tissue was lowered (P < 0.05) and that of prolactin was elevated (P < 0.05) by the melatonin implantation. Conclusion This study has shown little impact of melatonin implantation of cashmere goats on carcass quality. A few meat quality indices i.e., shear force, water loss rate, n-ary sumation n-3PUFA, n-ary sumation n-6PUFA, and crude protein content of Longissimus dorsi; water loss rate, cooking yield and crude protein content of Biceps femoris; ether extract, crude protein content of Gluteus; were affected briefly (at 1 month of implantation) but these effects were not evident after 2 months of implantation. There was little effect of the melatonin treatments on tissue levels of melatonin or prolactin except in lung.