The potential for the improvement of the nutritive value of soya-bean meal by different proteases in broiler chicks and broiler cockerels

1. The potential for improving the nutritive value of commercial solvent-extracted, heat-treated soya-bean meal (SBM) by protease treatment was measured using growing broiler chicks and tube-fed broiler cockerels. 2. SBM was pre-treated (50 degrees C for 2 h) with water alone; at alkaline pH (initial pH 8.25) with and without protease P1 (isolated from a Bacillus species) or at acid pH (initial pH 4.5) with and without protease P2 (isolated from an Aspergillus species) and incorporated into diets (290 g SBM/kg diet) for broiler chicks (20 chicks/treatment). Only protease P2 treatment improved chick performance; from 7 to 28 d of age, chicks fed on treated SBM had greater feed intakes and gained more weight than chicks fed on untreated SBM. Both proteases P1 and P2 significantly reduced chick serum anti-soya antibodies while protease P2 treatment increased apparent ileal nitrogen (N) digestibility and apparent N retention across the whole digestive tract. 3. Two tube-feeding experiments established that, of the treated SBMs used in experiment 1, only protease P2 treatment improved apparent N digestibility and true metabolisable energy. Also it was shown that increasing the temperature at which treated SBM was dried to 60 degrees C, compared with freeze-drying or drying at 50 degrees C reduced apparent N digestibility and true metabolisable energy of SBM with no significant interactions between enzyme treatment and drying temperature for both apparent N digestibility and TME. 4. It is concluded that, overall, the nutritional value of SBM assayed in a growth trial and by tube feeding was improved by treatment with protease P2 and not by treatment with protease P1.     

Sensitivity of broiler starters to three doses of an enzyme cocktail in maize-based diets

1. The aim of the present study was to investigate the effect of an enzyme cocktail composed of xylanase, amylase and protease on the performance and nutrient utilisation of broiler starters fed on a maize-based diet. A maize/soy-based control diet was formulated to be marginal in apparent metabolisable energy (AME) and amino acids and this diet was fed without or with two concentrations (250 and 500 g/tonne) of the exogenous enzyme cocktail. 2. Growth performance was measured over a 21-d period after which ileal contents were collected for measurement of digestible energy, nitrogen and dry matter. Excreta were collected from d 17 to 20 post-hatch and used to determine the AME, and retention of nitrogen and dry matter. 3. Supplementation of the control diet with 250 and 500 g/tonne of the enzyme cocktail resulted in enhanced performance of the chicks (1.4 and 8.3%, respectively, for weight gain and 1.2 and 2.2%, respectively, for feed per gain), but the improvements were significant (P < 0.05) only at 500 g/tonne. 4. Addition of both 250 and 500 g/tonne improved AME, nitrogen-corrected AME and dry matter retention compared with the control though the improvements were greater with the higher dose. These effects were also reflected in the apparent ileal digestibility coefficients of dry matter, nitrogen and energy, with 500 g/tonne of the enzyme cocktail improving ileal digestible energy by 3.4%. 5. These results demonstrate that a cocktail of exogenous enzymes containing xylanase, amylase and protease is effective in improving the performance of broiler chicks fed on a maize/soybean-meal-based diet. However, these benefits may be dose-dependent and so an economic analysis involving ingredient and enzyme pricing and the relative performance and digestibility enhancements could allow the end user to select the most economical dose to maximise return on investment.     

Supplementation of broiler diets with high levels of microbial protease and phytase enables partial replacement of commercial soybean meal with raw,full‐fat soybean

A 3 × 3 + 1 factorial, involving three levels of protease (0, 15,000 or 30,000 PROT/kg) and three levels of phytase (1,000, 2,000 or 3,000 FYT/kg), was used to evaluate the effect of replacing commercial soybean meal (SBM) with raw, full‐fat soybean (RFSB) at 75 g/kg of diet for broilers. A control diet was used for comparison. Each treatment was replicated six times, with nine birds per replicate. The concentration of trypsin inhibitors (TIs) in the test diets was approximately 10,193.4 TIU/kg. Regardless of enzyme supplementation, feed intake (FI) and body weight gain (BWG) of birds in the control group were superior to those on the test diets. Birds that received the protease‐free test diets had reduced FI and BWG, but when supplemented with protease, were similar to the control diet in BWG, FI (except 0–35 days) and feed conversion ratio (FCR). When the test diet was supplemented with elevated levels (extradose) of protease and phytase, the BWG was improved during 0–10 days (p = .05) and 0–24 days (p < .01). Regardless of protease supplementation, the weight of thighs was lower for birds fed the test diets. Birds that received the control diet had smaller weight of pancreas. Increasing the level of phytase supplementation reduced (p < .05) the weight of the pancreas. The apparent ileal digestibility (AID) of CP and AA was higher in birds on the control diets, but this was also improved in test diets by protease supplementation. The activities of trypsin (7%), general proteolytic (11%) and lipase (12%) were slightly increased because of protease supplementation. Mucosal depth and apparent villus surface areas were increased by about 2.9% and 20%, respectively, due to supplementation of elevated level of phytase. It can be concluded that RFSB could partially replace SBM in broiler diets, provided the diets are supplemented with elevated levels of protease and phytase.     

Dietary cholecalciferol and phosphorus influence intestinal mucosa phytase activity in broiler chicks

1. The role of cholecalciferol and phosphorus in the regulation of intestinal mucosa phytase was investigated in broiler chicks. 2. A total of 144 7-d-old male broiler chicks were grouped by weight into 6 blocks of 4 cages with 6 broiler chicks per cage. Four maize-soybean meal-based mash diets were randomly assigned to cages within each block. The 4 diets consisted of cholecalciferol at 0 or 75 microg/kg and total phosphorus at 3.6 or 7.0 g/kg in a 2 x 2 factorial arrangement. The birds were given the experimental diets for 12 d under conditions which excluded ultraviolet light. 3. Broiler chicks fed on diets with the higher concentration of cholecalciferol had higher Vmax and Km of the mucosa phytase, weight gain, feed intake, feed efficiency and percentage tibia ash, higher ileal digestibility of dry matter, energy, phosphorus (P) and calcium (Ca), and increased retention of dry matter, nitrogen, P, Ca and energy. 4. Broiler chicks receiving diets with the higher P concentration showed lower Vmax and Km of the intestinal mucosa phytase but greater weight gain, feed intake, feed efficiency and percentage tibia ash, higher ileal digestibility of dry matter, energy, P and nitrogen, and increased retention of dry matter, energy, nitrogen and Ca. 5. In conclusion, both dietary P and cholecalciferol influenced the activity of intestinal mucosa phytase.     

Sunflower seed meal as a substitute for soybean meal in commercial broiler chicken diets

1. An experiment was conducted to study the possibility of replacing soybean meal (SBM) with sunflower seed meal (SFM) in broiler chick diets. The SBM in broiler starter (317.9 g/kg) and finisher (275.4 g/kg) diets was replaced with SFM at 33, 67 and 100% on an iso-caloric and iso-nitrogenous basis using sunflower oil to balance the energy content of the diets. The metabolisable energy levels used in the diet were considerably less than the recommended levels for broilers. Each experimental diet was fed ad libitum from 2 to 42 d of age to 8 replicates of 5 birds. Parameters studied included amino acid and apparent metabolisable energy contents in food ingredients, body weight, food intake, food efficiency, leg abnormality score, dry matter digestibility, carcase traits, relative weight and length of intestine, fat and protein content in liver and serum biochemical profile. 2. SFM had higher concentrations of calcium, phosphorus, methionine and cystine and lower energy content than SBM. 3. Replacement of SBM with SFM up to 67% in starter and 100% in finisher diets did not affect weight gain. Total and 67% replacement of SBM with SFM depressed food efficiency at 21 and 42 d of age, respectively. Food intake was significantly higher in SFM-based diets than in the SBM reference diet at 21 and 42 d of age, except in groups given SFM100 at 21 d of age. In the latter group, the food intake was similar to that on the SBM reference diet. The digestibility of dry matter decreased with increased levels of SFM in the diet. 4. The relative weights of giblet, liver and abdominal fat, length of intestine, activity of alkaline phosphatase, concentrations of calcium and inorganic phosphorus in serum were not influenced by incorporation of SFM in the broiler diet. 5. The ready to cook yield and liver fat content decreased, while the relative weights of gizzard and intestine and protein content in liver increased, with increasing levels of SFM in the diet. 6. The concentration of HDL cholesterol increased while the concentration of LDL cholesterol decreased with increasing content of SFM (> or =67% of SBM) in diet. The serum protein concentration decreased progressively with increase in dietary SFM. The concentrations of protein and triglycerides in serum were lowest in groups receiving SFM100. 7. Body weight gain was not affected by total replacement of SBM with SFM at 42 d of age. However, considering food efficiency, carcase yields, serum lipid profile and level of supplemental fat in diet, it is concluded that SFM can replace up to two-thirds of soybean, corresponding to inclusion of 345 and 296 g SFM per kg for starter and finisher phases, respectively.     

Evaluation of growth performance of broiler birds fed with diet containing different levels of velvet bean meal as an alternative protein ingredient

The effect of replacement of soybean meal (SBM) by the velvet bean meal (VBM) as an alternative protein ingredient on the growth performance of broiler birds was investigated. The seed materials of velvet bean (VB) [Mucuna pruriens (L.) DC. var. utilis (Wall. ex Wight) Baker ex Burck], an under-utilized food legume collected from South India, was found to contain appreciable levels of proteins (265 g/kg DM); lipid (65.1 g/kg DM); Neutral Detergent Fiber (84.3 g/kg DM) and ash content (49.2 g/kg DM). Soaking in sodium-bi-carbonate solution + autoclaving treatment was found to cause substantial reduction on the levels of antinutritional compounds such as tannins (75%), L-Dopa (81%), phytic acid (70%), raffinose (92%), stachyose (89%), verbascose (71%), haemagglutinating activity (75%), trypsin inhibitor activity (78%) and α-amylase inhibitor activity (77%) without affecting the nutritional quality of VB seeds. Such processed VBM was incorporated as an alternative protein source by replacing the SBM protein at 0, 20, 40, 60, 80 and 100% levels in the commercial type broiler diets. Replacement of SBM up to 40% level with VBM as an alternative protein ingredient in the poultry diet, which corresponds to the inclusion of VBM up to 15.7% in the starter feed and 11% in the finisher phase poultry feed, exhibited better growth performance of the broiler birds without any adverse effects.     

Effects of nickel supply on the fattening performance and several biochemical parameters of broiler chickens and rabbits

Broiler chicken and rabbit experiments were carried out to study the effects of nickel (Ni) supplementation on growth performance and Ni metabolism. ROSS cockerels and New Zealand White female rabbits were fed a diet containing Ni in concentrations of 0, 50 and 500 mg/kg in dry matter (DM). Dietary supplementation of 50 mg Ni/kg slightly improved the body weight gain (BWG) and had a beneficial effect on the feed conversion efficiency (FCE) in broiler chickens. However, Ni added at a level of 500 mg/kg significantly (P < 0.05) reduced the BWG by 10% and resulted in significantly (P < 0.05) worse (2.3 +/- 0.2 kg/kg) FCE. The relative weight of the liver in cockerels was significantly (P < 0.05) decreased by Ni as compared to the control group (1.7 and 2.1% vs. 2.6%). The activity of AST and CHE enzymes was increased insignificantly by dietary supplementation of 500 mg Ni/kg, indicating damage of the liver parenchyma. The results of serum biochemistry were confirmed by a mild or moderate form of pathological focal fatty infiltration of the liver in broilers. Supplemental Ni of 50 mg/kg concentration resulted in non-significantly increased BWG in rabbits. Ni added to the diet at a level of 500 mg/kg reduced the digestibility of crude protein by 3-4% and that of crude fibre by 20-25% in rabbits. Approx. 98% of the ingested Ni was lost from the body via the faeces, 0.5-1.5% via the urine and approx. 1% was incorporated into the organs of rabbits. As a result of dietary supplementation of 50 and 500 mg Ni/kg, Ni accumulated in the kidneys (4.9 +/- 0.5 and 17.1 +/- 3.1 vs. 1.9 +/- 0.3 mg/kg DM), ribs (10.3 +/- 0.4 and 10.4 +/- 0.6 vs. 9.1 +/- 0.6 mg/kg DM), heart (1.4 +/- 0.2 and 2.5 +/- 0.4 vs. 1.0 +/- 0.1 mg/kg DM) and liver (1.3 +/- 0.1 and 2.2 +/- 0.2 vs. 0.9 +/- 0.05 mg/kg DM), as compared to the control animals. It can be stated that supplementation of the diet with 50 mg Ni/kg had slight but non-significant beneficial effects on the growth performance of broiler chickens and rabbits.     

Effect of food enzymes on AME and composition of digesta from broiler chickens fed on diets containing non-starch polysaccharides isolated from lupin kernel

1. The effects of lupin non-starch polysaccharides (NSPs) on apparent metabolisable energy (AME) and composition of digesta from broiler chickens were examined in a dose-response experiment in conjunction with a single combination of 2 commercial enzyme products known from previous studies to partially depolymerise NSPs in diets containing sorghum, casein and lupin kernel. The 7-d experiment was conducted on broiler chickens (24 to 31 d of age) in metabolism cages. 2. The basal diet used in this study contained (in g/kg) sorghum (low tannin) 800, casein 134, celite 20 and vitamins and minerals 46. The inclusion rate for each enzyme product was 0.2 g/kg. Lupin kernel isolate (containing 560 g/kg total NSPs) replaced some of the sorghum and casein. The dose rates of lupin kernel isolate (50, 100 and 150 g/kg) were equivalent to dietary inclusion rates of 80, 160 and 240 g/kg, approximately, of untreated lupin kernel from Lupinus angustifolius cultivar Gungurru. 3. Inclusion of lupin kernel isolate in the diet depressed AME and bird performance, and raised ileal viscosity and excreta moisture, in a dose-dependent manner. 4. A combination of 2 proprietary enzyme products improved dietary AME by 0.3 MJ/kg dry matter. Enzymes reduced excreta moisture when inclusion of lupin kernel isolate was 50 g/kg (equivalent to lupin kernel at 80 g/kg, approximately) but not at higher inclusions. 5. Food enzymes partially depolymerised some insoluble NSPs in lupin kernel isolate, which increased ileal viscosity and soluble NSP content of digesta. 6. It was concluded that development of appropriate exogenous enzyme products could lead to lupin NSPs being used as an energy source for poultry.     

泰乐菌素菌渣酶制剂对肉鸡饲喂效果的研究

试验选取1日龄健康AA商品代肉鸡180羽,随机分成2组,每组3个重复,每个重复30只鸡分别饲喂含0 g/kg(对照组)、3 g/kg(酶制剂组)泰乐菌素菌渣酶制剂的玉米-豆粕型日粮42 d,研究该酶制剂对肉鸡的饲喂效果。结果表明:酶制剂组肉鸡体重和饲料利用效率均显著优于对照组(P<0.05)。酶制剂能使饲料中干物质、粗蛋白质、粗脂肪、粗纤维和粗灰分的表观消化率显著提高(P<0.05),粪中大肠杆菌数和空肠内容物黏度显著降低(P<0.05)。添加酶制剂组肉鸡腹肌、肝脏、肾脏中均未检测到残留的泰乐菌素。     

Effect of dietary citric acid on the performance and mineral metabolism of broiler

The objective of this study was to investigate the effect of dietary citric acid (CA) on the performance and mineral metabolism of broiler chicks. A total of 1720 Ross PM3 broiler chicks (days old) were randomly assigned to four groups (430 in each) and reared for a period of 35 days. The diets of groups 1, 2, 3 and 4 were supplemented with 0%, 0.25%, 0.75% or 1.25% CA by weight respectively. Feed and faeces samples were collected weekly and analysed for acid insoluble ash, calcium (Ca), phosphorus (P) and magnesium (Mg). The pH was measured in feed and faeces. At the age of 28 days, 10 birds from each group were slaughtered; tibiae were collected from each bird for the determination of bone mineral density, total ash, Ca, P, Mg and bone‐breaking strength, and blood was collected for the measurement of osteocalcin, serum CrossLaps^®, Ca, P, Mg and 1,25(OH)₂Vit‐D in serum. After finishing the trial on day 37, all chicks were slaughtered by using the approved procedure. Birds that were fed CA diets were heavier (average body weights of 2030, 2079 and 2086 g in the 0.25%, 0.75% and 1.25% CA groups, respectively, relative to the control birds (1986 g). Feed conversion efficiency (weight gain in g per kg of feed intake) was also higher in birds of the CA‐fed groups (582, 595 and 587 g/kg feed intake for 0.25%, 0.75% and 1.25% CA respectively), relative to the control birds (565 g/kg feed intake). The digestibility of Ca, P and Mg increased in the CA‐fed groups, especially for the diets supplemented with 0.25% and 0.75% CA. Support for finding was also indicated in the results of the analysis of the tibia. At slaughter, the birds had higher carcass weights and higher graded carcasses in the groups that were fed the CA diets. The estimated profit margin was highest for birds fed the diet containing 0.25% CA. Birds of the 0.75% CA group were found to have the second highest estimated profit margin. Addition of CA up to a level of 1.25% of the diet increased performance, feed conversion efficiency, carcass weight and carcass quality, but only in numerical terms. The addition of CA up to 0.75% significantly increased the digestibility of macro minerals, bone ash content, bone mineral density and bone strength of the broiler chicks. It may, therefore, be concluded that the addition of 0.75% CA in a standard diet is suitable for growth, carcass traits, macromineral digestibility and bone mineral density of broiler chicks.     

Chemical composition and nutritive value of kapok seed meal for broiler chickens

1. Mechanically extracted kapok (Ceiba pentandra) seed meal (KSM) contained 324 g crude protein, 97 g ether extract, 289 g fibre, 94 g ash, 128 g available carbohydrates, 3-8 g calcium, 11 g phosphorus, 10.4 g cyclopropenoid fatty acids and 15 g tannins per kg. 2. In a 4 x 2 factorial experiment, KSM was incorporated in broiler starter and finisher feeds at 0, 30, 60 and 90 g/kg, replacing sunflower meal (SFM) w/w; without and with multi-enzyme supplementation. 3. No significant differences were noticed between treatments in body weight gain, feed consumption, feed conversion efficiency, mortality or carcase yields. 4. Multi-enzyme (amylase, endoxylanase, hemicellulase, beta-glucanase, pectinase, phytase and protease) supplementation did not improve the growth performance of broilers fed on the KSM diets.     

Prediction of ingredient quality and the effect of a combination of xylanase, amylase, protease and phytase in the diets of broiler chicks. 2. Energy and nutrient utilisation

1. In order to investigate the effects of xylanase, amylase, protease and phytase in the diets of broiler chickens containing graded concentrations of metabolisable energy (ME), two 42-d experiments were conducted using a total of 2208 broiler chicks (8 treatments with 12 replicate pens in each experiment). 2. Four diets including one positive and three negative control diets were used. Three maize/soybean meal-based negative control (NC) diets were formulated to be identical in available phosphorus (P), calcium (Ca) and amino acids but NC1 contained approximately 0.17 MJ/kg less ME than NC2 and approximately 0.34 MJ/kg less ME than NC3. A positive control (PC) was fed for comparison and was formulated to be adequate in all nutrients, providing approximately 0.63 MJ/kg ME, 0.13% available P, 0.12% Ca and 1 to 2% amino acids more than NC1. 3. The reduction in nutrient density between NC1 and PC was determined using ingredient quality models Avichecktrade mark Corn and Phychecktrade mark that can predict the response to exogenous enzymes in maize/soybean meal-based broiler diets. Supplementation of each diet with or without a cocktail of xylanase, amylase, protease and phytase gave a total of 8 dietary treatments in a 4 x 2 factorial arrangement. The same treatments and diet designs were used in both experiments but conducted in different locations using different batches of maize, soybean meal and minor ingredients. 4. In both experiments, digestibility was improved by the addition of exogenous enzymes, particularly those for P, Ca and certain amino acids. In addition, the supplementation of the PC with enzymes elicited a positive response indicating that over-the-top addition of xylanase, amylase, protease and phytase may offer a nutritionally and economically viable alternative to feed cost reduction. 5. It can be concluded that the digestibility of nutrients by broilers fed on maize/soybean meal-based diets can be improved by the use of a combination of xylanase, amylase, protease and phytase.     

Effect of wet feeding on growth performance of broiler chickens in a hot climate

1. The Guinea Savanna in the tropics is characterised by high diurnal temperatures, often beyond the thermo-neutral zone of modern poultry, which imposes heat stress on them. 2. An experiment was conducted to determine the effect of partially (12 h wet mash in the day and 12 h dry mash in the night) or wholly (24 h) feeding wet mash on the growth performance of broiler chickens. 3. Three treatments: dry mash (control), wet mash (day) + dry mash (night) and wet mash (day + night) were tested. At 28 d of age, a total of 120 broiler chickens (Hybro, Netherlands) were randomly divided, using a completely randomised design, into 12 groups of 10 birds, each with mean live weight of approximately 800 g/bird. A maize-soybean based grower mash (200 g CP/kg and 12·5 MJ/kg ME) was fed. The wet mash was prepared daily by addition of 1·3 parts of water to 1 part of dry mash and fed from 28 to 56 d of age. The birds were housed in raised-floor pens. Feed and water were given ad libitum and light provided 24 h. Mean daily room temperature was 28-29°C in the morning and 35-41°C in the afternoon. 4. Mean feed intake of birds fed the wet mash (174 g/day) or wet + dry mash (166 g/day) was higher than that of birds fed the dry mash (152 g/day). Mean live weight gain of birds fed the wet mash (64 g/day) or wet + dry mash (64 g/day) was higher than that of birds fed the dry mash (58 g/day). There were no differences in gain/feed ratios (0·38-0·39) of any of the treatments, neither were there any differences between the feeding of wet mash partly or wholly for all variables. 5. It was concluded that wet feeding, particularly during day-time, had the potential to improve growth performance of broiler chickens in a hot climate.     

The effects of supplementary bacterial phytase on dietary true metabolisable energy, nutrient digestibility and endogenous losses in precision fed turkeys

1. A total of 40 female BUT9 turkeys were used in a precision-feeding assay to investigate the effect of dietary phytase on true metabolisable energy corrected for N retention (TME(N)), coefficients of true dry matter (TDMD), mineral, amino acid and nitrogen (TND) digestibilities and the excretion of endogenous mucin, measured as sialic acid (SA). 2. Five treatments were used in this study: control (C), C + 250 phytase units (FTU) per kg feed, C + 500 FTU, C + 2500 FTU, and glucose only for endogenous losses estimation. Diets were formulated to be nutritionally adequate with the exception that the P content was relatively low (3·6 g/kg non-phytate P). 3. Inclusion of phytase increased TND in a quadratic manner with the optimum being achieved at approximately 500 FTU, at which TND was 37 % greater than in the control. The concentration of SA in the excreta decreased linearly with increased phytase supplementation. Dietary TME(N), TDMD and true mineral digestibility coefficients were not significantly affected by phytase supplementation. 4. Phytase inclusion increased digestibility coefficients for indispensable, dispensable and total amino acids in a linear manner. The scale of the response to phytase was greatest with threonine and least with lysine digestibility, suggesting a specific mechanism of action that benefits gut health. 5. The strong negative relationship between secretion of SA and threonine digestibility suggests that a large part of the threonine benefit may be from reduced mucin synthesis. This supports the hypothesis that dietary phytase may play a role in improving the health status of the intestine and, as a result, reduces the maintenance energy requirements of turkeys.     

Physiological and health‐related response of broiler chickens fed diets containing raw,full‐fat soya bean meal supplemented with microbial protease

A 2 × 3 factorial study (protease: 0 or 1,5000 PROT/kg and raw full‐fat soya bean meal [RSBM] replacing the commercial SBM at 0, 45 and 75 g/kg of diet) was conducted to examine the performance of broilers. Phytase (2000 FYT/kg) was uniformly added to each diet, each also replicated six times, with eight birds per replicate. Birds were raised in climate‐controlled rooms using sawdust as the bedding material and offered starter, grower and finisher diets. Feed intake (FI) and body weight gain (BWG) were reduced (p < .05) due to increasing levels of RSBM, but feed conversion ratio (FCR; 0–35 days) was unaffected. Over the first 24 days, neither RSBM nor protease supplementation affected (p > .05) mortality, footpad dermatitis or intestinal lesions in birds. At day 24, the weight, length, width and strength of tibia bone were reduced in chickens that received an elevated level of RSBM (75 g/kg of diet), but this was not significant at day 35. At day 24 (p < .05) and 35 (p < .01), Ca concentration in the litter was reduced when the RSBM level was increased in the diet, but P content was not affected. On days 24 (p < .05) and 35 (p < .01), the N content in litter was also increased with increase in dietary RSBM. Protease supplementation increased (p < .05) the uric acid concentration in the litter (at day 35), but the reverse was the case for ammonia concentration. Overall, the results of this study indicate that there are no major health‐related risks, associated with the replacement of commercial SBM with RSBM (≤25%) in broiler diets.     

复合酶对临武鸭几种饼粕饲料原料养分利用率和代谢能的影响

本试验旨在研究复合酶(蛋白酶、纤维素酶和木聚糖酶)对临武鸭几种饼粕饲料原料(大豆粕、大豆渣、棉籽粕、2种菜籽粕、花生仁粕、2种芝麻粕)养分利用率和代谢能的影响。试验选用48只体重2.0 kg左右的健康成年临武鸭公鸭,随机分为6组,每组8个重复,每个重复1只鸭。采用绝食强饲-全收粪法进行3个批次代谢试验,每种原料均设对照组和添加复合酶组(试验原料中添加250 mg/kg的复合酶),对每只试验鸭强饲60 g试验原料,内源组强饲60 g无氮饲粮。测定添加复合酶条件下,临武鸭对8个饼粕饲料原料的表观代谢能(AME)、真代谢能(TME)及干物质(DM)、粗蛋白质(CP)、粗脂肪(EE)和粗纤维(CF)表观利用率和真可利用率。结果表明:临武鸭对8个饼粕类原料的DM、CP、EE和CF表观利用率分别为38.85%~62.86%、50.73%~65.39%、50.16%~74.50%和32.32%~46.46%,AM E和TM E分别为6.82~12.72 M J/kg,8.79~14.69 M J/kg,添加复合酶使临武鸭对几种饼粕饲料原料的DM、CP、EE和CF的有效营养改进值(ENIV)分别为6.25~21.70 g/kg、2.60~16.73 g/kg、0.13~8.66 g/kg和0.66~2.74 g/kg,TM E提高了0.19~1.15 M J/kg。由此可知,添加复合酶能够一定程度地提高临武鸭对饼粕饲料原料的养分利用率和代谢能。     

Nutritional evaluation of high-digestible sorghum for pigs and broiler chicks

Two experiments were conducted to evaluate the nutritional quality of 2 varieties of Purdue high-digestible sorghum (PHD1 and PHD2) and a normal sorghum, compared with corn, in diets of pigs and broiler chicks. In Exp. 1, 12 pigs (average BW, 55 kg) fitted with ileal T-cannula were fed 4 diets containing 946 g of corn or sorghum (PHD1, PHD2, and normal) per kg in a 2-period crossover design (i.e., each pig received 2 diets over a 2-wk period with 6 pigs per dietary treatment) to determine apparent ileal or total tract digestibility of nutrients and energy. There was no difference in the ileal or total tract digestibility of DM, energy, P, Ca, or N among dietary treatments. In Exp. 2, a total of 192 broiler chicks were grouped by weight into 8 blocks of 4 cages each with 6 chicks per cage, and cages were assigned randomly to 1 of the 4 dietary treatments within each block. Chicks were fed corn-soybean meal (SBM) or sorghum-SBM diets for 21 d to determine apparent total tract retention and then switched to diets containing 935 g of the corresponding corn or 1 of the 3 sorghum varieties per kg for 7 d to determine apparent ileal digestibility and total tract retention. Apparent ileal digestibilities of DM and P, as well as energy, were not different in chicks fed diets containing 935 g of corn or 1 of the 3 sorghum varieties per kg. However, apparent total tract retention of DM, energy, and N in chicks fed corn was greater (P < 0.05) than those fed 1 of the 3 sorghum varieties. Although the apparent ME content of corn was greater than PHD1 and normal sorghum (P < 0.01), it was not different from PHD2 sorghum. There was no difference in apparent total tract retention of DM between chicks fed the corn-SBM and PHD-SBM diets, but it was greater (P < 0.05) in chicks fed the corn-SBM diet than those fed the normal sorghum-SBM diet. Apparent total tract retention of N in chicks fed the PHD1-SBM diet was lower (P < 0.05) than in those fed the corn-SBM diet but greater (P < 0.05) than in chicks fed the normal sorghum-SBM meal diet. No difference in the apparent ME content between the corn-SBM and PHD2-SBM diets was observed, but it was greater (P < 0.05) for the corn-SBM diet than the PHD1- or normal sorghum-SBM diet. Weight gain, feed intake, and feed efficiency were not different in chicks fed the corn-SBM or sorghum-SBM diets. Sorghum could serve as a substitute for corn in cereal grain-SBM diets for pigs and broiler chicks.     

葡萄糖处理豆粕对蛋白质保护效果的研究

以3头装有永久性瘤胃瘘管的中国荷斯坦奶牛为试验动物,采用尼龙袋法研究分别添加0、1%、3%、5%、7%、9%葡萄糖保护豆粕,对奶牛瘤胃内不同时间点DM、CP消失率及其动态降解率的作用效果。结果表明:在不同时间点下,提高葡萄糖添加量可使DM、CP消失率逐渐降低,所有试验组与未处理组差异均极显著(P<0.01),DM、CP有效降解率降低最高分别达28.78%和24.82%,不同添加量下,添加量为7%、9%的2组组间差异不显著(P>0.05)。本试验结果证明,葡萄糖加热处理是一种有效保护豆粕蛋白质的方法,且葡萄糖的适宜添加水平为7%。     

Lack of relationship between either specific weight or presence of the 1B1R gene and nutritive value of wheat in broiler diets

1. A study of the relationship between specific weight (SW) and nutritive value of wheat in diets offered to broilers up to 4 weeks of age was carried out using 10 varieties of wheat grown at three different locations; this gave rise to a range of specific weights from 59 to 76 kg/hl. 2. Because five varieties contained the 1B1R translocation and 5 did not, this allowed the effects of 1B1R on the performance of birds given high concentrations of dietary wheat to be further investigated. 3. The diets, which contained wheat at 744 g/kg with casein (142 g/kg) as the sole protein supplement, were heat-treated and pelleted. They were fed ad libitum to male, Ross broiler chicks from 7 to 28 d, in individual cages in a controlled environment room. 4. A 7 d excreta collection was made from 14 to 21 d for determination of apparent metabolisable energy (AME) content and wheat AME was calculated from the diet values. A separate determination of true metabolisable energy (TME) was undertaken using the method of McNab and Blair (British Poultry Science, 29: 697-707, 1988). 5. Wheat samples were analysed for proximate constituents, starch, total and soluble non-starch polysaccharides (NSP), amino acid content and gross energy and specific weight, thousand grain weight and in vitro viscosity were recorded. They were also subjected to near infrared reflectance spectroscopy (NIRS) with a view to establishing relationships with chemical constituents and performance parameters. 6. At 28 d the birds were humanely killed and in vivo viscosity was determined on the jejunal digesta supernatant. 7. There was quite a narrow range of crude protein content (N x 5.83) across the 30 wheat samples, the means for the three locations (Crossnacreevy, Downpatrick and Limavady, respectively) being 112, 121 and 122 g/kg. Starch contents of individual samples ranged from 604 to 679 g/kg, total NSP from 92.1 to 122.6 g/kg, soluble NSP from 17.6 to 32.6 g/kg and in vitro viscosity from 10.6 to 26.3 cps. 8. There were no significant varietal effects for dry matter intake (DMI), live weight gain (LWG) or gain:feed ratio. Apparent metabolisability of energy (ME:GE) for the diets ranged from 0.738 (Hussar) to 0.778 (Harrier) the effect being significant (P < 0.05) and there was a significant (P < 0.001) relationship (r(2) = 0.46) between ME:GE and gain:feed ratios. Calculated wheat AME for individual varieties ranged from 14.1 to 15.0 MJ/kg DM (P > 0.05). TME values ranged from 16.3 to 16.6 MJ/kg DM (NS). 9. In vivo viscosity ranged from 12.3 (Ritmo) to 23.7 cps (Hussar), the varietal effects being significant (P < 0.001). Viscosity was significantly higher for the 1B1R varieties than for the non-1B1R (22.7 vs 16.3 cps) but there were no significant effects on mean DM intake, LWG, gain:feed, ME:GE, calculated wheat AME, ME:gain (MJ AME per kg gain) or TME. 10. Wheat AME was negatively correlated (P < 0.05) with total NSP (slope -0.035) but was significantly affected by variety, constants ranging from 16.74 to 17.79. For wheat TME there were significant variety*total NSP interactions with slopes ranging from 0.29 to -0.07. There was no significant relationship between wheat AME and soluble NSP and there were significant variety*soluble NSP interactions for TME with slopes ranging from 0.09 to -0.14. 11. Despite the relatively wide range of in vitro viscosity there was no significant correlation of either calculated wheat AME or wheat TME with in vitro viscosity. For TME there were significant variety*viscosity interactions with slopes ranging from 0.21 to -0.13 (P < 0.001). There was also no significant correlation between soluble NSP and in vivo viscosity. 12. AME values for the NIRS calibration set varied from 13.7 to 15.6 MJ/kg and averaged 14.6 MJ/kg, whereas for the validation set, the values ranged from 14.0 to 16.1 MJ/kg with the mean value being 14.7 MJ/kg. The best correlation coefficient (r(2)) of 0.90 was obtained when the calibration sample set was subjected to SMLR using the second-order derivatised data. However, moving to validation, the outcome was extremely poor with 1-VR values being 0.12 and 0.09, respectively, for the external validation and an internal validation subset. 13. In summary, none of the production characteristics showed a good correlation with specific weight. Using the linear estimates for wheat AME and TME the effect of a 10 kg/hl change in SW equates to a 3 or 1.4% change, respectively. The estimate for AME is likely to be a worst-case value due to the high inclusion level of wheat. The range of calculated wheat AME (approximately 1 MJ) across the 30 wheat samples is similar to that seen in previous studies for wheat grown in Northern Ireland and much lower than in some other studies. 14. None of the other parameters examined gave any better relationship with nutritive value (assessed as AME or TME) than SW. This is a disappointing outcome, particularly in view of some previous studies which suggested that in vitro viscosity provides a good prediction of nutritive value.     

Impact of dietary chitosan oligosaccharide and its effects on coccidia challenge in broiler chickens

ABSTRACT

1. Two experiments were conducted, the first to determine the optimum inclusion of chitosan oligosaccharide (COS) in broiler diets to support growth performance, digestive functions, intestinal morphology, and immune organs. The second experiment evaluated the immune-protective properties of COS on broiler chickens during coccidia challenge (CC).

2. Experiment 1 investigated the effect of graded dietary concentration of COS in the diets of broiler chickens using eight cage replicates for each of the six diets. A corn-soybean meal-based diet was used as the basal diet and supplemented with 0.0, 0.5, 1.0, 1.5, 2.0, or 2.5 g of COS/kg feed to form the six treatments.

3. The diet supplemented with 1.0 g COS/kg of feed provided the optimal inclusion level for broiler chickens regarding body weight (BW) gain, jejunal villus height, villus height to crypt depth ratio, and ileal energy digestibility at d 22 of age.

4. Experiment 2 investigated the immune-protective properties of COS in broiler chickens during CC. A total of 224 male broiler chicks were randomly assigned to eight replicate cages in a 2 × 2 factorial arrangement of treatments with two COS concentrations (0 or 1 g of COS/kg of diet), with or without CC.

5. On d 18 of age, birds in the CC group received twice the recommended coccidia vaccine dose of 30 doses/kg BW.

6. Coccidia challenge reduced (P < 0.05) and dietary COS increased (P < 0.05) BW gain, and feed intake. Dietary COS mitigated (P < 0.05) the CC-induced effects on gain:feed. Dietary COS supplementation attenuated the CC-induced effects (P < 0.05) on the expression of occludin genes.

7. In conclusion, dietary COS improved performance, and the immune-related beneficial impact of COS supplementation was associated with reduced expression of pro-inflammatory cytokine genes.