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1.
ABSTRACT1. This study was conducted to assess the effects of graded levels of dietary corn resistant starch (RS) on growth performance, carcass traits, nutrient retention, digestive organ index, intestinal morphology, digestive enzyme activities, and mRNA expression of certain nutrient transporters in broiler chickens.2. A total of 320, 1-d-old Arbor Acres broiler chickens were randomly assigned to five dietary treatments, with eight replicates of eight birds in each. These treatments included one corn-soybean control diet, a corn-soybean based diet containing 20% corn starch, and three diets supplemented with 4%, 8% and 12% RS by replacing corn starch with 6.67%, 13.33% and 20% of Hi-Maize 260® (identified as control, RS1, RS2, RS3 and RS4, respectively). The feeding period lasted 42 days.3. Performance parameters including feed consumption, feed conversion, body weight gain and percentage of abdominal fat at d 42 of age, nutrient retention (including dry matter, fat, total starch and nitrogen free extract), and apparent metabolisable energy was measured from d 18 to 20 and d 39 to 41 and showed negative linear responses to increasing dietary RS level (P < 0.05). Birds fed the RS3 and RS4 diets showed higher relative weight of duodenum, jejunum and ileum, as well as lower villus height and villus height/crypt depth compared to the control (P < 0.05). The activity of pancreatic trypsin of birds at d 21 and 42 of age decreased linearly in response to the increase of dietary RS level (P < 0.01). There were linear changes in up-regulated mRNA expression of SGLT-1 and down-regulated mRNA expression of GLUT-2 with increasing proportion of RS at d 21 and 42 of age (P < 0.05), respectively.4. It was concluded that feeding broilers with diets containing higher concentrations of RS impaired the development of small intestine, which resulted in lower apparent total tract retention of nutrients and poorer body weight gain, feed efficiency and carcass traits of broiler chickens. 相似文献
2.
ABSTRACT 1. A 21-d experiment was conducted to investigate the effect of graded inclusions of waxy starch hull-less (WSHL) barley and a multi-component exogenous carbohydrase on the growth performance, nutrient digestibility and intestinal morphometry of broiler chickens. Five levels of WSHL barley inclusion (0, 65, 130, 195 and 260 g/kg) in a wheat-based diet, and two levels of enzyme supplementation (0 and 150 g/tonne of feed) were evaluated in a 5 × 2 factorial arrangement of 10 dietary treatments. All diets were equivalent in metabolisable energy and digestible amino acid content. A total of 400, one-d-old male broilers (five cages/treatment; eight birds/cage) were used in the experiment. 2. Regardless of enzyme supplementation, feed intake declined (P < 0.001) with increasing inclusion of WSHL barley. Increasing levels of WSHL barley (P < 0.001) and supplemental enzyme (P < 0.01) increased gain to feed ratio. 3. Birds fed diets with 0 g/kg WSHL barley showed the lowest (P < 0.001 to 0.01) digestibility for all nutrients except starch. Only starch digestibility was improved (P < 0.05) by enzyme supplementation. The nitrogen-corrected apparent metabolisable energy improved with increasing inclusion of WSHL barley (P < 0.001) and supplemental enzyme (P < 0.001). Increasing inclusion of WSHL barley increased the relative weight of gizzard (P < 0.001) and reduced jejunal digesta viscosity (P < 0.01). Supplemental enzyme (P < 0.001) reduced digesta viscosity. 4. All levels of WSHL barley inclusion improved digestibility of dry matter, nitrogen and fat, whilst energy utilisation improved at inclusions of 130 g/kg WSHL and above, probably due to lowered digesta viscosity and better development of the gizzard. Gain to feed ratio, starch digestibility, energy utilisation and jejunal digesta viscosity can benefit from carbohydrase supplementation in wheat-based diets, regardless of barley inclusion level. 相似文献
3.
ABSTRACT 1. The present study examined the potential of new-generation microbial enzymes to improve the utilisation of energy and protein of cottonseed meal (CSM)-containing diets, with the aim of increasing its inclusion level in broiler chickens diets. 2. Four hundred and eighty, one-day-old Ross 308 male broilers were used to assess the utilisation of energy and protein by broiler chickens fed diets containing four graded levels of CSM – none, low (4, 8, 12%), medium (5, 10, 15%) or high (6, 12, 18%) in the starter, grower, and finisher phases, respectively, supplemented with 100 mg/kg of a composite enzyme product (xylanase and β-glucanase). 3. Inclusion of CSM improved (P < 0.01) apparent metabolisable energy (AME), with further improvement (P < 0.001) seen in the enzyme-supplemented diets. Inclusion of CSM reduced (P = 0.002) the metabolisable energy intake (MEI), but this was increased (P < 0.05) with enzyme supplementation. 4. Enzyme addition increased (P < 0.001) the net energy of production (NEp), while heat production (HP) decreased (P < 0.001) with CSM inclusion. More energy was retained as fat (P < 0.05) and protein in birds fed diets with the enzyme, but this was reduced (P < 0.029) by CSM. 5. There was an increase (P < 0.05) in efficiencies of ME use for energy, lipid and protein retention, with higher CSM levels. The enzyme improved (P < 0.013) efficiency of ME use for lipid retention. 6. Feeding diets containing CSM to the broilers enhanced (P < 0.05) protein intake (PI) and protein efficiency ratio (PER). Positive effects (P < 0.05) of enzyme were observed on protein gain (PG) and net protein utilisation (NPU). 7. Results obtained from this study suggested that nutrient utilisation of diets containing CSM by broiler chickens can be improved by enzyme supplementation. 相似文献
4.
ABSTRACT1. The objective of this study was to investigate the effect of supplementing broiler diets with xylanase or xylo- oligosaccharide (XOS) on growth performance, the concentration of non-starch polysaccharide (NSP) hydrolysis products in the ileum and concentration of short chain fatty acids (SCFA) in the caeca of broiler chickens.2. In total, 500 male Ross 308 broilers were used in this 29-day (d) study. The treatments were organised into a 2 × 2 plus 1 factorial arrangement consisting of two additives (xylanase or XOS) at two levels (low or high) plus a control treatment with no additives. This gave five treatments with 100 birds in each treatment group. The diets were slightly deficient in protein by 20 g/kg and energy by 1 MJ/kg.3. On d 14 and 28, two birds per pen were euthanised, the caeca content collected and analysed for short chain fatty acid (SCFA) concentration. On d 29, six birds per pen were euthanised and ileal digesta were collected and analysed for the concentration of NSP fractions.4. On d 14, caecal acetic acid, iso-butyric acid, iso-valeric acid, n-valeric acid and total SCFA concentrations were significantly greater (P ≤ 0.05) when diets were supplemented with XOS compared with xylanase.5. Ileal concentration of arabinose, galactose and glucuronic acid (GlucA2) were significantly greater (P ≤ 0.05) in the insoluble NSP fraction when diets were supplemented with a high level of xylanase, compared with the control treatment. Ileal concentration of fructose was significantly greater (P ≤ 0.05) in the water soluble NSP when a high level of xylanase or low level of XOS were included in the diet compared with the control.6. It was concluded that xylanase and XOS had similar effects on NSP concentration and SCFA in the caeca, although there was little effect on performance. This observation demonstrated further benefits of xylanase supplementation in wheat-based broiler diets beyond digesta viscosity reduction and the release of extra nutrients. 相似文献
5.
ABSTRACT1. 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. 相似文献
6.
ABSTRACT 1. Two consecutive trials were conducted to evaluate the effects of guanidinoacetic acid (GAA) supplementation (a creatine precursor) and energy levels in broiler diets based on maize-soybean meal (Trial 1) or that additionally included poultry by-product meal (PBPM; Trial 2) on growth performance, carcass yield and breast meat quality to 41 days of age. 2. A total of 792, one-day-old male Ross 308 broiler chickens were randomly distributed into six treatments – three energy levels (sufficient AME n or 0.2 and 0.4 MJ/kg reduced AME n) and two GAA levels (0.00% or 0.06%) with eight replicates for each trial. 3. Reducing dietary energy resulted in poorer body weight gain (BWG) and feed conversion ratios (FCR) for each trial (P < 0.05). However, GAA supplementation improved FCR, BWG and European Production Efficiency Factor (EPEF) (P < 0.05). 4. Dietary energy level and GAA addition had no significant effect on carcass parameters, drip loss, pH and chemical composition of breast meat (P > 0.05), but decreased relative liver weight (P < 0.05). 5. It was concluded that, regardless of dietary energy levels, supplementation of GAA to plant-based diets or those including PBPM has the potential to improve growth performance in broilers. 相似文献
7.
A study was conducted to determine the effects of feeding dried broccoli floret residues on growth performance, apparent ileal digestibility ( AID) and apparent total tract nutrient digestibility ( ATTD) coefficients, and intestinal microbial populations in broiler chickens. One thousand two hundred day-old male Ross 508 broilers were randomly allotted to 4 dietary treatments and were grown over a 35-d experimental period. Dietary treatments included 4 levels of dried broccoli floret residues: 0, 3, 6, and 9%. Results showed that inclusion of dried broccoli floret residues increased body weight gain (quadratic effect, P = 0.004) and feed conversion ratio (quadratic effect, P = 0.002) with no effect on feed intake. Apparent ileal crude protein ( CP, quadratic effect, P = 0.003) and dry matter ( DM, quadratic effect, P = 0.002) digestibility for younger birds (25 d of age) increased as the level of dried broccoli floret residues in the diet increased. However, apparent ileal CP (linear effect, P = 0.022), DM (linear effect, P = <0.001) and gross energy (linear effect, P = 0.001) digestibility for older birds (35 d of age) decreased as a result of dried broccoli residue inclusion. Nitrogen ( N) corrected apparent metabolizable energy decreased (linear effect, P < 0.001) as the level of dried broccoli floret residues in the diet increased. However, N retention was not influenced by dried broccoli floret residue inclusion. It was concluded that incorporation of dried broccoli floret residues in broiler diet at moderate levels (i.e., 3 to 6%) may improve the growth of broiler chickens with no detrimental effects on nutrient digestibility and retention. However, at high levels (i.e., 9%), dietary dried broccoli floret residues may compromise ileal and total tract nutrient digestibility. 相似文献
8.
ABSTRACT1. Two separate experiments were conducted to evaluate the efficacy of either prebiotic or synbiotic on growth performance, carcass yield, organ weights, and serum metabolic profile of broilers under hot climatic conditions.2. In experiment 1, 150 1-d-old Ross 308 male broiler chickens were fed dietary synbiotic (Biomin® IMBO, 0, 1 or 1.5 g kg ?1 of the starter diets and 0, 0.5 or 0.75 g kg ?1 of the grower diets) for 6 weeks. In experiment 2, 150 1-d-old Ross 308 male broiler chickens were fed dietary prebiotic (Mannan oligosaccharide 0, 0.5 or 1 g kg ?1 of the starter diets and 0, 0.25 or 0.5 g kg ?1 of the grower diets) for 6 weeks. Each treatment had 10 replicates containing 5 broiler chickens each.3. Supplementation of synbiotic at 1 or 1.5 g kg ?1 feed to broiler diets during 1–21 d and 0.5 or 0.75 g kg ?1 feed, respectively, during 22–42 d improved (P < 0.01) body weight gain, feed conversion ratio (FCR), and decreased (P < 0.01) abdominal fat, serum total cholesterol, and low-density lipoprotein (LDL) cholesterol levels in experiment 1.4. Similarly, supplementation of the prebiotic at 0.5 or 1 g kg ?1 in broiler diets during 1–21 d and 0.25 or 0.50 g kg ?1 feed, respectively, during 22–42 d improved (P < 0.01) body weight gain, FCR, and decreased (P < 0.01) abdominal fat, serum cholesterol, and LDL-cholesterol levels in experiment 2. 相似文献
9.
1. The current study was conducted to investigate the effect of high phytase doses on growth performance and real-time gastric pH measurements in broiler chickens and pigs.2. In the first experiment, 576 male Ross 308 broilers were fed in two phases (0–21 and 21–42 d) with 4 treatment groups, with diets meeting nutrient requirements containing 0, 500, 1500 or 2500 FTU/kg phytase. In the second, 64 Landrace weaners were fed on diets meeting nutrient requirements with or without phytase (0 or 2500 FTU/kg) in two phases (0–21 and 21–42 d). Heidelberg pH capsules were administered to 7 broilers and approximately 13 pigs per treatment group, pre- and post-phase change, with readings monitored over several hours.3. Addition of phytase into an adequate Ca and P diet had no significant effect on broiler performance although phytase tended ( P < 0.07) to improve feed conversion in pigs over the entire experimental period. Real-time pH capsule readings in broilers demonstrated an increase ( P < 0.05) in gizzard pH when phytase was dosed at 500 or 1500 FTU/kg, while higher doses of 2500 FTU/kg phytase lowered pH to a level comparable to control birds. Gastric pH increased ( P < 0.01) when animals were exposed to dietary phase change, signifying a potential challenge period for nutrient digestibility. However, pigs fed 2500 FTU/kg were able to maintain gastric pH levels through diet phase change. In contrast, spear-tip probe measurements showed no treatment effect on gastric pH.4. These findings demonstrate dietary manipulation of gastric pH and the value of real-time pH capsule technology as a means of determining phytase dose response. 相似文献
10.
Growing male Cobb broiler chickens were fed on diets supplemented with additives reported as able to influence intestinal microbiota composition. The diets used were a balanced commercial diet (no additive), inulin (20 g/kg), fructose caramel (FC, 20 g/kg) and the garlic derivative PTS‐O (propyl propane thiosulfonate, 45 and 90 mg/kg diet). The composition of the intestinal microbiota was analysed by qPCR at different points of the intestinal tract, and a number of nutritional parameters were also determined. The relative amounts of bacteroides (bacteroides/total bacteria) in the ileal contents correlated (p < 0.05) positively with faecal NDF, ADF, hemicellulose and cellulose digestibility. The relative amounts of Escherichia–Shigella ( Escherichia–Shigella/total bacteria) in the crop contents correlated (p = 0.05) negatively with weight gain of broilers. Faecal N digestibility correlated (p < 0.05) negatively with total bacteria in the ileal contents of chickens. The relative amounts of Escherichia–Shigella ( Escherichia–Shigella/total bacteria) in the caecal contents correlated (p = 0.05) negatively with faecal fat digestibility of broilers. Total bacteria in ileal or caecal contents of growing chickens correlated (p < 0.05) negatively with ileal N digestibility. The results here reported suggest that positive or negative correlations can be found between performance parameters and changes in intestinal microbiota composition of growing broiler chickens. 相似文献
11.
A 4 × 2 factorial experiment was conducted to study the effect of feeding diets-containing dietary fibre (DF) sources and a source of bile acid (BA) on growth performance and lipid metabolism. In addition, in vitro BA-binding capacity of fibre sources was investigated. A total of 256 one-d-old male broiler chickens (Ross 308) were assigned to DF sources [maize-soybean meal (control, C), or 30 g/kg of wheat bran (WB), barley bran (BB) or soybean hulls (SH)] and BA (with or without 1.5 g Na-deoxycholate/kg). Each treatment was replicated 4 times with 8 broiler chickens per cage. The highest in vitro BA-binding capacity was observed with BB (8.76 mg/g BB). From 0 to 21 d, with the addition of BA, the average daily feed intake (ADFI) decreased in broiler chickens fed on the C, WB or BB diets, while there was no difference with the SH diet. With added BA, the average daily gain decreased in broiler chickens fed on the C or SH diets, but it did not change in those fed on the other diets. The addition of BA decreased feed conversion ratio (FCR) in broiler chickens fed on the BB or WB diets, but it increased in those fed on the C or SH diets. Interaction results indicated that the apparent ileal digestibility of lipid increased in broiler chickens fed the C and other DF diets with BA compared to those fed the diets without BA. The addition of BA decreased the pancreas lipase activity (PLA) in broiler chickens fed on the C diet compared to those fed the C diet without BA, while no changes observed in those fed the DF diets with or without BA. No interaction was observed in total liver bile acid (TLBA). The WB, BB and SH with little Na-deoxycholate-binding capacity (<10 mg/g of DF) under in vitro conditions had particular effects with BA on the measured criteria in broiler chickens. The magnitude of improvement in digestibility of lipid with the addition of BA depends on the source of fibre used and the addition of BA in DF diets had little effect on growth performance in young broiler chicken diets.
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12.
ABSTRACT1. The aim of this study was to evaluate the effects of phytase and xylanase and their interaction on laying hen performance, egg quality, phosphorus (P) digestibility, phytate breakdown, volatile fatty acid (VFA) production and peptide YY concentration.2. Two hundred and forty hens were allocated to cages at 22 weeks of age based on a 3 × 2 arrangement with phytase (0, 300 or 1500 FTU/kg) and xylanase (0 or 12 000 BXU/kg) as factors.3. Phytase increased hen-day production ( P < 0.05), daily egg mass ( P < 0.05) and P digestibility with increasing levels of phytase ( P < 0.001). Phytase fed at 1500 FTU/kg reduced IP6 and IP5 and increased myo-inositol concentration in gizzard digesta ( P < 0.05). Phytase fed at 300 FTU/kg reduced IP6 in ileal digesta ( P < 0.05); however, IP6 and IP5 were further reduced and myo-inositol increased when phytase was added at 1500 FTU/kg ( P < 0.05).4. Xylanase improved feed efficiency when phytase was fed at 300 FTU/kg ( P < 0.05). In the absence of phytase, xylanase reduced dry matter and Ca digestibilities ( P < 0.05).5. Neither phytase nor xylanase had an effect on peptide YY or caecal VFA concentrations. 相似文献
13.
1. The present study was designed to evaluate purified bee venom (BV) as an alternative to antibiotics in broiler chickens. The experimental treatment diets were formulated by adding BV into a maize-soybean meal-based diet to give 0, 10, 50, 100, and 500 μg BV per kg of diet. 2. Dietary BV quadratically improved (P < 0.05) feed conversion ratio and increased body weight gain at 1–21 d as level in diet increased. Higher BV levels lowered relative weight of spleen (linear and quadratic, P < 0.05), bursa of Fabricius (quadratic, P < 0.05), and liver (linear and quadratic, P < 0.05) at 21 d of age. Relative breast meat yields were increased quadratically at 21 d and linearly at 35 d with supplementation levels. Dietary BV increased (linear and quadratic, P < 0.05) lightness (L*) value for meat at 21 d, decreased (linear, P < 0.05) ileal villus height and narrowed (quadratic, P < 0.05) width. 3. Dietary BV inclusion linearly increased the concentration of secretory immunoglobulin A (sIgA) on ileal mucosa at 21 d and decreased (quadratic, P < 0.05) nitric oxide contents in serum samples at 21 d and 35 d. Total short-chain fatty acids (SCFA) in caecal digesta were reduced with increasing venom in diets at 21 d of age. None of the serum parameters except for creatinine was affected by dietary BV. 4. It was concluded that dietary BV exhibited wide range of in vivo biological properties in broiler chickens and could be incorporated into feed to promote growth and animal health. 相似文献
14.
ABSTRACT 1. This study investigated the nutritional value (digestibility of ileal crude protein and amino acids (AAs)) and the AME N value of legumes (pea, faba bean, yellow lupin, and narrow-leaved lupin) with or without protease. 2. Two hundred, one-day-old, male Ross 308 broiler chickens were randomly allocated to ten groups. Each group received one of five different protein raw materials – either peas, faba beans, yellow lupins or narrow-leaved lupins, with or without protease produced from Bacillus licheniformis. The birds were kept in individual cages. Nutrient digestibility was calculated using the difference method. The total duration of the study was 23 d, and the study involved two phases – accommodation phase (d 1–18) and experimental phase (d 18–23). 3. The effect of protease on response traits was not consistent between the legumes. The enzyme increased the digestibility of some AAs in the pea (arginine, leucine, phenylalanine, histidine, tyrosine, alanine, and proline), faba bean (lysine, arginine, glycine, and asparagine), and yellow lupin diets (lysine, valine, and serine), but this effect was not observed in the narrow-leaved lupin diet. The change in AME N values due to protease addition was only statistically significant for the pea diet (P < 0.05), whereas in the case of other legume species, the difference was insignificant (P > 0.05). 4. Exogenous protease increased the digestibility of AAs present in pea, faba bean, and yellow lupin seeds but not in narrow-leaved lupin diets. The AME N value of peas increased with protease supplementation, but no effect of protease was found for the AME N values of faba bean and both the lupin diets. 相似文献
15.
1. The objective of this study was to investigate the effects of cold‐pelleting, the length of the fasting period before feeding of the test diet and the nature of die test diet on apparent ileal nitrogen (N) digestibility in the broiler chicken. 2. Four‐week‐old broiler chickens were given a pelleted or non‐pelleted maize/soyabean meal (basal) diet. The birds were starved for 24 h, given a single test meal (25 g) by intubation and killed 4 h after the start of feeding by administration of a barbiturate, to allow sampling of ileal digesta (terminal 15 cm). Cold‐pelleting did not affect apparent ileal N digestibility. 3. Four‐week‐old broiler chickens were fasted for 12 or 24 h and then received a test meal (1 h free access) of either a pelleted soyabean meal or a pelleted meat‐and‐bone meal diet or were continuously fed on one of the two diets. The imposition of a fast did not affect apparent ileal N digestibility. However, a 24 h fasting procedure was preferred, as the between animal variation for apparent ileal N digestibility was lower than for the 12 h fast or for continuous feeding. 4. Four‐week‐old broiler chickens were given either semi‐synthetic starch‐based diets containing maize, wheat bran, meat‐and‐bone meal or fish meal as the sole sources of protein or each of these diets in combination with the basal diet (50:50 on a dry matter basis). With the exception of the maize diet, the apparent ileal N digestibility values calculated by correcting for the digestibility of the basal dietary component were significantly lower than when digestibility was determined directly using a diet in which the respective proteins were the sole protein source. This implies that interactions between the dietary ingredients influence estimates of apparent ileal N digestibility. 相似文献
16.
1. A study was conducted to determine the effects of dried broccoli floret (DBF) on egg production parameters, egg quality and apparent nutrient digestibility of laying hens. It was hypothesised that feeding DBF can improve egg quality without adversely affecting layer performance.2. Seventy-two White Leghorn layers aged 62 weeks were randomly allotted to 4 dietary treatments (6 cage replicates with 3 hens each) and fed diets containing 0, 40, 80 and 120 g/kg DBF in feed for 56 d.3. Inclusion of DBF had no effect on feed intake, egg production, feed conversion ratio or egg components. However, egg weight increased (linear effect, P < 0.05) as the level of DBF in the diet increased. Egg breakage strength, eggshell strength and Haugh unit were not influenced by dietary treatments. Egg yolk colour (quadratic effect, P = 0.002) and α-tocopherol concentration (quadratic effect, P < 0.0001) improved as a result of DBF inclusion. Egg yolk cholesterol concentration was not altered by DBF inclusion. Apparent total tract nutrient (dry matter, organic matter and crude protein) digestibility coefficients decreased (linear effect, P < 0.05) as the level of DBF increased.4. Feeding DBF to layers up to 120 g/kg of the diet had no negative effects on feed intake, egg production and feed efficiency and improved egg yolk colour and α-tocopherol concentration. However, total tract nutrient digestibility coefficients were negatively decreased as a result of DBF inclusion. 相似文献
17.
The purpose of this study was to determine the effect of limestone particle size and calcium (Ca) to non-phytate phosphorus (P) ratio on the true ileal Ca digestibility of limestone for broiler chickens. A limestone sample was passed through a set of sieves and separated into fine (<0.5 mm) and coarse (1–2 mm) particles. The analysed Ca concentration of both particle sizes was similar (420 g/kg). Six experimental diets were developed using each particle size with Ca:non-phytate P ratios of 1.5:1, 2.0:1 and 2.5:1, with ratios being adjusted by manipulating the dietary Ca concentrations. A Ca-free diet was also developed to determine the basal ileal endogenous Ca losses. Titanium dioxide (3 g/kg) was incorporated in all diets as an indigestible marker. Each experimental diet was randomly allotted to 6 replicate cages (8 birds per cage) and fed from d 21 to 24 post hatch. Apparent ileal digestibility of Ca was calculated using the indicator method and corrected for basal endogenous losses to determine the true Ca digestibility. The basal ileal endogenous Ca losses were determined to be 127 mg/kg of dry matter intake. Increasing Ca:non-phytate P ratios reduced the true Ca digestibility of limestone. The true Ca digestibility coefficients of limestone with Ca:non-phytate P ratios of 1.5, 2.0 and 2.5 were 0.65, 0.57 and 0.49, respectively. Particle size of limestone had a marked effect on the Ca digestibility, with the digestibility being higher in coarse particles (0.71 vs. 0.43).
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18.
ABSTRACT1. This study was conducted to investigate the effect of multi-strain probiotic (containing Lactobacillus acidophilus 2.5 × 10 7 cfu/g, Lactobacillus casei 2.5 × 10 7 cfu/g, Bifidobacterium thermophilum 2.5 × 10 7 cfu/g and Enterococcus faecium 2.5 × 10 7 cfu/g) and single-strain probiotic ( Pediococcus acidilactici 1 × 10 10 cfu/g) on broiler breeder performance and gastrointestinal health.2. A completely randomised trial was conducted using 300 broiler breeder hens (Ross 308) aged 51 weeks old which were randomly allocated to 1 of 5 dietary treatments with 6 replicates per treatment in a 10 week trial. Treatments included (1) the basal diet a negative control, (2) basal diet supplemented with 0.1 g/kg multi-strain probiotic (MS), (3) basal diet supplemented with 0.1 g/kg single-strain probiotic (SS), (4) basal diet supplemented with 0.1 g/kg of both of probiotics (MS+ SS) and (5) positive control basal diet supplemented with 0.5 g/kg oxytetracycline antibiotic (OX).3. Body weight, egg production, yolk weight, eggshell thickness and weight, Haugh unit, fertility and hatchability were determined. Results showed that dietary treatments had no significant effect on total hen house or total hatching egg production, egg weight, yolk colour index, shell weight, mortality, body weight, fertility, hatchability, oviduct and stroma weight or number of large and small yellow follicles ( P > 0.05). None of the jejunum morphological parameters, apparent ileal digestibility of protein and ileal Lactobacillus population were influenced by supplemental probiotics ( P > 0.05), although ileum Escherichia coli count was reduced by inclusion of dietary probiotics ( P < 0.05).4. It was concluded that although both probiotic treatments reduced coliforms, they did not improve broiler breeder performance or gastrointestinal tract (GIT) function. 相似文献
19.
1.?A factorial (2 × 3) feeding trial was set up to investigate the effects of coarse or finely ground brewers’ spent grain (BSG) and xylanase treatment, either with no xylanase, top-dressed with xylanase or pre-treated with xylanase. 2.?The experimental diets shared the same basal formulation and were fed to male broiler chickens (Ross 308) housed in individual cages from 12 to 29 d of age. 3.?Xylanase pre-treatment reduced the dietary concentration of arabinoxylan by 15–30%. Pellet durability increased when BSG was ground. 4.?Feed utilisation was significantly higher (6%) when the birds were given coarse BSG rather than ground BSG, whereas there was no significant effect of enzyme treatment. Apparent metabolisable energy was unaffected by the dietary treatments. 5.?The overall starch digestibility was high (99%), with no dietary differences, whereas ileal protein digestibility was low (57%). Xylanase top-dressing tended to improve ileal protein digestibility but, in general, xylanase treatment had no major effect on overall performance in male broilers given diets with BSG. 相似文献
20.
A 56-day feeding trial was conducted to investigate the effect of dietary supplementation of dried ginger meal (DGM) on the growth performance, nutrient digestibility, serum parameters, gut morphology, and microflora of growing helmeted guinea fowl ( Numidia meleagris). One hundred sixty 28-day-old male keets were assigned to four dietary treatments. There were 40 birds per treatment replicated four times with 10 keets each. The experimental diets consisted of the basal diet (control), ginger-supplemented diets containing 20, 40, and 60 g/kg DGM, respectively. Guinea fowls fed diet supplemented with DGM had higher ( P <0.05) final body weight, body weight gain and lower ( P <0.05) feed intake. Optimum weight gain was obtained with supplementation level of 36.15-g DGM ( R 2?=?0.923). Guinea fowls fed diet supplemented with 40 g/kg DGM recorded the highest ( P <0.05) coefficient of total tract apparent digestibility of dry matter, ether extract and longest ( P <0.05) duodenal and ileal villus heights. The crypt depth of the duodenum and ileum reduced ( P <0.05) with increasing level of dietary supplementation of DGM. Dietary supplementation of DGM resulted in increased ( P <0.05) total serum protein, serum albumin and low ( P <0.05) serum cholesterol concentration. Ileum content of birds fed diet supplemented with 40 g/kg DGM recorded the highest ( P <0.05) lactobacillus count. In conclusion, dietary inclusion of 40-g DGM per kilogram diet is hereby recommended for improved growth, apparent nutrient digestibility, gut morphology, serum chemistry, and stimulation of balanced intestinal microflora in growing guinea fowl. 相似文献
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