八角及其精油和残渣对肉仔鸡生长性能、肠道发育和养分利用率的影响

本试验旨在研究八角及其精油和残渣对肉仔鸡生长性能、肠道发育和养分利用率的影响。采用单因素完全随机试验设计,将1日龄爱拔益加肉仔鸡384只随机分为4组,每组12个重复,每个重复8只。对照组肉仔鸡饲喂玉米-豆粕型基础饲粮,试验组肉仔鸡分别饲喂在基础饲粮的基础上添加5 g/kg八角(八角组)、0.2 g/kg八角精油(精油组)和5 g/kg八角残渣(残渣组)的饲粮。八角组和精油组饲粮中反式茴香脑含量为0.204 g/kg,对照组和残渣组饲粮中反式茴香脑含量低于0.005 g/kg。试验期21 d。结果表明:1)八角组和精油组肉仔鸡平均日增重和平均日采食量显著高于对照组(P0.05),残渣组与对照组没有显著差异(P0.05)。与对照组和残渣组相比,饲粮中添加八角和八角精油显著提高了肉仔鸡21日龄体重(P0.05)。2)与对照组和残渣组相比,八角组和精油组肉仔鸡空肠的相对长度显著提高(P0.05),同时精油组小肠的相对重量显著提高(P0.05);此外,八角组和精油组肉仔鸡空肠的相对重量显著高于对照组(P0.05)。3)与对照组和残渣组相比,饲粮中添加八角和八角精油显著提高了十二指肠和空肠的绒毛高度(P0.05)。4)精油组粗蛋白质的表观和真实利用率及表观和真实代谢能均显著高于其余各组(P0.05)。由此可见,饲粮中添加5 g/kg八角或0.2 g/kg八角精油均可改善肉仔鸡的生长性能、肠道发育,并提高肉仔鸡对养分的消化利用,而添加5 g/kg八角残渣没有此作用效果。     

Effect of dietary Lycium barbarum polysaccharide on growth performance and immune function of broilers

Lycium barbarum polysaccharide (LBP) is a traditional Chinese herbal medicine possessing many properties such as anti-oxidant and immunomodulation. This study was conducted to evaluate the clinical efficacy of LBP in broilers. A total of 240 newly hatched broilers were randomly allotted into 4 treatments with 6 replicates. Diets in 3 treatment groups were supplemented with 2, 4, and 8 g/kg LBP, respectively, based on the control diet. Lymphocytes isolated from broiler blood were used to detect immunoregulation function of LBP in vitro. Results in vivo showed that average daily feed intake (ADFI) and feed conversion ratio (FCR) in the 4 g/kg LBP group were decreased significantly (P < 0.05). Dietary 4 g/kg LBP significantly increased immune organ indexes of broilers at 21 d (P < 0.05). Moreover, levels of serum total protein, globulin, albumin, and lysozyme of broilers were higher in the 8 g/kg LBP group (P < 0.05). CD4⁺/CD8⁺ ratio in blood T cells was higher in the 4 g/kg LBP group (P < 0.05). Results in vitro suggested that 100 and 1,600 μg/mL LBP supplementation significantly promoted blood B and T lymphocyte proliferation of broilers, respectively (P < 0.05). TNF-α mRNA abundance was observably decreased in the lower LBP concentration groups (P < 0.05). In conclusion, LBP may possess the clinical efficacy for growth promotion and immunomodulation and could be used as an alternative for nutritive additive in broilers.     

Anise oil dosage and its effect on growth performance and jejunal lesions during a Clostridium perfringens challenge in battery trials,and growth performance in a floor pen trial,

Anise oil (AO) is a phytochemical with antibiotic properties and it reduces the growth of Clostridium perfringens in vitro, which is the main causal agent of necrotic enteritis. A series of battery experiments was conducted to determine an AO dosage to feed to broilers and its effect during 2 C. perfringens challenges, and a floor pen experiment to determine its effect in performance. Anise oil linearly reduced (P < 0.05) ADFI and ADG, but feeding broilers 500 to 2,000 mg/kg of AO resulted in similar performance with positive control (PC) fed broilers. Broilers were challenged on d 10 (Experiment 2) or on d 10 and 13 (Experiment 3). Broilers fed AO had lower (P < 0.05) ADFI and ADG compared with broilers fed PC from zero to 18 d (Experiment 2). Growth performance of broilers fed AO was not affected (P > 0.05) during Experiment 3. In both challenges, the jejunum of broilers fed AO had fewer and milder (P < 0.05) lesions compared with broilers fed PC or negative control (NC) diets. In a floor pen trial, 1,000 mg/kg of AO was fed to broilers from zero to 42 days. Broilers fed AO or PC had similar (P > 0.10) growth performance for the entire trial. Broilers fed PC or AO had greater ADG (P < 0.05) and tended (P = 0.07) to be heavier than broilers fed NC at the end of the trial. Breast yield percentage was similar (P > 0.10) among broilers fed any of the dietary treatments. Residues of AO were not present at detectable levels in breast meat.     

Dietary organic acid and fiber sources affect performance,intestinal morphology,immune responses and gut microflora in broilers

This experiment was designed to investigate the effects of a dietary organic acid (OA) mixture and 2 fiber sources on performance, intestinal morphology, immune responses and gut microflora in broilers. A total of 390 one-day-old broiler chicks (Ross 308) were allocated to 6 dietary treatments with 5 replicate pens and 13 chicks each based on a factorial arrangement (2 × 3) in a completely randomized design. The experiment lasted 42 d. The following experimental diets and as well as their interaction were considered: a basal diet supplemented with or without OA (0 or 1 g/kg) and 2 fiber sources (sugar beet pulp [soluble fiber] or rice hull [insoluble fiber]; 0 or 30 g/kg). Dietary supplementation of OA increased daily weight gains of broilers across the entire rearing period (P < 0.05). The dietary fibrous materials did not affect the performance of broilers. Antibody titer against influenza disease virus was higher in birds fed diets containing rice hull compared with other experimental groups (P < 0.05). The population of Lactobacillus bacteria was greater in birds fed OA-added diets without or with 30 g/kg rice hull supplementation compared with other experimental groups (P < 0.05). In conclusion, dietary supplemental OA improved performance of broilers, and dietary supplemental OA with rice hull enhanced humoral immune responses.     

Assessment of interactions between glutamine and glucose on meat quality,AMPK, and glutamine concentrations in pectoralis major meat of broilers under acute heat stress

The objective of this experiment was to evaluate the effects of dietary glutamine and glucose on pectoralis major meat quality in broilers under acute heat stress. Three hundred 35-day-old male broilers (Arbor Acres) were randomly divided into 5 groups. Broilers in the positive control group were kept in a thermoneutral environment (23 ± 1°C, RH 45%–55%) and fed a basic diet, whereas the experimental (2 × 2) group was exposed to acute heat stress (34 ± 1°C, RH 65%–75%) for 12 h and fed the basic diet that contained glutamine (0 and 10 g/kg) and glucose (0 and 10 g/kg). Compared with the positive control group, acute heat stress without glutamine and glucose supplementation increased (P < 0.05) drip loss, L* values, and AMPK concentrations, but it decreased (P < 0.05) water-holding capacity, moisture, pH, a* values, b* values, and glutamine concentrations in pectoralis major meat of chickens. However, dietary glutamine (10 g/kg) increased (P < 0.05) water-holding capacity, moisture, pH, a* values, b* values, and glutamine concentrations, while it decreased (P < 0.05) drip loss, L* values, and AMPK concentrations in heat-stressed chicken pectoralis major meat. Dietary glucose (10 g/kg) increased (P < 0.05) water-holding capacity, moisture, pH, and a* and b* values, while it decreased (P < 0.05) L* values and AMPK concentrations of pectoralis major meat in chickens exposed to acute high temperature. There were significant interactions between glutamine and glucose in the water-holding capacity, pH values, AMPK, and glutamine levels of pectoralis major meat in the heat-stressed chickens. The above results suggest that the addition of glutamine and glucose in the diet is necessary for broilers during acute heat stress condition.     

Effect of polyphenols extracted from Tamarind (Tamarindus indica L.) seed coat on physiological changes,heterophil/lymphocyte ratio,oxidative stress and body weight of broilers (Gallus domesticus) under chronic heat stress

The aim of this experiment was to determine the effect of polyphenols extracted from tamarind (Tamarindus indica L.) seed coat on physiological changes, oxidative stress and production of male broilers maintained at high environmental temperatures. The results found that body temperature and respiratory rate of broilers maintained at 38 ± 2°C was higher than broilers maintained at 26 ± 2°C (P < 0.05). On day 1, the heterophil/ lymphocyte ratio of broilers maintained at 38 ± 2°C and received polyphenols at 300 and 400 mg/kg in diets was lower than broilers that received polyphenols at 0 and 200 mg/kg in diets (P < 0.05). At week 1, the malondialdehyde of the broilers maintained at 38 ± 2°C who received polyphenols at 400 mg/ kg in their diet was lower than broilers that received polyphenols at 100 and 200 mg/kg in diets (P < 0.05). At week 1, the body weights of broilers that were maintained at 38 ± 2°C who received polyphenols at 100–500 mg/ kg in diets, and broilers maintained at 26 ± 2°C were higher than that of the control group which had not been treated with a polyphenol diet (P < 0.05). This study indicated that polyphenols could reduce heat stress, oxidative stress and improve the growth rate of heat‐stressed broilers.     

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.     

Effect of Soybean Oil Supplementation to Low Metabolizable Energy Diets on Production Parameters of Broiler Chickens

Two experiments were conducted to study the performance and carcass quality of broilers in response to varying composition of a diet low in ME, through the supplementation of graded levels of soybean oil. In an initial study, isocaloric (2,965 kcal/kg) and isonitrogenous (21.7%) corn-soybean diets were supplemented with 10, 20, or 30 g/kg of soybean oil. In a second experiment, diets containing ME levels of 2,940 and 3,040 kcal/kg were supplemented with soybean oil levels of 20 or 40 g/kg. In both experiments, supplementation of up to 30 or 40 g of oil/kg of diet resulted in increases of 175 and 120 g (P < 0.05) in BW gain and 97 and 91 g (P ≤ 0.06) in ready-to-cook (RTC) carcass weight at 49 d, respectively. There was a linear decrease (P < 0.05) in percentage deposition of abdominal fat pad only in diets containing 2,965 (Experiment 1) or 2,940 (Experiment 2) kcal of ME/kg with no significant changes in RTC carcass and whole breast or pectoralis major muscle yields and RTC carcass composition. Improvements in production parameters can be achieved in broiler chickens fed a low ME diet through the addition of moderate levels of soybean oil.     

Effects of dietary distillers dried grains with solubles (DDGS) on growth performance,oxidative stress,and immune function in broiler chickens

Distillers dried grains with solubles (DDGS) from corn contain relatively large amounts of polyunsaturated fatty acids and some yeast components, which may increase oxidative stress and alter immune function, respectively, when fed to broilers. Therefore, the study was undertaken to assess the effects of distillers dried grains with soluble (DDGS) on broilers under immunosuppressive challenge. One-day-old male broiler chickens (300) were assigned to 2 treatments with 6 replicates pretreatment. Birds were fed diets formulated to contain 0, 15% corn-based DDGS, respectively. The experimental diets were fed for 6 weeks in 2 phases. On day 21, serum IgA, IgG content and malondialdehyde (MDA), glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD), and total antioxidant activity (T-AOC) capacity were analyzed. Chickens were then randomly allotted to 1 of 4 treatment groups: negative control (NC) corn-soybean meal diet without dexamethasone (DEX) challenge, positive control (PC) corn-soybean meal diet with (DEX) challenge, 15% DDGS without DEX challenge (D), 15% DDGS with DEX (D+DEX). Based on these results, dietary DDGS did not influence ADG, ADFI and F:G of 21 d, 28 d and 42 d chicks (P > 0.05), however, DEX affected ADG and F:G of 28 d chicks remarkably (P < 0.05). Relative weights of liver, abdominal fat, spleen, thymus, and bursa were influenced by DEX challenge on d 28 (P < 0.05). DDGS reduced serum T-AOC, T-SOD, whereas increased IgA, IgG and MDA of 21-day-old broilers significantly (P < 0.05). Dietary DDGS also reduced liver T-SOD of 21-day-old broilers significantly (P < 0.05). Based on real-time PCR, 28 d chicks fed DDGS had a greater relative abundance of mRNA encoding IL-4 and IL-6 (P < 0.05), whereas DEX decreased the expression of GPX, IL-6, IL-10 (P < 0.05). Thus, 15% dietary DDGS inclusion has the beneficial effects on immune functions for broilers to some degree.     

Growth performance,economic benefits and sensory characteristics of meat from broilers finished on <Emphasis Type="Italic">Acacia anguistissima</Emphasis> leaf meal-based diets

The objective of the study was to determine growth performance, viscera organ development, economic benefit and sensory characteristics of meat from broilers finished on Acacia anguistissima leaf meal-based diets. One hundred and eighty Cobb 500-day-old chicks were used in the study. Acacia anguistissima was used as a protein source and included in broiler diets at 0, 50 and 100 g/kg. Total feed intake (TFI), average daily gain (ADG), and gain to feed ratio (G:F) and cost benefit analysis were determined. There were no differences in TFI of broilers across treatments diets. Average daily gain and gain to feed (G:F) ratio were low (P?<?0.05) for broilers feeding on diet with100 g/kg acacia meal. Highest returns from weight gain were obtained from broiler chickens fed on diet with 50 g/kg inclusion level of A. anguistissima (P?<?0.05). Intestinal length increased with inclusion level of A. anguistissima whereas liver and spleen weight decreased with inclusion level of A. anguistissima (P?<?0.05). Female consumers gave higher scores for overall flavour intensity than male consumers (P?<?0.05). Treatment diets influenced consumer sensory characteristics of broiler meat (P?<?0.05). High sensory scores were observed for overall flavour intensity (OFI) for both boiled and deep fried meat from broilers fed 100 g/kg A. anguistissima. It can be concluded that A. anguistissima meal can be used effectively up to 50 g/kg in broiler diets without compromising performance of chickens and can influence a few sensory characteristics.     

Effects of star anise (Illicium verum Hook.f.) essential oil administration under three different dietary energy levels on growth performance,nutrient, and energy utilization in broilers

This experiment was conducted to investigate the effect of star anise essential oil (SAO) supplementation in diets with different energy levels on growth performance, nutrient metabolic efficiency of broilers. One hundred and ninety-two Arbor Acres male broiler chicks at 28 days of age were divided into a 3 × 4 factorial arrangement design with three dietary energy levels (13.41, 12.82, 12.23 MJ/kg) and 4 levels of SAO supplementation (0, 200, 400, and 600 mg/kg of diet). Dietary supplementation with SAO increased (p < .05) apparent metabolic efficiency of CP, EE, GE, and all of the amino acids except Trp. Significant interactions were noted between energy level and SAO administration for metabolic efficiency of CP, all of the amino acids except Cys. Inclusion of SAO enhanced apparent nutrient metabolic efficiency of broilers in a dose-dependent manner, birds supplemented with 400 mg/kg of SAO in high-energy diets appeared to contain highest nutrient metabolic efficiency, moreover, the metabolic efficiency of nutrients in low-energy diets along with 200 or 400 mg/kg of SAO was similar with that in high-energy diets without SAO, which indicated that the SAO might ameliorate the negative effects of reduced dietary metabolic energy on nutrient utilization in broilers.     

苯甲酸和精油对肉鸡生长性能、抗氧化状态和肠道微生物群的影响

本研究开展了3个饲养试验,旨在探讨苯甲酸和精油单独或联合使用对肉鸡生长性能、肠道微生物含量及肝脏抗氧化性能的影响。试验1和2均选择1日龄肉鸡450只,分为3组,每组5个重复,每个重复30只。对照组均饲喂相同的基础日粮,试验1处理组肉鸡分别饲喂基础日粮添加1.5和3 g/kg苯甲酸,试验2处理组肉鸡分别饲喂日粮添加2和4 mg/kg精油。试验3选择1日龄肉鸡300只,分为2组,每组5个重复,每个重复30只,对照组饲喂基础日粮,处理组饲喂基础日粮添加1.5 g/kg苯甲酸和4 mg/kg精油。3个试验均开展42 d。结果：试验1,1.5 g/kg苯甲酸组较对照组和3 g/kg苯甲酸组显著提了21和42 d肉鸡的体重及1～21 d、22～42 d、1～42 d日增重（P＜0.05）,同时1.5 g/kg苯甲酸组各阶段肉鸡料重比最低（P＜0.05）。与对照组相比,苯甲酸处理组显著提高了盲肠乳酸菌含量（P＜0.05）,显著降低了盲肠大肠杆菌数量（P＜0.05）。试验2,基础日粮添加4 mg/kg植物精油组42 d肉鸡体重和日增重、盲肠乳酸菌含量（P＜0.05）,料重比和盲肠大肠杆菌数量最低（P＜0.05）。同时,植物精油组较对照组显著提高了肝脏谷胱甘肽过氧化物酶（GSH-Px）和谷胱甘肽-S转移酶（GST）活性（P＜0.05）,显著降低了肝脏丙二醛含量（P＜0.05）。试验3,处理组较对照组显著降低了嗉囊大肠杆菌数量（P＜0.05）。处理组肝脏谷胱甘肽过氧化物酶（GSH-Px）和和谷胱甘肽-S转移酶（GST）活性显著高于对照组（P＜0.05）,但丙二醛含量显著降低（P＜0.05）。结论：日粮添加1.5 g/kg苯甲酸或4 mg/kg精油可以改善肉鸡生长性能,降低肠道有害微生物含量,而苯甲酸与精油无论是单独添加还是联合使用均可以提高肉鸡肝脏的抗氧化状态。 [关键词]苯甲酸|精油|肉鸡|生长性能|抗氧化|微生物     

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.     

Effects of alpha‐lipoic acid supplementation on growth performance,antioxidant capacity and biochemical parameters for ammonia‐exposed broilers

In order to estimate the effect of alpha‐lipoic acid (LA) supplementation on relieving ammonia stress of broilers, 180 22‐day‐old male broilers were assigned to three groups, six replicates in each group and 10 birds per replicate. The three groups were: (1) a control group without ammonia stress; (2) exposure to 70 ppm atmospheric ammonia (AM); (3) exposure to 70 ppm atmospheric ammonia and administration of 300 mg/kg LA (AM + LA). The experimental period was 3 weeks. Results showed that average daily weight gain was increased and feed conversion ratio was decreased in the AM + LA group, compared with the AM group (P < 0.05). Total superoxide dismutase and glutathione peroxidase activities in serum, and glutathione content in liver were higher in the AM + LA group than that in the AM group (P < 0.05); however, serum malondialdehyde content was decreased by LA addition (P < 0.05). Additionally, serum glutamic‐pyruvic transaminase, creatine kinase and lactate dehydrogenase activities were reduced and albumin level was increased by LA addition (P < 0.05). In conclusion, LA addition could relieve ammonia stress to restore broiler production performance to normal levels.     

Effect of thymol on the broiler chicken antioxidative defence system after sustained dietary thyme oil application

ABSTRACT

1. The purpose of this study was to examine if the concentration of thymol as the main compound of Thymus vulgaris essential oil (TEO) influenced the antioxidant defence system in broilers.

2. Twenty-four broiler chickens were randomly divided at the day of hatching into three dietary treatment groups (0%, 0.05% and 0.1%, w/w TEO) with eight birds in each and were fed until four weeks of age.

3. Thymol content in plasma, duodenal wall and breast muscle significantly increased when 0.1% of thyme oil was added to the diet (P < 0.05). Thymol concentration in plasma significantly correlated with levels measured in the duodenal wall and feed (r_s = 0.7857, P < 0.05; r_s = 0.7647, P < 0.05). Superoxide dismutase (SOD) activity increased, and malondialdehyde (MDA) concentration decreased significantly (P < 0.05) in blood from chickens fed 0.1% TEO supplementation. Although the thymol concentration did not significantly decrease MDA amounts in breast muscle, a declining trend was observed.

4. The trial data confirmed the efficient absorption of thymol from the digestive tract into the systemic circulation, but only traces were found in breast muscle. Thymol content was sufficient for expressing its antioxidant properties in blood, but its low content in breast muscle was insufficient to significantly affect lipid oxidation and fatty acid composition.     

Effects of dietary 1 alpha-hydroxycholecalciferol in calcium and phosphorous-deficient diets on growth performance,tibia related indices and immune responses in broiler chickens

This experiment was conducted to investigate the effect of dietary 1α-hydroxycholecalciferol (1α-OH-D₃) in calcium (Ca)- and phosphorous (P)-deficient diets on growth performance, carcass characteristics, tibia related parameters, and immune responses of broiler chickens. A total of 280 one-day-old broiler chickens (Ross 308) were assigned to 20 floor pens and 4 dietary treatments with 5 replicates. Dietary treatments consisted of starter diets (starter diet of treatment A: 1% Ca, 0.73% total phosphorus [tP]; starter diet of treatment B: 0.85% Ca, 0.64% tP + 5 μg/kg of 1α-OH-D₃; starter diet of treatment C: 0.85% Ca, 0.59% tP + 5 μg/kg of 1α-OH-D₃; starter diet of treatment D: 0.85% Ca, 0.54% tP + 5 μg/kg of 1α-OH-D₃), grower diets (grower diet of treatment A: 0.86% Ca, 0.68% tP; grower diet of treatment B: 0.73% Ca, 0.59% tP + 5 μg/kg of 1α-OH-D₃; grower diet of treatment C: 0.73% Ca, 0.55% tP + 5 μg/kg of 1α-OH-D₃; grower diet of treatment D: 0.73% Ca, 0.50% tP + 5 μg/kg of 1α-OH-D₃) and finisher diets (finisher diet of treatment A: 0.81% Ca, 0.64% tP; finisher diet of treatment B: 0.68% Ca, 0.56% tP + 5 μg/kg of 1α-OH-D₃; finisher diet of treatment C: 0.68% Ca, 0.52% tP + 5 μg/kg of 1α-OH-D₃; finisher diet of treatment D: 0.68% Ca, 0.48% tP + 5 μg/kg of 1α-OH-D₃). Results showed that body weight gain (BWG) and feed intake (FI) of broilers in treatment B were similar to those of broilers in treatment A at the end of the trial (P < 0.05). Broilers in treatments C and D had lower BWG and FI than those in treatment A during the whole trial (P < 0.05). Feed conversion ratio, carcass traits and relative weight of lymphoid organs were not affected by dietary treatments (P > 0.05). Dietary treatments had no significant effect on antibody titers against Newcastle and Influenza disease viruses as well as sheep red blood cells. Dietary treatments had no significant effects on tibia ash and tibial dyschondroplasia score. Broilers fed Ca-P deficient diets had lower tibia Ca and P than those in treatment A (P < 0.05). In conclusion, results indicated that broilers fed Ca-P deficient diets supplemented with 5 μg/kg 1α-OH-D₃ failed to achieve the same tibia Ca and P values as broilers fed nonphytate phosphorus adequate diets.     

Effect of dietary supplemental ascorbic acid and folic acid on the growth performance,redox status,and immune status of broiler chickens under heat stress

This experiment was conducted to investigate the effects of dietary supplemental L-ascorbic acid (AA) and folic acid (FA) on broiler chickens under heat stress (HS) conditions when supplemented either alone or in combination. For this aim, the effect of these supplements on the broilers’ growth performance, some blood parameters, antioxidant, and immune status were evaluated. Hatchling Cobb-500 broilers (total = 240) were fed either corn and soybean meal-based diet (control group) or basal diet supplemented with 200 mg AA/kg diet, 1.5 mg FA/kg diet, or 200 mg AA plus 1.5 mg FA/kg diet, for 35 days during the summer months (n = 6 replicates/group, 10 birds/replicate). The minimum and maximum average temperatures ranged from 84.5 to 96.2 °F, and the relative humidity ranged from 68.5 to 76.5%. Supplemented vitamins either alone and (or) in combination increased (P < 0.01) broilers’ growth performance, thyroid hormones levels, insulin growth factor1, blood hemoglobin, total protein, albumin, globulin, heat shock protein70, total antioxidant capacity, catalase enzyme activity, superoxide dismutase enzyme activity, antibody titer against Newcastle disease virus, and decreased (P < 0.01) heterophil/lymphocytes. The effects (P < 0.01) of the supplemented vitamins on the analyzed parameters were better when they were added in combination. In conclusion, the combination of AA and FA at 200 and 1.5 mg/kg, respectively, increased the broilers’ antioxidant status with coordinated improvement in the growth performance and health status under HS.

     

Growth,digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp Ctenopharyngodonidella fed graded levels of dietary threonine

Background

This study was carried out to investigate effects of threonine levels on growth, digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp (Ctenopharyngodonidella).

Results

Weight gain, specific growth rate, feed intake and feed efficiency were significantly improved by dietary threonine (P < 0.05). Intestinal activities of trypsin, chymotrypsin, alpha-amylase, lipase, alkaline phosphatase, γ-glutamyl transpeptidase and creatine kinase took the similar trends. Contents of malondialdehyde and protein carbonyl in intestine and hepatopancreas were significantly decreased by dietary optimal threonine supplementation (P < 0.05). Anti-superoxide anion capacity, anti-hydroxyl radical capacity, glutathione content and activities of superoxide dismutase, catalase and glutathione-S-transferase in intestine and hepatopancreas were enhanced by dietary threonine (P < 0.05).

Conclusions

Dietary threonine could improve growth, enhance digestive and absorptive capacity and antioxidant status in intestine and hepatopancreas of sub-adult grass carp. The dietary threonine requirement of sub-adult grass carp (441.9-1,013.4 g) based on weight gain was 11.6 g/kg diet or 41.5 g/kg of dietary protein by quadratic regression analysis.     

Effects of dietary inclusion of fermented cottonseed meal on growth, cecal microbial population, small intestinal morphology, and digestive enzyme activity of broilers

Two experiments were conducted to test the feeding value of fermented cottonseed meal (FCSM) in broilers. In experiment 1, 480 1-day-old male yellow-feathered broilers were allocated into 4 dietary treatments with 6 replicates (20 birds per replicate) to examine the effects of FCSM on the growth response of chickens. Experimental feeding was performed for 6 weeks in two phases (starter, days 0 to 21; finisher, days 22 to 42). FCSM was used at 0, 40, 80, and 120 g/kg levels to replace soybean meal in the basal diet. The dietary inclusion of 40 and 80 g/kg FCSM increased (quadratic (Q): p?<?0.01) the body weight gain of broilers in the starter and in the overall feeding periods. Experiment 2 determined the effect of FCSM on the cecal microbial populations, intestinal morphology, and digestive enzyme activity of broilers. The number of lactobacilli in the cecal digesta increased at day 21 (p?<?0.01) and day 42 (linear (L): p?=?0.01). Coliform bacteria counts decreased (L: p?<?0.05) with the increasing inclusion of FCSM at day 21. The inclusion of FCSM increased (L–Q: p?<?0.05) villus height in the duodenum and linearly elevated (p?<?0.05) villus height and the villus height to crypt depth ratio in the jejunum at day 21. Similar improvement (L: p?<?0.05) was noted in jejunal villus height at day 42. The inclusion of FCSM improved (p?<?0.05) the activities of amylase and protease at day 21, as well as protease at day 42. In conclusion, the appropriate inclusion of FCSM improves growth, cecal microflora, intestinal morphology, and digestive enzyme activity in yellow-feathered broilers.     

Growth performance,apparent nutrient digestibility,caecal fermentation,ileal morphology and caecal microflora of growing rabbits fed diets containing probiotics and prebiotics

Ninety eight male, mixed breed weaner rabbits were used in a 70 day feeding trial to study the performance, apparent nutrient digestibility, caecal fermentation, ileal morphology and caecal microflora of growing rabbits fed diets containing Prediococcus acidilactis (1×10¹⁰ cfu/g; 0.5 g/kg), Bacillus cereus (1×10⁹ cfu/g; 0.5 g/kg), mannan oligosaccharides (MOS; 1 g/kg), arabinoxylans oligosaccharides (AX; 1 g/kg), oxytetracycline (1 g/kg), or synbiotics (TGI; 1 g/kg). A basal diet containing no feed additive was formulated. There were 14 rabbits per treatment. Rabbits fed diets containing MOS had the highest (P<0.05) final live weight and weight gain. Dietary inclusion of prebiotics (MOS, AX) resulted in higher (P<0.05) weight gains and improved feed to gain ratios. Rabbits fed diets containing MOS showed the highest (P<0.05) while those fed diets containing probiotics (Prediococcus acidilactis, Bacillus cereus) had the least (P<0.05) caecal total volatile fatty acid (VFA) concentration. Rabbits fed diets containing prebiotics (MOS, AX) had longer ileal villi than groups fed with other treatments (P<0.05). Inclusion of various additives showed reduced caecal coliform counts. The lowest (P<0.05) lactobacillus count was obtained in the caecal content of rabbits fed diets containing MOS. Poor growth response was obtained with rabbits fed diets containing Prediococcus acidilactis or Bacillus cereus while inclusion of prebiotics in growing rabbits resulted in improved growth and gut morphology. Rabbits fed diet containing MOS showed the highest overall final live weight, weight gain, total VFA concentration and reduced caecal lactobacillus count.