High dietary biotin levels affect the footpad and hock health of broiler chickens reared at different stocking densities and litter conditions

Responses to stocking density (SD), dietary biotin concentration and litter condition were evaluated on 2016 Ross 308 male broilers in the fattening period (day 22–day 42). The birds were placed in 48 pens with either dry or wet litter to simulate the final stocking density of 30 kg (12 broilers/m²; normal stocking density, NSD) and 40 kg (16 broilers/m²; high stocking density, HSD) of body weight (BW)/m² floor space. A corn–soybean meal‐based diet was supplemented with biotin to provide a normal (NB; 155 μg/kg) or high (HB, 1521 μg/kg) level of dietary biotin. There were six repetitions per treatment. The inappropriate moisture content of litter associated with HSD was avoided (p < 0.05) by good management (SD difference: dry litter, 6.65% vs. wet litter, 13.23%; 42 days), which made it advantageous (p < 0.01) for footpad (SD difference: dry litter, 0.118 vs. wet litter, 0.312; weekly average value) and hock health (SD difference: dry litter, 0.090 vs. wet litter, 0.303; weekly average value) of HSD birds, but not (p > 0.05) for growth and processing yield. In HSD, the biotin effect (gains, FCR) was significantly higher (p < 0.01) than in NSD. The similar response of HSD birds to supplemental biotin was observed (p < 0.05) for lesion scores of footpad and hock in particularly finishing chickens, and a significant interaction (p < 0.01) among stocking density, biotin supplementation and litter condition existed from 35 to 42 days of age. Taken together, increasing dietary biotin improves the performance and well‐being of broiler chickens stocked at high densities in litter‐independent and litter‐dependent manners respectively.     

Suitability of poultry litter ash as a feed supplement for broiler chickens

An experiment was conducted to evaluate poultry litter ash (PLA) at graded levels (0, 25, 50, 75, and 100%) as a dietary substitute for dicalcium phosphate (dicalP) for broiler chickens, where PLA was substituted for dicalP on a wt/wt basis. A decreased BW gain was observed at 21 d from PLA at the 100% substitution rate when compared with the 25% substitution rate. No effects on BW gain, feed consumption, or FCR were incurred by study termination at 41 d, and the 100% substitution rate of dicalP did not cause any detrimental effects on the live performance in market age broilers. Although femur ash percentages decreased with increasing levels of PLA, bone integrity was not compromised by the addition of PLA to the diet. Dry matter digestibility of dietary Ca (26.32–58.65%) and P (30.23–42.68%) increased with increasing levels of PLA (0–100%), respectively, inferring that the Ca and P component of the diet was more efficiently used as the level of PLA increased. In conclusion, PLA resulting from the combustion of poultry litter can be used as a P and Ca source for broilers.     

Effects of alpha-lipoic acid supplementation in different stages on growth performance,antioxidant capacity and meat quality in broiler chickens

1. This experiment was conducted to investigate the effect of basal dietary supplementation with 500 mg/kg alpha-lipoic acid (LA) on growth performance, antioxidant capacity and meat quality in different stages in broiler chickens.

2. A total of 240 Arbor Acre chickens were randomly assigned into 4 treatment groups, each treatment containing 6 replicates of 10 chickens each. Group 1 was the control group without LA supplementation; Group 2 was supplied with LA in the starter period; Group 3 was supplied with LA in the grower period; and Group 4 was supplied with LA in the whole period.

3. The results showed that LA supplementation improved average feed intake and body weight gain in all three experimental groups, especially in Group 2. LA supplementation significantly decreased abdominal fat yield in Groups 3 and 4.

4. LA supplementation all improved hepatic total antioxidant capacity, the level of glutathione, the activities of total superoxide dismutase, catalase (CAT) and glutathione peroxidase, in particular in Group 4. LA supplementation decreased the activity of liver xanthine oxidase (XO) in all experimental groups, and that of liver monoamine oxidase in Group 3. The activities of liver CAT and XO in Group 2 were higher than that in Group 3. LA supplementation elevated the pH_24 h and decreased drip loss in breast meat in Groups 3 and 4.

5. In conclusion, LA supplementation can improve growth performance, antioxidant properties and meat quality in broiler chicken. LA supplementation in the starter period can improve growth performance and supplementation in the grower – and in the whole period can improve carcass characteristics. There was no significant difference in meat quality of broiler chickens fed on LA-supplemented diet in different stages.     

Growth performance and meat quality from broiler chickens reared with zeolite and halloysite in feed and straw pellet

The study's aim was to analyze the effects of different levels of halloysite (H) and zeolite (Z) in feed and pellets on the growth and meat quality in chickens; 500 Ross 308 broilers were assigned to five groups (1 g, control; 2–5 g, experimental). In Groups 2–5, different proportions of Z and H in feed (25:75 ratio; 0.5% to 2%) and pellet in kg/m² (2, 0.650H; 3, 0.325H and 0.325Z; 4, 0.650Z; 5, 0.160H and 0.490Z) were used. Body weight was higher than 1 in all experimental groups, and carcass weight was higher, except for Group 2. The feed consumption was lower in Groups 3 and 5 than in Group 4. The breast muscle weight was higher in Group 3 than in the control group. In Groups 2, 3, and 5, the water holding capacity in the breast muscles was better than in Group 4 and in the leg muscles in Groups 3 and 4 than in Groups 1 and 5. Most of the tested characteristics indicate a beneficial effect of aluminosilicates in feed and litter on the growth and quality of meat.     

Effects of strain and different skip-a-day feed restriction periods on the growth performance of broiler chickens

The effects of 6, 10 and 14 days of skip-a-day feed removal during the starter and grower periods on the growth performance of Ross 308 and Hubbard broiler chickens were studied in a 49-day production period. Ross 308 was superior to Hubbard in weight gain, market weight and feed utilization but consumed more feed, deposited more abdominal fat and had a higher mortality rate. Overall, feed removal improved feed efficiency, had insignificant effects on abdominal fatness and mortality rate and reduced feed intake, weight gain and market weight. On each restricted-feeding regime, the birds gained as much weight as their fully fed counterparts during the period of resumed full feeding but were unable to compensate fully for the weight loss and were lighter at the end of the trial. It is suggested that for profitable broiler production under tropical conditions, Ross 308 and skip-a-day feed removal for less than 6 days from 7 to 17 days of age be considered.     

Dietary supplementation with acidifiers improves the growth performance,meat quality and intestinal health of broiler chickens

This experiment was conducted to study the effects of dietary supplementation with acidifiers on the growth performance, meat quality, and intestinal health of broiler chickens. A total of 648 male Arbor Acres broiler chickens at 1 d old were randomly divided into 6 groups, and each group consisted of 6 replicates with 18 broilers per replicate. The dietary treatments were as follows: negative control (NC, the basal diet), NC + antibiotic (enramycin, 8 mg/kg, positive control [PC]), NC + phosphoric acid (PA, 0.1, 0.2, and 0.3 g/kg), and NC + lactic acid (LA, 0.3 g/kg). The feeding trial lasted for 42 d. The results showed that the feed-to-gain ratio of the NC + acidifier groups was lower than that of the NC and PC groups from 1 to 42 d (P < 0.05). Compared with the values in the NC group, the pH of breast muscle was significantly higher in the NC + PA (0.2 g/kg) and LA (0.3 g/kg) groups (P < 0.05), and the cooking loss was lower in the breast muscle of the NC + PA (0.1 g/kg) and LA (0.3 g/kg) groups (P < 0.05). In addition, the shear force of the breast muscle and thigh muscle and the pH value in the crop, gizzard and duodenum of the antibiotic and acidifier groups were significantly decreased (P < 0.05). Moreover, the trypsin, chymotrypsin, and lipase activities of the duodenum in the NC + PA (0.2 and 0.3 g/kg) groups, as well as the villus height-to-crypt depth (VH:CD) ratio of the duodenum in the NC + PA (0.1 g/kg) group was significantly greater (P < 0.05) compared with those in the NC group. Meanwhile, the number of total aerobic bacteria, Escherichia coli and Salmonella in the cecum of the NC + PA (0.1 g/kg) and LA (0.3 g/kg) groups were decreased (P < 0.05). Collectively, diet supplementation with acidifiers could improve the growth performance, meat quality, and intestinal health of broilers, in which the effects of PA (0.1 g/kg and 0.2 g/kg) are better than the other supplementations.     

品种对肉兔断奶后窝生长性状的影响

本研究旨在明确影响肉兔断奶后窝生长性状和料肉比的重要因素。利用一般线性模型分析了来自5个不同肉兔品种(新西兰白兔,加利福尼亚兔,比利时兔,青紫蓝兔和福建黄兔)的909只173窝肉兔断奶后窝生长和料肉比性状。结果表明,品种和断奶数对断奶窝重(5周龄窝重),窝增重,窝上市体重(10周龄窝重),个体平均上市体重,窝采食量和料肉比的影响极显著(P<0.01)。出生月份对窝采食量影响极显著(P<0.01),对断奶窝重和窝上市体重的影响显著(P<0.05)。比利时兔的断奶窝重、窝增重、窝上市体重、窝采食量和平均上市体重显著高于其他品种,而福建黄兔的上述5项指标显著低于其他品种(P<0.05)。断奶数与断奶窝重、窝采食量、窝增重、窝上市体重和料肉比的回归系数为正且显著。品种、断奶数和出生月份是影响肉兔断奶后窝性状和料肉比的重要因素。本研究的结果为将比利时兔作为杂交的终端父本提供重要依据。     

早期数量限饲对肉用仔鸡生产性能、胴体品质的影响

试验研究了早期数量限饲对肉用仔鸡生产性能、胴体品质的影响。以320只1日龄AA+肉用仔鸡为试验动物。设4个处理组,每个处理组4个重复,每个重复20只肉仔鸡。对照组根据AA+商品代肉鸡营养标准配制。各处理肉用仔鸡1～7日龄均为自由采食,8～14日龄对照组、限饲90%组、限饲80%组和限饲70%组分别饲喂自由采食量的100%、90%、80%和70%,15日龄恢复自由采食,以后按常规饲养管理。每周末,以重复为单位全部称重。分别于42、49日龄,每个重复随机抽取4只肉用仔鸡禁食12h、称重、屠宰、测定屠体品质。试验结果表明:在第2周,限饲各组肉仔鸡的体重和日增重分别显著低于对照组(P0.05);在第3周,限饲90%组完成补偿生长,体重与对照组差异不显著(P0.05);在第4周,限饲80%和70%组完成补偿生长,体重与对照组差异不显著(P0.05);5、6、7周及2～6、2～7周各组在体重、日增重、日采食量和饲料转化率等都无显著差异(P0.05)。早期数量限饲对肉仔鸡胴体特性没有显著影响(P0.05),限饲70%～80%,具有改善饲料转化效率、胸肌率、腹脂率的作用。     

乳酸杆菌(Lactobacillus fermentum 1.2029)对肉仔鸡胴体和肌肉品质的影响

旨在探讨乳酸杆菌对肉仔鸡胴体和肌肉品质的影响。72只1日龄的艾拔益加(AA)肉仔鸡分为2组,每组6个重复,每个重复6只。处理组每天口腔灌服发酵乳酸杆菌(Lactobacillus fermentum 1.202 9),对照组每天口腔灌服生理盐水。42日龄,每个重复随机选取2只鸡宰杀,测定屠宰性能和肉品质。结果表明:乳酸杆菌处理组的腹脂率显著低于对照组(P0.05),胸肌p H值高于对照组(P0.05),且在24 h内,乳酸杆菌处理组胸肌p H的下降速度低于对照组(P0.05);宰后24 h,乳酸杆菌处理组胸肌的亮度值(L*)显著低于对照组(P0.05),而红度值(a*)显著高于对照组(P0.05);乳酸杆菌处理组的胸肌和腿肌的剪切力显著低于对照组(P0.05)。结果提示,乳酸杆菌能够降低肉鸡腹脂的沉积,改善肉仔鸡肌肉的品质。     

商品肉鸡限饲技术

随着肉鸡育种技术的不断发展,肉鸡生长速度愈来愈快。目前国内塑料大棚及其它简陋鸡舍的环境条件与肉鸡的生长发育极不相适应,增重与成活率的矛盾表现的更加突出。考虑到目前国内鸡舍的现实条件,找到肉鸡生长发育的适应原点,现对肉鸡限制饲喂技术进行阐述,期望对广大肉鸡饲养者有所裨益。 1 肉鸡徒长的负影响 1.1 鸡只生长过快,体重的增长与骨骼发育不平衡,导致腿病 肉鸡育种存在着体重迅速增长和骨骼、内脏器官发育缓慢的矛盾。现代育种技术的进步,使肉鸡生长速度越发加快,这一矛盾就更加突出。肉鸡体重增加较快,而鸡腿、脚的骨骼发育缓慢,致使腿脚承受体重压力过大,造成肉鸡腿、脚病的发生。     

Effects of dietary supplementation with carnosine on meat quality and antioxidant capacity in broiler chickens

1. This study aimed to investigate the effects of carnosine supplementation on meat quality, antioxidant capacity and lipid peroxidation status in broiler chickens.

2. A total of 256 1-d-old male Arbor Acres broilers were randomly assigned to 4 treatments consisting of 8 replicates of 8 chickens each. The birds were supplied with 4 different diets: a basal diet or a basal diet supplemented with 100, 200 or 400 mg/kg carnosine, respectively. The whole experiment lasted 42 d.

3. The results showed that dietary supplementation with carnosine linearly increased the values of pH_45 min and redness and reduced drip loss of breast meat. Dietary carnosine increased the activity of antioxidant enzymes in liver, serum and breast meat and decreased the contents of lipid peroxides at 21 and 42 d of age.

4. These findings indicated that dietary supplementation with carnosine was beneficial to enhance meat quality, antioxidant capacity and decrease lipid peroxidation status of breast meat.     

Growth performance and meat quality of broiler chickens supplemented with Rhodopseudomonas palustris in drinking water

1. The effect of the bacterium, Rhodopseudomonas palustris, on the growth performance and meat quality of broiler chickens was investigated.

2. A total of 900-d-old Arbor Acres broilers were allocated to three experimental treatments for 6 weeks. Chicks were administered with R. palustris in drinking water as follows: (i) control group without R. palustris; (ii) treatment 1 (R1) with R. palustris of 8 × 10⁹ cells per chick per day in drinking water; (iii) treatment 2 (R2) with R. palustris of 1.6 × 10¹⁰ cells per chick per day in drinking water.

3. The results showed that, compared with that of control, both groups of R. palustris treatment increased daily weight gain and improved feed conversion ratio of broiler chickens significantly during the whole growing period of 6 weeks.

4. Both total and glutamic acid contents of chicken breast fillet in R. palustris treatment R2 were higher, while the fat content was lower, than those of the control group. Furthermore, R. palustris treatments also improved sensory attributes of chicken breast fillet.

5. As a probiotic providing rich nutrients and biological active substances, R. palustris administration in drinking water displayed a growth promoting effect and improved meat quality of broiler chickens.     

Dietary taurine supplementation enhances antioxidative capacity and improves breast meat quality of broiler chickens

ABSTRACT

1. The aim of this study was to determine the effect of dietary taurine supplementation on growth performance, meat quality and antioxidant responses in breast muscle of broiler chickens.

2. A total of 72 Arbor Acres broiler chickens (28-day-old) with similar body weight were randomly allocated into two groups, and fed either 0 g/kg (control; C) or 5 g/kg taurine-supplemented diets (TS) for 14 days.

3. The results showed that TS had no effect on growth performance or chemical composition of breast muscle in broilers. The drip and cooking losses were significantly decreased (P < 0.05), and the pH_24h of breast muscle were increased (P < 0.05) in the TS group. Meanwhile, broilers in the TS group exhibited significantly higher (P < 0.05) scavenging activities of superoxide and 2,2-diphenyl-1-picrylhydrazyl radicals, and lower (P < 0.05) contents of carbonyl, malondialdehyde, and 4-hydroxynonenal. TS increased (P < 0.05) total antioxidant capacity and superoxide dismutase activities. Moreover, TS significantly upregulated (P < 0.05) the mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1, NAD(P)H quinone dehydrogenase 1, superoxide dismutase, catalase, and glutathione peroxidase.

4. These findings suggested that TS enhanced antioxidative capacity and improved breast meat quality of broilers via activating the Nrf2 pathway.     

Problem of pale soft exudative meat in broiler chickens

1. The occurrence of the pale, soft exudative (PSE) problem in broiler breast meat was monitored in 700 birds (random samples from 7 flocks). A rapid method of colour measurement was used in the plant to assess the colour of skinless pectoralis muscles at 24 h post mortem. In addition, 10 selected samples from each flock were further evaluated for pH, water holding, cook loss, and texture.

2. The average L* value (lightness) was 47.1 with a variance of 5.38, skewness 0.33 and kurtosis 0.66. Minimum and maximum L* values recorded during the study were 35.3 and 55.5 respectively.

3. Correlations between colour and most of the physical measurements were observed, suggesting that a rapid colour measurement method could be used to recognise PSE meat or identify flocks with a high incidence of PSE.

4. Breast muscle samples with L*>49 showed poor water holding capacity, which indicated that these samples would be classified as PSE meat. Using this criterion it was shown that the occurrence of PSE ranged from 0% to 28%. However, the precise cut off point for PSE muscle should be determined by each processor depending on final product requirements.     

Chemical composition and the nutritive quality of different wheat cultivars for broiler chickens

1. Different wheat cultivar samples were grown in replicated trials on a single site in three harvest years. A total of 23 wheat samples were harvested. Nutritionally complete, meal-form diets that included each wheat sample at 650 g/kg were used to compare broiler growth performance and determine apparent metabolisable energy (AME). The relationships were examined between these variables of nutritive value for broilers and the chemical composition and tests of quality on the wheat samples. 2. The total starch contents of the wheat samples ranged from 594 to 732 g/kg dry matter (DM). The mean total non-starch polysaccharide (NSP) content was 100g/kg DM comprising 73.5 g/kg DM of insoluble material. Endosperm hardness ranged between 10 and 77 relative units and Beaver was the softest cultivar in two of the batches of samples. The AME of the wheat-based diets had a maximum range of 0.5 MJ/kg within each of the three batches of wheat that were tested. 3. Endosperm hardness of the wheat grains, within a harvest year, was positively correlated with broiler weight gain and the 1000-grain weight was negatively correlated with feed conversion efficiency (FCE). Starch content and gross energy were positively correlated with determined AME, and DM, 1000-grain weight and water holding capacity were negatively correlated with AME. 4. A step-wise regression technique indicated that endosperm hardness and ash content of the wheat were the explanatory variables that, within harvest years, significantly reduced the unexplained variation in broiler growth rate, feed intake and FCE. The contents of total starch, crude protein and ether extract were the explanatory variables that, within harvest years, significantly reduced the unexplained variation in AME.     

虾青素复合添加剂对肉鸡生长性能及肉质的影响

旨在研究饲粮中添加虾青素复合添加剂对肉鸡生长性能及鸡肉品质的影响。选用1日龄爱拔益加(AA)肉鸡500只,随机分为4组,每组设5个重复,每个重复25只鸡,其中:Ⅰ组为对照组,Ⅱ~Ⅳ组为试验组,分别添加虾青素复合添加剂0、0.5%、1%和1.5%,试验期42 d。结果:试验Ⅲ组和Ⅳ组的平均日增重、饲料转化率显著高于对照组(P0.05),而Ⅲ和Ⅳ组之间差异不显著(P0.05)。各试验组与对照组相比,肌肉亮度(L*)、红度(a*)显著提高(P0.05),黄度(b*)、滴水损失率、蒸煮损失率和剪切力差异不显著(P0.05),Ⅲ和Ⅳ组p H24h值下降速度显著降低(P0.05)。结果提示,肉鸡饲粮中添加虾青素复合添加剂可以提高其生长性能和改善鸡肉品质,添加量以1%为宜。     

Comparative investigations of the feed and nutrient consumption, growth, a nutrient efficiency of broiler chickens under different climatic conditions in Nigeria

Feed intake, growth and blood parameters were studied over 3 years, in 2,300 chickens started either during the cool, dry season or the hot, dry season. From day old to 4 weeks, fed was more efficiently used for growth during the hot, dry season than for the cool, dry season. Using Haemoglobin and Haematocrit as criteria, and on supplementing a practical type ration with copper and iron, it was observed that climatic stress, as distinct from mineral deficiency, plays an important role in the brooding of exotic chickens in the tropics. The importance of this in relation to housing and timing of brooding the chickens by commercial producers was highlighted.     

添加不同水平有机硒对红羽肉鸡生长和饲料报酬的影响

本试验通过研究蛋氨酸硒(Se-Met)对红羽肉仔鸡生产性能、饲料报酬的影响来探讨红羽肉仔鸡有机硒(蛋氨酸硒)的适宜添加量.选择1日龄红羽肉雏鸡180只,分为4组,分别饲喂在玉米-豆粕型基础日粮中分别添加蛋氨酸硒0、0.1、0.3、0.5 mg/kg的试验日粮.试验结果表明:在0～21日龄,0.1 mg/kg的蛋氨酸硒添加量效果最好,可提高日增重17.29%;不同蛋氨酸硒添加水平对红羽肉仔鸡胴体特性无显著影响(P＞0.05);可显著提高红羽内仔鸡的胸肌率与腿肌率(P＜0.05),降低红羽肉鸡的皮下脂肪厚与肌间脂肪宽.     

Reduction of dietary crude protein and feed form: Impact on broiler litter quality,ammonia concentrations,excreta composition,performance, welfare,and meat quality

Nitrogen(N) excreted by poultry is converted to ammonia(NH₃), presenting an environmental risk and a health risk to the farmer and animals. A study was performed to investigate the effect of reduced CP and feed form on broiler performance and welfare, meat and litter quality, N utilization, and NH₃concentrations at litter level. A total of 2,232 Ross 308 male broilers was divided into 6 treatments and 6replicates, which was fed diets in both pellet and mash forms with diffe...     

Protein digestive dynamics of meat and bone meals in broiler chickens

This study determined the variations in protein digestibilities and digestion rates in broiler chickens offered diets containing 7 different meat and bone meals (MBM). A total of 252 male Ross 308 broiler chickens were offered 7 atypical diets largely based on maize and MBM from 24 to 28 d post-hatch. Each experimental diet was offered to 6 replicates with 6 birds per replicate cage. Excreta were collected in their entirety from 25 to 27 d post-hatch and on 28 d post-hatch. Digesta samples were collected from the proximal jejunum, distal jejunum, proximal ileum and distal ileum. Apparent digestibilities of protein were determined in each segment and apparent digestibilities of amino acids were measured in the distal ileum. There were significant differences in apparent protein digestibility coefficients in the proximal jejunum (P = 0.006), where broiler chickens offered the high ash beef meal (diet 7) generated the lowest protein digestibility in the proximal jejunum (0.318). Similarly, there were significant differences in apparent digestibility coefficients in the distal jejunum (P < 0.001) and distal ileum (P < 0.001) but not in the proximal ileum. More pronounced differences were found in the disappearance rate of protein and there were significant differences in all 4 segments of the small intestine (P < 0.001). Broiler chickens offered the high ash beef meal had the lowest protein disappearance rate (P < 0.001). No difference was observed in the predicted protein digestion rate (P = 0.486) but chickens offered the high ash beef meal had the lowest potential digestible protein (0.662, P = 0.034) whereas the highest potential digestible protein (0.739) was detected in diet 5 (containing a beef meal). This study contributed to the establishment of a preliminary database to include digestion rates of starch and protein into practical diet formulation.