吡啶羧酸铬对生长肥育猪生产性能、胴体性状及血清生化指标的影响

本试验选用 40头体重约 2 8kg的杜× (大×长 )三元杂交猪 ,随机分为 4组 ,分别饲喂添加0、2 0 0、 40 0、 60 0 μg/kg铬 (吡啶羧酸铬 )的玉米—豆粕型饲粮 (生长、肥育期粗蛋白水平分别为1 7 0 %、 1 5 0 % ) ,直至体重约 95kg左右结束。结果表明 ,铬水平对生长期 (约 2 8～ 60kg)日增重、采食量、料重比无显著影响 ,也不影响血清钙、镁、钾、钠、氯、尿素氮浓度。虽然肥育阶段 (约 60～ 95kg) 40 0 μg/kg铬组的日增重和 60 0 μg/kg铬组的日增重、饲料转化效率有降低趋势 ,但各组间日增重、料重比、采食量差异不显著。铬不影响肥育猪血清镁、钾、钠、尿素氮浓度 ,但对氯、钙浓度有影响 (P <0 0 5 )。纵观全期来看 ,铬不影响生长肥育猪全期的生产性能 (P >0 0 5 )。虽然 60 0 μg/kg铬组有增加瘦肉率、降低脂肪率的趋势 ,但肥育猪各组间胴体性状无显著差别。以上结果提示 ,在本试验条件下 ,添加 2 0 0～ 60 0 μg/kg铬 (吡啶羧酸铬 )对生长肥育猪生产性能和胴体性状无显著影响。     

吡啶羧酸铬对罗斯肉鸡脂肪沉积及相关血清生化指标的影响

选取240只1日龄健康、体质量接近的罗斯肉仔鸡,随机分为Ⅰ~Ⅴ5个组,每组设4个重复,每个重复12只鸡。试验Ⅰ组为对照组,饲喂基础饲粮,Ⅱ~Ⅴ组为试验组,在基础饲粮中分别添加吡啶羧酸铬0.1、0.2、0.4和0.8mg/kg(以铬计),试验期为42d。结果表明,21日龄各试验组腹脂沉积有降低趋势,试验Ⅳ组降低44.64%(P0.05),其余各组差异不显著(P0.05);皮下脂肪厚度分别降低0.49%(P0.05)、0.99%(P0.05)、6.40%(P0.05)和3.45%(P0.05);肌间脂肪宽度没有规律性变化;试验Ⅱ、Ⅲ和Ⅳ组血清TG分别降低17.14%(P0.05)、14.29%(P0.05)和15.71%(P0.05);试验Ⅴ组血清HDL-C水平升高11.59%(P0.05);血清TC和TG变化不显著。42日龄试验各组腹脂率分别降低23.90%(P0.05)、24.88%(P0.05)、34.15%(P0.05)和29.76%(P0.05);试验Ⅳ组皮下脂肪厚度降低11.76%(P0.05);试验Ⅲ、Ⅳ组血清TC分别降低26.26%(P0.05)和25.32%(P0.05),试验Ⅱ和Ⅴ组有降低趋势,但差异不显著(P0.05);试验Ⅲ和Ⅳ组血清TG分别降低23.26%(P0.05)和22.48%(P0.05);吡啶羧酸铬能显著降低血清LDL-C的含量(P0.05),提高Ⅱ、Ⅳ和Ⅴ组血清HDL-C含量(P0.05),Ⅲ组提高达18.36%(P0.05)。因此,吡啶羧酸铬能有效降低罗斯肉鸡腹脂率,显著影响腹脂沉积;降低皮下脂肪厚度;对肌间脂肪宽度没有规律性的影响;对血清TC、TG、LDL-C和HDL-C有显著影响。罗斯肉鸡饲粮中降低腹脂率的吡啶羧酸铬最佳添加量为0.4mg/kg。     

Genetic parameters of ascites-related traits in broilers: correlations with feed efficiency and carcase traits

(1) Pulmonary hypertension syndrome followed by ascites is a metabolic disorder in broilers that occurs more often in fast-growing birds and at cool temperatures. (2) Knowledge of the genetic relationships among ascites-related traits and performance traits like carcase traits or feed efficiency traits is required to design breeding programmes that aim to improve the degree of resistance to ascites syndrome as well as production traits. The objective of this study was to estimate these genetic correlations. (3) Three different experiments were set up to measure ascites-related traits (4202 birds), feed efficiency traits (2166 birds) and carcase traits (2036 birds). The birds in different experiments originated from the same group of parents, which enabled the estimation of genetic correlations among different traits. (4) The genetic correlation of body weight (BW) measured under normal conditions and in the carcase experiment with the ascites indicator trait of right ventricle to total ventricle ratio (RV:TV) measured under cold conditions was 0.30. The estimated genetic correlation indicated that single-trait selecting for BW leads to an increase in occurrence of the ascites syndrome but that there are realistic opportunities of multi-trait selection of birds for improved BW and resistance to ascites. (5) Weak but positive genetic relationships were found between feed efficiency and ascites-related traits suggesting that more efficient birds tend to be slightly more susceptible to ascites. (6) The relatively low genetic correlation between BW measured in the carcase or in the feed efficiency experiments and BW measured in the ascites experiment (0.49) showed considerable genotype by environment interaction. (7) These results indicate that birds with high genetic potential for growth rate under normal temperature conditions have lower growth rate under cold-stress conditions due to ascites.     

生长肥育猪性别对甲基吡啶铬使用效果的影响

选择 48头平均体重为 30.7kg± 3.1kg的三元杂交健康生长猪，按单因子随机区组设计分为两个处理，分别饲喂未加甲基吡啶铬的日粮和添加 0.05％甲基吡啶铬的日粮。试验结果显示：同对照组青年母猪相比，试验组青年母猪的平均日增重（ ADG）（ P=0.27）、饲料转化效率（ FCR）（ P=0.08）和瘦肉率（ P=0.20）得到不同程度的提高和改善；同对照组阉公猪相比，试验组肥育阉公猪的 ADG和 FCR受到显著（ P=0.04）抑制，瘦肉率表现出降低的趋势（ P=0.27）。结论：性别是影响生长肥育猪对甲基吡啶铬使用效果的一个重要因素。     

Performance and welfare of broilers as affected by stocking density and zinc bacitracin supplementation

The influence of stocking density (16, 20 and 24 birds/m²) and zinc bacitracin (0 or 100 mg/kg) on the performance, carcass characteristics and some indirect welfare indicators of broilers were examined in a 35‐day trial. The weight gain, feed intake, liveability and carcass characteristics of broilers grown at densities of 16, 20 and 24 birds per m² were similar (P > 0.05). Over the whole trial period, however, feed per gain of birds at the highest density (24 birds/m²) was higher (P < 0.05) than those at the other two densities. Litter quality was poorer at high population densities, but there were no welfare implications as indicated by the lack of effect of density on gait scores and the incidence of hock and fat pad burns. Inclusion of zinc bacitracin improved weight gains and feed intake of broilers over the 35‐day trial period at all three stocking densities tested. Zinc bacitracin supplementation had no influence on the feed per gain of birds reared at densities of 16 and 20 birds/m², but improvements were observed at a density of 24 birds/m². The relative weights of lymphoid organs (spleen and bursa) were lowered (P < 0.05) with increasing density, suggesting a greater degree of stress on the birds. Zinc bacitracin supplementation had no influence on bursa weights of birds reared at densities of 16 and 20 birds/m², but increased the bursa weights of birds reared at a density of 24 birds/m². Overall, these data indicate that, with the removal of in‐feed antibiotics in the future, care should be taken when considering population densities of greater than 20 birds/m².     

Effects of supplemental nanoparticle trivalent chromium on the nutrient utilization,growth performance and serum traits of broilers

The aim of this study was to investigate the effect of dietary supplementation of nanoparticle trivalent chromium on nutrient utilization, growth performance and serum traits of broilers. This study included two trials. In trial 1, 32 three‐week‐old broilers were divided into four groups: the control, chromium chloride (CrCl₃), chromium picolinate (CrPic) and nanoparticle chromium picolinate (NanoCrPic). Chromium was added at a 1200 μg/kg level to evaluate the nutrient and chromium utilization. In trial 2, 160 one‐day‐old broilers were randomly divided into four groups as in trial 1, with four replicates. The results of trial 1 indicated that the chromium utilization is as follows: NanoCrPic > CrPic > CrCl₃ and control groups, with significant differences between groups (p < 0.05). Crude fat utilization in CrCl₃ group was lower than in that the control group (p < 0.05). The results of trial 2 indicated that feed intake of 4–5 weeks showed better result in the CrCl₃ group than that in the CrPic group (p < 0.05). The results of serum traits indicated that the LDL‐cholesterol in the NanoCrPic groups was lower than that in the CrPic group (p < 0.05). The NanoCrpic and CrPic groups showed significantly increased serum chromium concentration when compared with the control and CrCl₃ groups; the triglyceride level in the CrCl₃ group was lower than that in the CrPic group (p < 0.05). This study concluded that compared with CrPic, NanoCrpic supplementation could increase chromium utilization and lower the serum LDL‐cholesterol of broilers.     

Effects of chromium nicotinate on performance, carcase characteristics and blood chemistry of growing turkeys

1. The objective of this trial was to study the effects of chromium nicotinate (Cr) supplementation on the performance, carcase characteristics and blood constituents of 9 to 22 week-old male turkeys. 2. Fifty-four 8-week-old male turkeys weighing 2.9 +/- 0.28 kg were allocated at random into 9 groups with 3 dietary treatments and 3 replicates. The dietary treatment was different dietary concentrations of chromium in the basal diet, to provide 0 (control), 1 or 3 mg/kg. The feeding trial lasted for 14 weeks. 3. Results showed that 1 mg/kg chromium supplementation significantly improved weight gain and food intake at 9 to 18 weeks of age but did not significantly influence performance at 19 to 22 week of age. The breast and thigh muscle were significantly increased in birds receiving 1 mg/kg chromium supplementation but were decreased by 3 mg/kg of supplementation. 4. Dietary chromium supplementation did not significantly influence other serum constituents, including insulin, HDL, VLDL+LDL, HDL-C, VLDL-C+LDL-C, total protein, albumin, and gamma-globulin at 18 and 22 weeks of age. 5. The serum triacylglycerol (TG) and uric acid contents were significantly increased, while glycerol and alpha-globulin were significantly reduced by 3 mg/kg chromium supplementation. However, 1 mg/kg chromium supplementation significantly reduced serum cholesterol and glycerol at 18-weeks old. At 22 weeks of age, 1 mg/kg chromium supplementation significantly increased serum glucose and decreased the uric acid concentration whereas 3 mg/kg chromium supplementation significantly increased the creatinine concentration and decreased beta-globulin concentration.     

有机锰与铬互作对肉鸡脂质代谢及锰与铬在组织沉积的影响

本试验以玉米-豆粕型日粮为基础,添加不同水平的有机锰(以锰计:0,60,120 mg/kg)与有机铬(以铬计:0,400,600μg/kg),研究锰与铬对肉鸡脂质代谢及对肉鸡组织锰、铬沉积的影响。结果表明,7周末,单独添加锰、铬均显著降低血清TC含量(P0.01,P0.05);锰与铬同时添加,互作效应显著(P0.05)。单独添加锰对7周末血清TG含量表现极显著效应(P0.01)。与对照组相比,单独添加60 mg/kg锰或120 mg/kg锰血清TG含量分别降低31.91%或55.32%。单独添加400μg/kg铬和600μg/kg铬,血清G含量分别降低8.50%和26.58%;锰与铬互作对3、7周末血清G含量明显降低(P=0.026 8,orP=0.012 7)。单独添加铬使7周末血清TAA含量显著升高(P=0.006),随铬添加量增加,血清TAA含量分别高出对照组35.93%和40.97%。锰与铬互作,对7周末血清TAA含量表现显著效应(P=0.0388),与对照组相比,60 mg/kg锰600μg/kg铬互作组血清TAA含量增加43.57%;120 mg/kg锰互作组血清TAA含量分别增加29.19%和32.38%。单独添加锰仅对胫骨锰沉积产生显著影响(P0.05)。单独添加铬及锰与铬同时添加对各组织中锰的沉积均未表现出统计学上的显著互作效应(P0.05)。单独添加铬仅增加了肝脏铬沉积(P0.05)。单独添加锰减少了肝脏铬的吸收(P0.01),增加了肾脏铬的排出(P0.05)。锰与铬同时添加,对肝脏铬沉积表现显著互作效应。随饲粮铬添加量增加,60 mg/kg锰水平条件下,肝脏铬含量呈下降趋势;120 mg/kg锰水平条件下,肝脏铬含量显著降低(P0.01)。表现为锰颉颃铬,使铬在肝脏中的沉积明显下降。     

Effects of methionine and betaine supplementation on growth performance, carcase composition and metabolism of lipids in male broilers

1. This study was conducted to investigate the effects of methionine and betaine supplementation on growth performance, carcase composition and lipid metabolism in growing broilers. 2. A total of 450 commercial broilers, 22 d of age, were randomly allocated to three groups, each of which included three replicates (50 birds per replicate). The groups received the same methionine-deficient diet supplemented with 0 or 1 g/kg methionine, or 0.5 g/kg betaine, respectively. 3. Methionine and betaine supplementation significantly improved weight gain and feed conversion. Supplemental methionine and betaine also significantly increased breast muscle yield and decreased abdominal fat content. Meanwhile, addition of methionine and betaine significantly increased the contents of creatine and free carnitine in liver, the activity of hormone-sensitive lipase in abdominal fat and the concentration of free fatty acid in serum, whereas uric acid concentration in serum was significantly decreased. 4. The results of this study suggest that betaine can spare methionine in its function as an essential amino acid and is as effective as methionine in improving performance and carcase quality of growing broilers if the diet is moderately deficient in methionine. The decrease in abdominal fat may be due to the increased carnitine synthesis in liver and hormone-sensitive lipase activity in abdominal fat.     

Effect of less intensive rearing conditions on litter characteristics, growth performance, carcase injuries and meat quality of broilers

1. The objective was to compare the effect of two litter types (wheat straw and wood shavings) and two different rearing conditions (Treated and Control) on welfare indicators, broiler performance, carcase injuries, particularly hock and foot pad dermatitis (FPD), litter characteristics and meat quality. 2. Treated conditions were characterised by a low stocking density (11 birds/m(2)), short photoperiod (16 h light: 8 h dark) and a large amount of litter (3 to 4.5 kg/m(2), respectively, for wheat straw or wood shavings). Control conditions were a high stocking density (14 birds/m(2)), long photoperiod (23 h light:1 h dark) and small amount of litter (2.3 to 3 kg/m(2), respectively, for wheat straw or wood shavings). In addition, the effects of two widely used litter materials, wheat straw and wood shavings, were investigated. 3. The combined effects of lower stocking density, greater amount of litter material and a photoperiod similar to the natural one, reduced the occurrence of FPD in Treated groups keeping the FPD score under the European threshold. 4. Improved rearing conditions led to faster growth rate associated with inferior feed efficiency, whereas litter type exerted negligible effects on broiler performance. 5. Litter moisture content, nitrogen and ammonia released by the litter were lower in Treated groups than Control groups. The use of wood shavings resulted in lower moisture and nitrogen concentrations in the litter.     

能量与吡啶羧酸铬的互作效应对肥育猪肉质性状的影响

试验旨在研究能量与吡啶羧酸铬的互作效应对肥育猪肉质性状的影响。选择体重60 kg左右,杜×长×大三元杂交肥育猪36头,分为4组,分别饲喂低能日粮、低能+吡啶羧酸铬日粮、高能日粮、高能+吡啶羧酸铬日粮进行试验,对肥育猪背最长肌的肉色、pH值(屠宰后24 h)、大理石花纹、肌内脂肪(intramuscular fatI,MF)含量、剪切力、滴水损失、熟肉率、肌肉糖原含量指标进行测定。结果表明:①能量水平对肉色评分、滴水损失有极显著的影响(P<0.01);②能量水平对肌内脂肪(IMF)有显著影响(P<0.05);③能量水平对pH值、大理石花纹、剪切力、熟肉率、肌糖原含量均无显著影响(P>0.05);④添加吡啶羧酸铬对肉色评分、pH值I、MF、大理石花纹、滴水损失有极显著的影响(P<0.01);⑤添加吡啶羧酸铬对熟肉率、肌糖原含量有显著影响(P<0.05);⑥添加吡啶羧酸铬对剪切力无显著影响(P>0.05);⑦能量与吡啶羧酸铬互作对大理石花纹、熟肉率有显著影响(P<0.05);对其他肉质性状均无显著影响(P>0.05);⑧在低能日粮中添加200μg/kg吡啶羧酸铬,提高了肉色评分p、H值I、MF含量、大理石花纹和熟肉率;并降低了肌糖原含量。综上所述,在育肥后期采用低日粮能量水平并添加200μg/kg吡啶羧酸铬可改善肉质。     

Effects of fermented plant product on growth performance, some blood variables, carcase characteristics, and intestinal histology in broilers

1. Fermented plant product (FPP) is a natural fermented food which is produced from a mixture of fermented fruit and vegetables, and rice bran (1:9).

2. To investigate the effects of FPP on growth performance, some blood variables, carcase characteristics and intestinal histology were determined in 192 broilers. They were divided into 4 groups, with 4 replicates of 12 chicks each; the chicks were provided ad libitum access to a diet consisting of 0, 0·5, 2·0 and 4·0% dietary FPP.

3. The crude protein and metabolisable energy concentrations of these diets were adjusted to 230?g CP/kg and 13·40?MJ ME/kg for the 7 to 21?d old chicks, and 200?g CP/kg and 13·40?MJ ME/kg for the 22 to 49?d old chicks, respectively.

4. At 49?d of age, feed intake, body weight gain and feed efficiency tended to increase with increase in FPP concentrations. Feed intake increased in the 4·0% dietary FPP group, BW gain increased in the 2·0% and 4·0% dietary FPP groups and feed efficiency increased in all experimental groups.

5. There were no differences among diets in the blood variables and carcase characteristics, except for total visceral organ weight, increased in all experimental groups.

6. Most of the intestinal villus heights, villus areas, epithelial cell areas and cell mitosis tended to increase with increase in FPP concentrations; duodenal villus height and cell mitosis in the 2·0 and 4·0% dietary FPP groups, and jejunal cell mitosis in all experimental groups were significantly increased. Compared with flat cells on the villus apical surface in the 0% FPP group, all experimental groups had protuberant cells in all intestinal parts.

7. In conclusion, hypertrophy of the villi and epithelial cells was observed in the present study, indicating improved growth performance, especially in the 4·0% dietary FPP group. Furthermore, increased total visceral organ weights suggested that FPP has no harmful effects on broilers.     

Effect of dietary protein regime on meat quality traits and carcase nutrient content of broilers from two commercial genotypes

1. The present study aimed to evaluate breast muscle quality and muscle myofibre density in two broiler genotypes given three dietary protein feeding regimes. 2. A total of 1440 Ross 308 and 708 broilers (720/genotype) were given one of three dietary protein regimes (Low: 192, 166 and 155 g/kg, Control: 229, 199 and 182 g/kg and High: 266, 235 and 207 g/kg for starter, grower and finisher diets respectively). On d 21 and 42, initial protein solubility, DNA and myofibre density were determined. On d 42, breast meat samples were collected for meat quality analyses. 3. There were no genotype effects on pH(24), L*, a* or b* values. Thawing loss was higher in meat from the 708 than the 308 genotype. 4. Broilers given the low protein feeding regime had highest carcase fat, lowest pH(24) and palest meat. The low regression coefficients between dietary protein content and changes in pH(24) and lightness, however, demonstrated that dietary protein was not the principal factor influencing these traits. 5. Although sarcoplasmic protein solubility was similar among protein feeding regimes on d 21, the highest sarcoplasmic protein solubility on d 42 was in broilers on the high protein regime. 6. Myofibre density was highest in meat from broilers given the low protein regime. 7. It was concluded that dietary-protein content contributes significantly to both protein solubility and myofibre density.     

无机铬对肉用仔鸡生产性能及脂类代谢影响研究

铬作为葡萄糖耐量因子成分 ,能促进胰岛素调节动物体内脂类代谢 ,降低脂肪含量 ,改善胴体品质。有机铬无论是铬酵母还是吡啶羧酸铬都可以降低肉鸡脂肪含量。不同形式的铬 ,吸收率存在很大的差异 ,Ｓｅｅｒｌｙ(1 993)报道有机铬吸收率约为 1 0 %～ 2 5 % ,而无机三价铬仅为 1 %～ 3 %(Ａｎｄｅｒｓｏｎ等 ,1 985;Ｏｆｆｅｎｂａｃｈｅｒ等 ,1 986)。日粮中添加无机铬是否产生与有机铬相同的效果还不清楚 ,为此我们通过两个试验探索肉用仔鸡日粮添加不同含量的ＣｒＣｌ3·6Ｈ2 Ｏ ,对生产性能和脂类代谢的影响。1　材料和方法1 1　试验鸡分…     

Effect of chromium picolinate and chromium propionate on glucose and insulin kinetics of growing barrows and on growth and carcass traits of growing-finishing barrows

Two experiments were conducted to determine the effects of dietary Cr tripicolinate (CrPic) or Cr propionate (CrProp) on growth, carcass traits, plasma metabolites, glucose tolerance, and insulin sensitivity in pigs. In Exp. 1, 36 barrows (12 per treatment; initial and final BW were 20 and 38 kg) were allotted to the following treatments: 1) corn-soybean meal basal diet (control), 2) as 1 + 200 ppb Cr as CrPic, or 3) as 1 + 200 ppb Cr as CrProp. Growth performance data were collected for 28 d, and then 23 pigs (seven, eight, and eight pigs for treatments 1, 2, and 3, respectively) were fitted with jugular catheters and a glucose tolerance test (500 mg glucose/kg BW) and an insulin challenge test (0.1 IU of porcine insulin/kg BW) were conducted. Both CrPic and CrProp decreased (P < 0.05) ADG and ADFI but did not affect gain:feed (P > 0.10). Fasting plasma glucose, total cholesterol, urea N, insulin, and high-density lipoprotein cholesterol:total cholesterol concentrations were not affected (P > 0.10) by either Cr source. Pigs fed CrPic had lower (P < 0.02) fasting plasma NEFA concentrations than control pigs, but plasma NEFA concentrations of pigs fed CrProp were not affected (P > 0.10). During the glucose tolerance test, glucose and insulin kinetics were not affected by treatment (P > 0.10). During the insulin challenge test, glucose clearance was increased (P < 0.01) in pigs fed CrProp but not affected (P > 0.10) in pigs fed CrPic. Glucose half-life was decreased (P < 0.03) in pigs fed CrPic or CrProp, but insulin kinetics were not affected (P > 0.10). In Exp. 2, 48 barrows (four replicates of four pigs per replicate; initial and final BW were 23 and 115 kg) were allotted to the same dietary treatments in a growing-finishing study. Average daily gain, ADFI, and gain:feed were not affected (P > 0.10) by treatments. Carcass length tended (P = 0.10) to be greater in pigs fed CrPic than in pigs fed CrProp, but other carcass measurements were not affected (P > 0.10). Glucose kinetics from the insulin challenge test indicate that both CrPic and CrProp increase insulin sensitivity and that both Cr sources are bioavailable.     

Performance, carcass characteristics, and lipid metabolism in growing and finishing Simmental steers fed varying concentrations of copper.

An experiment was conducted to determine the effects of dietary copper (Cu) on performance, carcass characteristics, and lipid metabolism in Simmental steers. Thirty-six Simmental steers (329.3 +/-11.4 kg) were stratified by weight and randomly assigned to treatments. Treatments consisted of the following: control (no supplemental Cu) and 10 or 40 mg Cu/kg DM from Cu sulfate. Each treatment consisted of six replicate pens, with each pen containing two steers. A corn silage-soybean meal-based diet was fed for 56 d. Steers were then switched to a high concentrate diet. Performance was not affected by treatment during the growing or finishing phases. Plasma Cu concentrations were higher (P < 0.05) in steers receiving supplemental Cu by d 56 of the growing phase and remained higher (P < 0.05) at all 28-d sampling periods during the finishing phase. Liver Cu concentrations were higher (P < 0.001) in steers receiving supplemental Cu at the end of the growing phase and on d 84 and at the end of the finishing phase. Steers supplemented with 40 mg Cu had higher (P < 0.001) liver Cu concentrations than those supplemented with 10 mg Cu/kg DM. Serum and longissimus muscle cholesterol concentrations were similar between treatments. Longissimus muscle and backfat fatty acid composition was similar between treatments. These results indicate that Cu supplementation given to Simmental steers increased Cu status but had no effect on performance, carcass characteristics, or lipid or cholesterol metabolism.     

Aspects of lipid and carbohydrate metabolism, dietary biotin and fatty liver and kidney syndrome in broilers.

Two experiments were performed to investigate the biochemical changes associated with FLKS. A diet reported to induce FLKS was fed with or without supplementary biotin to broilers. In experiment 1 various stresses were applied to the birds. 2. In experiment 1 mortality from FLKS was 6% and in experiment 2 nil. Stress had little effect on the induction of the syndrome. 3. There were no significant differences due to diet in any of the variables examined in apparently normal birds. 4. Birds affected by FLKS showed the typical changes of increased liver and kidney weights and lipid contents but hepatic enzyme activities did not differ significantly from those of normal birds except that malate dehydrogenase (decarboxylating) (NADP) activity was significantly decreased. 5. Despite the low content of biotin in the unsupplemented diet (57 mug/kg) liver biotin content was not low in birds fed on this diet. 6. The results suggest that the incidence of FLKS is not related solely to dietary biotin content.     

Growth and carcass traits of heifers as affected by hormonal treatment

Seventy-seven heifers weighing about 200 kg were assigned randomly to intact control (C), ovariectomized (OVX) immunized against estradiol (BSA-E), BSA-E + trenbolone acetate (BSA-E + TBA), TBA or ovx + TBA groups. The objective of the study was to determine the effects of ovariectomy, immunoneutralization of estradiol and trenbolone acetate treatment on growth rate and carcass merit. Heifers were fed a corn-corn silage diet and were slaughtered when treatment groups attained live-animal weights of 433 kg. Observations of rate of growth, efficiency of feed conversion, characteristics of carcasses and characteristics of organoleptic properties of the cooked meat were made. Average daily gains (ADG) were similar in the control and OVX groups and tended to be less than in other treatment groups (P less than .36). Although not statistically significant, the observed mean for the BSA-E + TBA treatment suggests improved ADG and TDN per unit of gain, indicating a possible immunization X TBA interaction. Data also suggested that heifers implanted with TBA had increased ADG and efficiencies of gain. Possibly, immunoneutralization of endogenous estradiol can improve ADG as compared with control and OVX groups. Treatments had no effect on color or texture of lean muscle at the 12th rib interface. The OVX + TBA group had less (P less than .01) 12th rib fat cover than other groups and lower percent fat in the rib than C. The BSA-E + TBA and TBA groups also possessed larger (P less than .02) longissimus muscle areas than the control group. Observations of juiciness, tenderness and flavor were similar among all treatments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of manganese supplementation and source on carcass traits, meat quality, and lipid oxidation in broilers

An experiment was conducted using a total of 336 one-day-old, Arbor Acres commercial male broilers to investigate the effect of dietary Mn supplementation on carcass traits, meat quality, lipid oxidation, relative enzyme activities in abdominal fat and meat, and Mn-containing superoxide dismutase (MnSOD) mRNA level in meat. Broilers were randomly allotted by BW to 1 of 8 replicate cages (6 chicks per cage) for each of 7 treatments in a completely randomized design involving a 2 x 3 factorial + 1 arrangement of treatments. Dietary treatments included the corn-soybean meal-based diet (control) and the basal diet supplemented with 100 or 200 mg of Mn/kg as MnSO(4) x H(2)O, Mn AA A with a chelation strength of 26.3 formation quotient (8.34% Mn), or Mn AA B with a chelation strength of 45.3 formation quotient (6.48% Mn). Birds fed supplemental Mn had lower (P < 0.10) percentages of abdominal fat, lipoprotein lipase (LPL), and malate dehydrogenase activities and greater (P < 0.07) hormone-sensitive lipase activities in abdominal fat than birds fed a control diet. Birds fed supplemental Mn from Mn AA A or Mn AA B had lower (P < 0.05) LPL activities in abdominal fat than those fed supplemental MnSO(4) x H(2)O. Birds fed supplemental Mn had lower (P < 0.03) malondialdehyde content in leg muscle and greater (P < 0.02) MnSOD activities and MnSOD mRNA level in breast or leg muscle than those fed the control diet. Birds fed supplemental Mn from Mn AA A had a greater (P < 0.02) MnSOD mRNA level in leg muscle than those fed supplemental MnSO(4) x H(2)O. Results from this study indicated that organic Mn was more available than inorganic Mn for decreasing LPL activity in abdominal fat of broilers, and dietary Mn might reduce abdominal adipose deposition by decreasing LPL and malate dehydrogenase activities or increasing hormone-sensitive lipase activity in abdominal adipose tissue. The results also indicated that dietary Mn upregulated muscle MnSOD gene expression pretranslationally in association with increased MnSOD activity, which might explain the decrease of malondialdehyde content in leg muscle.