鸡胚注射肉碱对肉鸡孵化率、生长和屠宰性能的影响

文章旨在研究体外鸡胚注射肉碱对肉鸡孵化率及出壳后49 d肉鸡生长性能和屠宰性能的影响。鸡胚在孵化第18天通过羊膜注射0.6、2.4和9.6 mg左旋肉碱/100μL稀释液,此外还有3个对照组(非注射组、穿孔组和注射稀释液组),评估肉鸡孵化率、生长期肉鸡死亡率、增重、采食量和料比以及屠宰性能指标(屠宰率、腹脂、小腿肌、大腿肌、鸡翅和胸肌占比)。结果发现:鸡胚注射左旋肉碱对受精蛋孵化率无显著影响(P>0.05),但随左旋肉碱注射量的增加,受精蛋孵化率和仔鸡出壳时间有升高趋势(P=0.08)。鸡胚注射左旋肉碱对出壳后49 d肉鸡生长性能、死亡率及屠宰性能指标均无显著影响(P>0.05)。结论:鸡胚注射0.6、2.4和9.6 mg左旋肉碱/100μL稀释液对出壳后肉鸡生长性能和屠宰性能无显著影响,但可以改善肉鸡出壳时间和受精蛋孵化率。     

肉仔鸡胚期给养研究进展

随着现代肉仔鸡出栏时间不断提前,早期营养的重要性日益凸显。肉仔鸡孵化后期胚蛋内营养储备不足,不能完全满足出壳后快速发育的需求,加之出壳肉仔鸡普遍存在开食延迟的情况,极易造成雏鸡前期生长迟缓。在胚胎孵化期适时提供营养可以达到促进机体发育和机体健康的目的。文章从肉仔鸡出壳前后的营养特征,胚蛋给养的方法,胚蛋给养各种营养素或活性物质对肉仔鸡的作用效果等几方面进行了综述,以期为肉仔鸡胚蛋营养研究提供参考,为肉鸡产业从业者提供新的思路。     

影响鸡种蛋孵化率的因素

鸡种蛋孵化率的高低是决定种鸡场和养鸡行业的关键一步，作者就影响鸡胚发育的因素进行了简要叙述，以便更好的指导种鸡孵化生产。     

稀土对鸡胚细胞生长影响的探索

稀土对鸡胚细胞生长影响的试验结果表明,CL-1.CL-3.STV-2等三种剂型的稀土。在5ppm 时对鸡胚细胞均有促进生长的作用。其中 STV-2作用最佳。剂量过小时,作用不明显;剂量过大则呈现抑制作用。     

氦氖激光照射对鸡胚孵化率及雏鸡病的效应

本文扼要综述了氦氖激光照射提高孵化率,防治雏鸡病和激光照射剂量以及作用机制的研究情况。     

肉仔鸡可消化氨基酸营养的研究进展

肉仔鸡生长对蛋白质的需要实质上是对氨基酸的需要,但是不同饲料原料中氨基酸的消化率存在差异（计成等,１９８４）,因此用总氨基酸需要量为标准来配制肉鸡日粮往往不准确,而用可消化氨基酸更能反映肉仔鸡的实际需要量。从８０年代开始,各国科学家都对肉仔鸡可消化氨基酸的需要量作了大量研究,并取得了可喜成果,现将世界各国在这方面的研究进展综述如下。１　可消化氨基酸的概念及测定方法可消化氨基酸是指能通过肠壁被吸收的氨基酸。氨基酸的消化率分为表观消化率和真消化率,表观消化率扣除内源性的影响就得到真消化率。从理论上讲…     

胚蛋给养β-羟基-β-甲基丁酸对肉仔鸡生长性能、胴体组成和血浆激素指标的影响

β-羟基-β-甲基丁酸( HMB),是一种促进肌肉生长的营养补剂,本试验目的旨在探讨胚蛋给养HMB对肉仔鸡生长性能、胴体组成、肌肉品质、血浆生化和激素指标的影响。选用260枚爱拔益加( AA)肉鸡商品代受精蛋,随机分为2个组,分别在17.5胚龄向羊膜腔内无菌注射1 mL 0.1% HMB或等量的生理盐水(对照组)。出壳后,从每个组中各选取48只体重相近健康公雏随机分成6个重复,每重复8只,饲养试验期42 d。结果表明：1)与对照组相比,胚蛋给养HMB对肉仔鸡孵化率无显著影响( P>0.05),肉仔鸡的体重在1、21和42日龄时分别提高了1.9(P<0.05)、41.8(0.050.10);HMB组肉仔鸡的平均日增重在1~21日龄和1~42日龄均高于对照组(0.050.05);胚蛋给养HMB对肉仔鸡的胸肉品质无显著影响( P>0.05)。3)胚蛋给养HMB对肉仔鸡的肝脏和免疫器官指数均无显著影响( P>0.05)。4)胚蛋给养HMB对肉仔鸡血浆生化指标(总蛋白、尿酸、肌酐含量)以及甲状腺激素、生长激素和胰岛素含量均无显著影响( P>0.05)。综合本试验结果,胚蛋给养HMB可促进雄性肉仔鸡生长前期的平均日增重和肌肉发育,随日龄增加促生长作用逐渐减弱,且促生长作用与血浆甲状腺激素、生长激素和胰岛素含量变化无关,其机理有待进一步研究。     

In ovo feeding of creatine pyruvate modulates growth performance,energy reserves and mRNA expression levels of gluconeogenesis and glycogenesis enzymes in liver of embryos and neonatal broilers

The effects of in ovo feeding (IOF) of creatine pyruvate (CrPyr) on the growth performance, energy reserves and mRNA expression levels of gluconeogenesis and glycogenesis enzymes in liver of late‐term embryos and neonatal broilers were investigated. After candling on 16 day of incubation, a total of 960 eggs were randomly assigned to three treatments: (i) non‐injected control, (ii) saline group injected with 0.6 ml of 0.75% physiological saline and (iii) Creatine pyruvate group injected with 0.6 ml of physiological saline containing 12 mg CrPyr/egg. After hatching, 120 male chicks with average body weight (BW) were randomly allocated into each treatment group for a 7‐day feeding trial. The results showed that broilers subjected to CrPyr treatment had higher BW than those of the control and saline groups on 1, 3 and 7 day post‐hatch, as well as the yolk sac weight on 19 day of incubation (19 E), the day of hatch and 3 day post‐hatch (p < .05). Compared with the control and saline groups, IOF of CrPyr increased the plasma creatine concentration on the day of hatch, and the plasma pyruvate concentration on the day of hatch and 3 day post‐hatch (p < .05). Moreover, IOF of CrPyr increased the liver pyruvate and glucose concentrations on 19 E and the day of hatch, and the liver glycogen concentration during the experiment (p < .05). Broilers in the CrPyr group showed increased mRNA expression levels of pyruvate carboxylase (PC), phosphoenolpyruvate carboxykinase (PEPCK) and glycogen synthase 2 (GYS2) on 19 E and the day of hatch (p < .05). These results indicated that IOF of CrPyr increased energy reserves in liver of embryos and neonatal broilers possibly through upregulating the mRNA expression levels of PC, PEPCK and GYS2, which could benefit the increase of BW in broilers on 7 day post‐hatch.     

Effects of guanidinoacetic acid on growth performance,creatine metabolism and plasma amino acid profile in broilers

The objective of this study was to assess the effects of guanidinoacetic acid (GAA) on growth performance, creatine deposition and blood amino acid (AA) profile on broiler chickens. In Exp. 1, a total of 540 one‐day‐old Arbor Acres male broilers (average initial body weight, 45.23 ± 0.35 g) were divided randomly into five treatments with six replicates of 18 chicks each. Broilers were fed corn–soybean meal‐basal diets supplemented with 0, 600, 800, 1,000 or 1,200 mg/kg GAA for 42 days respectively. Results showed that dietary GAA inclusion increased average daily gain (ADG) and improved gain‐to‐feed ratio (G:F) from 1 to 42 days (p < 0.01). However, average daily feed intake was unaffected by dietary supplementation of GAA. As GAA inclusion increased, the contents of creatine in plasma and kidney were increased (linear, p < 0.01), while the contents of GAA and creatine in liver were decreased (linear, p < 0.01). Similarly, GAA supplementation was inversely related to concentrations of most essential AA in plasma. In Exp. 2, a total of 432 one‐day‐old Arbor Acres male broilers (average initial body weight, 39.78 ± 0.58 g) were divided randomly into four treatments with six replicates of 18 chicks each. Birds were fed a corn–soybean meal‐basal diet supplemented with 0, 200, 400 or 600 mg/kg GAA for 42 days respectively. Dietary inclusion of 600 mg/kg GAA significantly increased ADG and G:F of broilers (p < 0.05). In conclusion, dietary supplementation of 600–1,200 mg/kg GAA can effectively improve the growth performance in broiler chickens by affecting creatine metabolism and utilization efficiency of essential AA, and 600 mg/kg GAA is the minimum dose for improving performance.     

Response of in ovo administration of zinc on egg hatchability and immune response of commercial broiler chicken

An experiment was conducted to determine the effect of in ovo administration of different forms of zinc with respect to hatchability and performance of commercial broiler chicken. In trial 1, the fertile eggs on day 18 were divided into six treatment groups: Group I as control without any supplementation of zinc, group II to IV were supplemented with 0.5 mg zinc per egg as zinc sulphate, zinc methionine or nano zinc, respectively, and Group V with nano zinc at 0.25 mg zinc per egg. Sixth group received 0.5 ml citric acid per egg as sham control. The results of the first trial indicated that in ovo administration of nano zinc at both levels and zinc methionine resulted in complete failure of hatchability. A second trial to validate the result of trial 1 consisted of Group I control (no administration). Group II and Group III were supplemented with zinc sulphate and zinc methionine, respectively, at 0.5 mg zinc per egg. Group IV and Group V were supplemented with nano zinc at 0.04 and 0.08 mg per egg. In the second trial, again there was a similar pattern for zinc sulphate and zinc methionine. Administration of Zn by nano form had around 80% hatchability on fertile eggs in comparison with the unadministered control eggs (92%). There was no difference (p > .05) in body weight gain, feed intake and FCR. No difference (p > .05) was observed between treatments for cell‐mediated immune response and humoral immune response. Nano Zn‐administered group showed a non‐significant downregulation of MUC2 gene. It could be concluded that in ovo administration of higher levels of zinc has to be with caution for the developing embryo of commercial broiler chicken.     

Effects of in ovo injection of chrysin,quercetin and ascorbic acid on hatchability,somatic attributes,hepatic oxidative status and early post‐hatch performance of broiler chicks

An experiment was conducted to evaluate the effects of in ovo injection of chrysin, quercetin and ascorbic acid on hatchability, somatic attributes, hepatic antioxidant status and early post‐hatch growth performance of broiler chicks. Four hundred and eighty embryonated broiler breeder eggs containing live 18‐day‐old embryos were divided into six groups of 80 eggs each. One group remained intact and served as a control group (i), whereas the other five groups were injected with the prepared injection solutions as follows: (ii) 0.05 ml distilled water; (iii) 0.05 ml distilled water containing 6 mg ascorbic acid; (iv) 0.05 ml dimethyl sulfoxide (DMSO); (v) 0.05 ml DMSO containing 4.5 mg quercetin; and (vi) 0.05 ml DMSO containing 4.5 mg chrysin. The hatchability rate, hatching weight, residual yolk sac weight, yolk sac‐free body weight, liver weight, hepatic glutathione peroxidase and total superoxide dismutase activities, as well as malondialdehyde concentrations, were not affected by the injected solutions. There were no differences between chicks hatched from the control and in ovo injected eggs in weight gain, feed intake and feed conversion ratio from 0 to 11 days of age. However, the specific contrast performed between the in ovo injected groups and intact eggs revealed that in ovo injection significantly increased hatchability rate (p = .0493). This finding also implies that our injection procedure was harmless. In conclusion, the intra‐egg injection of chrysin, quercetin or ascorbic acid at the injection rates used in this study did not have a significant effect on hatchability, somatic characteristics, early growth performance and hepatic antioxidant status of broiler chicks. However, the overall hatchability was higher in the in ovo injected eggs as compared to non‐injected ones. These findings also confirmed the harmlessness of the procedure developed for in ovo injection in this study.     

理想氨基酸水平对肉仔鸡生产性能和屠体性状的影响

试验选用1日龄爱拔益加商品代肉仔鸡600只(公母各半),随机分为3个组,每组8个重复,每个重复25只鸡。分别饲喂高、中、低理想氨基酸水平的日粮,研究理想氨基酸水平对肉仔鸡生产性能和屠体性状的影响。结果表明,0~44日龄中氨基酸水平组和高氨酸水平组的出栏重显著高于低氨酸水平组(P<0.05)。高氨基酸水平组腹脂率显著低于低氨基酸水平组41.63%(P<0.05);高氨基酸水平组大腿肉率和净腿肉率均显著高于中和低氨基酸水平组(P<0.05)。     

Effects of in ovo feeding with glycerol for broilers

The objective was to evaluate the effect of in ovo feeding with glycerol on post‐hatch development in broiler chicks. A total of 408 fertile eggs were divided into six experimental groups consisting of five 0.9% saline solutions containing various concentrations of glycerol (12.5, 25.0, 37.5 and 50.0 nmol/ml), and a placebo group (inoculation with saline only) and a control group (without inoculation). Inoculations were performed at 17 days of incubation for the evaluation of hatchability, embryo mortality, body and viscera weights, intestinal epithelium morphometry, blood glucose and liver glycerol kinase activity of chicks at hatching. Inoculation of solutions containing glycerol did not influence body weight at hatching and relative weights of liver, pancreas, intestine and breast. There was a quadratic effect of glycerol levels on the weights of yolk residue and gizzard and on blood glucose, and an increasing linear effect on spleen and heart weights. Higher duodenum and ileum villous height and deeper jejunum and ileum crypts were obtained with 50.0 nmol/ml of glycerol. A linear increasing effect was also observed in liver glycerol kinase activity; however, lower blood glucose was observed with 37.5 and 50 nmol/ml of glycerol. It is therefore concluded that glycerol may be used at doses of 25 nmol/ml as a substrate in in ovo feeding of broiler chickens. However, further studies must be conducted not only to establish an optimal dose but also to evaluate the combination of this substrate with other nutrients used in the in ovo feeding.     

In ovo injection of branched‐chain amino acids: Embryonic development,hatchability and hatching quality of turkey poults

In this study, the influence of a branched‐chain amino acid blend (BCAA composed of 3 l ‐leucine:1 l ‐valine:2 l ‐isoleucine) injected into the amniotic fluid was evaluated for embryonic growth, yolk‐sac (YS) utilization and development of gastrointestinal tract (GIT) and skeletal muscles of turkey embryos from day 24 of incubation (24E) to hatching, together with hatchability, poult quality and liver L* (lightness), a* (redness) and b* (yellowness) values at hatch. At day 22 of incubation, embryonated eggs (n = 240) were assigned to three treatments, that is, eggs were not injected (control, NC) or injected with 1.5 ml sterile solution with 0.9% salt (SA) or 0.2% BCAA blend (BCAAb). These solutions were injected manually into the amniotic fluid of the embryonated eggs. To determine weights and lengths (where appropriate) of the studied organs and tissues, four embryonated eggs and poults per treatment were selected at 24E and at hatch. While the BCAAb decreased the YS and embryo weight, hatchability and the liver L* value, it increased the weight and quality of poults and the weights of breast and thigh muscles at hatch. In conclusion, the in ovo feeding of the BCAA blend negatively affected hatchability but positively affected hatching weight and poult quality by improving development of skeletal muscles and by regulating energy metabolism.     

Effect of arginine and threonine administered in ovo on digestive organ developments and subsequent growth performance of broiler chickens

This trial was conducted to investigate the effect of arginine (Arg), threonine (Thr) and Arg + Thr administered in ovo on growth performance, digestive organs and intestinal morphology in broiler chickens. On day 14 of incubation, 400 fertile eggs were randomly allotted to five experimental treatments through injection in the amniotic fluid including: (i) control (none injected), (ii) sham (0.5 ml of 0.5% saline), (iii) Arg (35 mg/egg), (iv) Thr (25 mg/egg) and (v) Arg + Thr (35 + 25 mg/egg). After hatching, chicks were given a commercial corn–soya bean diet up to 42 days of age. Daily feed intake (FI) and body weight (BW) of chicks were measured during different periods of the trial. Digestive organs were measured for their relative weight and intestinal length on days 11 and 42 of age. Intestinal morphometric traits were evaluated on day 11 of the experiment. Supplementing amino acids affected the performance of broiler chicks as Thr significantly increased FI and BW across starter, grower and finisher periods compared with sham and control (p < 0.05). Furthermore, Arg + Thr injection increased jejunal weight compared with control on day 42 (p < 0.05). Moreover, Arg inclusion led to the greatest villus height and crypt depth among treatments in duodenum (p > 0.05); however, amino acid supplemented groups had lower villus height than control in jejunum (p < 0.05). Negative correlations found between digestive organs related to day 11 of age containing pancreas (r = ?0.484; p = 0.030), duodenal (r = ?0.577; p = 0.007) as well as ileal lengths (r = ?0.471; p = 0.035) and FI of entire period. Otherwise, positive relationships were observed between duodenum (r = 0.580; p = 0.007) and ileum (r = 0.582; p = 0.007) weights on day 42 and FI of chickens across the entire phase. In conclusion, Arg and particularly Thr injection into amnion can improve FI and post‐hatch growth performance of chickens which may be mediated by the development of digestive organs.