Abstract
[Objectives]The effects of adjusting the proportion of miscellaneous meal additives including DDGS,palm meal,rapeseed meal in the diet at different seasons including spring,summer and winter on the growth performance,slaughter performance and apparent nutrient digestibility of Cherry Valley ducks were studied to provide theoretical support for the promotion and application of season-specific dietary formulations with alternative feed ingredients in farming Cherry Valley duck.[Methods]The experiment of three batches in-cluding spring(March 15th to April 11th,2023),summer(August 8th to September 5th,2023),and winter(De-cember 18th,2023 to January 14th,2024),with a experiment period of 28 days(14-42 days old)for a season was conducted in Chengdu City,Sichuan Province,China.1050 14-day old,healthy Cherry Valley ducks with similar weight(spring:0.607±0.002 kg;summer:0.572±0.002 kg;winter:0.543±0.002 kg)were selected from each batch to be fed with three proportions of miscellaneous meal including the low group with 6%DDGS+4%palm meal+4%rapeseed meal,the medium group with 12%DDGS+8%palm meal+8%rape-seed meal,and the high group with 18%DDGS+12%palm meal+12%rapeseed meal,3 treatments per sea-son,7 replicates per treatment,and 50 ducks per replicate.The entire flock was weighed at 28 and 42 days of age of the ducks,and two average-weight male ducks were selected from each pen for slaughter at 42 days of age.The slaughtered ducks were used only for determining the slaughter rate,total eviscerated rate,semi-eviscerated rate,breast muscle rate,leg ratio and abdominal fat rate.3 male ducks with average weight after the weighing completed were randomly selected from each pen and allowed to freely consume the test diet for 4 hours.They were then slaughtered and the ileal chyme was collected to determine the apparent nutrient digest-ibility.[Results]Increasing the proportion of miscellaneous meal in the diet at spring significantly increased feed intake(P＜0.05),and the cost of weight gain significantly decreased(P＜0.05).The high group performed the best with feed intake per duck from 14 to 42 days of 7.055 kg and the cost of weight gain of 7.779 yuan/kg.The crude fat digestibility in the high group(65.691%)and the crude ash digestibility in the medium group(26.183%)significantly increased(P＜0.05).There was no significant difference among the three groups in slaughter performance(P＞0.05).The feed intake,feed conversion ratio and cost of weight gain of the ducks at summer significantly increased(P＜0.05)with the increase of the proportion of miscellaneous meal in the diet.The low group performed the best with feed intake per duck from 14 to 42 days of 5.194 kg,feed conversion ra-tio of 2.168,and cost of weight gain of 7.532 yuan/kg.The indexes of apparent digestibility significantly de-creased(P＜0.05),and the low group performed the best.The final weight,body weight gain per duck,feed in-take per duck,feed conversion ratio,and cost of weight gain at winter all significantly increased(P＜0.05)with the increase of the proportion of miscellaneous meal in the diet.The low group performed the best with final weight of 3.809 kg,body weight gain per duck of 3.266 kg,feed intake per duck from 14 to 42 days of 7.526 kg,feed conversion ratio of 2.316,and cost of weight gain of 8.046 yuan/kg.The indexes of apparent digestibil-ity significantly decreased(P＜0.05),and the low group performed the best.The pectoral muscle ratio with the best in the low group at 18.785%and leg ratio with the best in the medium group at 21.532%significantly de-creased(P＜0.05),with no significant effect on other slaughter performance(P＞0.05).[Conclusions]A higher proportion of miscellaneous meal at spring could be replaced to soybean meal in the diet of ducks,but the appli-cation proportion at summer and winter should be reduced.The proportion of miscellaneous meal in the diet recommended in the practice of production is 18%DDGS+12%palm meal+12%rapeseed meal at spring,and 6%DDGS+4%palm meal+4%rapeseed meal at summer and winter.关键词
肉鸭/季节/杂粕比例/生长性能/屠宰性能/表观养分消化率Key words
duck/season/proportion of miscellaneous meal/growth performance/slaughter performance/apparent nutrient digestibility
