Dietary L-arginine supplement alleviates hepatic heat stress and improves feed conversion ratio of Pekin ducks exposed to high environmental temperature.
The current intensive indoor production system of commercial Pekin ducks never allows adequate water for swimming or wetting. Therefore, heat stress is a key factor affecting health and growth of ducks in the hot regions and season. Experiment 1 was conducted to study whether heat stress was deleterious to certain organs of ducks. Forty-one-day-old mixed-sex Pekin ducks were randomly allocated to four electrically heated battery brooders comprised of 10 ducks each. Ducks were suddenly exposed to 37 °C ambient temperature for 3 h and then slaughtered, in one brooder at 21 days and in another brooder at 49 days of age. The results showed that body weight and weight of immune organs, particularly liver markedly decreased in acute heat stress ducks compared with the control. Experiment 2 was carried out to investigate the influences of dietary L-arginine (Arg) supplement on weight and compositions of certain lymphoid organs, and growth performance in Pekin ducks, under daily cyclic hot temperature environment. A total of 151-day-old mixed-sex Pekin ducks were randomly divided into one negative control and two treatment groups, fed experimental diets supplemented with 0, 5, and 10 g L-Arginine (L-Arg)/kg to the basal diet respectively. Ducks were exposed to cyclic high temperature simulating natural summer season. The results showed that the addition of L-Arg improves feed conversion ratio (FCR) during a period of 7-week trial, as well as increases hepatic weight relative to body weight at 21 days, while decreases the hepatic water content at 49 days of age. This study indicated that the liver was more sensitive to acute heat stress, and the hepatic relative weight and chemical composition could be regulated by dietary L-Arg supplementation in Pekin ducks being reared at high ambient temperature. These beneficial effects of Arg on liver might be a cause of improved FCR.
Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan, China.
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Zhu
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Jiang
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Wu
D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000494:pharmacology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D004372:Ducks / Q000502:physiology*; D004734:Energy Metabolism; D005260:Female; D006358:Hot Temperature / Q000009:adverse effects*; D008099:Liver / Q000187:drug effects* / Q000502:physiology; D008297:Male; D013312:Stress, Physiological / Q000187:drug effects*
D001120:Arginine
Pekin ducks; arginine; feed conversion ratio; high temperature; liver; stress