低能日粮添加木聚糖酶或复合酶对肉鸡生产性能和养分消化率的影响

试验旨在研究肉鸡低能日粮中添加木聚糖酶或复合酶对肉鸡生产性能和养分消化率的影响。采用单因子的试验设计,试验分6个处理,每个处理8个重复,每重复10只肉仔鸡。6个试验饲粮处理分别为正对照组(PC)、负对照组(NC,在正对照组基础上降低表观代谢能836 kJ/kg)、以及4个在NC基础上的加酶组(分别为处理1:木聚糖酶添加量为4 000 U/kg饲料;处理2:木聚糖酶、α-淀粉酶和蛋白酶分别为300 U/kg、400 U/kg和4 000 U/kg饲料;处理3:木聚糖酶、α-淀粉酶和蛋白酶分别为:1383U/kg6、7U/kg和667U/kg;处理4:木聚糖酶、α-淀粉酶和蛋白酶分别为2 766 U/kg、134 U/kg和1 334 U/kg)。试验结果表明,与PC相比,NC降低了肉鸡的增重、提高了料肉比(P<0.05);与NC相比,4个加酶组提高增重3%~10%和改善料肉比2%~8%(P<0.05),加酶后NC组肉鸡的生产性能达到了PC水平。NC降低了干物质、粗蛋白和能量的表观消化率(P<0.05),加酶组对养分消化率具有提高作用,且达到了PC水平;木聚糖酶和复合酶两种酶制剂对肉鸡生产性能和养分消化率的影响差异不显著,处理3和4两组间差异不显著(P>0.05)。结果表明,在降低代谢能836 kJ/kg的肉鸡饲粮中添加木聚糖酶或复合酶,能够使肉鸡的生产性能和养分消化率得以补偿,低能负对照饲粮加酶后能够使肉鸡的生产性能达到与正对照组相同水平。     

高油脂日粮中添加外源性乳化剂对肉鸡饲料养分利用率的影响

选用48只体重一致的、健康的36日龄的爱拔益加(Arbor Acre)雄性肉鸡,随机分成6个处理,每个处理4个重复,研究等能和等蛋白情况下,在高油脂含量日粮中添加不同剂量(0、400、530、660、800g/t)的外源性乳化剂对肉鸡饲料营养物质表观和真实代谢率的影响。结果表明:高油脂饲料中添加不同水平的外源性乳化剂不同程度地提高了能量、粗脂肪和干物质的表观和真实代谢率以及表观和真实代谢能,并且随着乳化剂添加水平的提高而呈上升的趋势。其中800g/t乳化剂水平下,能量、粗脂肪的真实代谢率、真实代谢能都提高值最大,添加400g/t乳化剂处理组和对照组差异不显著。     

Effects of exogenous xylanase on performance,nutrient digestibility and caecal thermal profiles of broilers given wheat-based diets

1. Five dietary treatments were used in a 49 d broiler trial to assess the effect of xylanase on performance, nutrient digestibility and thermal profiles of the caeca and head. Treatments included an industry-standard control diet and four further diets where xylanase was introduced with or without a metabolisable energy density dilution either from day one or the introduction was delayed until d 28.

2. The addition of xylanase with no associated energy dilution from day one resulted in the most consistent beneficial effects on performance, with significant improvements in weight gain compared with the industry-standard to d 28 and at d 49. Addition of xylanase from d 28 (with no energy dilution) was the second most successful strategy and resulted in a significant improvement in feed conversion ratio (FCR) from d 29 to 49 and overall.

3. Addition of xylanase improved ileal digestible energy values at d 28 by around 0.35 MJ/kg and ileal nitrogen digestibility coefficients by around 3%. On d 49 xylanase improved ileal digestible energy values by around 0.9 MJ/kg and ileal nitrogen digestibility coefficients by around 4.6%.

4. Thermal imaging of the head and caeca of three birds per replicate on d 49 revealed a significant increase in caecal surface temperature following xylanase addition with no effect on head temperature profile. These increases were particularly large (around 1.4ºC, or 3.9%) when xylanase was added from day one with no corresponding energy dilution in feed formulation.

5. It can be concluded that supplemental xylanase is effective in improving performance and nutrient digestibility in broilers given wheat-based diets. The correlation between the magnitude of this effect and the increased temperature in the caeca presents additional evidence that the hind-gut microflora may play an important, if yet unquantified, role in the outworking of these mechanisms.     

Influence of partial replacement of ground wheat with whole wheat and exogenous enzyme supplementation on growth performance,nutrient digestibility and energy utilization in young broilers

This study investigated the influence of pre‐pelleting inclusion of whole wheat (WW) and exogenous enzyme supplementation on growth performance, coefficient of apparent ileal nutrient digestibility (CAID) and apparent metabolizable energy (AME) in broilers fed wheat‐based pelleted diets. A 2 × 3 factorial arrangement of treatments was used with two methods of wheat inclusion [622 g/kg ground wheat (GW) and 250 g/kg WW replaced GW (wt/wt) pre‐pelleting (PWW)] and three enzymes (xylanase, phytase and xylanase plus phytase). A total of 288, one‐day‐old male broilers (Ross 308) were individually weighed and allocated to 36 cages (8 broilers/cage), and the cages were randomly assigned to the six dietary treatments. Birds fed PWW diets gained more (p < 0.05) weight than those fed GW diets. There was no effect (p > 0.05) of WW inclusion on feed intake (FI). Phytase alone increased (p < 0.05) FI compared to xylanase or the combination. Whole wheat inclusion increased (p < 0.05) the gain‐to‐feed ratio (G:F). Feeding xylanase plus phytase and phytase‐added diets resulted in the greatest and lowest G:F, respectively, with xylanase supplemented diets being intermediate. Birds fed PWW diets had greater (p < 0.05) relative gizzard weights than those fed GW diets. There was no effect (p > 0.05) of WW inclusion on the CAID of nitrogen (N), starch and fat. Combination of xylanase and phytase resulted in greater (p < 0.05) digestibility of N, starch and fat than that of individual additions. Feeding PWW diets resulted in greater (p < 0.05) AME values than GW diets. Combination of xylanase and phytase increased (p < 0.05) the AME compared to the diets with individual additions of xylanase or phytase. The current results suggest that the influence of pre‐pelleting WW inclusion and exogenous enzymes on nutrient digestibility and broiler performance is not additive.     

不同能量和营养浓度饲粮添加益生素对生长肥育猪生长性能、养分消化率、肉品质和血液指标的影响

<正>本研究旨在测定添加益生素(枯草芽孢杆菌孢子和丁酸梭菌孢子混合物)以及不同能量和营养浓度对生长肥育猪生长性能、养分消化率和肉品质的影响。选择96头初始体重为(47.50±1.14)kg的生     

Effects of lysolecithin supplementation in low-energy diets on growth performance,nutrient digestibility,viscosity and intestinal morphology of broilers

1. The study aimed to investigate the effect of lysolecithin supplementation in low-energy diets on growth, nutrient digestibility and intestinal mucosa characteristics of broilers.

2. A total of 800 one-d-old Ross 308 broiler chickens were assigned to 4 dietary treatments consisting of 10 replicates of 20 broilers each. Broilers were fed with 4 different diets: (i) HE: positive control group broilers received a diet with unaltered energy; (ii) LE: negative control group broilers received a diet with lower energy of about 0.27 MJ/kg; (iii) LElys500: broilers received a diet similar to LE supplemented with 500 g/tn lysolecithin product (Lysoforte Booster Dry^TM); and (iv) LElys300: broilers received a diet similar to LE supplemented with 300 g/tn lysolecithin product. The experimental period was 42 d.

3. Body weight gain in treatments HE was higher than LE during the overall experimental period, while LElys500 and LElys300 had intermediate values. Feed conversion ratio was lower in HE and LElys500 than LE group, while the LElys300 had intermediate values. Fat digestibility was improved in both LElys 500 and LElys300 compared to the HE group. Apparent metabolisable energy (AMEn) was higher in HE, LElys500 and LElys300 than LE. Ileum viscosity at 42 d was also affected, being higher in LE group compared to HE. At 28 d mucosal thickness was lower both in LElys500 and LElys300 compared to HE and LE, while no difference occurred between treatment proliferation patterns of duodenal epithelial cells.

4. These findings indicated that lysolecithin supplementation at 500 g/tn of feed in low-energy diets maintained broiler performance. Supplementation of reformulated low-energy diets induced an increase in digesta viscosity. Lysolecithin supplementation resulted in variable alterations in the duodenum mucosal morphology.     

Effect of stachyose supplementation on growth performance, nutrient digestibility and caecal fermentation characteristics in broilers

1. The objective of this study was to evaluate whether the oligosaccharide stachyose enhances gastrointestinal tract health by fermentation and proliferation of desirable bacteria species and thus affects growth performance and nutrient digestibility in broilers. 2. A total of 432 1-d-old male Arbor Acres (AA) broilers were randomly allocated to one of 6 treatments, with 12 replicate pens per treatment and 6 birds per pen. Chicks were fed a maize-hamlet protein 300 (HP300) basal diet with 0, 4.0, 8.0, 12.0 or 16.0 g/kg stachyose. A sixth diet contained no HP300 but soybean meal (SBM) and provided 8.7 g/kg stachyose and 3.1 g/kg raffinose. The duration of the study was 42 d. 3. Stachyose contents above 12.0 g/kg depressed group body weights, average daily gain and feed/gain but not feed intake during the whole experimental period. Broiler growth decreased linearly and quadratically with increasing stachyose content. No differences were detected between diets supplemented with 12.0 g/kg stachyose and SBM. 4. Nutrient digestibility tended to decrease but not significantly with increasing stachyose. 5. Stachyose content had no significant positive effects on caecal pH, microflora population and the resulting short-chain fatty acid (SCFA) metabolites during the 42 d experiment, with only butyrate differing significantly in the initial period.     

Effects of dietary mannanoligosaccharide on growth performance,nutrient digestibility and gut development of broilers given different cereal-based diets

A feeding trial was conducted to evaluate the effects of mannanoligosaccharide (MOS) on the growth performance, nutrient digestibility and gut development of broilers given a corn or a wheat-based diet over a 21-day experimental period. Dietary MOS improved the growth performance of birds given the wheat-based diet compared to that of birds given the corn-based diet during 7–21 days of age. In line with this, the ileal digestibility of starch was increased by MOS at 21 days of age. The addition of MOS modulated the development of gut microflora. From day 7 to day 21, the numbers of mucosa-associated coliforms along the small intestine were decreased; whereas the numbers of mucosa-associated lactobacilli were increased by MOS, regardless of the cereal type in the diets. Dietary MOS also reduced the counts of coliforms and Clostridium perfringens in the caeca of birds by 21 days of age. Villus height at the jejunum was not affected by MOS but the crypt depth and the muscularis thickness were reduced. The specific activities of maltase and alkaline phosphatase were increased in birds given the MOS-supplemented diet; whereas the development of leucine aminopeptidase was delayed by MOS. All these changes in the mucosal morphology and function were dependent on the type of cereal and/or the age of the birds.     

Lysolecithin,but not lecithin,improves nutrient digestibility and growth rates in young broilers

ABSTRACT

1. The potential of lecithin and lysolecithin to improve lipid digestion and growth performance was investigated in three experiments: 1. an in vitro model that mimics the intestinal conditions of the chick, 2. a digestibility trial with chicks (5–7 days of age), and 3. a performance trial until 21 days of age.

2. In experiment 1, palm oil (PO), palm oil with lecithin (PO+L), and palm oil with lysolecithin (PO+LY) were subjected to in vitro hydrolysis and applied to Caco-2 monolayers to assess lipid absorption.

3. The in vitro hydrolysis rate of triglycerides was higher in PO+LY (k = 11.76 × 10³/min) than in either PO (k = 9.73 × 10³/min) or PO+L (k = 8.41 × 10³/min), and the absorption of monoglycerides and free fatty acids was highest (P < 0.01) for PO+LY. In experiment 2, 90 broilers were assigned to three dietary treatments: a basal diet with 4% palm oil, and the basal diet supplemented with either 250 ppm lecithin or lysolecithin.

4. ATTD of crude fat was higher in broilers supplemented with lysolecithin, but was lower in broilers supplemented with lecithin. DM digestibility and AMEn in birds supplemented with lysolecithin were significantly higher (3.03% and 0.47 MJ/kg, respectively).

5. In experiment 3, 480 broilers were randomly allocated to four dietary treatments: basal diet with soybean oil (2%), basal diet with lecithin (2%), soybean oil diet with 250 ppm lysolecithin, or lecithin oil diet with 250 ppm lysolecithin.

6. Lecithin diets significantly reduced weight at day 10 and 21 compared with soybean oil. However, the addition of lysolecithin to lecithin-containing diets significantly improved bird performance.

7. The results of these studies showed that, in contrast to lecithin, lysolecithin was able to significantly improve the digestibility and energy values of feed in young broilers.     

Effects of exogenous xylanase on performance,nutrient digestibility,volatile fatty acid production and digestive tract thermal profiles of broilers fed on wheat- or maize-based diet

1. A previous experiment reported that caecal temperature was negatively correlated with d 49 feed conversion ratio (FCR). This increased temperature in the caeca may indicate a prebiotic effect. An experiment was designed to investigate whether caecal temperature was affected in diets based on maize and whether other portions of the tract were affected.

2. A total of 25 Ross 308-d-old male broilers were allocated to each of 8 replicate pens per treatment. Treatments followed a 2 × 3 factorial design: two diets based on wheat or maize and three levels of enzyme addition, 0, 16 000 or 32 000 BXU/kg. Growth performance was assessed between d 1 and 49. Digestibility measurements were taken at d 28 and 49. On d 49, the excised small and large intestine of each bird was thermally imaged, weighed and volatile fatty acids (VFA) measured.

3. On d 28 and d 49, birds on the maize diets had higher feed intake and weight gain than those offered wheat diets. Additionally, on d 28, birds that received the maize diet had lower FCR than those offered the wheat diet. Enzyme improved FCR at d 49, independently of cereal. On d 28, enzyme improved the coefficient of apparent ileal DM digestibility and the coefficient of apparent ileal nitrogen digestibility. Enzyme only improved apparent ileal digestible energy in wheat-based diets (interactive term). On d 49, all digestibility parameters were improved by enzyme. Enzyme increased gizzard weight in maize-fed birds and the caeca of those fed wheat were heavier. The higher enzyme dose decreased duodenal temperature. In summary of VFA data, wheat-based diets produced more total VFAs and the total amount also increased with enzyme.

4. It appears from this study that there is equal potential in both wheat and maize diets for xylanase to improve performance of broilers probably through different mechanisms.     

Effects of mannanoligosaccharide in broiler chicken diets on growth performance, energy utilisation, nutrient digestibility and intestinal microflora

1. A study was undertaken to evaluate the effects of mannanoligosaccharide (MOS, Bio-MOS, Alltech Inc.) on the growth performance, energy utilisation, nutrient digestibility and intestinal microflora of birds given a sorghum-wheat based diet. Two MOS levels (1 and 2 g/kg) were included in the diet. 2. Inclusion of MOS at both levels in the diet improved the apparent metabolisable energy (AME) values of the diet. However, these effects were not as pronounced as those of zinc bacitracin (ZnB) treatment. Dietary ZnB also significantly improved the net energy value of the diet. No significant differences between the different levels of MOS were noticed in the growth performance, AME and net energy values of the diet. Compared to the negative control, inclusion of 2 g/kg MOS tended to improve feed conversion efficiency (FCE) in the starter phase. 3. Dietary MOS did not affect the apparent total tract digestibility of nutrients compared to the negative control. In contrast, ZnB significantly improved the protein digestibility and tended to increase the starch digestibility. The addition of MOS reduced the concentration of arabinose in the soluble non-starch polysaccharides (NSP) fraction in the excreta of birds; whereas, the concentrations of individual sugars in the insoluble NSP and free sugar fractions were increased by ZnB. 4. A decrease in the populations of lactobacilli and coliforms in the ileal and caecal lumen was observed for MOS and ZnB treatments. Correspondingly, pH and microbial fermentation in the gut was altered. The addition of MOS tended to reduce the coliform load at the gut mucosa. 5. Results from the current study suggest that MOS can improve the apparent energy utilisation of the diet and tend to improve FCE of birds in the first three posthatch weeks, which may be partly related to the modulatory effects of MOS on the gut microflora.     

非淀粉多糖酶对体外养分消化和肉鸡生长性能的影响

文章旨在研究两种非淀粉多糖(NSP)酶对肉仔鸡饲粮体外消化率和生长性能的影响。体外模拟消化试验中,采用单因素完全随机设计,分为3个处理组(基础饲粮,基础饲粮+酶A,基础饲粮+酶XB),每个处理5个重复,每个重复1个模拟器。添加酶A和酶XB两种酶制剂显著提高肉仔鸡基础饲粮干物质消化率、粗蛋白质消化率、总能消化率和体外消化能(P<0.05)。饲养试验选择320只1日龄科宝肉仔鸡,随机分为4个日粮处理组,每组8个重复,每个重复10只鸡,分别饲喂正对照组(PC,组1)、负对照组(NC,代谢能较PC低0.63 MJ/kg,组2)、NC+酶XB(组3)和NC+酶A(组4),分0～21 d和22～42 d两期进行。研究结果表明:与组1相比,组2的22～42 d及0～42 d平均体增重显著降低(P<0.05);组2在0～21、22～42 d和0～42 d的料重比均显著高于组1(P<0.05);组3的肉仔鸡体增重在0～21 d和22～42 d均有所改善,全期(0～42 d)组3平均体增重较组2提高47.1 g/只,但未达到显著性水平(P>0.05)。添加NSP酶可显著改善饲粮的体外消化性能,并在一定程度上提高肉仔鸡的体增重。就本研究结果而言,体外试验较准确地评定了两种商品酶制剂产品的效价。     

Effect of zinc bacitracin and phytase on growth performance,nutrient digestibility,carcass and meat traits of broilers

A total of 336 one‐day‐old Hubbard broiler chickens were randomly distributed among 8 groups, each containing six replicates (7 chickens/replicate). From 1 to 40 days of age, the groups fed the same starter, grower and finisher diets. The control group was unsupplemented; zinc bacitracin (ZnB) group received the antibiotic at 0.5 g/kg; fungal phytase (FP) groups received 250, 500 and 1000 U/kg diet of Aspergillus niger phytase (FP_250, FP_500 and FP_1000 groups), respectively; bacterial phyatse (BP) groups received 250, 500 and 1000 U/kg diet of Escherichia coli phytase (BP_250EP, BP_500EP and BP_1000EP groups) respectively. Considering the whole experimental period, body weight gain was unaffected by ZnB and different concentrations of bacterial and fungal phytase; however, the feed conversion ratio of the group fed a diet supplemented with 500 U of BP was better (p < 0.01) than those fed with a diet supplemented with 500 U of FP. BP_250 group had a higher (p < 0.05) apparent digestibility of ether extract compared to FP_250 group. In conclusion, bacterial phytase at 500 U may enhance performance of broiler chickens fed during days 1–40 of age and yield similar growth performance and economic efficiency to those of eB‐supplemented groups.     

Nutrient digestibility and feedlot performance of lambs fed diets varying protein and energy contents

Thirty-six Thalli male growing lambs were used in a completely randomized design with 2 × 2 factorial arrangement of treatments to evaluate the effect of varying levels of energy and protein on nutrient intake, digestibility, weight gain, and gain to feed ratio. Four experimental diets, i.e., low energy–low protein (LE-LP), low energy–high protein (LE-HP), high energy–low protein (HE-LP), and high energy–high protein (HE-HP) were formulated. The low- and high-energy diets contained 2.3 and 2.7 MJ/kg dry matter (DM) with 12% and 14% of crude protein. The lambs were fed ad libitum. Dietary energy and protein levels and their interactions influenced the nutrient intake. Maximum dry matter intake was noted in animals fed LE-HP diet followed by LE-LP, HE-HP, and HE-LP diets. Digestibility of DM and N increased (P < 0.01) and that of neutral detergent fiber decreased (P < 0.01) linearly with increasing levels of dietary energy and protein. Digestibility of N was only affected by protein level and interaction between energy and protein levels. Average daily gain was higher (P < 0.01) in lambs fed HE-HP diet followed by LE-HP, LE-LP, and HE-LP diets. Dietary energy and protein levels and their interaction had significant effect (P < 0.01) on gain to feed ratio.     

玉米麸质饲料在肉仔鸡中的能量和回肠氨基酸表观消化率的研究

<正>玉米麸质饲料又称为玉米蛋白饲料(corngluten feed)或简称玉米麸料,是玉米以湿磨法提取油脂和淀粉的过程中产生的工业副产品,其主要成分是由玉米     

葡萄糖氧化酶和过氧化氢酶对肉鸡生长性能及养分代谢率的影响

试验以玉米豆粕为基础日粮,在日粮中添加不同水平的葡萄糖氧化酶和过氧化氢酶,探讨了两种酶单独或者复合后替代抗生素对肉鸡生长性能及养分代谢率的影响。试验选用1 080只1日龄健康的肉仔鸡,公母各半,按照试验要求随机分为9组,即对照组,抗生素组,处理组Ⅰ、Ⅱ组和处理Ⅲ组均加葡萄糖氧化酶150 g/t,活力分别是1 000、2 000 U/g和4 000 U/g,处理Ⅳ、Ⅴ组和处理Ⅵ组均加过氧化氢酶150 g/t,活力分别是5 000、10 000、20 000 U/g,处理Ⅶ组复合酶150 g/t(葡萄糖氧化酶2 000 U/g、过氧化氢酶10 000 U/g)。结果表明,从料重比来看,与对照组和抗生素组相比,1～21 d各试验组显著降低(P0.05),22～42 d除了处理Ⅱ组和处理Ⅴ组外其余各组显著降低(P0.05),1～42 d除了处理Ⅱ组外其余各组显著降低(P0.05);粗蛋白质表观消化率方面,处理Ⅰ、Ⅲ、Ⅶ组比对照组显著增加(P0.05),相比抗生素组,除处理Ⅳ组外其余各试验组显著增加(P0.05);粗脂肪表观消化率方面,处理Ⅰ、Ⅱ、Ⅲ、Ⅶ组比对照组显著增加(P0.05),与抗生素组比,除添加CAT组外其余显著增加(P0.05);与对照组相比,各处理组钙和磷表观消化率差异不显著(P0.05);能量表观消化率上,与对照组和抗生素组相比,除处理Ⅳ、Ⅴ组外其余各试验组显著增加(P0.05)。因此,从结果来看,过氧化氢酶和葡萄糖氧化酶能够促进肉鸡的生长,增加肉鸡的养分表观消化率;在适宜添加量的前提下,能够替代抗生素。