饲粮中添加植物精油对黄羽肉种鸡产蛋性能、蛋品质、孵化性能、生殖器官发育以及血浆和肝脏生化指标的影响

本试验旨在研究饲粮中添加植物精油对黄羽肉种鸡产蛋性能、蛋品质、孵化性能、生殖器官发育以及血浆和肝脏生化指标的影响。选择288只产蛋率和体重接近的45周龄岭南黄羽肉种母鸡,随机分为4个组,每组6个重复,每个重复12只鸡。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加10、20、30 mg/kg植物精油。试验期10周。结果显示:1)饲粮中添加植物精油对黄羽肉种鸡的平均日产蛋重、料蛋比、平均蛋重、产蛋率、合格蛋率均无显著影响(P>0.05)。2)对照组的蛋白高度显著低于其他各组(P<0.05),对照组的哈氏单位显著低于10和20 mg/kg植物精油组(P<0.05),对照组的蛋壳厚度显著低于20 mg/kg植物精油组(P<0.05)。3)对照组的受精蛋孵化率显著低于10 mg/kg植物精油组(P<0.05)。4)对照组的卵巢系数显著低于10和20 mg/kg植物精油组(P<0.05),对照组的输卵管重量和输卵管系数显著低于10 mg/kg植物精油组(P<0.05)。5)对照组的血浆低密度脂蛋白胆固醇含量显著高于20 mg/kg植物精油组(P<0.05),对照组的肝脏甘油三酯含量显著高于10 mg/kg植物精油组(P<0.05)。由此可知,饲粮中添加植物精油不影响黄羽肉种鸡的产蛋性能,但能够改善蛋品质,提高受精蛋孵化率和生殖器官(输卵管和卵巢)系数,降低血浆低密度脂蛋白胆固醇含量和肝脏甘油三酯含量。本试验条件下,产蛋期黄羽肉种鸡饲粮植物精油适宜添加水平为10~20 mg/kg。     

Effect of dosage and application mode of l‐carnitine on plasma lipid and egg‐yolk cholesterol of turkeys,hatchability of eggs and post‐hatch growth of their offsprings

The effect of dosage and application mode of l ‐carnitine on plasma lipid and egg‐yolk cholesterol of breeder turkeys, hatchability of eggs and post‐hatch growth response was investigated using 180 breeder hens. The hens were assigned to six dietary treatments in a 2 × 3 factorial arrangements of two application modes of l ‐carnitine (diet and drinking water) supplemented at 0, 50 and 100 ppm (mg/kg or mg/l) levels, respectively. Each treatment was replicated five times with six hens per replicate. Dietary inclusion of 50 ppm l ‐carnitine showed the lowest (p < 0.01) plasma total cholesterol (TC) and low‐density lipoprotein concentration (LDL). Breeder hens offered 50 ppm l ‐carnitine with no regard to application mode recorded the highest (p < 0.01) plasma high‐density lipoprotein (HDL). Hens offered 50 and 100 ppm l ‐carnitine irrespective of application mode also showed reduced (p < 0.01) egg‐yolk TC concentration at 32 weeks of age. Dietary supplementation of 50 ppm l ‐carnitine for breeder turkeys recorded the lowest (p < 0.01) egg‐yolk triglyceride (TG) at 40 weeks of age. Hens offered 50 ppm l ‐carnitine irrespective of application mode recorded the highest (p < 0.05) hen‐day egg production. Incidence of dead‐in‐shell also reduced (p < 0.05) with increasing dosage of l ‐carnitine. Dietary supplementation of 50 ppm and oral application in drinking water of 100 ppm l ‐carnitine for breeder turkeys resulted in highest (p < 0.05) egg fertility. Offsprings from breeder hens fed diets supplemented with l ‐carnitine recorded no post‐hatch mortality. Highest (p < 0.05) post‐hatch final live weight and weight gain was obtained with poults obtained from hens fed diet supplemented with 50 ppm l ‐carnitine. In conclusion, dietary supplementation of 50 ppm l ‐carnitine for turkey hens showed improved serum lipid profile, egg fertility, reduced dead‐in‐shell, egg‐yolk cholesterol and resulted in improved post‐hatch growth performance.     

The effect of palm oil and safflower oil in the feed of parent fattening hens on fertility, hatchability and growth of progeny]

The aim of two experiments with broiler breeder hens was to evaluate the effect of diets containing palm butter or safflower oil (25 g and 50 g/kg feed, resp.) on fertility, hatchability and growth of progeny. Especially the incorporation of oleic and linoleic acid in egg yolk reflected the dietary fatty acid source. Eggs were collected and stored in the incubator at a hen age of 31, 40, 50, and 60 weeks. Hatched chicks were reared over 5 weeks. The number of fertile eggs (Experiment 1 and 2, 75 and 88%, resp.) differed between the experiments (P < or = 0.05). Neither embryonic mortality nor hatchability (Experiment 1 and 2, 76 and 78%, resp.) were significantly affected by fatty acid composition of yolk. No clear maternal dietary effect was recorded on chicken weight at hatching (Experiment 1 and 2, 43.3 g and 43.7 g, resp.) and at 35 days of age (Experimental 1 and 2, 1676 g and 1764 g, resp.) The fatty acid composition in the analysed egg yolk sac of chicks showed a different fatty level but corresponded to fatty acid composition of breeding eggs before incubation. According to a decreased level of docosahexaenoic acid in egg yolk due to increased incorporation of linoleic acid, the content of this fatty acid was also diminished in phospholipids of the brain of chicken on days 1 and 5 after hatching.     

Effects of supplemental vitamin E during the laying period on the reproductive performance of Taiwan native chickens

1. One-day-old Taiwan Native Breeder female chicks were fed on maize/soybean growing diets without supplemental vitamin E from hatch to 17 weeks of age. After 17 weeks the birds (n = 300) were randomly assigned to 5 dietary treatments and fed on maize/soybean laying diets supplemented with 0, 40, 80, 120 and 160 mg/kg of vitamin E (dl-alpha-tocopherol acetate), respectively, until 46 weeks of age. The variates measured included: age at first egg, feed consumption (FC), feed efficiency (FE), egg production (EP), egg weight (EW), egg specific gravity (ESG), eggshell strength (ESS), fertility and hatchability. 2. The addition of 120mg/kg of vitamin E lowered the first EW (P<0.05); however, there was no significant difference in the age or body weight (BW) of pullets at first egg or mortality rate to 46 weeks of age among the treatments. FE and egg mass were improved (P<0.05) in pullets fed 80 mg/kg of supplemental vitamin E. A significant increase in EP was observed after peak EP in pullets given 80 mg/kg of supplemental vitamin E. However, this favourable effect decreased as supplemental vitamin E exceeded 80 mg/kg. 3. From 17 to 46 weeks of age, egg quality (ESG and ESS) decreased with age. However, there was no correlation between age and fertility or hatchability during the experimental period, suggesting that egg quality is more age-sensitive than reproductive performance for breeder pullets. 4. Compared with the control, fertility and hatchability of all eggs set for the treatment with 80 mg/kg supplemental vitamin E increased by 7.7 and 13.4%, respectively. There was no difference in the hatchability of fertile eggs. 5. These results suggest that using supplemental vitamin E during the laying period can improve the reproductive performance of breeder pullets. The addition of 80 mg/kg of vitamin E obtained the best performance in EP, egg mass, FE (feed/egg), hatchability and fertility.     

Effects of Egg Yolk Source on the Cryopreservation of Stallion Spermatozoa

Three experiments were conducted to determine whether replacement of chicken egg yolk, as a component of freezing extenders, with egg yolk from other avian species would improve the post-thaw motility and percentage of intact acrosomes of stallion spermatozoa. In the first experiment, substitution of chicken egg yolk with chukar egg yolk, as a component of the lactose-ethylenediaminetetraacetic acid extender, improved (P ≤ .05) the post-thaw motility of stallion spermatozoa. These results were not replicated in (IMV Technologies, Maple Grove, MN, USA) a more expansive study comparing 2%, 4%, 6%, or 8% egg yolk combined with INRA 96 when a “slow freeze” method was used, or the same substitution at levels ranging from 13% to 22% when egg yolk was combined with lactose-ethylenediaminetetraacetic acid for diluents used for a “fast freeze” method of cryopreservation. In the third study, egg yolks from regular and high omega-3 chicken eggs as well as from turkey, chukar, and mallard duck eggs were analyzed for lipid content and fatty acid profile. The yolk from the turkey eggs was higher (1,300 mg/100 g) and that from mallard ducks was lower (560 mg/100 g) in cholesterol as compared with the two types of chicken eggs and chukar egg yolk (range, 1,046-1,094 mg/100 g). In addition, the high omega-3 eggs did test higher for fatty acids (4.51 g/100 g) than other types of eggs (range, 0.28-0.73 g/100 g). Substitution of chicken egg yolk with turkey, but not duck, egg yolk resulted in higher post-thaw total motility (P ≤ .05) for spermatozoa obtained from two of the three stallions used in the third experiment.     

The long-term effects of using a higher amount of iodine supplement on the efficiency of laying hens

1. Two different levels of dietary iodine supplement (K + 0, 3.57 mg/kg; K + I, 6.07 mg/kg) were used in a 52-week experiment using 32 ISA Brown laying hens. 2. The greater iodine content in the diet impaired the egg production (K + 0, 319.9 +/- 1.31 eggs/hen; K + I, 312.4 +/- 4.19 eggs/hen), the egg weight (K + 0, 64.4 + 0.66 g; K + I, 63.1 +/- 0.61 g) and the food to egg mass ratio (K + 0, 2.13 +/- 0.023 kg/kg; K + I, 2.22 +/- 0.030 kg/kg). 3. The greater dietary iodine content had significant (P<0.05) negative effects on Haugh units, yolk index and eggshell weight.     

茶多酚和酵母硒及其互作对绿壳蛋鸡生产性能、蛋品质及蛋黄中胆固醇和硒含量的影响

本研究旨在探讨茶多酚和酵母硒及其互作对绿壳蛋鸡生产性能、蛋品质及蛋黄中胆固醇和硒含量的影响。试验选用810只44周龄健康绿壳蛋鸡,随机分成9个组,每组5个重复,每个重复18只鸡。采用2因素3水平试验设计,在基础饲粮中分别添加不同剂量的茶多酚和酵母硒构成试验饲粮,茶多酚设0、200、400 mg/kg 3个添加水平,酵母硒(按硒计)设0、0.25、0.50 mg/kg 3个添加水平。预试期7 d,正试期28 d。结果表明:1)饲粮中添加茶多酚和酵母硒均有提高平均蛋重的趋势(P>0.05),添加200、400 mg/kg茶多酚能显著提高产蛋率且显著降低料蛋比(P<0.05);2)饲粮中添加茶多酚和酵母硒对蛋黄指数、蛋黄色泽和哈氏单位均有提高的趋势(P>0.05),添加0.50 mg/kg酵母硒能显著提高蛋形指数(P<0.05),同时使蛋壳厚度显著下降(P<0.05),添加200、400 mg/kg茶多酚能显著减缓鸡蛋在贮藏过程中哈氏单位的下降(P<0.01);3)饲粮中添加200、400 mg/kg茶多酚均能显著降低蛋黄胆固醇含量(P<0.01),添加0.25、0.50 mg/kg酵母硒均能显著提高蛋黄硒含量(P<0.01);4)茶多酚和酵母硒的互作对生产性能、蛋品质及蛋黄中胆固醇和硒含量均无显著影响(P>0.05)。由此可见,在基础饲粮中采用400 mg/kg茶多酚和0.25 mg/kg酵母硒的添加组合对蛋鸡生产性能和蛋品质不会产生拮抗作用,并可有效生产"富硒+低胆固醇"的绿壳鸡蛋。     

Effects of breeder hen age and dietary L-carnitine on progeny embryogenesis

1. Ross 308 broiler breeder hens were given diets containing 0 or 25 mg L-carnitine/kg (8 replications per treatment) from 21 weeks of age. 2. Hens were inseminated with semen from Ross broiler breeder males. In a common facility, subsequent progeny hatchability and embryonic mortality at 25, 30, 32, and 38 weeks of breeder age were evaluated. 3. Subsequent egg component weights, incubational egg water loss, progeny embryo growth, and embryo, yolk sac and liver composition through 18 d of incubation at 27, 32, and 38 weeks of breeder age were evaluated. 4. Calculated additions of L-carnitine were in agreement with analysed contents of 3.5 and 31.1 mg free L-carnitine/kg of diet, respectively, and total L-carnitine concentrations increased by 48.6, 21.7, and 10.0% in 0-d yolk, 18-d yolk sac, and 18-d liver samples, respectively, due to the addition of dietary L-carnitine. 5. Supplemental L-carnitine resulted in increased (0.6%) relative 0-d egg yolk weight across weeks 27, 32, and 38, and reduced (0.38%) 18-d yolk sac palmitoleic acid concentration at week 27 without altering embryogenesis. 6. In conclusion, dietary L-carnitine (25 mg/kg of the diet) was deposited in the yolks of broiler breeder hens and was subsequently transferred to the embryonic liver via yolk sac absorption through 18 d of incubation. Furthermore, dietary L-carnitine supplementation increased ovarian follicle yolk deposition in 27-, 32-, and 38-week-old breeder hens, and influenced yolk sac fatty acid beta-oxidation in embryos from 27-week-old breeder hens causing yolk sac palmitoleic acid concentrations to be reduced by 18 d of incubation.     

Comparison between wheat, triticale, rye, soyabean oil and strain of laying bird on the production, and cholesterol and fatty acid contents of eggs.

1. The effects of feeding three types of cereal grain (wheat, triticale or rye) and soyabean oil (0 or 20 g/kg) over a 12-week period on the production, yolk cholesterol and yolk fatty acid concentrations of three strains of laying pullets were studied. 2. Pullets fed on wheat- or triticale-based diets had higher body weight gains, egg productions, egg weights, egg mass and lower yolk cholesterol concentrations than pullets fed on rye-based diets. However, there were no significant differences between the cereals in yolk cholesterol content. 3. There were no significant differences between the three cereals in total food consumption of pullets nor of yolk weight nor yolk concentration of palmitic, stearic and oleic acids. 4. Pullets fed on triticale-based diets had higher yolk linoleic acid concentrations and lower yolk oleic acid: linoleic acid ratios than pullets fed on rye- or wheat-based diets. 5. Soyabean oil supplementation increased egg production, egg mass, yolk linoleic concentration and yolk unsaturated to saturated fatty acid ratio, but reduced yolk oleic acid: linoleic acid ratio. 6. There were differences between strains of pullets in weight gain, food consumption, rate of lay, egg weight and yolk cholesterol, but not in yolk fatty acid concentrations. 7. It was concluded that wheat- or triticale-based diets gave good production of eggs of lower cholesterol content, that soyabean oil supplementation gave eggs with a high unsaturated to saturated fatty acid ratio and that two strains of layers produced eggs with lower yolk cholesterol concentrations than a third strain.     

菊苣提取物对蛋鸡鸡蛋胆固醇、肠道菌群和生产性能的影响

本文旨在研究菊苣提取物对蛋鸡生产性能、鸡蛋品质、肠道菌群、血清胆同醇和卵黄胆同醇的影响.300只尼克红蛋鸡随机分为5组,每组6个重复,每个重复10只,各组日粮中分别添加0、0.5%、1.0%、1.5%的菊苣提取物和1.0%的菊粉,试验进行4周.结果表明:与对照相比,不同水平的菊苣提取物或菊粉对蛋鸡产蛋率、蛋重、采食量、料蛋比、破蛋率、蛋黄重、蛋壳厚度和哈氏单位没有显著影响(P>0.05),但能显著降低鸡蛋胆固醇浓度(mg/g蛋黄)和含量(mg/蛋黄)(P<0.05),1.5%菊苣提取物添加组的动脉粥样硬化指数显著降低(P<0.05);日粮添加菊苣提取物或菊粉显著降低蛋鸡盲肠大肠杆菌数量和pH(P<0.05),1.5%菊苣提取物添加组和菊粉添加组显著增加盲肠双歧杆菌数量(P<0.05);鸡蛋胆固醇含量和盲肠大肠杆菌数量随菊苣提取物添加水平的增加线性降低(r=-0.957和r=-0.977)(P<0.05).结论:本试验在蛋鸡日粮中添加菊苣提取物或菊粉能显著降低鸡蛋胆固醇和盲肠有害菌(大肠杆菌)的数量,且不影响蛋鸡生产性能和鸡蛋品质.故在蛋鸡日粮中添加菊苣提取物或菊粉可为生产低胆同醇鸡蛋提供一条途径.     

植酸酶对种鸡生产性能及种蛋孵化性能影响的研究

种鸡在生产条件下，利用植酸酶水解饲料中植酸的原理，观察商品植酸酶替代磷酸氢钙对种鸡生产性能和种蛋孵化性能的影响和评价其实际可应用性。选用２８～３６周龄的肉用黄种鸡（ＮＫ２７１），在饲料中添加３００单位植酸酶替代磷酸氢钙（ＤＣＰ）提供的１．８ｇ无机磷。结果表明：植酸酶使种鸡的产蛋率（＋０．６６％）、日耗料量（－０．７１％）、破蛋率（－９．３％）、不合格种蛋（－４．９５％）、种蛋受精率（＋０．２９％）和１２天活胚率（＋０．７８％）均得到改善，但差异不显著（Ｐ＞０．０５）；而入孵种蛋健雏率（＋１．８９％）、１２天活胚蛋健雏率（＋１．６６％）和残次雏率（－１６．１１％）则优于对照组，差异极显著（Ｐ＜０．０１）。因此，可以认为不仅在种鸡饲料中可用商品植酸酶替代磷酸氢钙，而且对种鸡和种蛋的几乎全部重要生产和繁殖指标，都有不同程度的良好作用。根据目前市场上磷酸氢钙的品质（含氟量）状况，使用植酸酶能够大幅度减轻以至于杜绝由磷酸氢钙导致的氟中毒问题。同时能够预见，使用植酸酶可以大幅度降低排泄物中的含磷量，并能减少对自然环境的污染。可见，植酸酶在种鸡饲料中具有重要的实际应用价值。     

Effects of electrical field on hatchability performance of eggs from a layer-type breeder

1. Eggs from a layer-type breeder flock (Baladi, King Saud University) between 50 and 63 weeks of age were used in three trials to study the effects of electrical field (EF) during incubation on albumen and yolk heights, incubation temperature, egg weight loss and hatchability traits. The effects of egg size and eggshell characteristics on hatchability traits of eggs incubated under EF were investigated. 2. Eggs were weighed and graded into three weight classes (small, medium, and large). The physical dimensions, eggshell characteristics, and conductance of eggs were examined. The incubator was divided into two compartments for the control and EF treatments. Two aluminium plates were fitted on the inside walls of the EF compartment, face to face, and connected to a step up electric transformer. Eggs were exposed constantly to the EF during the first 18 d of incubation at the level of 30 kV/m, 60 Hz. 3. Egg size influenced the physical dimensions and eggshell characteristics of eggs. Large eggs had higher egg weight, egg surface area, egg volume, eggshell conductance, and eggshell weight and lower yolk weight percentage than medium or small size eggs. Small eggs had lower egg length and higher egg density than large or medium size eggs. Large eggs had higher eggshell thickness than small size eggs. 4. EF incubation of eggs raised incubation temperature by 0.06 degrees C, and increased the percentage of egg weight loss, hatchability, and weight of hatching chicks and reduced the early embryo deaths, and length of incubation by approximately 9.8, 19.6, 1.7, 62.1 and 2.1%, respectively. 5. There was no significant difference between the two incubation treatments in the heights of albumen and yolk of incubated eggs, percentages of late embryo deaths, and pips with live and dead embryos. Hatchability traits were not significantly influenced by egg size. 6. It was concluded that EF incubation of eggs increased hatchability, chick-hatching weight, and reduced the length of incubation of Baladi eggs. Differences in the physical dimensions and eggshell characteristics of eggs did not influence hatchability traits of eggs under EF incubation.     

鸡 HMGCR 基因SNPs及其与鸡蛋胆固醇含量的关联性分析

为培育一种蛋黄胆固醇含量较低的蛋鸡新品系,以丝羽乌骨鸡为研究对象,测定675枚丝羽乌骨鸡蛋蛋黄胆固醇含量,通过DNA测序技术和创造酶切位点PCR-RFLP方法检测了丝羽乌骨鸡群体中3-羟基-3-甲基戊二酸单酰辅酶A还原酶基因的2个SNPs位点,分别分析这两个SNPs位点不同基因型与鸡蛋胆固醇含量的关联性。结果表明:(1)丝羽乌骨鸡蛋蛋黄胆固醇含量为13.41mg/g,鸡蛋中胆固醇含量为456.50mg/100g。(2)g.12217G>T位点中GG基因型的鸡蛋胆固醇含量最低,且与其他两种基因型具有显著的差异。     

酵母硒对吉林芦花鸡蛋品质及生产性能的影响

为研究添加不同浓度的酵母硒对吉林芦花鸡生产性能、蛋硒含量、蛋品质、鸡蛋胆固醇含量的影响,试验选用健康的21周龄吉林芦花鸡96只,平均体重1622 g。随机分成4组,每组6个重复,每个重复4只鸡。对照组饲喂基础日粮,其他3组分别添加0.3、0.6、0.9 mg/kg的酵母硒。预试期5 d,正式期21 d。结果表明:各组间料蛋比、采食量、哈氏单位、鸡蛋颜色无显著差异(P>0.05);0.3 mg/kg酵母硒组的平均蛋重极显著低于其他3组(P<0.01),产蛋率、软破壳蛋率均极显著高于其他3组(P<0.01);0.6 mg/kg酵母硒组的蛋黄比率、软破壳蛋率极显著低于其他3组(P<0.01);0.9 mg/kg酵母硒组胆固醇含量极显著低于其他3组(P<0.01);料蛋比(P=0.087)和胆固醇(P=0.061)随着酵母硒添加量的增加有降低的趋势。0.6 mg/kg酵母硒组蛋硒含量极显著高于对照组和0.3 mg/kg酵母硒组(P<0.01),显著高于0.9 mg/kg酵母硒组(P<0.05)。综上,在本试验条件下,酵母硒适宜添加量为0.6 mg/kg。     

Effects of some egg characteristics on the mass loss and hatchability of ostrich (Struthio camelus) eggs

1. This study was conducted to examine some egg characteristics and determine the effects of eggshell thickness and eggshell porosity on water loss and hatchability of eggs in ostriches. 2. Shell thickness did not correlate significantly with hatchability. However, eggs of low shell thickness lost more mass (13.03%) than those with intermediate (11.22%) and high (10.36%) shell thickness. Mass loss during incubation was higher in hatched (11.98%) than unhatched eggs (11.09%). Shell thickness was negatively correlated to egg mass loss (r = -0.65). 3. The pore density was correlated with hatchability. Hatchability was 50% lower in eggs with low pore densities (40.93%) than with high densities (80.94%). Pore density was positively correlated with egg mass loss (r = 0.63). Incubation mass losses of hatched and unhatched eggs were not significantly different. 4. Mean eggshell water vapour conductance (G) value and shell conductance constant (k) were 87.77 +/- 4.21 mg H2O/d/Torr and 2.44 respectively (n = 15). 5. Because of eggshell functional properties and resulting low egg mass loss hatchability is low when ostrich eggs are artificially incubated. The mass of eggs used in the experiment was relatively high and their eggshell water vapour conductance was low. As a result, egg incubation mass loss was lower than it should be. It is concluded that incubator humidity should be low (25%) to allow enough mass loss during incubation from the eggs.     

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.     

Influence of dietary energy, supplemental fat and linoleic acid concentration on performance of laying hens at two ages

1. The aim of this study was to investigate the influence of metabolisable energy (ME), supplemental fat (SFAT) and linoleic acid (LIN) content of the diet on the productive performance and weight of eggs and egg components of Isabrown hens of 22 or 74 weeks of age. 2. Six diets were formulated to contain the following concentrations of ME (MJ/kg), SFAT (g/kg) and LIN (g/kg), respectively: A) 11.8, 0 and 11.5; B) 11.8, 40 and 11.5; C) 11.8, 40 and 16.5; D) 11.2, 40 and 16.5; E) 11.2, 40 and 11.5; and F) 11.2, 0 and 11.5. Data were collected for 28 d and analysed using linear contrasts to test the effect of SFAT, LIN, ME and their interactions. 3. When the LIN content of the diets was maintained constant at 11.5 g/kg, an increase in the SFAT from 0 to 40 g/kg increased egg weight (63.8 vs 64.5 g; P<0.05), food intake (119 vs 124 g; P<0.01) and energy intake (1.36 vs. 1.42 MJ/d; P<0.01) and body weight change of the hens (-85 vs. 27 g; P<0.001). Supplemental fat also increased yolk (15.8 vs. 16.3 g; P<0.001) and albumen weight (40.8 vs. 42.3 g; P<0.01) but yolk to albumen ratio was not modified. 4. Egg and albumen weights were improved by SFAT in early but not in late producing hens. As a result, yolk to albumen ratio decreased in the younger hens, from 0.371 to 0.357, but increased in the older hens, from 0.408 to 0.415; P<0.01) with fat addition. 5. An increase in the LIN content of the diets from 11.5 to 16.5 g/kg did not modify any of the traits studied. 6. It was concluded that the LIN requirement of the hens for maximal productivity and weight of eggs is 11.5 g/kg or less. Supplemental fat increased the weight of eggs and albumen in the younger but not in older hens and the beneficial effect was independent of its LIN content.     

Inheritance of reproductive traits of female common ducks (Anas platyrhynchos) in pure breeding and in inter-generic crossbreeding with muscovy ducks (Cairina moschata)

1. Genetic parameters of reproductive traits were estimated in a population of common duck, in purebreeding and crossbreeding (with Muscovies) insemination systems. A total of 989 females were studied over three generations as well as 4025 purebred offspring and 4,125 male mule offspring. 2. Traits studied were age at first egg, total number of eggs laid until the age of 48 weeks, fertility and hatchability rates in pure and crossbreds, weight at 6 and 30 weeks of age, average egg weight and body weight of the male mule ducks at 6 weeks of age. 3. Heritability estimates were found to be medium range for reproductive traits (0.15 to 0.47). Heritability value for fertility or hatchability in crossbreds was twice as high as in purebreds (0.32 vs 0.15 for fertility; 0.36 vs 0.16 for hatchability). 4. Fertility in purebreeding and in crossbreeding were two different traits (r(g) = 0.49) while hatchability displayed a high genetic correlation between breeding systems (r(g) = 0.88). 5. Genetic correlations with number of hatched mule ducks were medium or high and favourable. Genetic correlations between reproductive traits and weights were low (< 0.36), the most related trait being the body weight of the male mule duck at 6 weeks of age.     

鸡蛋暗斑对蛋品质及抗氧化能力的影响

[目的]研究鸡蛋暗斑对蛋品质及其抗氧化能力的影响。[方法]从饲喂同种日粮、饲养环境相同、同日龄褐壳蛋鸡同一批次所产的褐壳蛋中,用灯光照射法挑选出24枚典型正常蛋、24枚典型暗斑蛋进行试验,并分别对正常蛋和暗斑蛋进行蛋品质、蛋黄抗氧化指标的测定及比较。[结果]蛋品质比较:暗斑蛋与正常蛋相比,其蛋形指数、蛋壳强度、蛋重、哈氏单位、蛋白高度、鸡蛋等级、蛋黄颜色、蛋黄重、蛋壳重、蛋清重、蛋壳厚度、蛋黄比重、蛋壳比重、蛋清比重均差异不显著(P>0.05);暗斑蛋蛋壳颜色极显著深于正常蛋(P<0.01)。抗氧化指标比较:暗斑蛋蛋黄的总抗氧化能力(T-AOC)显著低于正常蛋蛋黄的总抗氧化能力(P<0.05),暗斑蛋蛋黄的丙二醛(MDA)含量与正常蛋蛋黄的丙二醛含量相比差异不显著(P>0.05)。[结论]与正常蛋相比,暗斑蛋的蛋壳颜色较深,总抗氧化能力较差。