Pathology of vitamin D deficiency in growing turkeys

Turkey poults were fed a vitamin D-deficient diet and examined for clinical signs and structural changes of bone and parathyroid glands. Vitamin D-deficient poults developed ricketic changes during days 10 to 14. Control poults (deficient diet plus vitamin D) did not develop rickets. In deficient poults, lengths of proliferating-prehypertrophied zones of growth plates increased significantly in the proximal tibiotarsus but were only slightly elongated in the distal tibiotarsus. Unmineralized hypertrophic chondrocyte zones increased in length rapidly in conjunction with a decrease in the length of mineralized hypertrophic degenerative zones; this occurred more rapidly in proximal than in distal tibiotarsus. Other ricketic changes included decreases in bone ash, total femoral bone ash (calcium, phosphorus, magnesium), bone length, and body weight. Plasma alkaline phosphatase was increased, calcium was normal, and phosphorus was normal or elevated. Parathyroids were hyperplastic and had foci of degeneration. Vitamin D3 metabolites 25OHD3, 1,25(OH)2D3, and 24,25(OH)2D3 were rapidly depleted. Increase in bone ash Ca/P ratios in deficient poults suggests that phosphorus may be selectively released from ricketic bone. Low 25OHD3 and 1,25(OH)2D3 of control poults early in the experiment suggests that 1,400 IU of vitamin D3/kg of feed may not be an adequate level of vitamin D3 for growing turkey poults.     

Effects of dietary calcium and phosphorus on mineral retention,growth, feed efficiency and walking ability in growing turkeys

1. Large White male turkeys from a heavy commercial male-line were fed on 16 diets containing 4 concentrations of calcium (6, 10, 14 and 18 g/kg) and available phosphorus (3, 5, 7, 9 g/kg) in a 4 x 4 factorial experiment with three replicates (pens). Turkeys were weighed and food intakes recorded from 4 to 7, 8 to 10 and 11 to 13 weeks of age. 2. The diets containing 6 g/kg calcium and 5, 7 or 9 g/kg available phosphorus concentrations were associated with lower body weighs at 10 and 13 weeks of age. 3. Fewer than 6% of the turkeys had an abnormal gait at 13 weeks of age. 4. The optimum dietary concentrations were 10 g/kg of calcium and 3 g/kg of available phosphorus. It was concluded that these concentrations should be fed at least to 13 weeks of age. 5. Retentions of dietary calcium and phosphorus averaged 300 g/kg of intake. 6. Utilisation of dietary phytate ranged from 5 to 11 g/kg and it is recommended that organic phosphorus should be ignored in the formulation of diets for growing turkeys unless they are supplemented with a phytase enzyme.     

Role of dietary calcium and available phosphorus in the aetiology of tibial dyschondroplasia in growing turkeys

1. Large White male turkeys from a heavy commercial male-line were fed 16 diets containing 4 concentrations of calcium (6, 10, 14 and 18 g/kg) and available phosphorus (3, 5, 7 and 9 g/kg) in a 4 x 4 factorial experiment. There were three replicates (pens) of each treatment and the skeletal health, morphology and mineral status of 4 turkeys from each pen were assessed at 7, 10 and 13 weeks of age. 2. The prevalence of tibial dyschondroplasia increased after 7 weeks of age and was present in 50 and 71% of turkeys respectively at 10 and 13 weeks. The lesion was localised in the caudal aspect of the proximal tibiae. Dietary calcium and available phosphorus did not affect the prevalence of the lesion except in turkeys on the diet containing 6 g calcium/kg, where body weight and the incidence of tibial dyschondroplasia were low. 3. Histological investigation showed no evidence of rachitic changes. 4. Low dietary calcium was associated with lower tibial plateau angles at 10 and 13 weeks of age. Tibial torsion and the angle of rotation were not affected by dietary treatments or age. Tibial torsion and the angle of rotation were not affected by dietary treatments or age. 5. Increasing dietary calcium increased tibial radiodensity, cortical density and the widths of the cortex and proximal tibiotarsus. Radiodensities increased to 10 weeks and were significantly lower at 13 weeks of age. 6. Bone ash, calcium and phosphorus declined with age, particularly between 10 and 13 weeks, whereas bone calcium: phosphorus ratios were not affected by dietary treatment or age. 7. Dietary calcium was positively associated with blood calcium and calcium ion concentrations and was without effect on blood phosphorus. Available phosphorus was associated positively with increased blood phosphorus and lower calcium ion concentrations but had no effect on total calcium. Alkaline phosphatase activity was low at high concentrations of dietary calcium with low available phosphorus and there was higher activity on diets containing low calcium and high available phosphorus.     

日粮维生素水平对生长期蛋鸡影响的研究

选用4因素3水平正交试验设计，研究日粮维生素A、D3、E对生长期蛋鸡的影响。结果如下：6周末体重随VE水平的提高而提高，但差异不显著。14周末体重受VE的显著影响。高水平（100mg／kg）组显著大于低水平（10mg／kg）组与中水平（40mg／kg）组（P＜0．01），中、低水平之间差异不显著。血清新城疫抗体效价随VA水平的提高而显著提高（P＜0．05）。高水平VA和高水平VE组合组显著高于其它组（P＜0．05）。胫骨中的钙含量随VA水平的提高显著提高（P＜0．01）。VD3对体重、抗体滴度和胫骨Ca含量无显著影响。     

Environmental temperature and dietary protein concentrations for growing turkeys

Growing turkeys were kept at one of 4 constant temperatures (14, 17, 20 or 23 degrees C) from 10 to 15 weeks of age and given a food with one of three protein concentrations (201, 229 or 294 g/kg diet). Food intakes, food conversion ratios and breast meat yields (as a proportion of body weight) were decreased at the higher temperatures but there were no significant differences in growth. At each temperature, the turkeys given the higher dietary protein concentrations had increased body weight gains but their breast meat yields were similar. Thus the poor breast meat yields which resulted from rearing at high temperatures could not be counteracted by high dietary protein concentrations.     

Effects in sheep of high dietary levels of vitamin D3 as measured by circulating concentrations of some vitamin D metabolites and skeletal examination

Housed non-pregnant ewes were given diets supplemented with five, 10, 20, 40 and 80 times the Agricultural Research Council's recommended requirement for vitamin D for 16 weeks. The effects on vitamin D status were assessed by measuring 25-hydroxylated vitamin D metabolites (25-OHD) in plasma at intervals. After 16 weeks, animals on the lowest and two highest vitamin D intakes were killed for histological examination of selected soft tissues and bones. Circulating concentrations of 25-OHD increased with intake and time during the experiment. However the increases were not proportional to intake and only when intakes exceeded 20 times the recommended requirement were concentrations greater than those seen in summer in grazing sheep. There was some evidence for the production of an additional vitamin D metabolite in animals on high vitamin D intakes. No abnormalities were detected in any of the tissues examined histologically.     

The effect of dietary protein content on calcium and phosphorus retention in the growing Iberian pig

The effects of dietary protein content (DPC) from excessive (192 g/kg DM) to marginally deficient (101 g/kg DM) upon whole-body retention of Ca and P was studied in 25 purebred Iberian pigs growing from 15 to 50 kg BW by means of a comparative slaughter experiment which included a digestibility trial. Ca and P retention related to intake remained unaffected at 0.228 ± 0.0072 and 0.184 ± 0.0052, reaching 3.64 ± 0.119 and 2.00 ± 0.057 g Ca and P per day respectively. Pigs fed on diets containing protein levels in excess of requirements had significantly higher concentrations of Ca and P (P < 0.05) in their bodies (14.41–14.99 and 7.88–8.08 g Ca and P/kg fat-free empty-body gain respectively) than those given adequate or marginally deficient amounts of dietary protein (11.80–12.72 and 6.61–7.01 g Ca and P/kg fat-free empty-body gain respectively). In a second experiment, made with 25 Iberian pigs of 21 kg initial weight, daily intakes of Ca and P to maintain zero retention were determined using five experimental diets in which the concentrations of Ca and P were varied by the addition of graded levels of Ca carbonate and inorganic phosphate to a basal diet balanced in protein-to-energy ratio (131 g CP; 13.8–14.4 MJ ME/kg DM). Growth rate and protein deposition were unaffected by the level of Ca and P in the diet and reached average values of 485 ± 15.4 and 103 ± 1.2 g/d. Increasing the dietary Ca and P levels increased the absolute amounts of Ca and P retained daily from 0.69 to 5.77 and 1.12 to 3.70 g respectively (P < 0.001). Highly significant (P < 0.001) curvilinear regressions were obtained when relating Ca and P absorption or retention (g/d) with Ca and P intake (g/d). From these equations, daily maintenance requirements of 105 and 72 mg/kg BW for Ca and P respectively were obtained. Average total net requirements of Ca and P for the Iberian pig at this stage of growth were estimated to be 5.25 and 3.10 g/d respectively, considerably lower than those reported for conventional and high-performance pig genotypes.     

钙与维生素D_3对肉品质的影响

本文首次系统阐述了钙与维生素D3对肉的嫩度及其他食用品质与感官品质的影响 ,并对二者改善肉品质的机理作了深入分析 ,最后指出了今后的研究方向     

Effects of dietary vitamin E on muscle vitamin E and fatty acid content in Aohan fine-wool sheep

Background

Increasing the polyunsaturated fatty acid (PUFA) content and decreasing the saturated fatty acid (SFA) content of mutton can help to improve its nutritional value for consumers. Several laboratories have evaluated the effects of vitamin E on the fatty acid (FA) composition of muscle in sheep. However, little information is available on wool sheep, even though wool sheep breeds are an important source of mutton, especially in northern China where sheep are extensively farmed. The present study was designed to address the effects of vitamin E on muscle FA composition in male Aohan fine-wool sheep.

Methods

Forty-two male Aohan fine-wool lambs (5 mo old) with similar initial body weight were randomly divided into seven groups and fed diets supplemented with 0 (control group), 20, 100, 200, 1,000, 2,000, or 2,400 IU/sheep/d vitamin E for 12 mo. Three lambs from each group were slaughtered to measure vitamin E and FA content in the longissimus lumborum (LL) and gluteus medius (GM) muscles.

Results

Vitamin E concentrations in the LL and GM increased significantly after 12 mo of vitamin E supplementation (P < 0.05). However, this increase did not occur in a dose-dependent manner because the muscle vitamin E concentration was highest in the 200 IU/sheep/d group. Dietary vitamin E supplementation also caused a significant reduction in SFA content and an increase in monounsaturated FA (MUFA) content in the LL and GM (P < 0.05). All six doses of vitamin E significantly increased cis9 trans11-conjugated linoleic acid (c9t11-CLA) content in the LL compared with the control group (P < 0.05).

Conclusions

Dietary supplementation with vitamin E increased muscle vitamin E content and improved the nutritional value of mutton by decreasing SFA content and increasing MUFA and c9t11-CLA contents in Aohan fine-wool sheep. These effects were greatest in sheep fed a diet containing 200 IU/sheep/d vitamin E.     

Effects of dietary vitamin and fatty acid content in E on muscle vitamin E Aohan fine-wool sheep

Background： Increasing the polyunsaturated fatty acid （PUFA） content and decreasing the saturated fatty acid （SFA） content of mutton can help to improve its nutritional value for consumers. Several laboratories have evaluated the effects of vitamin E on the fatty acid （FA） composition of muscle in sheep. However, little information is available on wool sheep, even though wool sheep breeds are an important source of mutton, especially in northern China where sheep are extensively farmed. The present study was designed to address the effects of vitamin E on muscle FA composition in male Aohan fine-wool sheep. Methods： Forty-two male Aohan fine-wool lambs （5 mo old） with similar initial body weight were randomly divided into seven groups and fed diets supplemented with 0 （control group）, 20, 100, 200, 1,000, 2,000, or 2,400 IU/sheep/d vitamin E for 12 mo. Three lambs from each group were slaughtered to measure vitamin E and FA content in the Iongissimus lumborum （LL） and gluteus medius （GM） muscles. Results： Vitamin E concentrations in the LL and GM increased significantly after 12 mo of vitamin E supplementation （P 〈 0.05）. However, this increase did not occur in a dose-dependent manner because the muscle vitamin E concentration was highest in the 200 IU/sheep/d group. Dietary vitamin E supplementation also caused a significant reduction in SFA content and an increase in monounsaturated FA （MUFA） content in the LL and GM （P 〈 0.05）. All six doses of vitamin E significantly increased cis9 tronsl -conjugated linoleic acid （cgtl -CLA） content in the LL compared with the control group （P 〈 0.05）. Conclusions： Dietary supplementation with vitamin E increased muscle vitamin E content and improved the nutritional value of mutton by decreasing SFA content and increasing MUFA and c9tl 1-CLA contents in Aohan fine-wool sheep. These effects were greatest in sheep fed a diet containing 200 IU/sheep/d vitamin E.     

Effects of dietary energy and phosphorus content on blood chemistry and development of growing horses

Growth and clinical biochemistry were examined over 30 wk in 42 light horse weanlings fed high-forage diets (73 to 77% alfalfa) or high-concentrate diets (63 to 65% grain and grain by-products) that were either low (.24 to .35%), normal (.68%) or high (.95 to 1.06%) in P. Body weights and blood samples were taken every 2 wk. Forage and concentrate diets contained 2.65 and 3.09 Mcal digestible energy/kg DM, respectively. Calcium and P digestibilities were highest (P less than .01) in those horses fed the low P diets, but only horses fed forage-low P diets may have absorbed insufficient P. Serum alkaline phosphatase activity, serum Ca, serum Mg and plasma Cu concentrations were unaffected by diet but varied (P less than .01) among sampling periods. The concentrations of serum Ca and P of all groups fluctuated to wk 10 before being stabilized at means of 2.77 and 2.03 mmol/liter, respectively. Plasma Zn concentrations increased quadratically with age and were 3.8% greater (P less than .05) for concentrate-fed horses than for forage-fed horses. Mild to moderate physitis and flexure limb deformities occurred in 88% of the weanlings principally between wk 6 and 8 of the study. Limb deformities had largely resolved by wk 12. Marginally deficient P intakes did not alter productivity, feed intake, blood mineral concentration in the final 20 wk or the occurrence of musculoskeletal abnormalities in weanling horses.     

Pathology of experimental vitamin D deficiency in turkeys and the effects of various vitamin D supplements.

One-day-old poults fed a vitamin D3-deficient diet were examined for clinical, biochemical, and morphological changes at 14 days of age. Changes in these parameters were compared at 15.5 and 17 days of age after one of the following vitamin D-replacement therapies was provided: water-soluble vitamin-mineral packs that contained vitamin D3; vitamin D3 in the feed; or vitamin D, 1,25-dihydroxyvitamin D3 in the feed. The vitamin D3-deficient poults were lame and had significant decreases in weight gain and in longitudinal skeletal growth. None of the therapies alleviated all these changes, but clinical lameness subsided in poults provided 1,25-dihydroxyvitamin D3. Calcium concentrations were significantly improved by all therapies. Treatment with vitamin D3 in the feed and water significantly increased 25-hydroxyvitamin D3 concentrations in vitamin D-deficient poults. The growth plate zones, with the exception of the mineralized hypertrophied zone, were all increased in length and not modified by treatment. However, the mineralized hypertrophied zones in the 1,25-dihydroxy-vitamin D3 group and the group receiving vitamin D3 in the water were comparable to that in the controls on day 15.5.     

Effects of oral administration of "rumen-bypass" vitamin D3 on vitamin D and calcium metabolism in periparturient cows

Eleven late-pregnant Jersey cows were assigned to two groups; a group (PO-RBVD group) consisting of five cows treated with an oral administration of 10 million I.U. of an encapsulated form of vitamin D3 ("rumen-bypass" VD3; RBVD3) and another group (IMVD group) consisting of the other six treated with an intramuscular injection of 10 million I.U. of vitamin D3 (VD3). The cows received the RBVD3 or VD3 administration at 7 days before the expected parturition. The changes in the plasma concentrations of vitamin D metabolites, ionized Ca (Ca++) and inorganic phosphorus (iP) were evaluated. Of the vitamin D metabolites, the plasma 25-hydroxyvitamin D concentrations in PO-RBVD group increased significantly after the RBVD3 administration and remained in high levels that were significantly higher than those in IMVD group. This suggested that RBVD3 was absorbed rapidly and excellently from the post-ruminal digestive tract without the degradation by ruminal microorganisms. The plasma Ca++ and iP concentrations in PO-RBVD group tended to be higher after the administration and around parturition than those in IMVD group. From these observations, it was suggested the oral RBVD3 administration had more potent ability to prevent parturient paresis compared with the VD3 injection used widely in Japan.     

Effects of dietary vitamin E and C supplementation on heart failure in fast growing commercial broiler chickens

1. It has recently been shown that oxidative stress is involved in the pathogenesis of congestive heart failure (CHF) in broiler chickens. Vitamins E and C, common antioxidants, have been advocated for the prevention of heart failure in humans. The present study examines the effects of supplementation of these vitamins on incidence of CHF and prevention of oxidative stress in the myocardium.

2. Commercial male broilers were randomly allocated to three experimental groups and, respectively, offered commercial broiler diet (control), commercial diets fortified with vitamin E (960 IU/kg) or vitamin C (400 mg/kg). The broilers were monitored daily for overt signs of heart failure and clinical data including ECG and blood gas analysis were collected periodically. Lipid peroxidation was measured in cardiac tissues from apparently normal broilers and broilers developing CHF in each group using thiobarbituric acid reactive substances (TBARS) assay.

3. Overall, the incidence of CHF in broilers given diets fortified with vitamin E or vitamin C was not significantly different as compared to the control group. The incidence of overt signs of hypoxaemia was lower in the vitamin C group than in the control group. Lipid peroxidation was highest in broilers that developed CHF as compared to apparently normal broilers fed either vitamin E or C fortified diets. Neither vitamin E nor vitamin C was effective in preventing oxidative damage in broilers that developed CHF.

4. In conclusion, the present study confirmed that oxidative stress is involved in the pathogenesis of heart failure in broilers, but dietary supplementation of antioxidant vitamins did not prevent oxidative damage in broilers that developed CHF. Beneficial effects of vitamin C supplementation were evidenced by lower incidence of hypoxaemia, and the tendency to reduce the susceptibility of broilers to heart failure. However, vitamin E did not have any impact on clinical status or the incidence of CHF.     

Impacts of UVB provision and dietary calcium content on serum vitamin D3, growth rates,skeletal structure and coloration in captive oriental fire‐bellied toads (Bombina orientalis)

Many amphibian species are dependent on ex situ conservation interventions for their long‐term persistence. However, projects have been jeopardised by husbandry issues involving poor calcium metabolism and nutritional metabolic bone disease (NMBD). Healthy calcium metabolism requires appropriate dietary calcium content and access to vitamin D₃. In many animals, vitamin D₃ can be photobiosynthesised in skin exposed to UVB radiation, as well as extracted from the diet, but the extent of vitamin D₃ photobiosynthesis in amphibians is poorly known. Additionally, prey insects for captive amphibians are deficient in calcium and calcium content must be artificially increased, but the effects of different levels of augmentation and their interaction with UVB exposure are also little understood. We fed captive fire‐bellied toads (Bombina orientalis) with crickets augmented to contain 5% and 10% calcium and housed them with and without UVB exposure. Despite additional dietary vitamin D₃ supplementation, we found that toads exposed to UVB radiation exhibited significantly higher serum vitamin D₃ levels, indicating that this species may partly rely on photobiosynthesis sources of vitamin D₃. These data are the first to show a direct link between UVB exposure and serum vitamin D₃ in an amphibian. We found significant positive effects of UVB exposure and 10% dietary calcium content on skeletal structure, as well as complex interactions between treatments. We also found UVB radiation exposure resulted in more rapid natural coloration acquisition. Together, this indicates that standard calcium plus vitamin D₃ supplementation methods may not fully substitute for UVB exposure and for increased feeder insect calcium content. This may have implications for the success of ex situ amphibian conservation, as well as for the welfare of captive amphibians in general. Our data lend support for the provision of UVB radiation for captive, basking amphibians.     

纤维源对不同品种生长猪养分消化率和氮平衡的影响

试验旨在研究纤维源对不同品种生长猪养分消化率和氮平衡的影响试验选取体重相近、健康去势的烟台黑、鲁农2号生长猪各6头,饲喂玉米-豆粕型日粮,采用有重复的3×3拉丁方设计,三个处理分别为基础日粮组、10%大豆皮替代基础日粮组、10%地瓜蔓替代基础日粮组。于每期试验的第6、7 d连续收集48 h的粪样和尿样测定日粮养分消化率和氮平衡代谢。结果表明:日粮添加10%地瓜蔓,两品种生长猪养分消化率和氮平衡显著或极显著降低(P0.05或P0.01),添加10%大豆皮对其氮总利用率影响显著(P0.05),对其他则影响不显著(P0.05);除对干物质消化率(P0.01)、氮表观消化率(P0.05)外,猪的品种对养分消化率和氮平衡均有显著影响(P0.05);纤维源对养分消化率和氮平衡均影响极显著(P0.01);但二者的互作关系不明显(P0.05)。与烟台黑生长猪相比,纤维源对鲁农2号生长猪养分消化率及氮平衡代谢的影响更大。     

Effects of high dietary sodium chloride content on performance and sodium and potassium balance in growing pigs

Thirty castrated male Moo Lath pigs (6–8 weeks of age) were used in a 15-week growth trial to study the effect of high dietary sodium chloride (NaCl) content on feed and water intake, performance, sodium (Na) and potassium (K) balance, and plasma aldosterone concentration. The pigs were randomly allocated (ten per treatment) to diets containing 0.24 % Na (Na0.24), 0.28 % Na (Na0.28), and 0.32 % Na (Na0.32) per kg diet. Feed and water was provided ad libitum, and water consumption, feed offered, and feed residues were recorded daily. Every third week, the pigs were weighed, blood samples were collected, and a 3-day total collection of urine and feces was performed. Water intake was higher (P?=?0.001) in pigs fed with diets Na0.28 (3.7 L/day) and Na0.32 (3.9 L/day) than in pigs fed with diet Na0.24 (3.4 L/day), and dry matter (DM) intake was higher on diet Na0.32 (P?=?0.041) than on the other diets. The average daily body weight (BW) gain was higher on diet Na0.32 than on the other diets (P?=?0.031). The feed conversion ratio (in kilogram feed DM to kilogram BW gain) was 4.6, 4.6, and 4.1 on treatments Na0.24, Na0.28, and Na0.32, respectively (P?=?0.14). The highest Na balance was observed on diet Na0.32 followed by diets Na0.28 and Na0.24 (P?<?0.001), while there was no treatment-related pattern for the K balance. The Na/K ratio in feces and urine increased (P?<?0.001), and the K/Na ratio in feces (P?<?0.001) decreased with increasing Na content in the diet. Plasma aldosterone concentration decreased (P?<?0.001) with increasing dietary content of Na. These results indicate that high NaCl intake and free access to water will increase Na balance but do not negatively influence feed intake and performance of growing local pigs.     

Effects of dietary copper concentration and source on performance and copper status of growing and finishing steers

Performance and Cu status were measured in growing and finishing steers supplemented with different copper (Cu) concentrations and sources. Sixty Angus (n = 36) and Angus x Hereford (n = 24) steers were stratified by weight and initial liver Cu concentration within a breed and randomly assigned to treatments. Treatments consisted of 1) control (no supplemental Cu); 2) 20 mg Cu/kg DM from Cu sulfate (CuSO4); 3) 40 mg Cu/kg DM from CuSO4; 4) 20 mg Cu/ kg DM from Cu citrate (C6H4Cu2O7); 5) 20 mg Cu/kg DM from Cu proteinate; and 6) 20 mg Cu/kg DM from tribasic Cu chloride (Cu2(OH)3Cl). A corn silage-soybean meal-based diet that was analyzed to contain 10.2 mg of Cu/kg DM was fed for 56 d. Steers were then switched to a high-concentrate diet that was analyzed to contain 4.9 mg of Cu/kg DM. Equal numbers of steers per treatment were slaughtered after receiving the finishing diets for either 101 or 121 d. Performance was not affected by Cu level or source during the growing phase. Gain, feed intake, and feed efficiency were reduced (P < .05) by Cu supplementation during the finishing phase. Plasma and liver Cu concentrations were higher in steers receiving supplemental Cu at the end of both the growing and finishing phases. Steers supplemented with 40 mg Cu/kg DM from CuSO4 had higher (P < .05) liver Cu concentrations than those supplemented with 20 mg Cu/kg DM from CuSO4. Liver Cu concentrations did not increase over the finishing phase relative to liver Cu concentrations at the end of the growing phase. These results indicate that as little as 20 mg/kg of supplemental Cu can reduce performance in finishing steers.     

饲粮维生素E水平对公猪繁殖及精浆营养生化参数的影响

选择年龄、体重、精液质量较一致、正在使用的健康壮年杜洛克公猪5头,采用5×5正交拉丁方试验设计,在不同阶段分别饲喂含维生素E10.0mg/kg(处理1)、22.5mg/kg(处理2)、35.0mg/kg(处理3)、47.5mg/kg(处理4)、60.0mg/kg(处理5)的饲粮,研究饲粮中维生素E对公猪繁殖参数、精浆生殖激素、精浆营养生化参数的影响。结果表明,⑴处理3、4、5公猪精子活率显著高于处理1(P<0.05);处理1公猪精子畸形率显著高于处理3、4、5(P<0.05);精子活率、精子畸形率随饲粮维生素E含量(10.0mg/kg～60.0mg/kg)的增加而分别增加或降低。⑵采精量、精子密度、精浆FSH、精浆LH、精浆T、精液pH、精浆尿素含量、精浆总蛋白质含量,各处理间没有显著的差异(P>0.05)。⑶精浆的GSH-Px活力随饲粮维生素E含量的增加而升高。⑷结论,杜洛克公猪饲粮中维生素E的含量以35.0mg/kg较为适当。     

维生素C对中华鳖体组成及胶原蛋白含量的影响

本试验选取60只体重约150 g的中华鳖,随机分为5组,每组4个重复,每个重复3只进行为期60 d的养殖试验。1组为对照组,4个试验组分别对其投喂100、200、400 mg/kg和2000 mg/kg多聚磷酸酯维生素C,每天饲喂2次。养殖试验结束后,宰杀所有试验鳖,取腿肌、裙边和背甲样品进行分析。试验结果表明,饲料中添加维生素C能改善中华鳖体组成和增加组织胶原蛋白含量。随着饲料维生素C添加量的增加,肌肉和裙边必需氨基酸、非必需氨基酸、鲜味氨基酸和总氨基酸的含量也逐渐升高,且肌肉中的不饱和脂肪酸也逐渐升高,但肌肉中的饱和脂肪酸、单不饱和脂肪酸逐渐降低。饲料中添加维生素C能够提高肌肉、裙边、肝脏和背甲中胶原蛋白(以羟脯氨酸计)含量。