Effect of Using Baker＇s Yeast and Exogenous Digestive Enzymes as Growth Promoters on Growth, Feed Utilization and Hematological Indices of Nile tilapia, Oreochromis niloticus Fingerlings

The present study was conducted to evaluate the effect of baker yeast, Saccharomyces cerevisiae （SC） and exogenous digestive enzymes （pepsin, papain and a-amylase, EDE） dietary supplementation on growth performance, feed utilization and hematological indices of Nile tilapia, Oreochromis niloticus fingerlings. A total of 630 Nile tilapia fingerlings with an average body weight of 26.4 ± 0.2 g were divided in the seven experimental net-pen treatments （three replicates each）. The experiment was conducted for 119 days. Seven isonitrogenous （26.50%） digestible protein and isocaloric （13.40 MJ kgl） digestible energy experimental diets were formulated. The control diet had no SC and EDE added. Diets 2-3 each contained SC at levels of 2 and 4 g 100 g diet-t, respectively, while diets 4-5 each contained EDE at levels of （0.64, 1.28, 0.16） and （1.28, 2.56, 0.32） g 100 gdiefI of pepsin, papain and a-amylase, respectively. Diet 6 contained mixture of SC and EDE at levels of 1 g yeast and 0.32, 0.64, 0.08 g of pepsin, papain and a-amylase, respectively 100 gdiet1 and diet D7 contained 2 g yeast and 0.64, 1.28, 0.16 g of pepsin, papain and a-amylase, respectively 100 g dietl. Growth performance and feed utilization efficiency of Nile tilapia were significantly （P 〈 0.05） higher in all treatments receiving SC and/or EDE supplemented-diets than the control diet which suggests that the addition of SC and EDE enhanced the growth performance. Red blood cells counts, hematocrit and hemoglobin were significantly （P 〈 0.05） highest in all treatments receiving mixture of SC and EDE supplemented-diets （D6 ＋ D7）. The same trend was observed for total plasma protein and total plasma globulin levels. The results of present study suggested that Nile tilapia fingerlings fed diets containing the mixture of I g yeast, SC and 0.32, 0.64, 0.08 g of pepsin, papain and a-amylase, respectively 100 gdiet^-1, for 119 days had enhanced growth performance, diet utilization efficiency and hematological indices.

Effects of Using Exogenous Digestive Enzymes or Natural Enhancer Mixture on Growth, Feed Utilization, and Body Composition of Rabbitfish, Siganus rivulatus

This study was conducted to study the effects of a commercial exogenous digestive enzymes （EDE） containing cellulases, xylanases, u-amylase and proteases from anaerobic bacterium and natural enhancer mixture （NEM） containing allicin, high unit hydrolytic enzyme, Bacillus subtilis spores and ginseng extracts on survival, growth, carcass composition and feed cost/benefit in rabbitfish, Siganus rivulatus. Nine net cages （100 cm × 100 cm × 40 cm; L ×W ×H） were stocked with 10 juvenile rabbitfish （1.1 g per fish） each and placed in a large rectangular tank and offered feed at 4% body weight daily. Three replicates per treatment were offered three isonitrogenous and isocaloric diets, control and two supplemented diets with EDE or NEM at 2 g/kg diet for 74 days. Fish in all cages were weighed at two-week intervals and feed regimen was adjusted accordingly. Rabbitfish offered the control diet exhibited lower growth significantly （P 〈 0.05） and feed utilization than the other two experimental treatments. Experimental diet supplemented with NEM recorded the highest growth performance, feed conversion ratio, protein efficiency ratio, net protein utilization and energy retention significantly （P 〈 0.05） than the other two tested groups. Carcass composition and somatic parameters index was not affected by dietary EDE or NEM inclusion. Ultimately, when all variables are considered, EDE and NEM inclusion to diets appears to reduce feed cost per unit growth of rabbitfish.

The Effects of Size-fractionated Fish Hydrolysate in the Diet on Growth, and Feed Utilization of Turbot （Scophthalmus maximus）

Four experimental diets were fed to turbet to examine the effect of fish bydrolyside and ultra filtered fish hydrolysafe on growth performate feed utilization and growth regulation using diets low in dietary fish meal inclusion. Diets A, B contained 3.7%,1.2% fish hydrolysate to replace fish meal respectively and the fish hydrolysate in two diets was ultra filtered to keep low molecular weight compounds. The diets A,

The potential of Clostridium autoethanogenum,a new single cell protein,in substituting fish meal in the diet of largemouth bass(Micropterus salmoides):Growth,feed utilization and intestinal histology

This study investigated the effects of replacing fishmeal with Clostridium autoethanogenum protein(CAP)on growth,feed utilization and intestinal histology of largemouth bass(Micropterus salmoides).The control diet contained 350 g/kg fishmeal,and then dietary fishmeal was decreased to 300 g/kg,250 g/kg,200 g/kg,150 g/kg and 100 g/kg by CAP inclusion,respectively(FM-30,FM-25,FM-20,FM-15,FM-10).The largemouth bass(110.0±1.0 g)were fed one of the six diets for 8 weeks.The groups of FM-30,FM-25 and FM-20 showed the similar weight gain(WG)and feed conversion ratio(FCR)to the control(P>0.05),while the WG of FM-10 group was decreased by 15.9%,and FCR increased by 0.12 when compared to the control(P<0.05).FM-15 and FM-10 groups had lower protein retention,lower villus height in intestine and higher serum malondialdehyde content than the control(P<0.05).The protease activity in FM-20,FM-15 and FM-10 groups was lower than that in the control(P<0.05),but no difference was observed in crude protein digestibility among groups(P>0.05).In conclusion,CAP could replace 150 g/kg fishmeal in diet(350 g/kg fishmeal)without adverse effects on growth,feed utilization and intestinal histology of largemouth bass.

Effect of chicken haemoglobin powder on growth, feed utilization, immunity and haematological index of largemouth bass (Micropterus salmoides)

A 12-week feeding trial was conducted to evaluate the effects of replacing fish meal by chicken haemoglobin powder in largemouth bass diets.Four isonitrogenous(48%)and isolipidic(12%)diets were formulated to replace 0%(control),9.80%,19.61%and 29.41%of fish meal with chicken haemoglobin powder.Each diet was fed to triplicate groups of fish(initial weight:49.50±0.07 g)twice daily.The fish specific growth rate was significantly reduced when diet replacement level was up to 19.61%,which may be related to the feed intake and apparent digestibility coefficient of protein and amino acids.Meanwhile,the feed efficiency ratio and protein efficiency ratio were not significantly decreased until the replacement level up to 29.41%.The activity of CCP was significantly reduced when 19.61%of fish meal was replaced.Meanwhile,the activity of lysozyme and serum protein content was significantly altered in fish fed with the diets up to 29.41%replacement.Additionally,the red blood cell count and haemoglobin content was significantly decreased when the replacement level was up to 19.61%.In overall,the diet with 9.80%of chicken haemoglobin powder was more suitable for largemouth bass.

The digestible phosphorus requirement in practical diet for largemouth bass(Micropterus salmoides)based on growth and feed utilization

The present study was conducted to estimate the optimum requirement of phosphorus in practical diets for largemouth bass(Micropterus salmoides).Six iso-energetic and iso-nitrogenous diets were formulated with the supplementation of monocalcium phosphate(MCP)of 0,5,10,15,20 and 25 g/kg in basal diet containing 350 g/kg fish meal,respectively.The digestible phosphorus of the six diets was measured as 5.7,6.7,7.8,8.7,9.3 and 10.0 g/kg,respectively.Each diet was randomly fed to triplicate groups of 25 juvenile fish(initial body weight,16.0±0.2 g)for 60 days.The results showed that weight gain increased,and feed conversion ratio decreased with the increase of dietary phosphorus.When dietary MCP exceeded 15 g/kg(digestible phosphorus of 8.7 g/kg),the WG and FCR were maintained at the similar values.The crude ash,phosphorus and calcium contents in whole body,apparent digestibility of phosphorus and protein retention also increased with the increasing phosphorus level in diets.Vertebrae phosphorus and calcium levels and plasma phosphorus showed no further increase when dietary MCP reached 20,20 and 10 g/kg with digestible phosphorus of 9.3,9.3 and 7.8 g/kg,respectively.Broken-line analysis indicated that the digestible phosphorus requirement for largemouth bass were 8.9,8.7 and 9.6 g/kg based on weight gain,feed conversion ratio and vertebral phosphorus content.In conclusion,the supplementation of MCP in a diet containing 350 g/kg fish meal improved the growth and feed utilization of largemouth bass,and the digestible phosphorus requirement was suggested to be 8.7–8.9 g/kg with MCP supplementation of 15.0–15.8 g/kg.

Water Intake and Utilization in Mithun (Bos frontalis):Effect of Environmental Temperature,Rearing System and Concentrate Feed Supplement

Seasonal and sexual variations as well as the effect of dry feed supplement on total drinking water intake and its utilization were observed in mithun （Bosfrontalis） - a semi-wild animal found in North Eastern Hill Region （NEHR） of India. In a completely randomized design, twelve adult mithuns （B. frontalis） as per their sex and body weight were assigned in two different rearing systems （free grazing and free grazing with dry concentrate feed supplementation）, and ten growing male mithuns as per their body weight assigned in two different levels of dry concentrate feed supplementation （1.o kg and 2.0 kg dry concentrate feeds on green forage based diet） and in two different seasons （summer and winter）. It was observed that the environmental temperature had a significant effect on drinking water intake by mithuns. Drinking water consumption （per unit of body weight） was significantly （P 〈 0.05） higher in summer than in winter. Supplementation of concentrate feed on free grazing animals resulted in increase in water consumption. Total water consumption （drinking as well as performed water） was found to be 15.18 litres per 100 kg body weight by growing mithun. Feed dry matter and digestible nutrient intakes by growing mithun were observed to be increased with the increase of supplementation of dry concentrate feed. Roughage to concentrate ratio did not affect the nutrient digestibility. Mithun calves drank an average of 4.30 litres water for each kg of dry matter intake. Metabolic water was significantly （P〈0.01） increased with the increase of supplementation of concentrate feed whereas water turn over, which depends upon the body weight of the animals, did not differ significantly on offering of lower or higher level of dry feed. Faecal water loss of growing mithun was decreased with the increase in intake of concentrate feed and was estimated to be 33 - 46 % of total water intake. Excretion of water through faeces of mithun was about 3.8 % of body weight. It could, therefore, be inferred that water intake by mithun varied with seasons, rearing systems and dry feed consumption. As far as the water nutrition is concerned, it is needed to give an attention while feeding mithun in summer with dry feed supplementation under semi-intensive system of rearing.

Growth performance,feed utilization,body and fatty acid composition of Nile tilapia (Oreochromis niloticus) fed diets containing elevated levels of palm oil

This study was conducted to evaluate effects of dietary palm oil levels on growth performance,feed utilization,body composition and serum metabolites of Oreochromis niloticus.Five isonitrogenous diets,32% crude protein with increasing palm oil levels of 0(Control,CTRL),2%,4%,6% and 8% were used as the major lipid source for the trial.The results showed that greatest weight gain,specific growth rate,and protein efficiency ratio occurred at 6% dietary palm oil level.Dietary palm oil levels significantly(P<0.05)affected lipid,moisture,ash and crude protein contents in muscle and whole body.Serum triglycerides,cholesterol and total protein were significantly affected by elevated palm oil levels.Furthermore,total saturates,total n-3 poly unsaturated fatty acids(PUFA),total n-6 PUFA as well as DHA/EPA in muscle were significantly affected by different levels of palm oil.Fish fed the 6% palm oil level recorded the highest level of whole body docosahexaenoic acid(DHA),which was significantly higher than that of the control.The nutritional quality of O.niloticus was altered by different palm oil levels.The present study suggests that 6% dietary palm oil is the best feed formulation for tilapia,Oreochromis niloticus.

Effect of Feeding on Fresh(wet)Housefly Maggots(Musca domestica)with or without Artificial Diet on Water Quality and Growth Rates of African Catfish(Clarias gariepinus Burchell,1822)Fry under Laboratory Conditions

No or little information on the use fresh(wet)housefly maggots(Musca domestica)in African catfish(Clarias gariepinus)fry feeding.Therefore,this study was conducted to investigate the effect of feeding on fresh(wet)housefly maggots with or without artificial diet on water quality,growth performance,survival percentage and feed utilization of African catfish fry under laboratory conditions.Housefly maggots produced from a mixture of poultry droppings and foods wastes,it was used to replace artificial feed at 0,50 and 100% levels.Catfish were fed artificial diet alone(Feed 1),fresh(wet)housefly maggots alone(Feed 2),and 50% fresh housefly maggots with 50% artificial diet(Feed 3)were prepared and tested on triplicate groups of African catfish fry(initial weight of 0.25±0.02 g)for 60 days.Results showed that final weight(g/fish)was significantly(P≤0.05)higher in fish fed on feed 3(6.03±0.08),followed by fish fed feed 2(4.62±0.27),followed by fish fed feed 1(3.15±0.68).Specific growth rate(%/day)was also significantly higher in fish fed on feed 3(5.31±0.10),followed by fish fed feed 2(4.86±0.03),followed by fish fed feed 1(4.18±0.24).The same trend was observed with total weight gain,percentage weight gain,daily growth rate and relative growth rate.Feed intake and protein intake were significantly(P≤0.05)higher in fish fed on feed 3 and fish fed on feed 2,followed by fish fed feed 1.While,feed conversion ratio(FCR)and protein efficiency ratio were not significantly(P>0.05),but the improvement in FCR recorded in catfish fry fed feed 3 and feed 2 under the experimental conditions.Survival percentage was within the range 55-75%,with insignificant differences(P>0.05)among treatments.The water quality parameters such as temperature,pH,dissolved oxygen,total ammonia,nitrite and nitrate were not significantly(P>0.05)between the treatments and were tolerable for Catfish culture.Accordingly,use of the 50% fresh(wet)housefly maggots with 50% artificial diet in African catfish fry feeding had positive effect on growth performance and reduce of the feed cost.

Effect of Different Dietary Protein and Lipid Levels on the Growth,Body Composition,and Intestinal Digestive Enzyme Activities of Juvenile Yellow Drum Nibea albiflora(Richardson)

An 8-week feeding trial was conducted to determine the optimal dietary protein-to-lipid ratio for juvenile Nibea albiflora with an initial weight of(11.76 ± 0.20) g.Nine experimental diets containing different concentrations of protein(40%,47%,or 54%) and lipids(5%,9%,or 13%) in a 3 × 3 factorial experimental design were tested in triplicate groups of fish,while the protein-to-energy(P/E) ratios of the diets varied in the range of 19.74–28.32 mg k J^(-1).Results showed that fish fed diets containing 9% or 13% lipids with 54% protein exhibited significantly higher weight gains and specific growth rates than those fed other diets.The feed conversion rate of fish fed the diet with 40% protein and 5% lipids was significantly poorer than that of fish fed other diets.The protein efficiency rate of fish fed diets with 5% lipids was significantly lower than that of fish fed 9% or 13% lipid diets.Carcass lipid and energy contents were positively correlated with dietary lipid level regardless of protein level.Fish fed a 54% protein diet showed the highest trypsin activity.The intestinal lipase activity of fish fed the diet containing 13% lipids was significantly higher than that of fish fed 5% or 9% lipid diets.These results demonstrate the high protein dietary requirements of N.albiflora.A diet containing 54% protein and 9%–13% lipids with a P/E ratio of 26.2–27.81 mg protein k J^(-1) can be considered optimal for juvenile N.albiflora.

Feasibility of Partial Replacement of Fishmeal with Proteins from Different Sources in Diets of Korean Rockfish(Sebastes schlegeli)

An 8-week feeding experiment was conducted in an indoor recirculation seawater system to investigate the effects of partial replacement of dietary fishmeal with proteins from five sources on the growth performance and feed utilization of Sebastes schlegeli. Six isonitrogenous and isoenergetic diets were formulated using fishmeal(FM, the control) as sole protein source, or proteins from five sources including poultry by-product meal(PBM), meat and bone meal(MBM), soybean meal(SBM), cottonseed meal(CSM) and canola meal(CNM). Fifteen percent of the crude protein provided by fish meal was replaced, respectively. The results showed that the differences in specific growth rate(SGR) and survival rate(SR) among fish fed PBM, MBM, SBM, CSM and whole FM diets were not significant. However, SGR and SR of fish fed CNM diet was significantly lower than that of other treatments. Feeding rate, feed conversion, nutrient retention showed similar patterns to that of growth. Fish fed CSM and CNM showed significantly lower apparent digestibility coefficient(ADC) of dry matter and gross energy than those fed others while fish fed CNM showed lower ADC of crude protein than those fed others(P<0.05). These results suggested that it was feasible to substitute 15% dietary protein provided by fishmeal with PBM, MBM, SBM and CSM, respectively, but not with CNM as the replacement with CNM reduced fish growth and feed utilization.

Effects of different protein and lipid levels on the growth performance and intestinal microflora of loach(Paramisgurnus dabryanus)

The aim of this study was to examine the effects of dietary protein and lipid levels on the growth per-formance and homeostasis of the intestinal flora in Paramisgurnus dabryanus.An 8-week 3×3 two-factorial experiment was conducted to investigate the interaction between dietary crude protein(CP:30%,35%,40%)and ether extract(EE:6%,10%,14%)on the growth rate and the intestinal microflora of P.dabryanus.A total of 2,160 fish(5.19±0.01 g)were randomly allotted to 36 aquariums each with 60 fish.Fish were fed the experimental diet twice daily.Results revealed that weight gain rate(WGR),specific growth rate(SGR),protein efficiency ratio and net protein utilization significantly increased when increasing protein levels from 30%to 40%(P<0.05).Both WGR and SGR enhanced first but reduced thereafter with maximum value at 10%lipid level as dietary lipid increased from 6%to 14%(P<0.05).Significant interactions between protein and lipid were found with feed conversion rate,lipid efficiency ratio and net lipid utilization(P<0.05).At the phylum level,Proteobacteria and Actinobacteria were the dominant bacteria;at the genus level,Burkholderia-Caballeronia-Paraburkholderia was the dominant bacteria.Fish fed the diet containing 10%lipid had a higher abundance of Proteobacteria and unclassi-fied_f_Eenterobacteriaceae than those fed the 14%lipid diet,and a higher abundance of Rhodobacter than those fed the 6%lipid diet(P<0.05).Analysis of the predicted functions showed that metabolism in the intestine of fish in the CP40EE10 group was more active than that in CP30EE14 group.Polynomial regression analysis found that a diet containing 40.87%protein and 9.88%lipid can be considered optimal for P.dabryanus.