Relationship between the weight of hatching eggs and subsequent early performance of broiler chicks

1. The effect of egg weight on the subsequent performance of individual growing chicks was studied. Eggs from commercial broiler breeder hens were collected at 52, 55 and 57 weeks of age and incubated. The chicks were reared for 18 d. 2. Egg weight and hatched chick weight were not affected by the age of the hens during the 52 to 57-week period, but there was a close correlation between egg weight and hatching weight, irrespective of the age of the hens (r = 0.89). Chick:egg weight ratio at hatching was about 0.71 and independent of hen age. One d after hatching, chick weights had decreased by about 1.5 g. 3. The initial high correlation between egg weight and chick weight decreased markedly during post-hatching growth, becoming insignificant 5 d after hatching. At 18 d of age, however, chicks from eggs of older hens tended to be heavier than those from younger birds. The greater 18-d weights appeared to be associated more with higher food intake during that period, than with greater egg weight. 4. It was concluded that, in individual broiler chicks, the advantage of the initially higher weight attributable to a larger egg diminishes rapidly after hatching, and the main factor affecting final body weight is food intake.     

Effects of dietary concentrations of methionine on growth performance and oxidative status of broiler chickens with different hatching weight

1. A study was conducted to evaluate the effects of two hatching weight (HW) levels and two dietary concentrations of methionine on the growth performance and oxidative status of broilers. Male Arbor Acres chickens were divided into two groups on their HW (low and high HW, H and L). Each HW group was then distributed into two subgroups, of similar HW, receiving either low or high dietary concentrations of methionine (4.9 g methionine/kg, LM; 5.9 g methionine/kg, HM). Thus, all day-old birds were distributed into 4 treatments (H-LM, H-HM, L-LM, L-HM) × 6 replicates × 10 birds for 21 d.

2. Broilers with high HW were heavier than those with low HW during the 21 d assay, which appeared to result from increased body weight gain rather than improved feed conversion efficiency. A higher dietary concentration of methionine (5.9 g/kg) improved growth performance of broilers with low HW in terms of body weight gain and feed conversion ratio.

3. Broilers with different HW had similar antioxidant status both in serum and liver.

4. Broilers given a diet containing 5.9 g/kg methionine had enhanced serum superoxide dismutase (SOD) activity and decreased hepatic malondialdehyde (MDA) content at day 7.

5. Broilers given a diet containing 5.9 g/kg methionine had a higher hepatic reduced glutathione (GSH):glutathione disulphide (GSSG) ratio than those given a diet containing 4.9 g/kg methionine at day 21. High dietary methionine concentration reduced hepatic GSH content and glutathione peroxidase (GPX) activity of broilers with high HW at day 7 and at day 21, respectively, but increased hepatic GSH content of broilers with low HW at day 7.

6. Although broilers with different HW had similar oxidative status as indicated by several parameters in blood and liver, HW can have positive effects on the subsequent growth performance of broilers, and a higher dietary methionine concentration (5.9 g/kg) can improve growth performance and antioxidant status in broilers exhibiting low HW.     

Relationship between parental age, egg weight and hatching weight of Japanese quail

1. The relationships between egg weight or age of breeder quails (Coturnix coturnix japonica) and 1-d-old chick weight were determined. 2. Significant correlations were found between egg weight and chick weight (R2 = 0.32) and age and chick weight (R2 = 0.86). Thus, hatching weight was influenced more by the age of breeder quails than by egg weight as such. 3. Chick weight was accurately predicted by the use of age as a single independent variable; egg weight did not explain any further variation.     

本交笼模式对肉种鸡产蛋性能、种蛋品质及繁殖性能的影响

为了研究本交笼对肉种鸡生产性能、种蛋品质及繁殖性能的影响,试验组选择108只29周龄的健康罗斯308肉种鸡,公母比例1∶8,随机分为6笼,每组16只母鸡、2只公鸡,以同舍内"两高一低"平养模式大群为对照组,比较种鸡产蛋性能、种蛋品质、孵化性能及行为差异。结果显示:本交笼养模式下种鸡产蛋率、破蛋率有升高趋势,料蛋比呈下降趋势;与平养模式相比,本交笼养模式下肉种鸡种蛋的平均蛋重极显著提高(P<0.01),蛋形指数显著增加(P<0.05),蛋壳厚度显著增加(P<0.05),蛋壳亮度L值极显著降低(P<0.01);2种饲养模式下,肉种鸡种蛋的受精率、种蛋的孵化率及后代健雏率没有明显差异(P>0.05),但本交笼饲养肉种鸡后代雏鸡初生重显著增大(P<0.01);动物行为观察发现,种鸡在本交笼内自由舒适,分布均匀,饮水采食频率增加,不存在扎堆现象,几乎没有打斗行为,说明本交笼内动物福利水平更高。提示:肉种鸡本交笼养模式可以应用于肉种鸡生产。     

Automatic weight separation of broiler chickens

1. The individual weight gains of 371 broiler chickens in a commercial flock were monitored to establish individual growth patterns.

2. The relationship between early and final body weight was investigated for individual chickens.

3. The feasibility of automatic separation of birds into different weight groups was evaluated and consideration given as to whether this technique could be used for sex‐separation of an as‐hatched flock.

4. The results suggest that the present commercial practice of male selection at flock depopulation may be less reliable than many producers believe.     

贵妃鸡蛋重和繁殖率关系探讨

选２８￣２９周龄贵妃鸡新产种蛋，按蛋重分４组作蛋重和繁殖率关系试验。结果表明，蛋重４１￣４５克组受精率，孵化率和健雏率分别达９８．１１％，９４．２３％和９７．９６％，极显著高于蛋重３０克和３１￣３５克组，４５克内蛋重与三率呈强正相关，小于３０克重组三率极显著低于其它组（Ｐ〈０．０１），试验说明贵刀鸡种蛋最佳蛋重为４１￣４５克，小于３０克的蛋不宜作种用。     

蛋重对蛋鸭孵化效果的影响

将三个品种(攸县麻鸭、麻旺鸭和三穗鸭)种鸭蛋按蛋重各分5个组在相同的条件下孵化,研究蛋重对不同品种孵化效果的影响。结果表明,种蛋受精率和入孵蛋孵化率:攸县麻鸭蛋重在65~73 g最高,麻旺鸭蛋重在66~70 g最高,三穗鸭蛋重在66~74 g最高,种蛋过重或过轻均不利于种蛋孵化。胚胎死亡率:攸县麻鸭在蛋重61~65 g最低,三穗鸭在蛋重小于62 g时最低,麻旺鸭在蛋重小于58 g时最低,攸县麻鸭种蛋重量适中有利于胚胎成活,三穗鸭和麻旺鸭种蛋重量较轻时有利于胚胎成活。     

The relationships between egg weight and yolk weight

Figures on egg weight and yolk weight from a commercial strain of White Leghorn pullets obtained during the early part of their laying year have been analysed to obtain estimates of heritability and phenotypic, genotypic and environmental correlations.

The heritability figure of 0.50 for egg weight agrees with the majority of those in the literature. The larger value of 0.71 derived from the sire component compared with that from the dam component of 0.29 is in agreement with a number of other reports suggesting the existence of sex linkage.

The heritability of yolk weight was estimated to be 0.43 with no difference between estimates derived from sire and dam components. Attention is drawn to the lower precision of the figures based on dam components because of the small number of daughters per dam available.

Correlations between egg weight and yolk weight are high. The phenotypic correlation is 0.58 and the genetic correlation 0.82, whereas the environmental correlation is only 0.33.

Continuing selection for increased egg weight is therefore expected to lead to a concomitant increase in yolk weight nearly as great as that expected from direct selection for yolk weight.

The heritability of the yolk weight/egg weight ratio is low, of the order of 0.20. The negative phenotypic correlation of —0.42 of this ratio with egg weight is the joint effect of a large negative genetic correlation of — 1.00 and a small positive environmental one (0.02). Direct selection for a higher yolk ratio would therefore be tantamount to selecting for small eggs.     

The effect of maternal vitamin D source on broiler hatching egg quality,hatchability, and progeny bone mineral density and performance

Vitamin D is involved in calcium metabolism as well as bone and shell quality, and is therefore important to broiler breeders. In this research we investigated the effects of maternal dietary 25-OH vitamin D₃ on broiler breeder egg quality and hatchability, as well as on progeny bone mineral density and performance. In a field study, all hens were fed 3,000 IU of vitamin D₃ (D) per kilogram of complete feed; in addition half of the hens also received 34.5 µg of 25-OH vitamin D₃ per liter in the drinking water (25OHD). Eggs from each treatment group were incubated and hatched; chicks were fed a common diet and grown to 41 d of age. Eggs from hens in the 25OHD treatment had a nearly 30% reduction in early embryo mortality. However, a larger egg size resulted in greater chick BW for the D chicks, although this did not affect broiler production performance. Broilers from the maternal 25OHD treatment had a lower FCR during the grower phase. Unexpectedly, chick plasma 25-OH vitamin D₃ was only greater for the maternal 25OHD treatment at 4 d of age, but not at hatch, 2, 6, 8, 10, 12, or 14 d of age. Maternal vitamin D₃ source did not affect progeny 41-d bone mineral density. Maternal 25-OH vitamin D₃ had a protective effect on the growing embryo, reducing early embryonic mortality, with minimal effects on progeny performance and bone mineral density to processing at 41 d of age. The previously reported effects of 25-OH vitamin D₃ on increasing broiler performance and breast yield seem to be dependent on supplementation of the broiler diet; a carry-over effect of maternal supplementation is insufficient to achieve these effects.     

用不同消毒剂消毒肉鸡种蛋对孵化效果的影响

肉鸡种蛋从母鸡体内产出后经泄殖腔,到产蛋箱接触垫草和粪便,表面就会逐渐沾染细菌.在贮藏、运送、孵化过程中,种蛋上的致病菌在适宜的温度和湿度条件下,就会迅速繁殖.虽然蛋壳表面上的细菌容易被杀死,但还有相当一部分细菌可以直接通过蛋壳上的微小气孔和蛋壳膜进入蛋内,进行生长繁殖.     

仙湖肉鸭A系种蛋重与蛋形指数对孵化效果的影响

将仙湖肉鸭A系种蛋按蛋重分为7组、按蛋形指数大小分为6组,在相同条件下孵化,结果表明,蛋重不仅对孵化率、死胚率影响较大,而且对受精率亦有影响。当蛋重在95～99g(D组)时,孵化效果最好,种蛋受精率96.18%,受精蛋孵化率高达83.86%,入孵蛋孵化率达80.66%。当蛋重大于110g时,种蛋受精率下降至89.74%,受精蛋孵化率下降至71.43%,入孵蛋孵化率下降至64.10%;当蛋重小于85g时,受精蛋孵化率、入孵蛋孵化率分别下降至73.02%和71.88%。蛋形指数对孵化率、死胚率影响也较大,当蛋形指数为0.66～0.74时,受精蛋孵化率达80%以上,入孵蛋孵化率达76%以上,死胚率小于15%,孵化效果较好,且与其它各组差异显著。     

Effect of low doses of gamma irradiation prior to egg incubation on hatchability and body weight of broiler chickens

1. Four experiments involving 23,800 settable eggs of commercial broiler parent stocks were conducted to determine the effect of gamma irradiation before egg incubation on hatchability and body weight of hatched chicks. 2. Irradiation doses were 0, 0.05, 0.10, 0.15, 0.20, 0.40, 0.80 and 1.2 Grays (Gy) for experiment 1; 0, 0.15 and 1.2 Gy for experiment 2; 0 and 0.15 Gy for experiment 3; 0, 1.6 and 2.1 Gy for experiment 4. Dose rate was about 0.12 Gy/min. 3. Gamma irradiation at doses of 0.05 to 1.6 Gy before incubation did not affect embryo development, whereas a dose of 2.1 Gy was harmful.     

Correlations between changes in intestinal microbiota composition and performance parameters in broiler chickens

Growing male Cobb broiler chickens were fed on diets supplemented with additives reported as able to influence intestinal microbiota composition. The diets used were a balanced commercial diet (no additive), inulin (20 g/kg), fructose caramel (FC, 20 g/kg) and the garlic derivative PTS‐O (propyl propane thiosulfonate, 45 and 90 mg/kg diet). The composition of the intestinal microbiota was analysed by qPCR at different points of the intestinal tract, and a number of nutritional parameters were also determined. The relative amounts of bacteroides (bacteroides/total bacteria) in the ileal contents correlated (p < 0.05) positively with faecal NDF, ADF, hemicellulose and cellulose digestibility. The relative amounts of Escherichia–Shigella (Escherichia–Shigella/total bacteria) in the crop contents correlated (p = 0.05) negatively with weight gain of broilers. Faecal N digestibility correlated (p < 0.05) negatively with total bacteria in the ileal contents of chickens. The relative amounts of Escherichia–Shigella (Escherichia–Shigella/total bacteria) in the caecal contents correlated (p = 0.05) negatively with faecal fat digestibility of broilers. Total bacteria in ileal or caecal contents of growing chickens correlated (p < 0.05) negatively with ileal N digestibility. The results here reported suggest that positive or negative correlations can be found between performance parameters and changes in intestinal microbiota composition of growing broiler chickens.     

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.     

蛋重对海兰褐鸡种蛋孵化率的影响

在相同的饲养条件下,随机选取320枚海兰褐鸡种蛋进行孵化。按蛋重将种蛋分为4组:Ⅰ组(51.0～55.9)g,Ⅱ组(56.0～61.0)g,Ⅲ组(61.1～66.0)g,Ⅳ组(66.1～70.6)g。通过研究比较4组不同蛋重区间内,海兰褐鸡种蛋的受精率和孵化率的变化情况,及胚胎在各胚龄失重和失重率的变化情况。结果表明:(1)Ⅱ组的入孵蛋孵化率分别比Ⅰ组、Ⅲ组、Ⅳ组高9.81%、4.62%、7.11%(P> 0.05)。Ⅱ组的18胚龄失重率分别比Ⅰ组、Ⅲ组、Ⅳ组低10.99%、5.33%、34.82%(P <0.05)。(2)海兰褐鸡种蛋孵化的最佳蛋重区间为56.0～61.0 g。超出此范围,种蛋的受精率和孵化率均有所降低。在生产实践中,必须选择适宜重量的种蛋进行孵化,以保证较好的孵化效果。(3)海兰褐鸡种蛋整个孵化期内,失重过程稳定。入孵蛋重不同,种蛋的失重率不同。失重率越高,种蛋孵化率越低。     

The relationship of right ventricular hypertrophy, right ventricular failure, and ascites to weight gain in broiler and roaster chickens

Nine hundred twenty-five male progeny from 50 sire families of a commercial sire line were weighed at 14, 28, and 47 days and scored for right ventricular hypertrophydilation at 48 days. Broilers with marked hypertrophy of the right ventricle at processing (298 of 925) were significantly heavier than their more normal contemporaries at 14 and 28 days of age. These results suggest that rapidly growing broilers are more susceptible to increased pulmonary arterial pressure resulting in right ventricular hypertrophy, right ventricular failure, and ascites than slower-growing broilers. Thirty-five (3.5% of 997) broilers died from right ventricular failure and ascites, and 14 (1.5% of 925) has ascites at processing. Two hundred fifty-nine sibs were kept on full feed to 16 weeks of age. Between 7 and 16 weeks, 68 (26.3%) of these cockerels died from right ventricular failure and ascites and a further 27 (10.4%) had marked right ventricular hypertrophy-dilation when processed at 16 weeks. Thus most of the 298 broilers classified as having marked right ventricular hypertrophy at 7 weeks would likely have died from right ventricular failure and ascites if they had been kept on full feed until 16 weeks.     

白鹅、籽鹅蛋重和蛋形指数对孵化率的影响

随机选取白鹅和籽鹅种蛋各251枚,测量蛋重和蛋形指数,研究蛋重和蛋形指数对种鹅孵化率的影响,结果表明:白鹅和籽鹅的蛋重分别为128.11±12.04 g,129.25±13.07 g;蛋形指数分别为1.457±0.065,1.457±0.068;白鹅和籽鹅的蛋重、蛋形指数无明显差异;白鹅和籽鹅种蛋孵化率随蛋重、蛋形指数的增加呈现先增大后减小的趋势,白鹅蛋重在131.16～144.88 g范围内,蛋形指数在1.387～1.496范围内种蛋孵化率最高;籽鹅蛋重在137.08～151.04 g范围内,蛋形指数在1.349～1.449范围内种蛋孵化率最高.