Xiaofen LI,Xiaozhi YANG,Yong TAO,Ling ZHANG,Wenjie GU,Xuhong YUAN

Jiangsu Agri-animal Husbandry Vocational College,Taizhou 225300,China

Responsible editor:Tingting XU Responsible proofreader:Xiaoyan WU

China is the first country which domesticated mallard ducks into domestic ducks,and it is also the country where the largest numbers of ducks are bred.In recent years,with the improvement of people’s living standards,the consumer market of duck products has been expanded from urban to rural,and the expanded market has been extended continuously.Cherry Valley ducks have advantages of fast growth,high meat yield,good meat quality and high feed conversion rate.They were introduced to China in large scale in 1992,and have now become one of the main meat duck varieties in China[1-2].In this study,different probiotics were added to the feed of Cherry Valley ducks so as to investigate the effects of probiotics on growth performance and blood biochemical indexes of Cherry Valley ducks,providing a scientific basis for the rational development and utilization of probiotics.

Material and Methods

Test animal and design

The test was started in the Jiangsu Fengda Waterfowl Breeding Farm on October 22,2013.A total of 240(male:female=1:1)1-d-old Cherry Valley ducks,in weight of (56±5)g,were selected.They were randomly divided into 4 groups (I,II,III,IV).There were 3 replicates for each group,and there were 20 ducks for each replicate.In the control groups,the ducks were only fed basal diet;while in the treatment groups,the duck were fed basal diet added with Lactobacillus (10 ml/kg),Bacillus natto(10 ml/kg)and florfenicol(50 mg/kg),respectively.The addition lasted for 5 d every 20 d.The Lactobacillus and Bacillus natto were all probiotics.The test period was 42 d.During the entire test period,the ducks were all raised on ground.The photoperiod was 23 h/d.The ducks were fed 2 times a day,and they all had free access to feed and water.The feed and water tanks were cleaned once a day.The immunization was carried out according to conventional program.

Basal diet

The basal diet was prepared according to the nutritional levels recommended by the Cherry Valley farms in England[3].The basal diet composition was shown in Table1.

Probiotics

The probiotics were provided by the Biotechnology Laboratory of Jiangsu Agri-animal Husbandry Vocational College.They were composed of Lactobacillus,Bacillus natto,metabolite protease,amylase,etc.

Determination methods

During the test period,the put amount and remaining amount of feed and the number of deaths in each replicate were recorded.The Cherry Valley ducks were weighed once a week.Then the average feed intake,average daily weight gain,feed conversion ratio and survival rate were calculated[4-5].When the test ended,the blood was sampled under a wing of each duck for the determination of blood biochemical indexes[6-7].At the same time,the costs of raising Cherry Valley ducks were calculated,and then,the economic benefits were analyzed.

Data processing and statistics

The data was processed using Excel 2007 and analyzed by the single-factor analysis of SPSS 19.0.The results were expressed as mean ±standard deviation.

Results and Analysis

Effects of probiotics on growth performance of Cherry Valley ducks

The addition of Lactobacillus and Bacillus natto into the feed could also significantly reduce the glutamic-pyruvic transaminase activity,alkaline phosphatase activity and serum urinary nitrogen content in duck blood,and reduce the creatinine content and total cholesterol content in Cherry Valley ducks.For creatinine content and total cholesterol content,there were significant differences among Lactobacillus,antibiotic and control groups;but in the Bacillus natto group,the creatinine content and total cholesterol content were all higher than those in the control group (P＜0.05).The addition of probiotics or antibiotic all reduced the triglyceride level in blood of Cherry Valley ducks(P＞0.05).In overall,the addition of antibiotic reduced the blood biochemical indexes in varying degrees,but no significant differences were found in the blood biochemical indexes,except in glutamicpyruvic transaminase activity (P＜0.05)and alkaline phosphatase activity (P＜0.05),between the antibiotic and control groups.Compared with those in the probiotics groups,the glutamicpyruvic transaminase activity (P ＞0.05),alkaline phosphatase activity(P＜0.05),serum urinary nitrogen content (P ＜0.05) and total cholesterol content(P＞0.05)in the antibiotic group were all higher(Table3).

The addition of Lactobacillus and Bacillus natto could improve the average daily weight gain and final average weight of Cherry Valley ducks,and there were significant differences among treatment groups (Table2).In addition,adding Lactobacillus also improved the feed conversion ratio in Cherry Valley ducks.The addition of antibiotic showed no significant effects on growth performance of Cherry Valley ducks,but it could improve their survival rate.

Effects of probiotics on blood biochemical indexes of Cherry Valley ducks

Table1 Composition of basal diet for Cherry Valley ducks

Table2 Effects of different probiotics on growth performance of Cherry Valley ducks

Table3 Effects of different probiotics on blood biochemical indexes of Cherry Valley ducks

Table4 Effects of different probiotics on economic benefits of Cherry Valley ducks

Effects of probiotics on economic benefits of Cherry Valley ducks

The addition of probiotics and antibiotic in feed all increased the gross economic benefits of raising Cherry Valley ducks,but the economic benefits in the probiotics groups were higher than that in the antibiotic group(Table4).

Conclusions and Discussion

Effects of probiotics on growth performance of Cherry Valley ducks

There are a wide variety of probiotics.In this study,the Lactobacillus and Bacillus natto were used.Adding Lactobacillus and Bacillus natto into feed improved the feed intake,average daily weight gain and feed conversion ratio in Cherry Valley ducks,which were consistent with the study results of Kong et al[6].This might be because that the probiotics could improve the palatability of feed and regulate the intestinal microflora,promoting the digestion and adsorption of feed and enhancing the immunity,thereby improving the survival rate of Cherry Valley ducks.

Effects of probiotics on blood biochemical indexes of Cherry Valley ducks

Glutamic-pyruvic transaminase is a key enzyme involved in the metabolism in bodies.It participates in the metabolism of proteins,and its activity is an important indicator reflecting the health status of liver.Under normal circumstances,after entering into blood,the enzymes with various sources will be gradually cleared by the liver or decomposed in the blood vessels.If the activity of glutamic-pyruvic transaminase is above the normal range,the liver may have been diseased or the enzyme scavenging function of the liver may have been disordered.The results of this study showed that after adding probiotics into the feed,the glutamic-pyruvic transaminase content in serum of Cherry Valley ducks was decreased,indicating that the probiotics might have improved the live functions in Cherry Valley ducks,which was consistent with the study result of Jiang et al[8].

Urinary nitrogen is an important indicator evaluating nitrogen retention in bodies.The reduced serum urinary nitrogen content indicates weakened deposition of amino acids,which provides a reference for the deposition of proteins in bodies.In this study,the addition of probiotics in feed reduced the serum urinary nitrogen content in Cherry Valley ducks.It was indicated that probiotics could better adjust the balance between protein metabolism and amino acids,promoting the deposition of proteins,which was consistent with the study result of Li et al[9].

Serum triglycerides and total cholesterol contents reflect the digestion,as well as the metabolism and utilization of lipids in livestock.In this study,the addition of probiotics in feed reduced the serum triglycerides and total cholesterol contents in Cherry Valley ducks,which was consistent with the study result of Huo et al[10].

Effects of probiotics on economic benefits of Cherry Valley ducks

The addition of probiotics and antibiotic in the feed undoubtedly increased the costs of raising Cherry Valley ducks.However,the addition of Lactobacillus improved both feed conversion ratio and survival rate of Cherry Valley ducks; although the addition of Bacillus natto and antibiotic reduced the feed conversion ratio,the survival rate of Cherry Valley ducks was improved.Thus the gross economic benefits were all increased.Based on the results above,it could be concluded that the effects of adding Lactobacillus and Bacillus natto were all better than those of adding antibiotic.

Adding Lactobacillus and Bacillus natto in the feed reduced the glutamicpyruvic transaminase activity,alkaline phosphatase activity,serum urinary nitrogen content,creatinine content and total cholesterol content in the blood,and increased the survival rate and gross economic benefits of Cherry Valley ducks.Moreover,the effects of adding Lactobacillus were better.Therefore,Lactobacillus can be added to the feed of Cherry Valley ducks as a replacement for antibiotics,avoiding the adverse effects of drug deposition in ducks on human health,thereby effectively improving the economic and social benefits.

[1]HAN TY (韓廷義).Effects of probiotics on growth performance of meat ducks(微生態(tài)制劑對肉鴨生長性能的影響)[J].China Animal Husbandry & Veterinary Medicine (中國畜牧獸醫(yī)),2012,39(2):79-81.

[2]SHENG ZX (盛祖勛),KONG LY (孔令勇),YANG XL (楊雪林),et al.Effects of probiotics on growth performance of Cherry Valley ducks(微生態(tài)制劑對櫻桃谷肉鴨生產(chǎn)性能的影響)[J].Animal Husbandry & Veterinary Medicine(畜牧與獸醫(yī)),2012,44(6):50-52.

[3]JIANG QD(江慶娣).Nutritional requirements and raising management of Cherry Valley ducks(櫻桃谷鴨的營養(yǎng)需要與飼養(yǎng)管理)[J].China Feed (中國飼料),2001,2:31-32.

[4]YANG CJ (楊承劍),HUANG XG (黃興國).Probiotics and their application in husbandry production (微生態(tài)制劑及其在畜牧生產(chǎn)中的應用)[J].Feed Review(飼料博覽),2006,2:9-12.

[5]HOU HF(侯海鋒),LI Q(李茜),SHI WY(史萬玉),et al.Application actuality and expectation of microecological preparation in breeding production (微生態(tài)制劑在養(yǎng)殖生產(chǎn)中的應用現(xiàn)狀與展望)[J].China Animal Husbandry & Veterinary Medicine (中國畜牧獸醫(yī)),2011,38(7):27-30.

[6]KONG LY (孔令勇),SHENG ZX (盛祖勛),YANG XL (楊雪林),et al.Effects of microecological agent on growth performance,slaughter performance and development of immune organs of Cherry Valley ducks(微生態(tài)制劑對櫻桃谷肉鴨生長性能? 屠宰性能及免疫器官發(fā)育的影響)[J].Chinese Journal of Animal Nutrition (動物營養(yǎng)學報),2012,24(8):1577-1582.

[7]ZHAO L(趙麗),CUI HM(崔恒敏),YANG F (楊帆),et al.Effect of high dietary copper on blood parameters in ducklings (日糧中添加高水平銅對雛鴨血液指標的影響)[J].China Poultry (中國家禽),2008,30(5):24-28.

[8]JIANG WX(姜衛(wèi)星),LI W(李偉),TANG SY (唐松元),et al.Effect of probiotic in diets of the growth performance and blood biochemistry parameters of porcupine(日糧中添加微生態(tài)制劑對豪豬生產(chǎn)性能及血液生化指標影響的研究)[J].Journal of Economic Animal (經(jīng)濟動物學報),2011,15(1):14-17.

[9]LI C(李超),BIAN LQ(邊連全),LIU XJ(劉顯軍),et al.Comparative study of the effects of several effective microorganisms on growth performance,serum biochemical indexes if growing pigs (幾種微生態(tài)制劑對生長豬生產(chǎn)性能和血清生化指標影響的比較研究)[J].Heilongjiang Animal Science and Veterinary Medicine (黑龍江畜牧獸醫(yī)),2012,5(9):66-68.

[10]HUO YM(霍妍明).Effect of microecological agent and nano-activated water on production performance,egg quality and serum biochemical parameters of laying hens(微生態(tài)制劑及納米活化水對蛋雞生產(chǎn)性能、蛋品質和血液生化指標的影響)[D].Baoding:Heibei Agricultural University (保定:河北農(nóng)業(yè)大學),2008.