The effect of dietary sodium on right ventricular failure-induced ascites, gain and fat deposition in meat-type chickens.

Experiments were carried out using various levels of sodium (Na+) from NaCl or NaHCO3 to determine: 1) the level of Na+ required to induce ascites alone or in combination with cold temperature and 2) the effect of Na+ on weight gain and fat deposition in broiler chickens. In experiment 1, there were no cases of ascites using levels of Na+, from NaCl at 0.14% to 0.44% in the feed from day 3 or using added Na+, from NaCl at 0.0% to 0.12% in the water from day 3 with a level of 0.14% in the feed. There was no significant difference in 21 or 42 day body weight, feed conversion, or right ventricle:total ventricle (RV:TV) ratio between treatment groups. Day 3 to 4 body weight gains were significantly increased in all treatment groups with added Na+ (p less than 0.01). In experiment 2, with levels of added Na+, from NaCl, at 0.0% to 0.12% in the water with a level of 0.20% in the feed there were two cases of ascites, one at day 7 and one at day 40 at the 0.12% level. There were no significant differences in body weight at days 21 or 42 or in the RV:TV ratios between groups. Feed conversions were improved (p less than 0.01) with the lowest and highest levels of Na+ and a significant increase in day 3 to 4 body weight gain, with increasing Na+ in all treatment groups, was observed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Changes in light intensity during the rearing period can influence egg production in domestic fowl

1. A total of 240 Shaver White and 240 ISA Brown pullets that had been reared in multi-bird cages on a 10-h photoperiod, and maintained at a light intensity of 3 or 25 lux, or changed from 3 to 25 lux or from 25 to 3 lux at 9 or 16 weeks of age, were moved into individual-bird cages at 20 weeks and transferred to 15-h photoperiods at 25 lux. 2. In both breeds, birds transferred from 3 to 25 lux at 16 or 20 weeks laid significantly more eggs than birds maintained on the brighter intensity from one day or increased to it at 9 weeks. 3. Mean egg weight, shell deformation, albumen height, feed intake and body weight gain in lay were not significantly affected by the light intensity treatments during the rearing period. There was, however, a small, but significant, negative correlation of egg numbers with mean egg weight, although this only partially explained the difference in egg numbers. The differences in egg production were unrelated to rate of sexual maturation.     

Effect of dietary flaxseed, flax oil and n-3 fatty acid supplement on hepatic and plasma characteristics relevant to fatty liver haemorrhagic syndrome in laying hens

1. Two experiments were carried out to investigate the effect of dietary flaxseed, flax oil and n-3 fatty acid supplementation (Dry n-3) on hepatic fat content, plasma triglycerides, hepatic haemorrhage score, egg production, food intake and body weight in an inbred line of Single Comb White Leghorns (UCD-003) predisposed to fatty liver haemorrhagic syndrome (FLHS) and normal SCWL hens. 2. Feeding diets containing 100 g/kg ground flaxseed, 40 g/kg flax oil, or 100 g/kg Dry n-3 reduced body weight and significantly reduced hepatic fat content compared to feeding the control diet with animal and vegetable oil as a fat source. 3. Hepatic malondialdehyde, an indicator of lipid peroxidation within the liver, was not significantly affected by dietary treatment. 4. Normal SCWL hens tended to have higher egg production, greater body weight, greater food intake and higher blood triglyceride concentrations than UCD-003 hens, although the strain effects were not significant. Liver weight as a percent of body weight was significantly lower in normal SCWL hens. Treatments by strain interactions were not found. 5. The result suggested that dietary flaxseed, flax oil and Dry n-3 decrease hepatic fat content and reduce body weight, 2 of the predisposing factors believed to contribute to FLHS onset. However, haemorrhages were still apparent in both strains regardless of treatment, indicating that other unknown underlying mechanisms may also be responsible for FLHS.     

Voluntary food restriction by laying hens mediated through dietary self‐selection

1. Individually caged Single Comb White Leghorn hens simultaneously received two diets which allowed selection of certain nutrients: these “ split‐diets “, essentially provided concentrated sources of either protein and energy (191 g crude protein, 12.82 MJ ME and 4.7 g Ca/kg diet), or calcium (107 g CP, 7.28 MJ ME and 131 g Ca/kg).

2. During four, 28‐d periods of lay, birds offered these split‐diets consumed some 7% less food in total than did control birds receiving a conventional diet ad libitum.

3. Calculation of nutrient intakes showed that birds on the split‐diets consumed significantly less protein, energy and calcium than the control birds.

4. Giving split‐diets also resulted in superior shell quality; treatment differences were also noted in the timing of oviposition.

5. It is suggested that the voluntary reduction in food intake noted for birds offered split‐diets is associated with an appetite for calcium.     

防制霉菌毒素的实用方法

尽管在谷物的生长、收割和储藏期间实施了减少霉菌毒素形成的农艺措施,但饲料污染的情况依然显著。因此,防止霉菌毒素的形成,是控制饲料原料受霉菌毒素污染最明智和最经济的方法。由于人们对食品和动物饲料受霉菌毒素污染问题的日益关注,科研人员进行了广泛研究,以阐明能够影响     

饲养密度可能限制肉鸡采食量（续完）

3鸡场中的采食活动 肉鸡仍然是为能量而进行采食的,因此饲料的能量浓度将影响其采食量。如果大龄肉鸡可完全自由接近料槽,当饲料的代谢能为2650～3250kcal／kg（约11．0～13．5MJ／kg）时,能量摄入量几乎不受影响;如果饲料的能量密度进行调整,生长速度也几乎不受影响。     

全球家禽业发展现状及未来展望

30年来,肉鸡业取得了很大成功,而蛋鸡业也在新产品开发中大步前进,在未来的10～20年间家禽业还将继续发展。近年来,肉鸡业的舍饲和生产系统已经越来越标准化,在蛋鸡舍饲系统这一问题上的分歧越来越多。肉鸡和蛋鸡保持了良好健康状况,死亡率达到前所未有的低水平。这些成果均源于遗传选择,采用有效的疫苗和抗生素,以及对生物安全重要性和农场全面卫生的日益增长的认知度。尽管目前养鸡业还没有受到其他规模化养殖业中出现的环境因素的影响,但饲养数量的增加不可避免地对合理处理粪便提出了更大挑战。在未来20年,家禽的营养需要不会发生太大的变化,其研究将以开发不断增长的遗传潜力,提供不含药物添加剂的天然饲料配方,以及研究家禽产品对人类健康的影响为指导。动物生产和畜产品对人类健康的影响是目前政府极为重视的问题,我们应该支持改进生产及其产品,以便让这些产品对人体健康产生积极的影响。     

Metabolisable energy studies with Turkeys: Metabolisable energy of dietary ingredients

Experiments have been performed to determine the metabolisable energy, content (ME) of a range of dietary ingredients for the young turkey. Determinations were carried out by a total collection procedure and test ingredients were substituted into a basal diet composed of commercially obtainable ingredients. Test ingredient ME values were obtained by regression analysis and extrapolation based on two levels of inclusion. For cereals and where possible for protein concentrates, inclusion levels of 20 and 40% were used.

The ME values found with the turkey were generally similar to those found with the chick; however, values obtained with the turkey for more fibrous materials appeared to be substantially greater than have been found with the chick. A simultaneous comparison of the ME values obtained for samples of oats and maize with turkeys and chicks showed that the ME value to be assigned to oats was approximately 8% greater when determined with the turkey than when determined with the chick. Similar values for maize were obtained with the two species.