Effect Of Diet Type And Conditioning Temperature On Feed Processing Quality,growth Performance And Intestinal Health Of Meat Rabbits

This experiment was conducted to investigate the effects of diet type and conditioning temperature on feed processing quality,growth performance and intestinal health of meat rabbits.A 2×2 two-factor experimental design was used,the two factors were diet type and conditioning temperature,and the diet types were conventional diet(CD,corn,soybean meal and alfalfa meal as the main raw materials)and unconventional diet(UCD,corn was replaced with wheat middlings and rice bran meal,soybean meal was replaced with rapeseed meal and sunflower meal,alfalfa meal was replaced with peanut vine powder and rice hull powder).The CT were 80℃(LCT)and 90℃(HCT).The feed quality indexes in different conditioning temperature were determined.A total of 240 35-day-old meat rabbits with an average body weight of 858.77±43.60 g,they were randomly assigned into 4groups,with 30 replicates per group and 2 rabbits per replicate.The groups were:CD+LCT group,CD+HCT group,UCD+LCT group,UCD+HCT group,respectively.The experiment lasted for 42 days.Growth performance and intestinal health related indexes of meat rabbits were determined.On the 14 th day of the experiment,10 replicates rabbits from each group were selected for digestion experiment,and feces were collected continuously for 4 days.The apparent digestibility of dietary conventional nutrients and amino acids were determined and calculated.The experiment results are as follows:1.Feed processing quality: Compared with CD,UCD significantly decreased the hardness,bulk density and protein solubility(P < 0.05),and significantly increased the meal content,percentage of powdered and starch gelatinization of pelleted feed(P < 0.05).Compared with LCT,HCT significantly decreased the bulk density and percentage of powdered(P < 0.05),and significantly increased the protein solubility and starch gelatinization of pelleted feed(P < 0.05).DT and CT had interaction effects on bulk density,meal content,percentage of powdered and protein solubility of pelleted feed(P < 0.05).2.Growth performance: Compared with CD,UCD significantly decreased the average daily gain(ADG)(P < 0.05)and tended to decrease the diarrhea rate of meat rabbits(P = 0.078,P = 0.095);and UCD significantly increased the average daily feed intake(ADFI)and feed/gain(F/G)of meat rabbits(P < 0.05).Compared with LCT,HCT significantly decreased the ADFI of meat rabbits(P < 0.05)and tended to increase the diarrhea rate of meat rabbits(P = 0.095).DT and CT had no interaction effect on ADG,ADFI and F/G of meat rabbits(P > 0.05).The mortality rate of UCD+HCT group was significantly lower than that of other groups on the 1-21 days of the experiment(P < 0.05).3.Nutrient apparent digestibility: Compared with CD,UCD significantly decreased the apparent digestibility of dry matter(DM),gross energy(GE),crude protein(CP),Ash,acid detergent fiber(ADF),acid detergent lignin(ADL),calcium(Ca),phosphorus(P),methionine(Met)and lysine(Lys)(P < 0.05).Compared with LCT,HCT significantly increased the apparent digestibility of ADL(P < 0.05),and decreased the apparent digestibility of P,Ash and Cys(P < 0.05).DT and CT had interaction effects on the apparent digestibility of ADL,aspartic acid(Asp),valine(Val),isoleucine(Ile),phenylalanine(Phe)and proline(Pro)of meat rabbits(P < 0.05).4.Intestinal health: Compared with CD,UCD significantly decreased the ileal amylase activity and contents of acetic acid,butyric acid and total volatile fatty acid of cecal chyme(P < 0.05),increased the p H in cecal chyme(P < 0.05);DT had no significant effects on the small intestinal morphology and the number of Escherichia coli,Bifidobacterium,Lactobacillus and Total bacteria in cecal chyme of meat rabbits(P >0.05).Compared with LCT,HCT significantly decreased the duodenum crypt depth and content of propionic acid in cecal chyme(P < 0.05),and significantly increased the number of Lactobacillus in cecal chyme(P < 0.05).CT had no significant effect on intestinal digestive enzyme activities(P > 0.05).DT and CT had no interaction effects on intestinal morphology,digestive enzyme activities,cecal environment and microbial number(P > 0.05).5.Slaughter performance and organ indexes: DT and CT had no significant effects on slaughter performance and organ indexes of meat rabbits(P > 0.05),and there was no interaction effects(P > 0.05).6.Economic benefit: Compared with CD,UCD increased economic benefit by16.53%.Compared with LCT,HCT increased economic benefit by 11.69%.The UCD+HCT group had the highest economic benefit,reaching 205.16%.In conclusion,compares with conventional diet(Corn-Soybean meal-Alfalfa meal type),unconventional diet(Wheat middlings-Rice bran meal-Rapeseed meal-Sunflower meal-Peanut vine powder-Rice hull powder type)decreases the feed processing quality,and the apparent digestibility of most nutrients;and decreases the growth performance of meat rabbits.However,it does not affect on the intestinal health and slaughter performance,and reduces the diarrhea of meat rabbits,and improves the economic benefits of feeding.Compares with low conditioning temperature,high conditioning temperature decreases the cecal fermentation products of meat rabbits.However,can improve the feed processing quality,and has no significant effect on nutrient digestibility,growth performance and slaughter performance.In conclusion,unconventional diet can replace conventional diet for meat rabbit production.It is recommended that the conditioning granulating temperature of meat rabbit feed is 90℃.