The influence of folic acid, vitamins B(2) and B(6) supplementation on feed intake, body and organs weight, and liver fatty acids composition of rats subjected to 3 months moderate protein deprivation

This study was conducted to determine the effect of a 3-month dietary protein restriction - protein provided 9% of energy (20% in control group). In this dietary restriction folic acid, vitamins B(2) and B(6) were delivered in amount three times above the standard level. It was observed that animals fed a protein restricted (PR) diet weighed about 5% less than animals consuming adequate diet, but the difference was not statistically significant. Enrichment of PR diet with vitamin B or folic acid caused tendency to further suppression of weight gain, and in case of vitamin B(6) these differences were statistically significant. However, such body weight (BW) suppression was not observed when all studied vitamins were used together. Significant reductions in relative liver weight (vitamin B(2) addition), the heart (folic acid) and the lungs (vitamin B(6)) were observed. The PR diet, when all vitamins were added together, caused a decrease in weights of the lungs, heart and liver scaled to BW of rats, simultaneously with a significant increase in testis weight. Feed intake and feed conversion ratio were higher in animals given PR diet without a significant influence of vitamin supplementation (except vitamin B(6) causing further increase in feed conversion ratio). Hepatic fatty acids composition of rats was not affected by protein restriction, as well as by single vitamin supplementation. However, dietary supplementation of all examined vitamins together caused a decrease in monounsaturated fatty acids followed by an increase in polyunsaturated fatty acids participation in total fatty acids pool. It seems that enrichment of PR diet with a mixture of folic acid, vitamins B(2) and B(6) resulted in a partial reverse of growth suppression and reduction in testis size in rats.     

Investigation on the growth of coprophagy-prevented rats with supplemented vitamin B12

The growth of coprophagy-prevented rats was compared under administration of normal levels of vitamin B12 and supplemented amounts. Two experiments in which supplemented amounts of vitamin B12 were administered were conducted under different conditions. Six rats per group were fed under coprophagy-allowed (conventional feeding) and coprophagy-prevented conditions respectively. In the first experiment, coprophagy-prevented rats were fed only feed containing recommended vitamin B12 level and forced fed hydrous faeces, vitamin B12 and folic acid respectively. In the second experiment, coprophagy-prevented rats were fed AIN-93G at the recommended vitamin B12 level (25 microg/kg diet), at 100 times the level and at 1000 times the level respectively. Body weight, feed consumption and amounts of each faeces type were determined in both experiments. In a comparison of body weight gain, we learned that coprophagy prevention reduced the values, but that there was no significant difference in the forced feeding group in the first experiment. Similar results were recognized in the second experiment. Vitamin B12 supplementation was not able to raise feed intake significantly and hence it obviously was not a severely limiting factor under the respective experimental condition which depressed feed intake.     

Evaluation of amino acids, B vitamins and butylated hydroxyanisole as protective agents against pyrrolizidine alkaloid toxicity in rats

Supplementation of the diets of rats with branched chain amino acids (BCAA: leucine, isoleucine, valine) did not alter their susceptibility to chronic poisoning by tansy ragwort (Senecio jacobaea), which contains hepatotoxic pyrrolizidine alkaloids (PA). Phenobarbital in the diet, which alters liver microsomal enzyme activity, also did not alter susceptibility to PA poisoning. A combination of butylated hydroxyanisole (BHA), cysteine and BCAA did increase (P less than .05) survival time of rats fed tansy ragwort. Dietary BHA and cysteine increased the survival time of rats injected with the PA monocrotaline, with evidence that addition of vitamin B12 and folic acid improved the effectiveness of this treatment. In a chronic feeding trial with tansy ragwort, a combination of BHA and cysteine increased (P less than .05) the survival times of rats, showing protective activity against PA poisoning. A mixture of B-complex vitamins, or vitamin B12-folic acid, was not effective in improving the response.     

The effect of dietary vitamin E level on selenium status in rats

The effect of varying levels of dietary vitamin E on selenium status was determined using 40 Wistar rats with similar initial body weight. The rats were equally divided into four groups and fed the following dietary treatments (mg vitamin E/kg DM): 18 (control; C‐diet), 0 (0E‐diet), 9 (0.5E‐diet) and 36 (2E‐diet) for either 4‐week (Phase 1) or 8‐week (Phase 2) period. At the end of experiment, animals were slaughtered to measure vitamin E and selenium levels in the brain, liver, spleen, kidney, muscles and blood tissues. Dietary vitamin E levels did not affect feed and water intake and body weight. But whole‐blood selenium concentration in rats fed 0E‐diet was higher than in rats fed 2E‐diet after 4 weeks. Selenium level in muscle, spleen and brain was also higher (p < 0.05) in rats fed the 0E‐diet than in rats fed C‐diet after 4 weeks of feeding. On the other hand, selenium level in the muscle was lower (p < 0.05) in rats fed 0.5E‐diet than in those fed 0E‐diet after 4 weeks of feeding, but not after 8 weeks of feeding. Increasing dietary vitamin E level directly influenced selenium content of the spleen and brain after 8 weeks of feeding 2E‐diet. Moreover, the twofold increase in vitamin E intake resulted in a tendency to reduce whole‐blood selenium level and total selenium in the liver and kidney after 4 and 8 weeks. The results showed that the increasing dietary vitamin E level resulted in a tendency to reduce Se contents in some vital organs of the body such as the liver and kidney, suggesting their close compensatory interrelationship. Therefore, dietary vitamin E level directly influenced selenium metabolism in the animal body.     

Effects of dietary supplementation with ethoxyquin, magnesium oxide, methionine hydroxy analog, and B vitamins on tansy ragwort (Senecio jacobaea) toxicosis in beef cattle

Dried tansy ragwort containing pyrrolizidine alkaloids was fed as 2.5% of a complete (control) diet to Hereford steers, with and without (basal) a mixture of additives. The additives provided a dietary supplement equivalent to 0.1% ethoxyquin, 1% methionine hydroxy analog, 2% MgO, 2.7 mg of vitamin B6/kg of diet, 50 micrograms of vitamin B12/kg of diet, 0.45 g of folic acid/kg of diet, and 0.2 g of cobalt/kg of diet. The additives did not alter tansy ragwort toxicity substantially, as assessed by liver histologic changes, sulfobromophthalein clearance rate, and serum gamma-glutamyl transpeptidase activity. After 281 days, 1 of 4 steers fed the basal diet was alive, whereas 3 of 4 steers in the basal plus additives group were alive, suggesting some protective activity. The chronic lethal dose of tansy ragwort in steers was 3.6% of initial body weight.     

Effects of dietary supplementation with butylated hydroxyanisole, cysteine, and vitamins B on tansy ragwort (Senecio jacobaea) toxicosis in ponies

Dried tansy ragwort, which contains pyrrolizidine alkaloids, was fed as 10% of a complete diet to ponies, with and without a mixture of additives. The additives provided a dietary supplement equivalent to 1% cysteine, 0.75% butylated hydroxyanisole, 200 micrograms of vitamin B12/kg of feed, and 5 mg of folic acid/kg of feed. The additives did not alter tansy ragwort toxicity, as assessed by survival time, liver changes, sulfobromophthalein (BSP) clearance rate, serum gamma-glutamyl transpeptidase activity, and plasma amino acid patterns. In ponies fed tansy ragwort, BSP clearance rate was a sensitive indicator of liver damage, and decreased to about 20% of control values. gamma-Glutamyl transpeptidase activities showed considerable variability, but generally were elevated in animals fed tansy ragwort. Liver iron and copper concentrations increased, and liver zinc concentrations decreased in tansy ragwort-fed ponies. Plasma amino acid patterns in tansy ragwort-fed ponies showed changes typical of those observed in liver disease.     

A first estimate of the amino acid requirement for milk production of the high-producing female mink (Mustela vison)

Thirty mink dams nursing litters of six kits were assigned to one of three dietary treatments [high protein (HP), medium protein (MP) and low protein (LP)], fed ad libitum for 4 week from parturition, to investigate the effects of protein supply on milk yield and milk composition in order to estimate the amino acid requirement of the lactating mink. Twelve dams were held in an intensive care unit and subjected to balance experiments and the kits were injected with deuterium oxide to determine water kinetics and milk yield. Eighteen dams were kept under normal farm conditions but with feed intake of dams and live weight gain of kits being determined and milk samples collected. The ME intake was higher (p < 0.05) in dams fed the LP and MP diets than in dams fed the HP diet, whereas the amino acid intake (g/day) was lowest (p < 0.05) in dams fed the LP diet. In the third and fourth weeks of lactation milk yield was higher (p < 0.05) in dams fed the LP and MP diets than in dams fed the HP diet. Chemical composition of milk was not affected (p > 0.05) by dietary treatment. However, protein content tended (p = 0.06) to be lower in dams fed the LP diet. Amino acid content (g/16 g N) of milk was higher (p < 0.05) in dams fed the LP and MP diets than in dams fed the HP diet. This resulted in the highest (p < 0.05) amino acid intake and highest (p < 0.001) live weights of kits nursed by dams fed the LP and MP diets, which may be explained by a combined effect of higher ME intake and reduced energetic costs for glucose production through less amino acids being used in gluconeogenesis. In conclusion, the improved performance of dams fed the LP diet suggested that their requirement of essential amino acids and non-specific N were covered, and the requirement of digestible amino acids of lactating mink (kg(0.75)) was, thereby, estimated by use of a factorial approach including the amino acid excretion in milk of LP dams.     

微生物法测定婴幼儿配方乳粉中的生物素、叶酸和VB12

目的:采用微生物法测定婴幼儿配方乳粉中生物素、叶酸和VB12.方法:利用不同乳酸菌对特定维生素具有敏感性的特点,通过测定菌株的生长变化来反映样品中相应微生物的维生素含量,对市售的13种婴幼儿配方乳粉维生素进行测定.结果:微生物法对于生物素和VB12测定数据更稳定,重复性好,生物素相对标准偏差为0.056％～4.158％,VB12的相对标准偏差范围为0.112％～3.848％,而叶酸的检测数据之间波动稍大,相对标准偏差为1.236％～8.332％.结论:本法适合婴幼儿配方乳粉中生物素、叶酸和VB12这3种维生素的分析定量研究.     

Chromium picolinate, rather than biotin, alleviates performance and metabolic parameters in heat-stressed quail

1. The effects of chromium picolinate and biotin supplementation alone and in combination on performance, carcase characteristics, malondialdehyde (MDA), vitamin C, vitamin E, glucose and cholesterol levels were evaluated in Japanese quail exposed to high ambient temperature. 2. Two hundred and forty quails (10d old) were assigned randomly to 4 dietary treatments at room temperature (22 degrees C; thermoneutral, TN) or ambient (34 degrees C for 8 h/d; heat stress, HS). Both TN and HS were fed either on a basal (control) diet or the basal diet supplemented with 400 microg of Cr/kg (Cr group), 0.5 mg of biotin/kg of diet (biotin group) or both (Cr + Biotin group). 3. Supplementing the diet of heat-stressed quails with chromium picolinate improved live weight gain, feed intake, feed efficiency and carcase traits. Biotin supplementation during TN and HS conditions did not have any beneficial effects on body weight gain, feed intake, feed efficiency or carcase traits. 4. Either in combination or alone, chromium picolinate increased serum concentrations of vitamins C and E, but decreased MDA, glucose and cholesterol concentrations in birds kept at high ambient temperature. There was no difference in vitamins C and E and MDA concentrations between birds given chromium picolinate and birds receiving chromium picolinate plus biotin, while glucose and cholesterol levels were significantly lower in all groups. The lowest concentrations of cholesterol and glucose were found in the combination group under both TN and HS conditions. An interaction between diet and temperature was detected for glucose and cholesterol concentrations. 5. Excretion rates for zinc, iron and chromium were lower in TN groups than in the corresponding HS groups. Supplementing diet with chromium picolinate and chromium picolinate plus biotin decreased excretion of minerals while biotin alone did not effect excretion of minerals. 6. Chromium supplementation, but not biotin supplementation, attenuated the decline in performance and antioxidant status resulting from heat stress.     

The impact of nutrient density in terms of energy and/or protein on live performance,metabolism and carcass composition of female and male broiler chickens of two commercial broiler strains

The objective of this study was to investigate the effects of diet composition on performance, slaughter yield and plasma metabolites, as different modern broiler strains show different responses to feed intake. Broilers of two commercial strains and of both sexes received one of three diets being different in energy and/or protein level [control diet, low energy/low protein diet (LM/LP) and low protein diet (LP)]. Low energy/low protein diet chickens were characterized by significantly lower body weights and feed intake compared with their LP and control counterparts. Broilers of the Cobb strain or broilers that were fed the control diet were most efficient in converting energy to body weight. No significant differences in plasma metabolites were detected due to diet composition or genotype. The diet with the lower energy and crude protein levels reached the lowest slaughter yield but the highest drumstick and wing percentages. The lowest mortality percentages were observed for broilers fed the LM/LP diet, and Cobb birds appeared to be more sensitive for metabolic disorders resulting in death. It is obvious from this study that different genotypes respond differently to changes in diet composition and therefore have adjusted nutritional requirements.     

Effect of vitamin supplements on some aspects of performance, vitamin status, and semen quality in boars

The aim of the present study was to determine the effects of dietary supplements of vitamins on vitamin status, libido, and semen characteristics in young boars under normal and intensive semen collection. Sixty Landrace, Yorkshire, and Duroc boars were allocated randomly from 6 to 10 mo of age to one of the following diets: 1) basal diet (industry level) for minerals and vitamins (Control, n = 15); 2) basal diet supplemented with vitamin C (ASC, n = 15); 3) basal diet supplemented with fat-soluble vitamins (FSV, n = 15); and 4) basal diet supplemented with water-soluble vitamins (WSV, n = 15). After puberty (approximately 12 mo of age), semen was collected at a regular frequency (three times every 2 wk) for 5 wk. Thereafter, all boars were intensively collected (daily during 2 wk). A recovery period (semen collection three times every 2 wk) followed and lasted for 10 wk. Sperm quality (percentage of motile cells and percentage of morphologically normal cells) and quantity (sperm concentration, semen volume, and total sperm number) were recorded as well as direct and hormone related measurements of boar libido. Blood and seminal plasma samples were taken to monitor vitamin status. High concentrations of B6 (P < 0.05) and folic acid (P < 0.05) were observed in the blood plasma of WSV boars, whereas greater concentrations of vitamin E (P < 0.01) were obtained in FSV boars. In the seminal plasma, folic acid concentrations tended to be greater in WSV boars (P < 0.08). During the intensive collection period, there was a tendency (P < 0.06) for semen production to be greater in WSV boars, the effect being less pronounced (P < 0.10) in FSV boars. During the recovery period, the percentage of motile sperm cells was greater in WSV boars (P < 0.03) and, to a lesser extent, in FSV boars (P < 0.10) compared with Control boars. Sperm morphology and libido were not affected by treatments. These results indicate that the transfer of vitamins from blood to seminal plasma is limited and the dietary supplements of water-soluble and fat-soluble vitamins may increase semen production during intensive semen collection.     

Effects of dietary supplementation with vitamin C or vitamin E on cardiac lipid peroxidation and growth performance in broilers at risk of developing ascites syndrome

OBJECTIVE: To assess effects of high dietary amounts of vitamin C or vitamin E and oxidative stress on the heart and growth performance of broilers maintained at an altitude of 2,200 m above sea level. ANIMALS: 360 chicks (1-day-old broilers). PROCEDURE: Birds were randomly assigned to 3 groups (120 chicks/group). Each group of birds was fed a specific diet (control group, basal diet containing 12 mg of vitamin E (DL-alpha-tocopherol acetate)/kg of feed without additional ascorbic acid; vitamin E group, basal diet supplemented with 75 mg of vitamin E/kg of feed; and vitamin C group, basal diet supplemented with 400 mg of ascorbic acid/kg of feed) throughout the entire 7 weeks of the study. Feed consumption and body weight of chicks were recorded on a weekly basis. Nine randomly selected birds from each group were euthanatized each week. Remaining birds were euthanatized at the end of the study. Samples of cardiac tissues were obtained to measure thiobarbituric acid reactive substances (TBARS), an indicator of oxidative stress. RESULTS: Vitamin E-supplemented diets resulted in better growth performance, lower rates of feed conversion, and lower TBARS content. Vitamin C-supplemented diets resulted in lower feed consumption and lower rates of feed conversion. When used separately, neither of the vitamins had any effect on mortality attributable to ascites syndrome. CONCLUSION AND CLINICAL RELEVANCE: It is recommended that diets supplemented with vitamin C, vitamin E, or both be fed to broilers maintained at an altitude of 2,200 m above sea level to improve growth performance.     

Effect of benzoic acid on growth performance, nutrient digestibility, nitrogen balance, gastrointestinal microflora and parameters of microbial metabolism in piglets

In order to investigate the effects of benzoic acid on growth performance, nutrient digestibility, nitrogen balance and gastrointestinal microflora of piglets, we conducted a performance experiment and a separate balance study. The performance experiment involved four different dietary treatments: (1) basal diet (negative control); (2) basal diet supplemented with benzoic acid at 5 g/kg; (3) basal diet supplemented with benzoic acid at 10 g/kg; (4) basal diet supplemented with potassium diformate at 12 g/kg. Each dietary treatment was assigned to nine replicate groups, each consisting of two piglets. Live weight, daily weight gain, feed intake and feed conversion ratio were monitored as performance parameters over a 35-day period. Supplementation of the diet with benzoic acid resulted in a dose-dependent increase in feed intake and body weight gain and an improved feed conversion ratio. Piglets fed the diet supplemented with benzoic acid at 10 g/kg outperformed the control piglets in mean feed intake, body weight gain and feed conversion ratio by 9%, 15% and 6% respectively. Growth performance of the piglets fed the diet with benzoic acid at 10 g/kg was similar to that of piglets fed the diet supplemented with potassium diformate. In the balance experiment three groups of six piglets each were fed either a control diet or diets supplemented with benzoic acid at 5 or 10 g/kg respectively. Benzoic acid did not significantly affect nutrient digestibility but increased nitrogen retention. Piglets fed the diets supplemented with benzoic acid at 5 or 10 g/kg retained 5% and 6% more nitrogen, respectively, than control piglets. Supplementation of benzoic acid did not influence the pH value or the concentration of ammonia in the gastrointestinal tract but reduced the number of bacteria in the digesta. In the stomach the number of total aerobic, total anaerobic, lactic acid forming and gram-negative bacteria was reduced; in the duodenum the presence of benzoic acid reduced the number of gram-negative bacteria and in the ileum the number of total aerobic bacteria in a dose-dependent manner. Benzoic acid also considerably reduced the concentration of acetic acid in the duodenum. In conclusion, the data of this study suggest that benzoic acid exerts strong antimicrobial effects in the gastrointestinal tract of piglets and therefore enhances growth performance and nitrogen retention.     

The optimal vitamin B 6 requirement of early weaned piglets

In a two-period rearing trial (1st to 24th and 24th to 45th experimental day) using 72 early-weaned piglets, the optimal vitamin-B6 requirement was determined on the basis of different performance criteria and biochemical parameters. In the corresponding live weight ranges of 3.5 to 10 kg and 10 to 21 kg, the animals allotted in 6 groups were ad lib. fed a prestarter and starter feed, respectively containing 0.5, 1.2, 2.0, 2.8, 3.5 and 6.6 mg vitamin B6 per kg dry matter. For adequate feed intake and weight development, a dietary vitamin B6 content of 2.0 mg/kg and 1.2 mg/kg proved necessary for the 1st and 2nd part of the experiment, respectively. An optimal intermediary metabolic situation and thus an optimum vitamin B6 requirement covering, which was derived from the renal xanthurenic acid excretion and the SGOT activity, was attained only at a vitamin B6 supply level of 3.5 and 2.8 mg/kg for the 1st and 2nd experimental periods, respectively. This corresponds to an average vitamin B6 requirement per animal and day of 0.8 mg for the weight range 3.5 to 10 kg, and of 1.9 mg for the weight range 10 to 21 kg.     

Comparison of cupric and sulfate ion effects on chronic selenosis in rats

The ameliorating effects of Cu++ and SO4--ions on concurrent selenite toxicity were compared in two factorial experiments using 60 weanling rats each. In the first experiment, 0, 500 and 1,000 mg Cu (as CuCl2)/kg diet were fed in conjunction with 0, 5, 10 and 20 mg Se (as Na2SeO3)/kg diet. In the second experiment, the treatments were 0, 500 and 1,000 mg SO4 (as Na2SO4)/kg fed in conjunction with 0, 5, 10 and 20 mg Se/kg diet. A paired-feeding experiment using 10, 15 and 20 mg Se/kg diet was also conducted with 28 rats to compare the influence of inanition in control and selenite-fed rats. Cupric++ ion, but not SO4--ion, prevented mortality among selenite-intoxicated rats. There were significant Cu X Se interaction effects on feed intake, daily gain, packed cell volume (PCV), serum Cu and Fe, sperm counts, and weights of liver, kidney and testis. There were main effects of Cu and Se on serum Se and liver Cu. In Exp. 2 there were significant SO4 X Se interaction effects on feed intake, daily gain, serum Cu and testis weight. There were main effects of Se on PCV, sperm count, serum testosterone, liver Se, liver Cu and the absolute weights of liver and kidney. The only main effect of SO4 was that of increased liver Cu concentrations. Among the pair-fed rats, the selenite-fed rats, with one exception, died before their paired rats.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dietary B vitamin needs of strains of pigs with high and moderate lean growth

Ten sets of 5 littermate pigs from each of 2 genetic strains were utilized to determine the impact of the dietary concentration of 5 B vitamins (riboflavin, niacin, pantothenic acid, cobalamin, and folacin) on growth from 9 to 28 kg of BW in pigs with high or moderate capacity for lean growth. All pigs (penned individually) were reared via a segregated, early weaning scheme, so that the lean growth potential of each strain could be expressed. The basal diet provided the 5 test vitamins at concentrations of total and estimated bioavailability equivalent to a minimum of 100 and 70%, respectively, of their estimated requirements (NRC, 1998) for 5- to 10-kg pigs. At a BW of 9 +/- 0.9 kg, pigs within each litter were allotted to the basal diet supplemented with sources of the 5 test vitamins equivalent to an additional 0, 100, 200, 300, or 400% (bioavailable) of the NRC requirements. Pigs from the high lean strain consumed less feed (P < 0.05) and gained BW faster (P < 0.02) and more efficiently (P < 0.01) than pigs of the moderate lean strain. In both lean strains, the rate and efficiency of growth were improved (P < 0.01) as dietary B vitamin concentrations were increased. However, the dietary B vitamin concentrations needed to optimize G:F were greater (P < 0.03) in the high (>470% of NRC, 1998) vs. moderate (270%) lean strain. Based on these data, the dietary needs for 1 or more of the 5 B vitamins are greater than current NRC (1998) estimates, particularly in pigs expressing a high rate of lean tissue growth. The greater need for these vitamins is not associated with greater dietary energy intake or body energy accretion rate but is potentially due to shifts in the predominant metabolic pathways.     

日粮添加虾青素和维生素B2对鸡蛋品质的影响

试验旨在探究虾青素和维生素B2在日粮中的添加量对鸡蛋品质的影响。选择1200只体重相近、健康的45周龄海兰褐蛋鸡,随机分成5组,每组4个重复,每个重复60只鸡。对照组蛋鸡饲喂基础日粮,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组蛋鸡饲喂固定比例的基础日粮和0.25%虾青素,混合不同含量的维生素B2(5.0、8.0、11.0、14.0 mg/kg)。预试期1周和正式试验期4周,预试期各组蛋鸡均饲喂基础日粮,正式试验期分别投放上面试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组的配比的饲料。结果表明,试验组蛋黄颜色、哈夫单位均显著高于对照组(P<0.05)。试验Ⅱ、Ⅲ、Ⅳ组鸡蛋粗脂肪含量显著低于对照组(P<0.05)。试验组鸡蛋平均蛋重、蛋壳厚度、蛋壳强度、蛋比重与对照组相比有增大的趋势。试验表明,日粮添加虾青素和维生素B2能提高蛋品质,添加0.25%虾青素和14.0 mg/kg维生素B2效果最好。     

紫花苜蓿对母猪生产性能的影响

紫花苜蓿Medicago sativa粗蛋白含量高,氨基酸平衡,粗纤维利用率高,且含有丰富的维生素、矿物质,其中的β-胡萝卜素、维生素E、维生素B2、叶酸和硒等可以降低母猪胚胎死亡率,增加窝产仔数,延长母猪的利用年限。因此,在母猪饲粮中添加适量紫花苜蓿鲜草或草粉代替部分精料,能降低饲料成本,提高母猪的生产性能。研究主要综述了紫花苜蓿粗纤维和几种重要维生素对母猪生产性能的影响。     

钴和铜对肉用绵羊维生素B_(12)合成、瘤胃发酵及造血机能的影响

为研究不同水平的钴和铜对肉用绵羊维生素B12合成、瘤胃发酵及造血机能的影响,试验选20只体重相近(28.9±1.1)kg、装有永久瘤胃瘘管的杂交一代羯羊,随机均分为5组,定量饲喂对照组日粮,4种不同水平的钴铜(0.3:10、0.3:20、0.6:10和0.6:20)日粮。结果表明:瘤胃维生素B12合成主要取决于钴的摄入量,日粮中同时添加钴、铜及其不同的配比对维生素B12合成未显协同效应和影响。钴与铜合用可增加瘤胃挥发性脂肪酸的浓度,并改变乙酸、丙酸和丁酸比例,用量越多其影响越大。随肉羊日粮中钴与铜合用及其用量增加,可更有效地促进铁的吸收和利用,从而更加明显地改善机体的造血机能。     

Behaviour,production and health of organically reared fast-growing broilers fed low crude protein diets including different amino acid contents at start

Abstract

Only fast-growing broilers are available for organic production in Sweden, and due to organic legislations and long rearing periods feed restriction has to be practised. To evaluate the effect on welfare aspects and health, two diets, low in crude protein content, with (LPA) and without amino acid supplements (LP) were fed to 1400 Ross 308 chickens, divided over eight pens in two chicken houses, with access to outdoor pasture. Behavioural observations were conducted at 2, 6 and 10 weeks. In general, birds fed the LP diet used their outdoor pasture more, and showed a higher frequency of behaviours related to feed search, than the LPA birds. The LPA diet resulted in higher live weight, mortality and more leg problems. However, cannibalism outbreaks which are rarely seen in broiler production occurred in the LP birds. This indicates that new problems were introduced that are not beneficial for animal welfare. Furthermore, the behaviour differences related to feed search, changes between behaviours and preening might have indicated a frustration related to the qualitative feed restriction for the chickens given the LP diet.