大蒜粉对黄羽肉鸡生产性能和脂肪沉积的影响

将96只1日龄的黄羽肉仔鸡随机分成3组,第1组为对照组,第2组为大蒜素组,第3组为大蒜粉组,每组设2个重复,每个重复16只鸡。大蒜素的添加量为200 mg/kg,大蒜粉的添加量为1.5%试验期为42 d。试验期内测定每组平均日增重、平均日采食量、料重比,并在试验结束时进行屠宰试验,测定各组试验鸡的皮下脂肪厚度和腹脂率。结果表明:①从试验全期看,大蒜素组和大蒜粉组的平均日增重,平均日采食量均显著高于对照组(P<0.05);而料重比低于对照组。表明大蒜素和大蒜粉均可提高肉鸡的生产性能。②大蒜素组和大蒜粉组市相比,两者的平均日采食量、平均日增重和料重比差异不显著(P>0.05)。③大蒜素组和大蒜粉组的皮下脂肪厚度和腹脂率略低于对照组,但差异不显著(P>0.05)。     

壳聚糖对黄羽肉鸡早期生长性能与脂肪代谢的影响

本试验旨在探讨壳聚糖对黄羽肉鸡早期生长性能、脂肪代谢的影响。120只健康1日龄黄羽肉鸡随机分成4个处理．每个处理2个重复．每个重复15只鸡（早）。对照组饲喂基础日粮为试验Ⅰ组，试验Ⅱ、试验Ⅲ、试验Ⅳ组饲喂在基础日粮分别添加0．10％、0．30％、0．50％壳聚糖的日粮，试验期21d。试验结果表明：（1）在黄羽肉鸡早期日粮中添加一定量的壳聚糖能提高日增重和饲料转化率，具有提高生产性能的趋势。在日粮中添加0．10％-0．30％壳聚糖组的促生长效果较好；（2）在日粮中添加0．10％-0．50％壳聚糖不影响0-3周龄的优质黄羽肉仔鸡的血脂浓度。     

低聚壳聚糖和丁酸钠对黄羽肉鸡免疫功能的影响

本试验以黄羽肉鸡为试验对象,旨在研究低聚壳聚糖、丁酸钠单独及组合使用对1～60日龄黄羽肉鸡免疫功能的影响.试验选取200只1日龄黄羽肉公雏,然后随机分为4组,每组50只,分为对照组、试验1组、试验2组、试验3组,每组5个重复,每个重复10只;对照组饲喂基础日粮,试验1组饲喂添加50mg/kg低聚壳聚糖的基础日粮,试验2...     

壳聚糖对河田鸡脂肪沉积的影响

将360羽56日龄雌性河田鸡随机分为4个处理,每处理3个重复,每重复30羽。对照组饲喂基础日粮,试验组在基础日粮中分别添加0.1%、0.3%、0.5%壳聚糖,分2个阶段饲养至110d后,进行采血与屠宰,测定其体脂及血脂指标。结果表明:添加0.3%、0.5%壳聚糖均能显著降低雌性河田鸡的腹脂率、皮下脂肪、肌间脂肪、血清甘油三脂及总胆固醇(P0.05),添加壳聚糖对高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、载脂蛋白AI及载脂蛋白B均无显著影响(P0.05)。     

共轭亚油酸对黄羽肉鸡脂肪沉积及部分免疫指标的影响

选用90只1日龄黄羽肉鸡,探讨添加不同水平（0%、1%、3%）共轭亚油酸（CLA）对不同部位脂肪沉积及部分免疫指标的影响。结果显示：日粮中添加CLA对黄羽肉鸡体增重无影响,但显著降低其腹脂沉积（P〈0.05）,使腹部脂肪细胞直径减小（P〈0.05）。日粮中添加3%CLA显著提高胸肌和腿肌中的脂肪含量（P〈0.05）。日粮添加CLA显著降低血清中甘油三酯和高密度脂蛋白胆固醇（P〈0.05）,升高游离脂肪酸（P〈0.05）,而对血清总胆固醇、血清中瘦素和脂联素水平无显著影响。此外,日粮添加CLA还显著提高胸腺指数和法式囊指数（P〈0.05）,而对血清中抗新城疫病毒抗体和脾脏指数无影响。结果提示,CLA对肉鸡腹脂和肌内脂肪的沉积有不同的作用,可改善肉鸡的胴体品质,并影响其免疫功能。     

半胱胺对黄羽肉鸡生长及内分泌的影响

480只29日龄黄羽肉鸡随机分成2组,每组4个重复,每个重复60只。试验组喂以半胱胺100mg/kg体重,每周一次,57日龄结束。结果,试验组与对照组相比增重提高14.7%,血液生长抑素下降65.3%,甲状腺素T3、T4则分别升高12.5%和9.7%,生长激素升高4.5%。     

添加亚麻油对肉鸡脂肪沉积影响的研究

试验旨在研究在日粮中添加3%、5%亚麻油对血清甘油三酯、总胆固醇、高密度脂蛋白胆固醇和低密度脂蛋白胆固醇的含量及对肝脏脂肪酸合成酶、腹脂脂蛋白脂酶活性和肉鸡腹脂沉积的影响。选择216只21日龄罗斯308商品代肉用母雏,随机分为3组,每组6个重复,每个重复12只。3组分别饲喂基础日粮（对照组）、添加3%亚麻油和5%亚麻油日粮,试验期3周。试验结果表明,血清甘油三酯水平在各组之间差异不显著（P>0.05）,与对照组相比,3%、5%亚麻油组总胆固醇水平上升（P>0.05）,高密度脂蛋白胆固醇水平下降（P>0.05）,3%亚麻油组显著提高了血清低密度脂蛋白胆固醇水平（P<0.05）。各处理组降低了肝脏脂肪酸合成酶和腹脂脂蛋白脂酶活性（P>0.05）,但与腹脂沉积的趋势并不一致。     

霉变饲料对黄羽肉鸡生长发育的影响

试验选用180只1日龄健康雌性黄羽肉鸡进行,基础日粮育雏一周后,随机分成6组,每组3个重复,每个重复10只鸡.第1组为对照组,饲喂基础日粮,第2、3、4、5、6组分别饲喂10%、20%、40%、60%、90%的霉变基础日粮.结果表明:饲喂不同浓度的霉变日粮均会造成仔鸡生长发育受阻并引起相应的病变,其中饲喂40%及以上霉变日粮饲喂组均使仔鸡的生长发育显著抑制或停滞(P＜0.05).     

黄羽肉鸡对胆碱的需要量研究

试验选用岭南黄羽肉鸡300只,随机分为5个处理,每个处理设3个重复,每个重复20只,进行52d饲养试验,研究玉米一豆粕日粮中胆碱的添加量对岭南黄羽肉鸡生产性能和屠宰指标以及血清中脂代谢相关指标的影响.试验分为1～21日龄和22～52日龄两个阶段进行,其中第一组为空白对照,其余4个处理在1～21日龄添加胆碱量分别为500、750、1 000、1 250 mg/kg;22～52日龄添加量为250、500、750、1 000 mg/kg.结果表明:岭南黄羽肉鸡胆碱的最佳需要量在1～21日龄生长阶段为750 mg/kg,在22～52日龄生长阶段为500 mg/kg.     

半胱胺对黄羽肉鸡增重及有关激素的影响

４８０羽２８日龄黄心肉鸡随机分成两组,每组４个重复,每个重复６０羽,试验组喂以半胱胺１００ｍｇ／ｋｇ体重,每周１次,对５７日龄结束,结果表明,试验组比对照组增重提高１４．７％,血液生长抑制素（ＳＳ）下降６５．３％）,甲状腺素Ｔ３、Ｔ４则分别升高１２．５％和９．７％,生长激素（ＧＨ）升高４．５％。     

Influence of amount and type of dietary fat on deposition, adipocyte count and iodine number of abdominal fat in broiler chickens

This study described the relation between the type and amount of dietary fat on the deposition of abdominal fat by broiler chickens. It was hypothesized that at higher fat intakes, the well-known lowering effect of polyunsaturated fatty acids on the deposition of abdominal fat would be diminished. Experimental diets were formulated to contain three levels of added fat (3%, 6% and 9%). Each level had different proportions of the saturated fatty acids (SFA) and unsaturated fatty acids (UFA) by installing the ratios of 1:1, 1:2, 1:3, 1:4 and 1:5 with the use of tallow and soybean oil. Arbor Acres chicks, aged 7 days, were fed one of the 15 experimental diets until they were aged 42 days. Feed and water were provided ad libitum. There was no systematic effect of the dietary fat type and the amount on the weight gain and the feed intake. The lowest SFA:UFA ratio of 1:5 produced the lowest feed conversion rates, irrespective of the amount of the fat in the diet. The abdominal fat deposition was similar in the birds fed on diets containing either 3% or 6% added fat, but deposition was lower than in those fed 9% fat. A decrease in the SFA:UFA ratio of the diet was associated with a dose-dependent decrease in abdominal fat, irrespective of the amount of fat in the diet. This observation leads to the rejection of the hypothesis stated above. A decrease in the dietary SFA:UFA from 1:1 to 1:4 caused a decrease in the number of the fat cells per surface unit of breast meat. It is concluded that an increased intake of soybean oil at the expense of tallow reduced the abdominal fat deposition and the number of fat cells in the breast meat of broiler chickens.     

谷氨酰胺对黄羽肉鸡生长和蛋白质代谢的影响

选用450只健康的黄羽肉鸡随机分为5组,分别饲喂含0、0.6%、0.8%、1.0%、1.2%的谷氨酰胺的日粮。试验结果表明,1～28日龄黄羽肉鸡日粮中添加0.6%和0.8%谷氨酰胺可使平均日增重分别提高8.8%和7.2%(P<0.05),29～49日龄日粮中添加0.8%和1.0%谷氨酰胺可使平均日增重分别提高9.1%和11.9%(P<0.05),添加0.8%和1.0%谷氨酰胺使血清中尿酸含量分别下降40.6%和45.6%(P<0.05)。     

Effects of dietary chitosan on fat deposition and lipase activity in digesta in broiler chickens

1. The effect of dietary chitosan on fat deposition and lipase activity in the small intestinal contents was investigated in broiler chickens fed an adequate or high metabolisable energy (ME) diet. 2. Male broiler chickens at 14 d old were fed on the adequate or high ME diet supplemented with 0 or 50 g/kg chitosan, which has a low viscosity, for 3 weeks. 3. Dietary chitosan did not affect food intake, body weight gain or food efficiency in either dietary ME groups. 4. Dietary chitosan reduced the excessive abdominal fat deposition induced by the high ME diet. 5. Dietary chitosan increased the weight of intestinal contents irrespective of dietary ME concentration. 6. Dietary chitosan decreased the lipase activity per g of small intestinal contents. 7. These results suggest that dietary chitosan with low viscosity decreases lipase activity and fat absorption in the small intestine, consequently resulting in a reduction of fat deposition in broiler chickens. 8. It was concluded that dietary chitosan with low viscosity can decrease body fat deposition without reducing food intake and body weight gain in broiler chickens.     

Hepatic lipolysis in broiler chickens with different fat deposition during embryonic development

The aim of this study was to explore the hepatic lipolysis in broiler chickens with different fat deposition during embryonic development. The mRNA expression of CPT-1 (carmitine palmtoyltransferase-1), PPARα (peroxisome proliferator-activated receptor alpha) and LPL (lipoprotein lipase) genes were determined using Real time RT-PCR. The start of incubation was called day 1 (E1) and after hatching called day 1 (H1). On incubation days 9 (E9), 14 (E14) and 19 (E19) as well as at hatching (H1), samples of liver were collected. Blood samples were obtained during days 14 (E14) and 19 (E19) of embryonic development and at hatching. This study showed that serum TG (triglycerol) decreased and TC (total cholesterol) and NEFA (non-estered fatty acid) increased during embryonic development. The expression of CPT-1, PPARα and LPL genes exhibited different developmental changes. For example, little LPL gene was expressed at hatching and PPARα gene expression peaked before hatching. However, CPT-1 gene exhibited no significance during the embryonic development. Our results showed that expression of these genes in Arbor Acres (AA) broilers was significantly higher than that in San Huang (SH) broilers. Therefore, this study suggested that hepatic lipolysis in broiler chickens exhibited developmental changes during embryogenesis and breed difference which may be one of the factors in the fat deposition difference between fat line and lean line broilers during embryonic development.     

Dietary L-arginine supplementation beneficially regulates body fat deposition of meat-type ducks

1. Unlike mammals, uricotelic species, such as the duck, cannot synthesise endogenous arginine (Arg). This study was conducted to test the hypothesis that dietary L-Arg supplementation might regulate body fat deposition in ducks without affecting their fast growth rate. 2. A total of 160 21-d-old male and female White Pekin ducks were assigned randomly to two treatments: a non-supplemented control and supplementation at 10 g/kg L-Arg of a maize and soybean meal-based diet. 3. The 3-week feeding trial showed that the addition of L-Arg had no significant effect on feed intake, but significantly increased body weight gain by 5·2 %, breast muscle weight relative to live body weight by 9·9%, carcase crude protein content by 9·2%, ether extract content in breast muscle by 11·9%. Arg supplementation significantly decreased skin with fat and abdominal fat pad contents by 7·6% and 4·9% respectively and the ether extract content of carcase by 7·2%. 4. The results of this study indicate that a diet with 10 g/kg supplemental L-Arg could reduce the fat deposition of carcase and abdominal adipose cell size (diameter and volume), enhance intramuscular fat in breast muscles, as well as increase muscle and protein gain. The decreased fat depot in the carcase may be attributed to a reduction of hepatic lipogenic enzyme activity.     

Effects of dietary protein concentration and corticosterone injections on energy and nitrogen balances and fat deposition in broiler chicks

Reducing dietary protein concentration in isocaloric diets consistently decreased nitrogen and energy excretion, and increased dry matter (DM), non-protein DM (NPDM), energy retention and fatness. There were significant correlations, negative between dietary energy-to-protein (E:P) ratio and nitrogen excretion and positive between the E:P ratio and the retention of DM, NPDM and energy. Nitrogen excretion was correlated with energy excretion, and NPDM retention with energy retention. Corticosterone injections increased fatness despite significantly increasing nitrogen and energy excretion. A positive relationship was observed in corticosterone-treated birds between nitrogen excretion on the one hand and the retention of DM and NPDM on the other. Increased food intake because of a low dietary protein concentration was not evident when a sorghum-based diet was used. Moreover, corticosterone injections increased neither the food intake nor the fatness of chicks fed this diet. Decreasing the protein concentration in diets containing identical metabolisable energy (ME) levels slightly, but significantly increased apparent ME values in three out of four experiments. Corticosterone injection did not affect this variable.     

The effect of pregnancy on protein,water and fat deposition in the body of gilts

Nineteen mated and 17 unmated Landrace gilts were divided into two feeding groups which were given daily (for 111 days of experiment) 2.5 or 3.5 kg of diet containing 120 g digestible protein (DP) and 12.6 MJ metabolizable energy (ME). On day 112 of experiment the animals were slaughtered and analysed for protein, water and ether extract content in the body.At both feeding levels live weight gain was greater (P < 0.001) in pregnant than in virgin gilts, while the maternal body gain was greater (P < 0.05) in pregnant gilts only at the higher feeding level.Pregnant gilts deposited more (P < 0.01) protein in the whole body than their nonpregnant analogues, but protein deposition in the maternal body was similar in both groups. On the other hand, more (P < 0.01) water was deposited in the whole and maternal bodies of pregnant versus non-pregnant gilts. No effect of pregnancy, however, was found on the deposition of fat in the body.The energy costs of maintenance and of protein deposition in the body of pregnant gilts were estimated at 444 kJ ME kg^−0.75 and 65.4 kJ ME g⁻¹, while in non-pregnant animals the respective values equalled 424 kJ ME kg^−0.75 and 104.3 kJ ME g⁻¹.     

快速与慢速肉鸡脂肪生长与肌苷酸含量比较

本试验旨在相同条件下,比不同品种和性别肉鸡的脂肪生长量和肌苷酸含量及其相互关系。比较发现:(1)快速与慢速肉鸡的各项脂肪指标均无显著差异(p>0.05),但慢速鸡的肌肉脂肪、皮下脂肪和腹脂率分别比快速鸡高7%、13%和37%;(2)慢速肉鸡肌苷酸含量比快速高50%,且差异显著(p<0.05);(3)母鸡皮下脂肪(p<0.01)和腹脂率(p<0.05)显著高于公鸡,母鸡肌间和肌肉脂肪也分别高于公鸡6%和12%(p>0.05);(4)肌苷酸与腹脂率存在显著正相关(r=0.61,p<0.05)。     

Corticosterone and fat deposition in broiler chicks: Effect of injection time,breed, sex and age

1. Corticosterone (680 μg/kg body weight per day) given as six daily injections to 3‐ or 7‐week‐old chicks decreased weight gain, but increased food consumption, abdominal fat pad weight, skin dry matter, relative liver size and liver fat concentration.

2. Time of day of injection did not modify the response to corticosterone of 3‐week‐old chicks kept under natural daylight nor of 7‐week‐old broilers receiving additional illumination.

3. Pure White Rock chicks and Cornish x White Rock crossbred chicks responded similarly to corticosterone injections at 3 weeks of age.

4. Seven‐week‐old female birds treated with corticosterone had significantly larger abdominal fat pads than similarly treated males.

5. Corticosterone injection was more effective in increasing the proportion of liver fat in 7‐week‐old birds than in 3‐week‐old ?hicks.

6. The increased amount of abdominal and liver fat due to corticosterone injections administered at 3 weeks of age disappeared after 3 weeks, but growth depression was still evident.