20～50 kg川藏黑猪的能量代谢与沉积规律研究

本试验旨在研究20~50 kg川藏黑猪的能量代谢与沉积规律。试验一:选择体重接近[(20.17±3.46)kg]的川藏黑猪配套系商品猪64头,预试7 d后屠宰4头猪测定胴体成分;其余试验猪按公母随机分成5个组,每个组4个重复,每个重复3头,各重复单圈饲养,自由采食消化能(DE)水平分别为13.79、13.37、12.96、12.54和12.12 MJ/kg的饲粮。试验猪体重达50 kg时,结束试验一,测定平均日采食量、平均日增重和料重比,并在各组选择1头猪屠宰测定胴体成分。试验二:选择试验一中15头体重接近[(48.34±4.07)kg]的公猪,随机分成5个组,每个组3个重复,每个重复1头,单独饲养于代谢笼,分别采食上述5种DE水平的饲粮,进行消化代谢试验。预试期3 d,正试期4 d。采用析因法建立能量需要量预测模型。结果表明:饲粮DE水平影响了20~50 kg川藏黑猪的平均日采食量、平均日增重和料重比;饲粮DE转化为代谢能(ME)效率(ME/DE)为97.26%~98.10%,ME用于沉积产品能的效率(DED/ME)平均值为41.71%;此阶段川藏黑猪维持需要ME平均值为0.49 MJ/W~(0.75)或0.85 MJ/W~(0.60)(按DE计为0.50 MJ/W~(0.75)或0.87 MJ/W~(0.60)),增重需要DE和ME平均值分别为18.91和18.47 MJ/kg。由此得出,20~50 kg阶段川藏黑猪能量需要模型为:DE(MJ/d)=0.504 W~(0.75)+18.91ΔW或DE(MJ/d)=0.867 W~(0.60)+18.91ΔW;ME(MJ/d)=0.492 W~(0.75)+18.47ΔW或ME(MJ/d)=     

Energy requirements of pregnant and lactating sows

The energy requirement of pregnant and lactating sows is derived on the basis of extensive experimental studies of the energy metabolism (indirect calorimetry, slaughtering) according to the factorial method. For the first reproduction cycle (RC) 0.41 MJ metabolizable energy (ME) or 0.29 MJ net energy fat, pig (NEFpig) resp. were necessary for energy maintenance requirement for pregnant and lactating sows and, depending on age, 0.44 MJ ME or 0.31 MJNEFpig in the second or third RC and 0.47 MJ ME/kg LW0.75.d or 0.33 MJ NEFpig/kg LW0.75.d in the 4th-8th RC. A linear increase of up to 6% of the energy requirement caused by pregnancy between the 85th and 115th day of pregnancy is taken into consideration. Energy requirement per 1 MJ retention both in pregnancy and lactation is 1.45 MJ ME or 1.03 MJ NEFpig, per 1 MJ milk yield it is 1.33 MJ ME or 0.91 MJ NEFpig. 1 MJ body energy for milk yield corresponds to 1.20 MJ ME or 0.82 MJ NEFpig. Equations describing energy retention in the products of conception, uterus and udder are established as well as equations characterizing the connections between live weight gain or loss and energy content of the gain or loss.     

Effects of dietary chitosan on fat deposition and lipase activity in digesta in broiler chickens

1. The effect of dietary chitosan on fat deposition and lipase activity in the small intestinal contents was investigated in broiler chickens fed an adequate or high metabolisable energy (ME) diet. 2. Male broiler chickens at 14 d old were fed on the adequate or high ME diet supplemented with 0 or 50 g/kg chitosan, which has a low viscosity, for 3 weeks. 3. Dietary chitosan did not affect food intake, body weight gain or food efficiency in either dietary ME groups. 4. Dietary chitosan reduced the excessive abdominal fat deposition induced by the high ME diet. 5. Dietary chitosan increased the weight of intestinal contents irrespective of dietary ME concentration. 6. Dietary chitosan decreased the lipase activity per g of small intestinal contents. 7. These results suggest that dietary chitosan with low viscosity decreases lipase activity and fat absorption in the small intestine, consequently resulting in a reduction of fat deposition in broiler chickens. 8. It was concluded that dietary chitosan with low viscosity can decrease body fat deposition without reducing food intake and body weight gain in broiler chickens.     

Nutrient and energy retention in weaned Iberian piglets fed diets with different protein concentrations

Fifty-eight purebred castrated male Iberian (IB) piglets (initial BW 9.9 ± 0.1 kg) were used in an experiment to determine the effect of dietary protein content (PC) and feeding level (FL) on the rates of BW gain, whole body protein deposition (PD), and energy utilization between 10 and 25 kg of BW using the serial slaughter method. Treatments followed a 4 × 2 factorial arrangement with 4 PC (201, 176, 149, and 123 g of CP/kg of DM) and 2 FL (0.95 and 0.70 × ad libitum) and 6 or 7 piglets per combination of treatments. All diets were formulated to have an optimal AA pattern. Six piglets were slaughtered at the start of the trial to estimate initial body composition. The experimental pigs were individually housed in an environmentally controlled room (27 ± 2°C) until they reached 25 kg of BW, when they were slaughtered and analyzed for body composition. Positive linear effects of dietary PC on ADG, G:F, and gain:ME intake were observed (P < 0.001). Piglets fed at the highest FL showed greater ADG, G:F, and gain:ME intake (P < 0.001). An average increase was estimated to be 38.0 g of gain/MJ of ME intake. Protein deposition increased linearly from 35.6 to 50.9 g/d with increasing dietary PC (P < 0.001). A daily increase was estimated to be 0.35 g of PD/g of CP intake. Although the maximal genetic potential for PD of the IB piglet was not attained, a maximal value of 59.9 g/d for whole-body PD was achieved when the diet provided 201 g of CP/kg of DM and was fed at 0.95 × ad libitum. Piglets on the highest FL deposited on average 39% more body protein (P < 0.001) than restricted piglets. An average value of 4.39 g increase in PD/MJ of ME intake was obtained for diets containing 201 and 176 g of CP/kg of DM. Maintenance energy requirements and net efficiency of utilization of ME for growth, calculated by linear regression of ME intake on body retained energy, were 427 kJ/kg of BW(0.75)·d(-1) and 0.552, respectively. The corresponding partial efficiencies of utilization of ME for protein and fat deposition were 0.378 and 0.672, respectively, considerably less than the accepted values for conventional pig breeds. Practical diets of the young IB piglet should contain at least 201 g of ideal CP/kg of DM.     

Energy and nitrogen metabolism of chickens infected with either Eimeria acervulina or Eimeria tenella.

1. The effects of sublethal infections of E. acervulina and E. tenella on the energy and nitrogen metabolism of groups of five broilers aged 16 d were studied for 16 d in respiration chambers. 2. The metabolisable energy content of the diet for chickens infected with E. acervulina was 0.689 of its gross energy content and N retention was 42.5 g/100 g N intake compared with 0.738 and 47.1 g respectively, in uninfected pair-fed controls. Chickens infected with E. tenella were similarly affected. 3. Efficiency of utilisation of ME by chickens infected with E. acervulina was 0.43 during the first 8 d after infection, and 0.52 during the second 8 d compared with an overall efficiency by non-infected chickens fed ad libitum of 0.73. Maintenance energy requirement of infected chickens was higher during the first 8 d after infection than during the second 8-d period. 4. Body composition measurements showed that of the total gain in weight of chickens infected with E. acervulina, only 7.5 g/kg gain was fat and 213 g/kg was protein compared with 45 g and 210 g respectively for non infected chickens fed ad libitum. 5. E. acervulina and E. tenella infections reduced the apparent digestibility of total mineral, calcium and phosphorus.     

The effects of feeding level upon protein and fat deposition in Iberian heavy pigs

Eighteen Iberian barrows of 100 kg initial BW were used in a comparative slaughter experiment to investigate the effects of feeding level (FL; 0.70 and 0.95 × ad libitum) on growth, protein- and fat-deposition rates and body composition. They were fed on a diet supplying the optimum level of digestible ideal protein:ME ratio (4.82 g/MJ) and slaughtered at 150 kg BW. The apparent digestibility of DM, OM, total N and GE, and the ME:GE and ME:DE ratios were not affected by FL. The average daily gain increased with the increase in FL (691 and 918 g/day respectively). Neither the gain:feed (g/g DM) nor the gain:ME intake (g/MJ) ratios were significantly affected however. An energy cost of 59.9 kJ ME/g gain was calculated. The rate of whole-body protein deposition was not significantly altered by FL. On average it reached 80 g/day. The pigs fed at the lowest level exhibited lower fat deposition (P < 0.01) and total energy retention (P < 0.01) than those in the group subjected to only a slight feed restriction. The overall efficiency of utilization of ME for energy gain (ER:ME intake) remained at 0.363 on average, irrespective of the FL imposed. Relative proportions of energy retained as protein and fat were not statistically altered by changes in FL. Mean values for ERP:ER and ERF:ER were 0.100 and 0.903 respectively. No differences between treatments were observed in fat, ash, water or energy content of the whole-body (g/kg) at 150 kg empty BW, the mean values (n = 12) being 512 ± 8.5, 27.6 ± 0.63 and 353 ± 6.7 g/kg for fat, ash and water respectively and 22.90 ± 0.31 MJ/kg for energy. Nevertheless, the proportion of protein tended to decline with the increase in FL (111 vs 104; P = 0.069). At 150 kg the Iberian pigs contained more fat and energy and less ash and water than at 100 kg. Whilst the percentage of lean tissue decreased significantly (P < 0.05) and protein content in the carcass showed a strong tendency to decline in the pigs fed close to ad libitum (104 vs 96; P = 0.056), the proportions of fat, ash, water and energy remained constant at 564 ± 9.0, 22.2 ± 0.91, 312 ± 6.6 g/kg, and 24.82 ± 0.32 MJ/kg, respectively. It was concluded that a degree of feed restriction may result in a discernible improvement in carcass quality.     

代谢能水平对6～10周龄扬州鹅增重效率及体脂沉积的影响

为研究日粮代谢能水平对6～10周龄扬州鹅增重效率及体脂沉积的影响,试验选用35日龄、体重相近的扬州鹅200只,随机分成4组,日粮代谢能水平分别为10.11、11.19、12.37、13.45 MJ/kg,进行为期35 d的饲养试验。结果表明:代谢能水平对腹脂率、胸腿肌脂肪含量影响显著,随代谢能水平升高而升高;皮下脂肪厚、肌间脂肪宽度、胸腿肌的蛋白和水分含量组间差异都不显著(P0.05)。日采食量随代谢能水平的上升显著下降(P0.05),但日进食代谢能却依次增加。日增重以试验3组最高为54.81 g,显著高于试验1组。代谢能增重比率以试验3组最高,随代谢能水平的增加呈现S型曲线变化。综上代谢能水平对体脂沉积和增重效率有显著的影响,为获得最高的代谢能增重比率,日粮代谢能以12.37 MJ/kg组最佳。     

Energy utilisation in germ-free and conventional chicks fed diets containing sorbose

1. In experiment 1, growing conventional (CV) chicks were fed on diets containing graded amounts (0, 100, 200 and 300 g/kg diet) of sorbose from 4 to 14 d. Protein, fat and energy deposition were determined after carcase analysis. The values for growth, food efficiency, metabolisable energy (ME) and fat and energy depositions declined as the dietary sorbose content increased. 2. In experiment 2, the performances of germ-free (GF) and CV chicks fed on diets with (100 g sorbose/kg diet) or without sorbose were investigated. On both diets, body weight gain, food consumption and protein accumulation in GF chicks were significantly higher than those in CV birds. No significant differences were observed between the dietary treatment except for ME values, which were significantly lower for the sorbose diet. 3. It is suggested that dietary sorbose decreased energy utilisation, and that the microbial contribution to the utilisation of dietary sorbose was negligible in the chicken.     

Effect of supplementary choline on the performance of broiler breeders fed on different energy sources

1. Laying performance, egg quality, fertility and hatchability, and fat deposition in liver and abdomen were recorded in broiler breeders (29 to 48 weeks of age) fed on diets containing perarl millet (Pennisetum typhoides) (PM), broken rice (BR) or yellow maize (YM) (600 g/kg diet). Constant ratios of metabolisable energy (ME) to other nutrients were maintained in all the diets. Food grade choline chloride (50%) was added to the diets at 3 concentrations (0, 760 and 1,520 mg/kg). Each diet was offered to 3 replicate groups of 15 birds (12 hens and 3 cockerels), maintained in deep litter pens, to provide 1.46 MJ ME/bird/d. 2. Neither the source of energy nor dietary choline content had any influence on hen-d egg production, fertility or hatchability. Food efficiency and egg weight were significantly reduced in BR-fed groups compared to those fed on the other energy sources. 3. The efficiency of energy and protein utilisation increased and liver fat content was decreased significantly by dietary choline supplementation. 4. Haugh unit score, egg shell weight, liver weight and intestinal weight were not influenced by either supplementary choline or the source of energy. However, the yolk colour index was significantly reduced in PM- or BR-fed groups compared to those fed on the maize-based diet. 5. Deposition of abdominal fat was significantly greater in BR-fed birds compared to those fed on the YM-based diet, while liver fat content was significantly greater in the birds fed on the PM-or BR-based diets than those based on YM. Although supplementation of the diet with choline had no influence on abdominal fat deposition, liver fat content was significantly reduced in birds given diet containing 760 mg supplemental choline/kg diet. 6. The present study indicates that PM or BR can be used as principal energy sources in place of YM in broiler breeder diets without affecting egg production, fertility or hatchability. Liver fat content can be reduced by adding choline at 760 mg/kg to diets based on different energy sources.     

Influence of energy intake on growth and utilisation of dietary protein and energy in germ-free and conventional chicks

The effect of metabolisable energy (ME) intake on the growth and utilisation of dietary protein and energy in germ-free (GF) and conventional (CV) chicks was investigated in two experiments. In experiment 1 a high energy diet (HED, 14.8 kJ ME/g) and a marginally-adequate energy diet (AED, 11.7 kJ ME/g) were fed to the GF and CV chicks at 240 g/2 birds/10 d. In experiment 2 a diet with 13.7 kJ ME/g was fed at 118 g (low level, LL) or 128 g (high level, HL)/bird/10 d. Body weight gain, protein retention and protein retention rate were similar in GF and CV chicks on both AED and HED in the first experiment, but in the second were higher in GF than in CV chicks. The increased ME intake of the CV chicks in experiment 2 may be too small to compensate for the increased requirement. ME intake was significantly higher in the CV chicks than in the GF chicks, whereas energy retention was similar in both groups.     

空怀期陕北白绒山羊的能量需要量

本试验旨在研究空怀期陕北白绒山羊母羊对能量的适宜需要量。选择1.5岁陕北白绒山羊母羊24只,随机分为4组,每组6个重复,每个重复1只羊。控制各组试羊粗蛋白质摄入量一致(实测值为74.0 g/d),测得各组消化能摄入量分别为7.6、8.3、8.9和9.6 MJ/d,进行为期40 d的饲养试验(前10天为预试期);饲养试验结束后,每组选择3只羊进行为期7 d的消化代谢试验。结果表明:空怀母羊对4种饲粮总能的消化率和代谢率分别为(65.3±3.23)%和(54.7±3.16)%。空怀期母羊平均日增重随能量摄入量增加呈线性增长。空怀母羊消化能和代谢能需要量分别为DE(MJ/d)=0.507 0W0.75+0.026 3 ADG和ME(MJ/d)=0.413 0W0.75+0.024 5 ADG(式中DE为消化能,W0.75为代谢体重,ADG为平均日增重,ME为代谢能)。综合得出,空怀期陕北白绒山羊饲粮中消化能和代谢能分别以9.17～10.14 MJ/kg和7.70～8.60 MJ/kg(风干基础)较为适宜。     

Inclusion of low metabolisable energy wheat in broiler diets and the incidence of the fatty liver and kidney syndrome

Chickens were fed a diet containing wheat of low metabolisable energy (ME) content (11.3 MJ kg-1 dry matter [DM]) or a diet containing a wheat of high-ME content (14.5 MJ kg-1 DM). The diets, although of identical ingredient composition differed in energy to protein ratio. Chicks fed the diet containing the low-ME wheat and with the low ratio had more severe biotin deficiency lesions but a much reduced incidence of the fatty liver and kidney syndrome.     

Metabolic utilization of energy and maintenance requirements in growing pigs: effects of sex and genotype.

An experiment was conducted in which the metabolic utilization of energy was measured in individually penned pigs from seven groups that differed in genotype and(or) sex and ranged in body weight between 20 and 107 kg. The animals were fed a diet containing, on a DM basis, 14.7 MJ ME and at least 21% CP. Heat production was measured in an open-circuit calorimeter, and energy, nitrogen, and fat balances were determined at regular intervals over the growing period; a total of 177 measurements were performed. Body composition of the animals was measured by serial slaughter, and these data were used for estimating the body composition of an animal at a given weight through allometric regression. A factorial analysis procedure was used to estimate the utilization of ME by regressing the ME intake on the observed protein and lipid deposition rates. The intercept of this equation is the maintenance energy requirement (MEm) and was represented either as a function of body weight with group-specific parameters (MEm = a(i) BWb) or as a function of the muscle and visceral mass with an additional additive group effect (MEm = aM muscle(b) + a(v) viscera(b) + G(i)). With BW as dependent variable, the exponent b was close to .60 and differed significantly from .75. The regression coefficient (a(i)) averaged 1.02 MJ ME/kg.60 but it was different for most groups, indicating that different groups of animals have different maintenance requirements. Fixing the exponent to .75 consistently underestimated the maintenance requirement. When the exponent b was not fixed to .75 but estimated, the partial efficiencies for protein and lipid deposition were .62 and .84, respectively. Body muscle and visceral mass could explain a large part of the variation in MEm. Viscera contributed three times more to MEm (per kilogram of mass raised to the .70 power) than did muscle. Even though the muscle mass exceeds to a large extent the visceral mass in animals, the contribution of muscle to MEm was lower than that of viscera for most groups.     

The effect of dietary energy and protein levels on production in breeding female ostriches

1. In a study spanning two breeding seasons, we assessed the effect of different dietary energy and protein levels on body mass, body condition, and egg production of female ostriches. 2. During the first breeding season, groups were given diets with energy concentrations of 8.5, 9.5 and 10.5 MJ/kg dry mass (DM) metabolisable energy (ME) and protein concentrations of 135, 150 and 165 g/kg. In the second breeding season, groups were given diets with ME of 7.5, 8.5 and 9.5 MJ/kg and protein contents of 105, 120 and 135 g/kg. 3. Body mass of birds on diets of 7.5 and 8.5 MJ/kg ME decreased significantly in the course of the breeding season compared with birds fed on diets with higher energy contents and body measurements decreased, suggesting a loss of body condition. 4. Females fed on diets containing only 7.5 MJ/kg ME produced significantly fewer eggs at significantly longer intervals, resulting in fewer chicks hatched. 5. There was no significant difference in egg mass, initial chick mass, chick survival to one month of age and body mass of chicks at one month. 6. Dietary protein concentrations had no effect on egg production, egg mass, hatchability, initial chick mass, chick survival or chick mass at one month old. 7. The female ostriches regained their original body mass during the 4-month rest period between breeding seasons, but significant differences in some parameters during the second breeding season suggest that they may not have fully recovered their body condition. 8. A dietary energy content of 7.5 MJ/kg proved to have an adverse effect on egg production by breeding female ostriches, and it may be concluded from this study that a diet containing 8.5 MJ ME/kg DM and 105 g/kg protein should be regarded as the minimum that can be used for breeding female ostriches without compromising egg production.     

Synergistic effects of betaine and conjugated linoleic acid on the growth and carcass composition of growing Iberian pigs

An experiment was conducted to determine the efficacy of dietary betaine, CLA, or both as growth promotants and carcass modifiers in growing Iberian pigs. Twenty gilts (20 kg of BW) were individually penned and fed barley- and soybean meal-based diets (12% CP, 0.81% Lys, and 14.8 MJ of ME/kg of DM) containing either no added betaine or CLA (control), 0.5% betaine, 1% CLA, or 0.5% betaine + 1% CLA, at 95% of ad libitum energy intake. An additional group of 5 pigs was slaughtered at the beginning of the experiment to obtain the initial body composition. At 30 kg of BW, a balance experiment was conducted. At 50 kg of BW, pigs were slaughtered and viscera was removed and weighed. Betaine or CLA alone did not affect growth performance. However, betaine + CLA increased ADG (601 vs. 558 g, P = 0.03) and gain relative to ME intake (25.4 vs. 22.2 g/MJ, P = 0.03) compared with control pigs. Digestibility of nutrients and metabolizability of energy did not differ among diets (P = 0.46 to 0.75). Carcass protein, water, and lean deposition (g/d) increased (19.8, 24.2, and 23.4%, respectively, P < 0.01) in pigs fed betaine + CLA compared with control pigs. Similarly, protein deposition relative to ME intake increased by 28% in betaine + CLA-supplemented pigs (P < 0.05). Fat and mineral deposition did not differ among treatments. Carcass protein, water, and lean content (g/kg of carcass) of pigs fed betaine + CLA-supplemented diets tended to increase (P = 0.07 to 0.09) and carcass fat content tended to decrease (P = 0.09). Similarly, estimated composition of carcass gain was affected, such that water and lean content tended to increase (P = 0.06 to 0.08), whereas fat tended to decrease (P = 0.08) in pigs fed betaine + CLA-supplemented diets. Longissimus muscle area was not altered by treatments (P = 0.49). The liver of pigs fed betaine + CLA diets had increased weight (19%, P < 0.05) compared with control pigs. Overall, dietary supplementation of betaine + CLA increased ADG, protein, water, and lean deposition in growing Iberian gilts. There appears to be a synergistic action when betaine and CLA are used together.     

Calorimetric measurements on chickens given diets with a range of energy concentrations

Eight diets with metabolisable energy (ME) concentrations ranging from 9–1 to 15–3 MJ/kg were given to groups of five chickens kept in respiration calorimeters for 3 to 4 d. Availability of ME ranged from 57% to 79%. One diet differed from the others, but for those groups of chickens on the other seven diets availability of ME was 80% when energy balance was negative and only 60% when positive.

Protein synthesis appeared to continue when chickens were in negative energy balance and fat was frequently catabolised when birds were in positive energy balance, apparently to support protein synthesis.     

Energy and protein concentration of broiler rations in Cuba. 2. Female broilers in winter

Four energy concentrations (10.5, 11.5, 12.6 and 13.6 MJ ME) and four protein concentrations (15.0, 17.5, 20.0 and 22.5% CP) were tested with a total of 1,900 female broilers of the breed White Plymouth Rock in their first 56 days of life in 16 experiment groups. The animals were kept in cages and were directly exposed to the natural Cuban winter temperatures from their 15th day of life. As six repetitions were carried out in every test group, the results could be variance-analytically calculated. In winter the female broilers of the breed White Plymouth showed a lower intake of feed, metabolic energy and crude protein than male animals. They achieved a lower live weight, lower amount of body protein and fat and worse feed, protein and energy utilisation. Possibilities are shown to meet the crude protein and energy requirement in monophase feeding systems with 11.5 MJ ME and 20% CP or with 12.6 MJ ME and 17.5 or 20% CP.     

43～63日龄黄羽肉鸡饲粮代谢能需求参数的研究

用1600只42日龄岭南黄鸡以2(性别)×5(代谢能水平)试验设计,向玉米-豆粕型日粮中添加不同剂量植物油、沸石粉和玉米芯粉,使5种代谢能水平分别为:12.134,12.552,12.970,13.389,13.807MJ／kg,观测鸡的生产性能。结果:以生长性能、能量和粗蛋白质沉积率以及胴体品质为评价指标时,43~63日龄最适饲粮代谢能水平分别为13.376MJ／kg、12.958MJ/kg和12.540MJ/kg;以肌肉脂肪含量为评价指标时,公、母鸡饲粮代谢能最适需要量分别为12.958和13.376MJ／kg;以空体成分为评价指标时,母鸡最适饲粮代谢能水平为12.540MJ/kg。     

日粮能量和粗蛋白质水平对灰雁生长性能、血清生化指标及屠宰性能的影响

本试验旨在研究日粮能量和粗蛋白水平对灰雁生长性能、血清生化指标及屠宰性能的影响,为灰雁的科学饲养提供理论基础。试验采用双因子试验设计,粗蛋白质及代谢能水平分别为14.0%、15.0%、16.0%及11.0、12.0、13.0 MJ/kg,选取450只28日龄灰雁,随机分为9组,每组5个重复,每个重复10只灰雁,每组饲喂1种日粮。预试期12 d,正试期80 d。结果表明：①代谢能为12.0 MJ/kg组灰雁的平均日增重显著高于代谢能为11.0和13.0 MJ/kg组（P<0.05）;粗蛋白质水平为14.0%组灰雁的平均日增重显著低于蛋白质水平为15.0%组（P<0.05）;②代谢能为13.0 MJ/kg组灰雁的血清甘油三酯含量显著低于代谢能为11.0 MJ/kg组（P<0.05）,粗蛋白质水平为16.0%组灰雁的血清尿素氮含量显著高于蛋白质水平为14.0%组（P<0.05）。③代谢能为11.0 MJ/kg组灰雁的半净膛率、全净膛率、胸肌率和腿肌率均低于代谢能为12.0和13.0 MJ/kg组,代谢能为13.0 MJ/kg组灰雁的腹脂率显著高于代谢能为11.0和12.0 MJ/kg组（P<0.05）;粗蛋白质水平为14.0%组灰雁的胸肌率和腿肌率低于粗蛋白质水平为15.0%和16.0%组;综合得出,日粮代谢能水平显著影响灰雁的末重、腹脂率、血清甘油三酯含量（P<0.05）,过高的代谢能水平增加腹脂率,增加饲料成本;日粮蛋白质水平对灰雁的末重和血清尿素氮影响显著（P<0.05）;推荐5~16周灰雁的蛋白质水平为15.0%,能量水平为12.0 MJ/kg。     

木聚糖酶在蛋鸡饲料中代谢能当量值的评定

试验通过蛋公鸡排空强饲法研究了2种木聚糖酶在5种能量饲料和6种产蛋鸡日粮中代谢能的当量值。结果表明:2种木聚糖酶都显著提高了蛋鸡对小麦和玉米小麦豆粕、玉米小麦豆粕棉粕、玉米小麦豆粕菜粕型日粮的代谢能(AME和TME)(P<0.05);酶A显著提高了小麦麸的代谢能(P<0.05);酶B对次粉、玉米豆粕、玉米豆粕棉粕型日粮的代谢能都有显著提高的趋势(P=0.089,P<0.05,P=0.070)。除酶A的代谢能当量值在小麦麸上为ME1.22 MJ/kg外,2种木聚糖酶的代谢能当量值在ME0.21-0.53MJ/kg之间。