维生素C对笼养蛋雏鸭的生产性能和机体抗氧化能力的影响

本文旨在研究玉米-豆粕型日粮添加不同水平维生素C(VC)对笼养蛋鸭育雏期(1～28日龄)的生产性能和抗氧化能力的影响.试验采用单因素随机分组设计的方法,选用1日龄平均体重相近的金定蛋雏鸭288只,随机分为6组(各处理日粮中分别添加VC 0、150、300、400、800、1 400 mg/kg),每组6个重复,每个重复8只鸭,结果表明:①在笼养蛋鸭育雏期添加150～1 400 mg/kg VC能显著提高日增重、饲料效率和抗氧化能力,显著降低丙二醛(MDA)的浓度(P<0.05).②5日龄,日粮添加800 mg/kg VC时血清和肝脏中超氧化物岐化酶(SOD)、过氧化氢酶(CAT),总抗氧化能力(T-AOC)的活性最高;28日龄,日粮添加300～400 mg/kg VC时血清和肝脏中SOD、CAT和T-AOC活力较高;28日龄血清和肝脏抗氧化指标高于5日龄.③大剂量的VC对蛋鸭的生产性能和机体的抗氧化指标都有降低的趋势.因此在本试验条件下得出:笼养蛋雏鸭日粮中适当添加VC可提高生产性能和机体抗氧化能力,1～5日龄日粮添加VC 800 mg/kg,6～28日龄添加VC 300～400 mg/kg为适宜.     

欧亚鲈幼鱼饲料中维生素C适宜含量的研究

选用初始体质量为(7.46±0.29)g的欧亚鲈幼鱼为试验对象,投喂6种不同水平的维生素C(0、50、100、200、400和800 mg/kg)的试验饲料,饲养8周,探讨欧亚鲈幼鱼饲料维生素C的适宜含量。结果表明,饲料中维生素C添加量从0.0升高到100 mg/kg时,鱼体增重率呈上升趋势,添加量为100 mg/kg显著高于对照组(P<0.05),但添加量继续增大,对鱼体增重率无显著变化(P>0.05);经折线模型分析表明,欧亚鲈鱼种达到最大生长时,饲料中的维生素C的最低添加量为93.58 mg/kg。欧亚鲈肝脏中维生素C含量随着饲料中维生素C(0～200 mg/kg)的增加而显著升高(P<0.05),但添加量继续升高,则肝脏中维生素C达到饱和状态,经折线分析表明,肝脏中维生素C达到饱和时,饲料中的维生素C的最低添加量为149.27 mg/kg。急性胁迫前,各组血糖之间无显著差异(P>0.05),急性胁迫后,血糖升高峰值最低和恢复最快的是饲料中维生素C为400～800 mg/kg。在本试验条件下,欧亚鲈幼鱼达到最大生长、肝脏维生素C饱和及抗拥挤胁迫的维生素C适宜添加量分别为93.58、149.27 mg/kg和400 mg/kg。     

In vivo antioxidant properties of vitamin E and chromium in cold-stressed Japanese quails.

An experiment was conducted to determine if vitamin E (alpha-tocopherol-acetate) and chromium (chromium picolinate, Cr Pic) supplementation attenuate the negative effects of cold stress on egg production, egg quality, serum metabolites, and antioxidant status in Japanese quails (Corurnix coturnix japonica). One hundred and fifty laying Japanese quails (50-day-old) were divided into five groups, 30 birds per group. The laying quails kept at 6 degrees C for 12 h/d (08.00 p.m. to 08.00 a.m.) were fed either a basal diet (low temperature-basal diet, CS group) or the basal diet supplemented with either 400 microg of Cr/kg of diet (Cr group), 250 mg of alpha-tocopherol-acetate per kg of diet (Vit. E group) or 400 microg of Cr plus 250 mg of alpha-tocopherol-acetate per kg of diet (Vit. E + Cr group) while quails kept at 18 degrees C were fed a basal diet (thermo-neutral-basal diet, TN group). Performance and egg quality were significantly reduced in CS group compared with TN group. Supplemental chromium and vitamin E significantly increased live weight change, egg production, and improved feed efficiency in cold-stressed laying hens compared with the group fed the basal diet at 6 degrees C. Egg production and egg weight were also greater (P < 0.05) in each supplemental group compared with the CS group. However, a combination of vitamin E and chromium, rather than each separately, provided the greatest performance. Supplemental vitamin E and chromium also increased serum vitamin C and E but, decreased malondialdehyde (MDA) concentrations (P < 0.05); the combination of vitamin E and chromium resulted in the highest levels of serum vitamin C and E within the cold-stressed quails. Results of the present study indicate that combined antioxidant supplements increased performance, egg quality and serum antioxidant levels while lowering MDA in cold-stressed quails.     

军曹鱼幼鱼维生素C需要量的研究

选用初体均重为25.85 g的军曹鱼幼鱼225尾随机分为5组,每组设3个重复,每个重复15尾.分别投喂添加5种不同剂量维生素C(添加量分别为0、37.5、75、150和300 mg/kg)的试验饲料,试验期为56 d,观察维生素c对军曹鱼幼鱼生长、组织维生素C积累量及非特异性免疫的影响.结果表明,随着饲料中维生素C添加量增加,军曹鱼幼鱼增重率和特定生长率呈现出上升后下降趋势,在75 mg/kg时达到最高值,显著高于0和300 mg/kg组(P<0.05).全鱼粗蛋白质含量随着饲料中维生素C添加量的升高亦呈现先上升后下降趋势,在75 mg/kg时达到最高值,全鱼干物质、粗蛋白质、粗脂肪、灰分含量在各组之间均无显著差异(P>0.05).血清维生素C积累量随着饲料中维生素C添加量的增加呈现先上升后下降趋势,在150 mg/kg时达到最高值且显著高于0 mg/kg组(P<0.05);脑和肝脏中维生素C含量在300 mg/kg时达到最高值.300 mg/kg组脑中维生素C含量显著高于0,37.5和75 mg/kg组(P<0.05),肝脏中维生素C含量显著高于0,37.5和150 mg/kg组(P<0.05).随着饲料中维生素C添加量的增加,溶菌酶活性呈现先上升后下降趋势,在75 mg/kg达到最高,显著高于0,37.5和300 mg/kg组(P<0.05);血清总抗氧化能力呈现上升趋势,75、150和300 mg/kg组显著高于0 mg/kg组(P<0.05);肾抗氧离子自由基在150 mg/kg组达到最高,但各组之间无显著差异(P>0.05).以鱼体增重率和血清溶菌酶含量为指标,经折线模型回归分析求得军曹鱼幼鱼饲料中维生素C的适宜添加量分别为70和80.72 mg/kg.     

饲粮维生素D添加水平对蛋雏鸭免疫及抗氧化功能的影响

本试验旨在研究饲粮维生素D添加水平对1～28日龄蛋雏鸭免疫及抗氧化功能的影响,以探讨饲粮维生素D的适宜添加量。试验选取健康、体重相近的1日龄金定蛋雏鸭180只,随机分为5组(Ⅰ～Ⅴ组),每组6个重复,每个重复6只试鸭。采用玉米-豆粕型基础饲粮,Ⅰ组(对照组)试鸭饲喂基础饲粮,Ⅱ～Ⅴ组试鸭分别饲喂在基础饲粮中添加110、220、550、1 000 IU/kg维生素D的试验饲粮,试验期4周。结果表明:饲粮添加550 IU/kg维生素D可显著提高胸腺指数、脾脏指数(P<0.05),并显著增强肝脏超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性(P<0.05),降低血清白细胞介素-2(IL-2)及血清和肝脏丙二醛(MDA)含量(P<0.05);饲粮添加220、550 IU/kg维生素D可显著提高血清总蛋白(TP)和白蛋白(ALB)含量(P<0.05),并显著增强血清SOD和GSH-Px活性及血清和肝脏总抗氧化能力(T-AOC)(P<0.05)。综合本试验结果,在玉米-豆粕型基础饲粮中添加适量的维生素D可提高1～28日龄蛋雏鸭的免疫及抗氧化功能。综合考虑各指标,通过二次回归模型估测得出维生素D适宜添加量为512.8～550.0 IU/kg。     

Serum Profiles of Luteinizing Hormone,Oestradiol and Cholesterol and Ovarian Functions in Layer Poultry Birds (Gallus domesticus) Fed Diets Containing Furazolidone

This study was carried out to assess the serum profiles of luteinizing hormone (LH), oestradiol, cholesterol and ovarian functions in layer poultry birds (Rhode Island Red: Gallus domesticus) fed a diet containing various concentrations of furazolidone (FZ). A total of 40 birds were randomly assigned to receive FZ 0, 200, 400 or 800 mg/kg feed (ppm) daily during the pre-laying age, i.e. 13-18 weeks (for 5 weeks). Blood samples were collected at weekly intervals. Concentrations of LH and oestradiol in serum were estimated at alternate weeks using radioimmunoassays. Serum cholesterol levels were analysed by an enzymatic calorimetric method. Furazolidone administration was terminated at the 18th week of age. The birds were sacrificed at 22nd week of age and ovarian tissues were processed for morphometric studies. Serum LH, oestradiol and cholesterol levels were affected by age (p < 0.001) and FZ dose (p < 0.001). Serum LH and oestradiol levels were lower (p < 0.05) in birds receiving FZ 800 mg/kg feed daily compared with the controls, whereas serum cholesterol profiles were lower (p < 0.05) in all FZ-administered groups than in the control group. The mean weight of ovaries having no yolky follicles observed in the group receiving FZ 400 or 800 mg/kg feed per day was reduced (p < 0.05) compared with the control group. Dosing FZ at 800 mg/kg feed per day reduced (p < 0.05) the mean volume of ovaries having no yolky follicles compared with the control group. In birds receiving FZ 800 mg/kg feed per day, the mean length of the oviduct was reduced (p < 0.05) as compared with the control group. Morphometric studies revealed that the mean number of oocytes with diameter in the range 401-800 microm decreased (p < 0.05) in birds fed FZ 400 or 800 mg/kg feed per day. Initial egg production was affected by age (p < 0.001) and dose (p < 0.001) of FZ. The mean number of eggs laid by different groups revealed that egg production was reduced (p < 0.05) in birds receiving FZ 800 mg/kg feed per day as compared with the controls. The present data suggest that FZ causes suppression in serum profiles of LH, oestradiol, cholesterol and ovarian functions in Rhode Island Red layer poultry birds. Therefore, great care must be taken with use of FZ in layer poultry birds (Gallius domesticus) with regard to dosage and duration of administration.     

Hypocholesterolemic effect of karaya saponin in Japanese laying quails (Coturnix coturnix japonica)

The effect of karaya saponin supplementation on the serum and egg yolk cholesterol and fatty acid composition in egg yolk were investigated in Japanese quails. A total of 80 Japanese quails aged 5 weeks were equally divided into four groups of 20. Four levels (0, 25, 50 and 75 mg/kg feed) of karaya saponin were included in the basal diet and experiment was lasted for 6 weeks. The cholesterol fractions in the egg yolk and serum were measured by enzymatic assay, and the fatty acid composition in egg yolk was determined by gas chromatography. The results revealed that the supplementation of 75 mg/kg karaya saponin significantly reduced (p < 0.05) cholesterol and triglycerides concentration in serum and egg yolk. High-density lipoprotein-cholesterol was increased, low-density lipoprotein-cholesterol and the atherogenic index were decreased (p < 0.05) by the dietary supplementations. Hepatic cholesterol was reduced (p < 0.05) by the 25 mg/kg karaya saponin. A higher degree of yolk colour was improved (p < 0.05) when 75 mg/kg saponin was supplemented in the diet. The concentration of polyunsaturated fatty acids (PUFA) in egg yolk was increased (p < 0.05) in a dose-dependent manner in quails fed the supplemented diet than the control diet. The ratio of PUFA to saturated fatty acids in egg yolk was improved (p < 0.05) by 75 mg/kg feed karaya saponin-supplemented diet. Therefore, the dietary supplementation of 75 mg/kg karaya saponin may be a feasible means of producing quail eggs with lower cholesterol and higher PUFA content for health conscious consumers.     

Effects of yeast selenium supplementation on the growth performance, meat quality, immunity, and antioxidant capacity of goose

The aim was to investigate the effects of yeast selenium (YS) supplementation on the growth performance, meat quality, immunity, and antioxidant variables of geese. A total of 96 one-day-old geese with similar body weight were randomly divided into four groups, with three replicates per group and eight geese in each replicate. The birds were fed basal diets supplemented with 0, 0.10, 0.30, 0.50 mg/kg YS (on selenium basis) during the 63-day experiment. Yeast selenium supplementation showed no effect on the growth performance of geese, but significantly improved the meat quality. No changes in ash or fat content were observed in breast muscle, but significant (p < 0.05) protein content increase was detected in the 0.1 and 0.5 mg/kg groups. Yeast selenium supplementation significantly (p < 0.05 or p < 0.01) promoted Se deposition in liver, kidney, pancreas, and muscle and the highest increases were all detected in the 0.5 mg/kg group. Yeast selenium supplementation enhanced the organ and cellular immunity of geese, but did not alter the humoral immunity. Furthermore, dietary YS significantly (p < 0.05) promoted the antioxidant capacity of both muscle and liver, but the effects varied with YS levels and organs. Hence, dietary YS supplementation was a good measure to improve the meat quality, Se content, immunity function, and antioxidant capacity of goose.     

黄芪多糖对断奶幼兔生长性能、腹泻率及免疫功能的影响

为研究黄芪多糖（APS）对断奶幼兔生长性能、腹泻率及免疫功能的影响,试验选取100只28日龄的断奶幼兔,随机分为5组,每组20只幼兔。对照组饲喂基础日粮,试验组在基础日粮中分别添加100、200、400、800 mg/kg的APS,预试期5 d,正式试验期30 d。结果表明：（1）与对照组相比,200 mg/kg APS组幼兔的末重、增重、平均日增重显著提高,分别提高了12.42%、19.95%、20.36%（P ＜ 0.05）,料重比显著降低11.11%（P ＜ 0.05）|400 mg/kg APS组幼兔的末重、增重、平均日增重显著提高,分别提高了17.73%、28.42%和28.45%（P ＜ 0.05）,料重比显著降低13.55%（P ＜ 0.05）。（2）与对照组相比,400 mg/kg APS组幼兔的腹泻率和死亡率显著降低,均降低了50%（P ＜0.05）|800 mg/kg APS组腹泻率显著降低37.5%（P ＜ 0.05）。（3）与对照组相比,400 mg/kg APS组IgA的含量显著提高,提高了13.04%（P ＜ 0.05）|200、400 mg/kg APS组IgG含量显著提高,分别提高了4.98%和6.31%（P ＜ 0.05）。综上所述,在幼兔基础日粮中添加APS可以显著提高幼兔生长性能,降低腹泻率和死亡率,并提高机体免疫力,且最适添加量为400 mg/kg。 [关键词] 黄芪多糖|兔|生长性能|腹泻率|免疫功能     

Influence of dietary rapeseed oil, vitamin E, and copper on the performance and the antioxidative and oxidative status of pigs.

We investigated the effects of dietary copper and vitamin E in diets containing 6% rapeseed oil on the performance and the antioxidative and oxidative status of growing pigs. The 10 dietary treatments consisted of a basal diet (9 mg of vitamin E/kg feed, 15 mg of Cu/kg feed), the basal diet + 6% rapeseed oil (Diet 1; 18 mg of vitamin E/kg feed, 15 mg of Cu/kg feed), and Diet 1 plus supplements of vitamin E (0, 100, and 200 mg of dl-alpha-tocopheryl acetate/kg feed) and copper (0, 35, and 175 mg of Cu/ kg feed) in a 3 x 3 factorial arrangement of treatments. Eight or nine pigs were given ad libitum access to each diet from 25 to 100 kg of live weight. The inclusion of rapeseed oil tended (P < .10) to improve ADG and feed utilization. Compared with the addition of 35 mg of Cu/kg, the addition of 175 mg/kg improved growth rate and increased feed intake early in the experiment, but, over the total experiment, neither 35 nor 175 mg of Cu/kg affected performance. Compared with the addition of 100 mg of vitamin E/kg or no addition, the addition of 200 mg/kg reduced ADG over the total experiment (P = .05). The antioxidative and oxidative status of the pigs was evaluated in terms of blood and liver concentrations of antioxidants (alpha-tocopherol, ascorbic acid, vitamin A, superoxide dismutase, glutathione peroxidase), prooxidants (Cu), concentrations of lipids (triglycerides and cholesterol), fatty acid composition, thiobarbituric acid-reactive substances (TBARS), and clinical chemical (creatine kinase and glutamate-oxaloacetate-transaminase) and hematological variables that indicate the level of oxidative stress. There were no vitamin E deficiency signs or increased oxidative stress in pigs fed low dietary vitamin E levels, and no prooxidative effect of Cu was found. Increasing dietary levels of vitamin E increased the concentration of alpha-tocopherol in plasma and liver. Supplementation with Cu increased liver concentrations of Cu and alphatocopherol. The progression in liver TBARS was reduced by the addition of vitamin E and Cu. The addition of rapeseed oil changed the fatty acid composition of liver, increased alpha-tocopherol concentration in plasma and Cu concentration in liver, and reduced the rate of lipid oxidation in liver. In conclusion, even though the effects were minor, vitamin E, Cu, and rapeseed oil improved the antioxidative status of the live pigs.     

Effect of maternal canthaxanthin and 25‐hydroxycholecalciferol supplementation on the performance of ducklings under two different vitamin regimens

This study investigated the effects of maternal canthaxanthin (CX, 6 mg/kg) and 25‐hydroxycholecalciferol (25‐OH‐D₃, 0.069 mg/kg) supplementation on the performance of Cherry Valley ducklings under two different vitamin regimens. A total of 780 duck breeder females and 156 males were randomly allotted to two diets with or without the addition of the mixture of CX and 25‐OH‐D₃ (CX+25‐OH‐D₃) for 32 weeks. Ducklings (males and females separately) hatched from eggs laid at 24 weeks of the duck breeder trial were fed with a NRC vitamin regimen, and ducklings (males and females separately) hatched from eggs laid at 32 weeks of the duck breeder trial were fed with a HIGH vitamin regimen (had higher levels of all vitamins except biotin than NRC vitamin regimen), for 14 days. The results showed that, maternal CX+25‐OH‐D₃ supplementation increased the shank pigmentation for 7‐days post hatch in ducklings under a NRC vitamin regimen, and for 14‐days post hatch in ducklings under a HIGH vitamin regimen. Growth performance, antioxidant status and serum phosphorus of ducklings under a NRC vitamin regimen were increased by maternal CX+25‐OH‐D₃ supplementation; however, these positive effects were not observed in ducklings under a HIGH vitamin regimen. Males revealed increased growth performance in ducklings under both NRC and HIGH vitamin regimens. Sexual differences in shank pigmentation, antioxidant status, tibia strength and serum phosphorus were not consistent as they were dependent on maternal CX+25‐OH‐D₃ status or dietary vitamin regimens. Data suggest that maternal CX+25‐OH‐D₃ supplementation is important for starter ducklings under a NRC vitamin regimen, but not HIGH vitamin regimen.     

Effects of vitamin C and vitamin E on performance, digestion of nutrients and carcass characteristics of Japanese quails reared under chronic heat stress (34 degrees C)

This study was conducted to determine the effects of vitamin C (L-ascorbic acid) and vitamin E (DL-alpha-Tocopheryl acetate) on performance, digestion of nutrients and carcass characteristics of Japanese quails reared under chronic heat stress (34 degrees C). A total of 180 10-day-old Japanese quails were randomly assigned to six treatment groups, three replicates of 10 birds each. The birds with a 2 x 3 factorial design received either two levels of vitamin C (100 and 200 mg/kg of diet) or three levels of vitamin E (125, 250, or 500 mg/kg of diet). Then, 200-mg vitamin C/kg of diet, compared with that of 100 mg/kg of diet, and higher dietary vitamin E inclusions resulted in a higher performance. The interaction between vitamin C and vitamin E for final body weight change (p=0.01) and feed efficiency (p=0.02) was detected. Final body weight change and feed efficiency increased to a higher extent by increasing dietary vitamin C when higher vitamin E levels were fed. Carcass characteristics improved with an increase of both dietary vitamin C and vitamin E (p=0.004). The interactions on carcass characteristics were all significant (p=0.02) and manifested themselves in a way that they were improved to a higher extent by an increase of dietary vitamin C when higher vitamin E levels were fed. Digestibility of nutrients (DM, OM, CP and EE) was greater with higher dietary vitamin C (p < 0.02) and also with higher vitamin E (p=0.07). There were no interactions detected for digestibility of nutrients (p=0.32). Taken together, the results of the present study conclude that a combination of 200 mg of vitamin C and 250 mg of vitamin E provides the greatest performance in Japanese quails reared under heat stress and can be considered as a protective management practice in poultry diet, alleviating the negative effects of heat stress.     

Long-term effects of early-life dietary L-carnitine on lymphoid organs and immune responses in Leghorn-type chickens

The long-term effects of supplementing Leghorn-type chickens with dietary L-carnitine after hatching for 4 weeks on growth, lymphoid organ weights, humoral and cell-mediated immune responses were assessed in a 12-week study. A commercial starter feed supplemented with 0 (control), 100 (LC) or 1,000 (HC) mg L-carnitine/kg was offered to day-old ISA Brown cockerels for 4 weeks, then all birds were given a commercial pullet grower feed for another 8 weeks. No differences (p > 0.05) in growth rates, feed intake or feed utilisation efficiency existed among the dietary treatments throughout the study. Compared with control birds, HC-fed birds had a lower (p < 0.05) thymus weight relative to bodyweight (BW) at Week 4, but a higher (p < 0.05) relative thymus weight at Week 12. A higher (p < 0.05) serum primary antibody response to sheep red blood cells (SRBC) in HC-fed birds than in the other two groups was also detected at Week 12. Relative spleen or bursa weights and cutaneous responses of toe webs to phytohaemagglutimin (PHA) (an in vivo indicator of cell-mediated immune responses) did not differ (p > 0.05) among dietary treatments at any time. It is concluded that a short-term supply of dietary L-carnitine to a conventional commercial feed after hatching enhanced subsequent humoral immunity in Leghorn-type chickens. Further study is warranted to confirm such a long-term effect.     

维生素D对蛋雏鸭生长性能及免疫功能的影响

试验选取1日龄健康、体重相近的金定蛋雏鸭180只,随机分为5个处理组,每个处理6个重复,每个重复6只试鸭。采用玉米-豆粕型基础饲粮,Ⅰ组试验鸭饲喂基础饲粮,Ⅱ～Ⅴ组分别饲喂在基础饲粮中添加110、220、550、1000 IU/kg维生素D的试验饲粮,试验期4周。旨在研究不同维生素D添加水平对1～28日龄蛋雏鸭生长性能及免疫功能的影响,以探讨维生素D的适宜添加量。结果表明,添加550 IU/kg维生素D能显著提高蛋雏鸭平均日增重、降低料重比(P<0.05),显著提高IgA、IgG、T3、T4含量(P<0.05),并显著降低Cort含量(P<0.05)。由此可见,在玉米-豆粕型基础饲粮中添加适量的维生素D可提高蛋雏鸭生长性能及免疫功能。通过二次回归模型分析,估测蛋雏鸭日粮中维生素D的适宜添加量为523.1～560.6 IU/kg。     

饲粮添加吡咯喹啉醌对围产期母猪繁殖性能和抗氧化功能的影响

本试验旨在比较吡咯喹啉醌(PQQ)与维生素E和有机硒对围产期母猪繁殖性能和抗氧化功能的影响。选用40头体重和背膘厚接近且妊娠90 d的第3胎大约克母猪,随机分为2组,每组20头。对照组在基础饲粮中添加60 mg/kg维生素E和0.20 mg/kg有机硒,试验组在基础饲粮中添加1 mg/kg PQQ。试验期为妊娠第90天至分娩后第7天。结果表明:与对照组相比,饲粮添加PQQ对母猪产程、产仔数、产活仔数及仔猪初生窝重、仔猪平均初生重以及产后7 d仔猪平均日增重均无显著影响(P0.05),但数值上有所升高;饲粮添加PQQ显著提高了初生仔猪和母猪血清总超氧化物歧化酶、谷胱甘肽过氧化物酶活性及还原型谷胱甘肽含量(P0.05),显著降低了血清丙二醛含量(P0.05),对血清过氧化氢酶活性、总抗氧化能力及氧化型谷胱甘肽含量均无显著影响(P0.05)。综合得出,围产期饲粮中添加PQQ较维生素E和有机硒对母猪繁殖性能无显著影响,能显著增强围产期母猪及初生仔猪的血清抗氧化功能。     

Effects of vitamin E and selenium on performance, digestibility of nutrients, and carcass characteristics of Japanese quails reared under heat stress (34 degrees C)

This study was conducted to determine the effects of vitamin E (dL-alpha-Tocopheryl acetate) and selenium (Se; Na2-SeO3) on performance, digestibility of nutrients and carcass characteristics of Japanese quails reared under chronic heat stress (34 degrees C). A total of 120 10-day-old Japanese quails were randomly assigned to four treatment groups, three replicates of 10 birds each. The birds with a 2 x 2 factorial design received either two levels of vitamin E (125 and 250 mg/kg of diet) or two levels of Se (0.1 or 0.2 mg/kg of diet). A 250-mg vitamin E/kg of diet compared with that of 125 mg/kg of diet and higher dietary Se inclusions (0.1 vs. 0.2 mg/kg) resulted in a better performance (p=0.001). The interaction between vitamin E and Se for feed intake (p=0.03), final body weight change (p=0.03) and feed efficiency (p=0.001) was detected. Carcass yield increased with increasing both dietary vitamin E and Se (p=0.001). The interactions on carcass characteristics were all non-significant (p > 0.06). Digestibility of nutrients (DM, OM, CP and ether extract) was higher with higher dietary vitamin E (p=0.03), and DM digestibility was also higher with higher dietary Se (p=0.05). There were no interactions detected for digestibility of nutrients (p=0.28). From the results of the present study, it was concluded that a combination of 250 mg of vitamin E and 0.2 mg of Se provides the greatest performance in Japanese quails reared under heat stress and this combination can be considered as a protective management practice in Japanese quail diets, reducing the negative effects of heat stress.     

Performance, serum characteristics, carcase traits and lipid metabolism of broilers as affected by supplement of chromium picolinate.

1. This study investigated the effects of dietary supplementation with chromium picolinate on the performance, serum and carcase traits and lipid metabolism of broilers. In trial 1, 120 1-day-old broilers with an equal number of males and females were assigned at random to 4 groups with 3 replicates. Four treatments with dietary supplements of 0 (control), 800, 1600 and 3200 microg/kg of chromium picolinate were used. In trial 2, 6-week-old broilers (20) were used to determine how supplements of 0, 200, 400 and 800 microg/kg chromium in an incubation medium influence their hepatocyte lipogenic capacity and adipocyte lipolysis, in vitro. 2. Dietary supplements of 1600 and 3200 microg/kg chromium in broiler diets significantly increased food consumption (P<0.05); 1600 microg/kg markedly improved weight gain (P<0.05); 1600 and 3200 microg/kg groups showed increased liver lipid content (P<0.05). However, the abdominal fat content tended to decrease in these 2 groups. 3. Dietary supplements of 1600 and 3200 microg/kg of chromium decreased serum glucose and nonesterified fatty acids (NEFA) concentrations while increasing serum phospholipid content (P<0.05). Insulin concentration decreased only in birds receiving 3200 ppb chromium (P<0.05). Serum triacylglycerol (TG) clearance rate in chromium-supplemented groups was markedly enhanced (P<0.05). 4. In addition, chromium supplemented groups had increased serum HDL contents and also reduced serum VLDL and LDL contents (P<0.05). 5. Trial 2 indicated that lipogenesis from [U-14C]glucose by isolated hepatocytes was significantly enhanced by 400 ppb chromium (P<0.05). 6. The results from this study demonstrate that a supplement of 1600 microg/kg of chromium picolinate in the ration influences the growth, carcase, serum traits and lipid metabolism of broilers.     

饲粮维生素E水平对43～63日龄黄羽肉鸡肉品质和抗氧化功能的影响

本试验旨在研究饲粮维生素E水平对43 ～ 63日龄黄羽肉鸡肉品质和抗氧化功能的影响.选用1 440只43日龄岭南黄羽肉公鸡,采用单因子随机分组试验设计,共设6个处理,每个处理6个重复,每个重复40只鸡.试验采用玉米淀粉-豆粕型基础饲粮,各处理饲粮营养水平除维生素E水平不同外,其他均相同.空白对照组饲喂未添加维生素E的基础饲粮,其余各处理饲粮中分别添加5、10、20、40、80 mg/kg维生素E.试验期21 d,试鸡地面平养,自由采食颗粒料和自由饮水.结果表明:1)饲粮中维生素E添加水平对试鸡生长性能和胴体品质无显著性影响(P＞0.05).2)胸肌肉色的L*、a*、b *值和肌肉嫩度也未受饲粮维生素E添加水平显著影响(P＞0.05).添加各水平维生素E均显著提高了宰后45 min胸肌pH(P ＜0.05),添加5、10、40、80 mg/kg维生素E均显著提高了宰后24 h胸肌pH(P ＜0.05).添加20、40 mg/kg维生素E显著降低了宰后45 min胸肌滴水损失,添加5、10、40、80 mg/kg维生素E显著降低了宰后48 h胸肌滴水损失(P＜0.05).3)饲粮中添加不同水平维生素E对试鸡血清中丙二醛(MDA)含量和总超氧化物歧化酶(T-SOD)活性无显著性影响(P＞0.05),添加10、20 mg/kg维生素E使试鸡血清中谷胱甘肽过氧化物酶(GSH-Px)活性分别比对照组提高了27.51％、30.57％(P＜0.05).添加各水平维生素E均使试鸡肝脏中GSH-Px活性显著提高(P＜0.05),添加20、40、80 mg/kg维生素E均显著降低了肝脏中MDA含量(P＜0.05),显著提高了肝脏中α-生育酚含量和肌肉中T-SOD活性(P＜0.05).以上试验结果提示,饲粮中添加维生素E可提高43～63日龄黄羽肉鸡机体抗氧化功能,改善肉品质,且添加20 mg/kg效果较好.     

饲粮锌水平对笼养蛋雏鸭生长性能、抗氧化功能及免疫器官发育的影响

本试验旨在研究饲粮锌水平对笼养蛋雏鸭生长性能、抗氧化功能及免疫器官发育的影响.试验采用单因素完全随机分组设计,选择健康1日龄金定蛋雏鸭180只,随机分成5组,每组6个重复,每个重复6只鸭.对照组(Ⅰ组)饲喂基础饲粮,试验组(Ⅱ～Ⅴ组)分别饲喂在玉米-豆粕型基础饲粮中添加20、40、60、80 mg/kg锌(ZnSO4·7H2O)的试验饲粮.试验期4周.结果表明:1)Ⅲ、Ⅳ组蛋雏鸭的料重比和Ⅲ组的平均日增重显著高于对照组(P＜0.05),雏鸭平均日增重、料重比随饲粮锌水平的增加呈明显的二次曲线变化,以此为指标估测的锌适宜添加水平分别是50.4和54.7 mg/kg;2)Ⅲ组血清和肝脏总抗氧化能力(T-AOC)、血清铜锌超氧化物歧化酶( CuZn-SOD)活性、肝脏丙二醛(MDA)含量、肝脏谷胱甘肽过氧化物酶(GSH-Px)活性与对照组相比差异显著(P＜0.05),估测的锌适宜添加水平分别是44.6、47.8、55.7、43.4、54.2 mg/kg,而血清MDA含量、血清GSH-Px活性和肝脏CuZn-SOD活性与对照组差异不显著(P＞0.05);3)Ⅲ组胸腺指数、脾脏指数、法氏囊指数均显著高于对照组(P＜0.05).由此可见,蛋雏鸭采食玉米-豆粕型基础饲粮(含锌33.3 mg/kg)时,锌的适宜添加水平为55.7 mg/kg.     

Humoral and cell-mediated immune response and performance of weaned pigs fed four supplemental vitamin E levels and housed at two nursery temperatures

Three trials using 80 Yorkshire x Hampshire x Duroc crossbred pigs (avg initial wt, 6.9 kg) were conducted to determine the effects of four dietary vitamin E levels (11, 110, 220 and 550 IU/kg of feed) on the humoral and cell-mediated immune response and performance of 4-wk-old weanling pigs housed at two nursery temperatures (19 or 30 degrees C). Interactive effects of temperature and vitamin E were not observed for any measurements. Serum and liver vitamin E levels increased linearly with increasing level of dietary vitamin E, but performance, cortisol, antibody levels and mitogen-induced stimulation indices were not affected by supplemental levels of vitamin E. Average daily gain and feed intake were higher (P less than .01) for pigs housed at 19 degrees C than for pigs housed at 30 degrees C, but feed:gain ratios, mitogen stimulation index of white blood cells, plasma cortisol levels and antibody titers were not altered. Although supplemental vitamin E above the NRC estimated requirement increased serum and liver vitamin E concentrations, no differences were observed in humoral and cell-mediated immune response, cortisol levels or performance for weanling pigs housed at either 19 or 30 degrees C temperatures.