Effects of Dietary Zinc Deficiency on Skin Breaking Strength and Fatty Acid Composition in Broiler Chickens and Pekin Ducks.

Abstract

This study is aimed at investigating the effect of dietary zinc deficiency (ZnD) on skin breaking strength and skin chemical and fatty acid composition in broiler chickens and Pekin ducks. A total of 200 1-day-old male broiler chickens and 200 1-day-old male ducklings were used in a 2 × 2 factorial design and randomly allocated to 4 treatments with 10 replicated cages of 10 birds per cage. Diets containing zinc at 84.77mg/kg and 20.42mg/kg were regarded as the control diet and zinc-deficient diet, respectively. The results showed the following: (1) dietary ZnD decreased (P < 0.05) the breast skin weight (day 21), breast skin index (day 21), skin fat content (day 7), and skin Zn content (days 7, 14, and 21) of ducks, but only increased (P < 0.05) the skin fat content of broiler chickens at 7days of age; ducks had a higher (P < 0.05) breast skin weight, breast skin index, and skin breaking strength as well as a lower skin fat content (days 7 and 14) than those in broiler chickens. (2) Dietary ZnD decreased the content of myristic acid (day 21) and increased the content of oleic acid (day 7) content in the skin of ducks and increased the palmitic acid (day 7) content in the skin of broiler chickens (P < 0.05) and increased the MUFA (day 7) content in the skin and the atherogenic index (day 21) in ducks. The contents of myristic acid (day 21), stearic acid (day 21), and oleic acid (days 7, 14, and 21) in the skin of broiler chickens were lower (P < 0.05) than those in ducks of the same age. In conclusion, using skin weight, skin index and skin MUFA content as criteria, the results indicated that meat ducks were more sensitive to dietary ZnD than broiler chickens. Using skin fat content as criterion, the results indicated that broiler chickens were more sensitive to dietary ZnD than meat ducks.