Effects of Compound Acidifier on Growth Performance and Serum Biochemical Parameters of Heat-stressed Wenchang Chickens

[Objective]The paper was to investigate the effects of compound acidifier on growth performance and serum biochemical parameters of heat-stressed Wenchang chickens.[Method]A total of 28881-day-old Wenchang chickens with the same genetic background and similar initial weight(985.63±20.35 g)were randomly divided into four groups,four replicates per group and 18 chickens per replicate.Birds were fed the basal diet supplemented with 0 g/kg(control group),1 g/kg(groupⅠ),2 g/kg(groupⅡ)and 3 g/kg(groupⅢ)compound acidifier.The trial lasted 35 d.[Result]The daily gain of experimental groupⅠwas significantly higher than those of control group and groupⅢ(P<0.05),and the feed intake of experimental groupⅠwas also markedly higher than that of control group(P<0.05),but the feed gain ratio of experimental groupⅠwas significantly lower than that of groupⅢ(P<0.05).Compared with control group,the serum total protein and albumin levels of experimental groupⅠincreased(P>0.05),but the serum uric acid concentration decreased(P>0.05).[Conclusion]Supplementing 1 g/kg compound acidifier could improve the growth performance of heat-stressed Wenchang chickens.

Effects of early energy and protein restriction on growth performance, clinical blood parameters, carcass yield, and tibia parameters of broilers

This study was conducted to investigate the effects of dietary energy and protein dilution from age 8 to 14 d on growth performance,clinical blood parameters,carcass yield,and tibia parameters of broilers.Treatments were assigned in a completely randomized manner with factorial arrangement(4x4) including 4 levels of energy dilution and 4 levels of protein dilution.All birds were fed the same diet during the remaining period of time.The feeds were weighed every week,and the birds were weighed at 7,14,and 42 d.At 14 d,blood samples were taken for clinical chemistry measurements,and 4birds from each replicate were sacrificed to measure carcass yield and tibia parameters at 42 d.From 8 to 14 d,average daily feed intake(ADFI) of the 20%protein dilution group increased significantly compared with that of the 10%protein dilution group(P<0.05).The feed conversion ratio(FCR) of the group with 30%protein dilution and 15%energy dilution creased the most among all treatment groups.From 15 to 42 d,the ADFI and FCR of the 20%protein dilution group were greater than those of the 0 and 10%protein dilution groups(P<0.05),and the FCR of the 15%energy dilution group increased significantly(P<0.05).At 42 d,body weight(BW) of the 15%energy dilution group was less than that of the other groups(P<0.05).Significant interactions were observed in ADFI,FCR,and BW at 42 d of age between energy dilution and protein dilution(P<0.05).At 14 d,serum total protein levels of birds in the 20 and 30%protein dilution groups decreased significantly compared to that of the 10%protein dilution group(P<0.05).Blood urea nitrogen concentration of birds in the 20 and 30%protein dilution groups decreased significantly compared with those in 0 and 10%protein dilution groups(P<0.05).Triacylglycerol concentration of birds in the 20%protein and 10%energy dilution groups decreased significantly compared with that of the 0 dilution group(P<0.05).The carcass yields were unaffected by dilution of energy and protein(P>0.05).The bone breaking strength of the 15%energy dilution group decreased significantly compared with that of the5%energy dilution group(P<0.05).This study suggested that dietary protein and energy reduced 10%from 8 to 14 d of age can not affect the growth performance and other indexes in broilers.

Effects of protein sources for milk replacers on growth performance and serum biochemical indexes of suckling calves

This study investigated the effects of protein sources for milk replacers on growth performance and serum biochemical indexes of suckling calves. Fifty Chinese Holstein bull calves with similar BW and age were randomly allocated to 5 groups(1 control and 4 treatments) of 10 calves in each group. Five types of milk replacers were designed to have the same level of energy and protein. The protein source for milk replacers of the control group was full milk protein(MP). The protein source of milk replacers of the 4 treatment groups was composed of MP and one vegetable protein(VP)(30 and 70% of total protein). The4 types of VP were soybean protein concentrate(SP), hydrolyzed wheat protein(WP), peanut protein concentrate(PP), and rice protein isolate(RP). Results of the experiment showed: 1) there was no significant difference on average daily gain(ADG) and feed:gain ratio(F:G) among the MP, SP and RP groups(P > 0.05), whereas the ADG and F:G of the WP and PP groups were significantly lower compared with the MP group(P < 0.05); 2) there was not a significant difference in withers height, body length and heart girth among treatment groups compared with the MP group(P > 0.05). Thereby the 4 VP milk replacers had no adverse effects on body size of calves; 3) all groups showed no significant difference in the serum contents of urea nitrogen, total protein, albumin, globulin, β-hydroxybutyrate, growth hormone, insulin-like growth factor-1, and the ratio of albumin to globulin(A:G)(P> 0.05). In conclusion, SP or RP(accounts for 70% of the total protein) as calf milk replacers could substitute MP, whereas wheat gluten and PP had a significant adverse effect on growth performance in this experiment.