Investigations on the effect of maternal dietary riboflavin supplementation during gravidity and lactation on riboflavin concentrations in blood,liver, and total body of rat offspring

The present study investigated the effect of various maternal dietary riboflavin supplementations during gravidity and lactation on riboflavin concentrations in blood, liver, and total body of their offspring. Therefore, two experiments with a total of 154 female rats were conducted. In the first experiment the animals received a semisynthetic diet (basal riboflavin concentration of 0.9 mg/kg diet) with various riboflavin supplementations during lactation (0, 2, 4, 6, 8, 10, 12, 40, 400, 4000 mg riboflavin/kg diet). In the second experiment, during gravidity, the rats were fed supplements of 1 or 20 mg riboflavin/kg diet. After parturition each group was divided into three subgroups that received 1, 5 or 20 mg riboflavin/kg with their feed during the following lactation. Both investigations continued until the 14th day of the lactation period just before the pups would start to eat the diets. The total body weights of the offspring in the first experiment only showed an effect of the riboflavin supplementation during lactation in the riboflavin‐deficient group (supplementation of 0 mg/kg diet). Regarding the second experiment, the total body and liver weights of the offspring on the 14th day of lactation were not significantly influenced by the various maternal riboflavin supplements during gravidity and lactation. The data of the first experiment clearly show that there exists a slight dose‐response relationship between the maternal dietary riboflavin supplementation during lactation and the riboflavin concentration in the blood and total body of the offspring. However, a riboflavin supplementation over 8 mg/kg diet led to a saturation of the riboflavin concentration in the body. Also, a dietary supplementation above 2 mg riboflavin/kg diet had no influence on the liver riboflavin concentration. The second investigation showed that the riboflavin concentration in all samples was influenced predominantly by the maternal riboflavin supply during lactation. The riboflavin supply during gravidity had no or only a very slight effect on the riboflavin concentrations in blood, liver, and total body of the offspring. In conclusion, these results indicate the necessity of a sufficient maternal dietary riboflavin supply (8–9 mg/kg diet) during lactation in regard to the health of their offspring and that a high riboflavin supply during gravidity cannot compensate for a deficient supply during lactation.     

Effects of vitamin E, age and sex on performance of Japanese quail. 1. Haematological indices and liver function

1. A trial was conducted to examine the effects of dietary vitamin E content, age and sex on haematological indices and liver enzymes of Japanese quails. A total of 800 1-d-old quail chicks were assigned at random into 4 equal groups and fed on starter and layer diets containing 0, 1, 5 or 10 times the NRC recommended supplements of vitamin E. No selenium was added to the basal deficient diets; the other diets were supplied with 0.2 mg selenium/kg diet. 2. The investigation covered the age span of 3 to 12 weeks in female and male birds. Blood samples were collected at 3-week intervals and tested for haematological indices (erythrocyte count; leucocyte count; susceptibility of erythrocytes to haemolysis; haemoglobin concentration (Hb); packed cell volume (PCV); and mean corpuscular volume (MCV)) and liver enzymes (aspartate transaminase, AST, and glutathione peroxidase, GSH-Px). 3. The significant differences between the 4 dietary treatments indicated that as the levels of selenium and/or vitamin E increased, the percentage of erythrocytes haemolysed and AST activity decreased, whereas Hb and GSH-Px concentrations increased. 4. Differences between age groups showed that older quails had higher erythrocyte susceptibility to haemolysis, higher AST levels and but lower erythrocyte count and PCV. 5. Females had lower erythrocyte haemolysis and higher Hb concentrations than males. 6. The interaction between dietary groups and age groups revealed that the differences between age groups were reduced as the level of selenium and/or vitamin E increased, leading to similar group means over the age period of study. 7. In conclusion, NRC recommended supplements of vitamin E (12 and 25 mg/kg diet) were not adequate. Doses equal to, at least, 5 times that recommended were advised to improve GSH-Px (index of antioxidant status) and Hb concentrations.     

Effect of selenium and vitamin E content of the maternal diet on the antioxidant system of the yolk and the developing chick

1. The effects of selenium and vitamin E supplementation of the maternal diet on their transfer to the egg yolk and tissues of the newly hatched chick and on the development of the antioxidant system in the chick liver in early postnatal life were investigated. 2. One hundred Cobb broiler breeder hens were divided into 10 equal groups and housed in pens at 25 weeks of age. Each hen received 1 of the treatment diets which included 0.2 or 0.4 mg/kg selenium, 40, 100, 200 mg/kg vitamin E or their combination. After 6 weeks, the hens were artificially inseminated once per week. From week 8, eggs were collected and placed in an incubator. After hatching, chicks from each group were reared (under standard commercial conditions) to 10 d of age. The chicks were fed on a standard starter commercial broiler diet. At the time of hatching, and at 5 and 10 days old, 4 chicks from each group were sacrificed and blood, liver and brain were collected for the subsequent biochemical analyses. 3. The inclusion of organic selenium or vitamin E in the commercial diet significantly increased their concentration in the egg and in the liver of 1-d-old chicks obtained from the eggs enriched with these substances. A positive effect of such dietary supplementation was seen at d 5 and d 10 of postnatal development. 4. There was a positive effect of selenium supplementation of the maternal diet on glutathione concentration in the liver of 1-d-old and 5-d-old chicks. A combination of a dietary selenium supplementation with high vitamin E doses further increased glutathione concentration in the liver. Dietary selenium supplementation significantly increased selenium-dependent glutathione peroxidase (Se-GSH-Px) activity in the liver of the 1-d-old and 5-d-old chicks and decreased liver susceptibility to peroxidation. 6. It is concluded that the nutritional status of the laying hen determines the efficiency of the antioxidant system throughout embryonic and early postnatal development of the offspring.     

Perinatal maternal feeding with an energy dense diet and/or micronutrient mixture drives offspring fat distribution depending on the sex and growth stage

Maternal nutrition during pregnancy and lactation influences offspring development and health. Novel studies have described the effects on next generation obesity‐related features depending on maternal macro‐ and micro‐nutrient perinatal feeding. We hypothesized that the maternal obesogenic diet during pregnancy and lactation programs an obese phenotype, while maternal micronutrient supplementation at these stages could partially prevent these features. Thus, the aim was to assess the influence of a perinatal maternal feeding with an obesogenic diet enriched in fat and sucrose and a micronutrient supplementation during pregnancy and lactation on offspring growth and obese phenotypical features during life course. Female Wistar rats were assigned to four dietary groups during pregnancy and lactation: control, control supplemented with micronutrients (choline, betaine, folic acid and vitamin B₁₂), high‐fat sucrose (HFS) and HFS supplemented. At weaning, the offspring were transferred to a chow diet, and weight and fat mass were measured at weeks 3, 12 and 20. At birth, both male and female offspring from mothers fed the obesogenic diet showed lower body weight (?5 and ?6%, respectively), while only female offspring weight decreased by maternal micronutrient supplementation (?5%). During lactation, maternal HFS diet was associated with increased body weight, while micronutrient supplementation protected against body weight gain. Whole body fat mass content increased at weeks 3, 12 and 20 (from 16 to 65%) due to maternal HFS diet. Maternal micronutrient supplementation decreased offspring fat mass content at week 3 (?8%). Male offspring showed higher adiposity than females at weeks 12 and 20. In conclusion, maternal HFS feeding during pregnancy and lactation was associated with a low offspring weight at birth and obese phenotypical features during adult life in a sex‐ and time‐dependent manner. Furthermore, maternal methyl donor supplementation protected against body weight gain in male offspring during lactation and in female offspring also during juvenile period.     

Effects of continuous supplementations of ascorbic acid, aspirin, vitamin E and selenium on some haematological parameters and serum superoxide dismutase level in broiler chickens

1. This study was conducted using male broiler chickens to determine the effects of ascorbic acid, aspirin, ascorbic acid+aspirin, vitamin E+selenium and ascorbic acid+aspirin+vitamin E+selenium supplementations on haematological parameters and serum superoxide dismutase concentration. 2. One hundred and twenty day-old male Hubbunt broiler chicks were randomly divided into 6 experimental groups of 20 chicks each and placed in different pens. Groups 2, 3, 4, 5 and 6 were given a diet supplemented with ascorbic acid, aspirin (in water), ascorbic acid+aspirin, vitamin E+selenium and ascorbic acid+aspirin+vitamin E+selenium, respectively for 45 d while group 1 was given a commercial broiler diet. 3. There was no significant effect of ascorbic acid, aspirin, ascorbic acid+aspirin, vitamin E+selenium supplementations on any of the haematological parameters (red blood cell, haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin concentration, mean corpuscular haemoglobin) in broilers but ascorbic acid+aspirin+vitamin E+selenium supplementation significantly decreased the white blood cell counts. 4. In addition to this, ascorbic acid, aspirin, ascorbic acid+aspirin and ascorbic acid+aspirin+vitamin E+selenium supplementations had no significant effect on the serum superoxide dismutase level, but vitamin E+selenium supplementation increased the serum superoxide dismutase level.     

Vitamin B1 content of liver, brain and muscles of pregnant and nonpregnant rats with different vitamin B1 supplies

The purpose of this publication was to examine the effects of a wide variation of dietary vitamin B1 supply (0-12,000 mg vitamin B1 per kg diet) to gravid and non gravid rats on their vitamin B1 content in liver, brain and muscle. The experiment was designed with 176 (2 x 11 x 8) female Sprague-Dawley-rats. Additionally, the organs and tissues were tested as criteria for requirement recommendations. The animals were sacrificed on the 20th day of gravidity of the pregnant rats. Before gravidity the vitamin-B1-contents were 4.7 micrograms/g liver, 2.5 micrograms/g brain and 1.5 micrograms/g muscle. At the end of the experiment the gravid rats had a 19 per cent higher liver content than the non gravids. With a dietary supply of 8-10 ppm vitamin B1 the liver content plateaued until about 120 ppm. Vitamin B1 concentration in brain was about 2 micrograms/g and gravidity was of no effect. Vitamin B1 concentration in muscle was significantly influenced by both factors and saturation was reached at 1.3 and 1.7 micrograms/g muscle. These data showed that the response of the liver to dietary supply was the most sensitive and should therefore be considered in requirements. The requirement for non gravid animals is therefore 4 mg vitamin B1 per kg diet at minimum, gravid animals should be supplied by 7 mg per kg diet.     

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.     

Caprine hepatic lipidosis induced through the intake of low levels of dietary cobalt

Forty-one, 10-week-old newly weaned goats were randomly allocated into two groups, namely control (n=22) and treated (n=19). Kids in both groups were fed Rhodegrass hay ad libitum that contained < 0.1 mg/kg DM cobalt and 150 g/day of a commercially prepared ruminant concentrate that contained approximately 0.12 mg/kg DM cobalt. This diet provided the minimum daily requirement of cobalt as specified for sheep. The treated goats were supplemented with bi-monthly subcutaneous injections of 2000 microg of hydroxycobalamin. All goats were weighed and blood samples collected monthly for haematological, clinical biochemical and serum vitamin B12 analysis. After a 10-month experimental period the goats were slaughtered. The control animals exhibited significantly (P<0.05) lower weight gains, and had dry scruffy hair coats. In addition, there was a decline in erythrocyte counts, mean haemoglobin, packed cell volume, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration. Controls also exhibited significantly (P<0.05) lower levels of total serum proteins and elevated levels of serum alkaline phosphatase compared to treated goats. Fourteen (63.6%) of the control goats developed pathology consistent with reported field cases of hepatic lipidosis associated with low liver levels of cobalt. Only one (5.3%) of the treated goats developed hepatic lipidosis. Contrary to previous reports that suggested that goats are less sensitive to low levels of dietary cobalt than sheep, it is apparent that this is not the case with Omani goats. This is the first report of the induction of hepatic lipidosis in goats due to feeding low levels of cobalt in their diet.     

Investigation into selenium requirement of growing turkeys offered a diet supplemented with two levels of vitamin E

To evaluate dietary selenium (Se) requirement in turkeys offered a diet supplemented with two levels of vitamin E (VE), 96 newly hatched male BIG 6^® chicks (58.4 ± 4.12 g) were divided into eight groups of 12 animals each and fed maize soya diets containing 0.05, 0.10, 0.20 and 0.30 mg Se/kg from sodium selenate in combination either with the natural VE content (approximately 10 IU/kg) or with a VE addition of 50 IU/kg. Animals from all the groups were highly performant and their final body weights (1746 ± 190 g) after 35 days on experiment were not significantly different. According to its dietary supply, Se concentration in the liver and plasma increased dose dependently. Independent of dietary VE, the activities of GPx3 in plasma and of GPx1 in liver and breast muscle increased to a larger extent in turkeys supplemented with 0.10 and 0.20 mg Se/kg in relation to animals with low marginal Se supply (0.05 mg/kg). Supplementation of 0.30 mg Se/kg only slightly increased further selenoprotein activities. 2‐Thiobarbituric acid reactive substances in the liver were strongly reduced by dietary VE, but not by Se. Plasma aspartate aminotransferase (AST) and creatine kinase (CK) activities did not show muscular lesions in none of the groups. Although there were no signs of muscular lesions even in turkeys with marginal Se and moderate VE supply, the activity of selenoproteins in various organs increased up to 0.30 mg Se/kg diet, independent of VE supply. It was concluded that for growing turkeys the Se supply should meet at least a level of 0.20 mg/kg diet as currently recommended by the National Research Council and Gesellschaft für Ernährungsphysiologie. Vitamin E addition confirmed the particular function of the vitamin as a lipid antioxidant and should be taken into consideration when diets with high PUFA concentrations are fed.     

Effects of high-level dietary B-vitamins on performance, body composition and tissue vitamin contents of growing/finishing pigs

Forty-eight growing pigs were randomly assigned to five dietary groups and penned individually. They received a diet based on barley, wheat, corn and soya bean meal according to requirement. The experimental groups were supplemented with 400% or 800% of vitamins B(2), B(6) and pantothenic acid, or 400% or 800% of biotin, while all other vitamins were administered according to requirement. Growth performance, carcass characteristics, aspartate aminotransferase (AST), and content of vitamins in blood, liver and muscles were recorded. Growth performance showed no influence of supplementation, while backfat thickness in the group with 800% B(2)/B(6)/pantothenic acid was significantly higher. Content of B(2) in blood, liver and muscle was similar in all groups. Content of B(6) in blood and liver showed significant differences according to supplementation. The content of vitamin B(6) in muscle in the experimental groups was significantly higher than that in the control group. The content of pantothenic acid in blood and muscle in the experimental groups was significantly higher, while in liver all groups were significantly influenced by the supplementation level. Biotin content in liver showed no influence, but the content in plasma was significantly higher in the experimental groups and the content in muscle was significantly higher according to supplementation. The activity of AST showed no significant influence of the dietary vitamin level, but it was obviously decreased in the groups supplemented with biotin. The findings indicate that the dietary supplementation of vitamin B(2), B(6), pantothenic acid and biotin could not improve performance, but the contents in blood, liver and muscle.     

Influence of supplementation of all-rac-alpha-tocopheryl acetate preweaning and vitamin C postweaning on alpha-tocopherol and immune responses of piglets

This study was designed to test whether dietary maternal supplementation of all-rac-alpha-tocopheryl acetate during lactation and dietary vitamin C supplementation after weaning could increase the alpha-tocopherol status pre- and postweaning and the immune responses of piglets postweaning. The experiment involved 12 crossbred sows that were fed increasing levels of all-rac-alpha-tocopheryl (70, 150, and 250 IU/kg, as-fed basis) during lactation. After weaning (d 28 of age), litters were divided into two groups that were supplemented with or without vitamin C (500 mg/kg of feed, as-fed basis). Milk and blood samples were obtained from the sows during lactation. Pigs were bled at 4, 16, 28, 35, 42, and 49 d of age. Liver, heart, muscle, and s.c. adipose tissues were collected (on 28, 35, 42, and 49 d of age) and analyzed for alpha-tocopherol. On the same days, alveolar macrophages of the lungs were collected, and analyzed for the concentration of alpha-tocopherol and its stereoisomer composition, fatty acid composition, and release of prostaglandin E2, leukotriene B4, and thromboxane B2. Increasing dietary all-rac-alpha-tocopheryl acetate concentration increased the concentration of alpha-tocopherol in plasma (P = 0.02) and milk (P = 0.007) of sows, and the sow milk concentrations of alpha-tocopherol and vitamin A were greater on d 2 of lactation than later on during lactation. The plasma concentration of alpha-tocopherol in piglets decreased from d 4 to later on during suckling (P < 0.001) and again as the postweaning period progressed (P < 0.001). When lipid-standardized, plasma alpha-tocopherol was increased in piglets of sows fed 250 IU of all-rac-alpha-tocopheryl acetate compared with other sow-groups (P = 0.005). At 28 d of age, alpha-tocopherol concentrations in tissues were increased with supplementation of the high dietary all-rac-alpha-tocopheryl acetate levels to the sows; however, after weaning, a decrease in alpha-tocopherol concentration in most tissues (except liver) was observed, but the decrease tended to be less in the muscle (P = 0.099) and adipose tissue (P = 0.11) of piglets suckling sows fed 150 and 250 IU of all-rac-alpha-tocopheryl acetate. Vitamin C supplementation after weaning increased liver alpha-tocopherol (P = 0.01) and serum immunoglobulin M concentration (P = 0.04), and vitamin C supplementation increased the proportion of the RRR-alpha-tocopherol (P = 0.03) at the expense of the RRS-stereoisomer form (P = 0.05) of alpha-tocopherol in alveolar macrophages of the piglets. In conclusion, this study on maternal all-rac-alpha-tocopheryl acetate and postweaning vitamin C supplementation suggests a nutritional strategy for increasing alpha-tocopherol status and immune responses of weaned piglets.     

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.     

Effects of vitamin C supplementation on growth performance and antioxidant status of layer ducklings

The study was conducted to evaluate the effects of increasing dietary vitamin C supplements on growth performance, antioxidant status and humoral immunity of layer ducklings. The results showed that the body weight and daily body weight gain of ducklings increased (p < 0.05) with increasing dietary vitamin C supplementations and reached a maximum at 400 mg vitamin C/kg feed. The dietary vitamin C supplementations reduced the malondialdehyde concentration (p < 0.05) and increased the activities of superoxide dismutase and glutathione peroxidase (p < 0.05) in serum and liver of ducklings at day 5 and 28. Additionally, feeding 400 mg/kg or 800 mg vitamin C/kg feed increased IgM and IgA concentrations in sera (p < 0.05) and serum IgG concentrations increased (p < 0.05) following supplementation in concentrations of 150-800 mg vitamin C/kg feed. In conclusion, the results suggested that dietary vitamin C supplements of 400 mg/kg feed provide optimal effects on growth performance, antioxidant status and parameters of humoral immunity.     

Effect of gender and exercise on haematological and biochemical parameters in Holsteiner horses

The objective of this study was to assess the influence of exercise of average intensity in the haematological and biochemical values, as well as acidic resistance of erythrocytes in mares and stallions of Holsteiner breed. A total of seventeen horses of Holstein breed (seven mares and 10 stallions aged 6 years) were used in this study. The blood samples were assessed for haematocrit (HCT) value, haemoglobin concentration (HGB), the amount of red blood cells (RBC), white blood cells (WBC), platelets (PLT), leucogram, mean corpuscular haemoglobin concentration (MCHC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), red cell distribution width (RDW) and platelet distribution width (PDW). Serum concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) as well as oxidative stress biomarkers were analysed. Stallions showed a significant increase in leucocytes and granulocytes amount, as well as erythrocytes, haemoglobin and haematocrit levels after exercise test. Pre‐exercise level of mean corpuscular haemoglobin concentration was higher in stallions. At the same time, mares showed significant decrease in platelet volume after exercise test. Physical effort in stallions leads to significant increase in aspartate aminotransferase activity. Trained mares and stallions showed a decrease in lipid peroxidation after exercise. Exercise also caused increase in oxidative modified protein of erythrocytes in stallions indicating by exercise‐induced oxidative stress. The resistance of erythrocytes in 0.1 m HCl was similar between females and males. No statistically significant differences in the percentage of haemolysed erythrocytes before and after exercise were observed.     

Effect of source and quantity of dietary vitamin D in maternal and creep diets on bone metabolism and growth in piglets

Piglets are born with reduced plasma concentrations of 25-hydroxycholecalciferol (25-OH-D(3)) and are thus highly predisposed to vitamin D deficiency. Furthermore, sow milk contains little vitamin D, and the slow intestinal vitamin D absorption of sows limits the efficacy of dietary vitamin D supplementation. Hence, the neonate depends, to a large extent, on the vitamin D stores built up in fetal tissues from maternal sources. The current study was undertaken to evaluate whether the source and quantity of dietary vitamin D provided to the gestating and lactating sow, and also directly in the form of creep feed to the piglet, would influence the vitamin D status, growth performance, and skeletal development of piglets. A total of 39 primiparous and multiparous sows were randomly assigned to 1 of 3 dietary treatments (13 in each treatment), supplemented with either 5 or 50 μg of the commonly used cholecalciferol (vitamin D(3)) or 50 μg of 25-OH-D(3) per kilogram of feed. By wk 3 of lactation, piglets were offered a creep diet with vitamin D supplementation according to the treatment of the dam, and they were offered the same creep diets after weaning at d 35 of age until they reached a BW of approximately 20 kg. When dietary 25-OH-D(3) was provided, circulating concentrations of 25-OH-D(3) in piglet serum increased (P < 0.05) as early as d 21 and later at d 33 and 77, indicating greater body stores in those animals. Bone-breaking strength and cortical bone mineral content and density at the tibial midshaft of piglets were reduced (P < 0.05) when vitamin D(3) was supplemented at 5 μg/kg compared with the bone traits of other groups, but no differences (P > 0.05) were observed between the 2 other groups. After weaning, ADFI was greater (P < 0.05) and growth performance tended (P = 0.08) to improve when doses of 50 μg/kg were administered, regardless of the vitamin D source. In conclusion, supplementation of the diet with 50 μg/kg of either source of vitamin D was proved to be adequate in meeting the needs of gestating sows and in permitting the accumulation of vitamin D in fetal tissues, as well as for normal skeletal mineralization and growth in the offspring. Furthermore, the markedly improved vitamin D status of piglets whose mothers received 25-OH-D(3) possibly resulted from greater tissue reserves present at birth and a greater availability of vitamin D when released from those stores.     

Influence of cobalt concentration on vitamin B12 production and fermentation of mixed ruminal microorganisms grown in continuous culture flow-through fermentors

An experiment was conducted to determine the effects of dietary concentrations of Co on vitamin B12 production and fermentation of mixed ruminal microbes grown in continuous culture fermentors. Four fermentors were fed 14 g of DM/d. The DM consisted of a corn and cottonseed hull-based diet with Co supplemented as CoCO3. Dietary treatments were 1) control (containing 0.05 mg of Co/kg of DM), 2) 0.05 mg of supplemental Co/kg of DM, 3) 0.10 mg of supplemental Co/kg of DM, and 4) 1.0 mg of supplemental Co/kg of DM. After a 3-d adjustment period, fermentors were sampled over a 3-d sampling period. This process was repeated 2 additional times for a total of 3 runs. Ruminal fluid vitamin B12 concentrations were affected by Co supplementation (P < 0.01), and there was a treatment x day interaction (P < 0.01). By sampling d 3, cultures fed the basal diet supplemented with 0.10 mg of Co/kg had greater (P < 0.05) vitamin B12 concentrations than those supplemented with 0.05 mg of Co/kg of DM, and increasing supplemental Co from 0.10 to 1.0 mg/kg of DM increased (P < 0.01) ruminal fluid vitamin B12 concentration. Ruminal fluid succinate also was affected (P < 0.10) by a treatment x day interaction. Cobalt supplementation to the control diet greatly decreased (P < 0.05) succinate in ruminal cultures on sampling d 3 but not on d 1 or 2. Molar proportions of acetate, propionate, and isobutyrate, and acetate:propionate were not affected by the addition of supplemental Co to the basal diet. However, molar proportions of butyrate, valerate, and isovalerate increased (P < 0.05) in response to supplemental Co. The majority of long-chain fatty acids observed in this study were not affected by Co supplementation. However, percentages of C18:0 fatty acids in ruminal cultures tended (P < 0.10) to be greater for Co-supplemented diets relative to the control. Methane, ammonia, and pH were not greatly affected by Co supplementation. The results indicate that a total (diet plus supplemental) Co concentration of 0.10 to 0.15 mg/kg of dietary DM resulted in adequate vitamin B12 production to meet the requirements of ruminal microorganisms fed a high-concentrate diet in continuous-flow fermentors.     

Dietary iron and broiler performance

1. An experiment was conducted with female broilers from 1 to 39 d of age in which the effects of increasing amounts of extra dietary ferrous sulphate on growth performance, some haematological measurements and Fe, Zn and Cu status were studied. A conventional maize-soyabean diet (107 mg Fe/kg) was supplemented with 0, 20, 60, 180, 540 and 1620 mg Fe to provide 6 treatments. 2. Weight gain responses rose to a plateau between 20 and 60 mg added Fe/kg diet, but further additions of Fe increasingly depressed growth. 3. In this study the apparent Fe requirement was 100 mg/kg diet (80 mg from dietary components and 20 mg Fe from supplement). 4. The efficiency of food utilisation decreased linearly, while the proportion of chicks affected by leg weakness increased. 5. In blood, the haemoglobin concentration increased slightly with extra dietary Fe. 6. The iron content of the liver increased with higher dietary Fe supplementation. Furthermore, increased liver Fe content was associated with a higher Zn content in the liver. 7. This study indicated that a maize-soyabean diet containing about 30% more Fe than has generally been accepted to be adequate for healthy broilers was still marginal in Fe concentration.     

Effects of concentrations of cyanocobalamin in the gestation diet on some criteria of vitamin B12 metabolism in first-parity sows

In swine nutrition, little is known about the role of vitamin B(12) in the reproductive processes. The current study was undertaken to obtain information on the dose-response pattern of different metabolic criteria related to the homeostasis of vitamin B(12) and homocysteine in gestating sows receiving various concentrations of dietary vitamin B(12) (cyanocobalamin). Homocysteine is a detrimental intermediate metabolite of the vitamin B(12)-dependent remethylation pathway of Met. Forty nulliparous (Large White x Landrace) sows were randomly assigned during gestation to dietary treatments containing 5 concentrations of cyanocobalamin (0, 20, 100, 200, or 400 microg/kg). During lactation, a diet containing 25 microg of cyanocobalamin/kg (as-fed) was given to all sows. During gestation, plasma vitamin B(12) increased as concentrations of dietary cyanocobalamin increased (linear and quadratic, P < 0.01) and the effect persisted during lactation (21 d postpartum) both in plasma (linear and quadratic, P < 0.05) and the liver (linear and quadratic, P < 0.04). Plasma homocysteine decreased with concentrations of cyanocobalamin provided to sows during gestation (linear, quadratic, and cubic, P < 0.01). At parturition, vitamin B(12) in colostrum increased as concentrations of cyanocobalamin increased (linear and quadratic, P < 0.01), but the treatment effect persisted (linear, P = 0.01) only up to 1 d postfarrowing. However, in piglets there was no treatment effect (P = 0.59) on plasma vitamin B(12) before colostrum intake, but a linear effect of concentrations of cyanocobalamin (P = 0.04) was observed 1 d later. Plasma homocysteine in piglets during lactation decreased with increasing concentrations of cyanocobalamin given to sows in gestation (linear and quadratic, P < 0.01). Based on a broken-line regression model, the concentrations of dietary cyanocobalamin that maximized plasma vitamin B(12) and minimized plasma homocysteine of sows during gestation were estimated to be 164 and 93 microg/kg, respectively. The maximal residual responses in sows and piglets during lactation were observed with treatments of 100 or 200 microg of cyanocobalamin/kg. The dietary cyanocobalamin concentration necessary to optimize the response of these metabolic criteria remains to be refined within lower and narrower ranges of cyanocobalamin concentrations (i.e., <200 mg/kg). Moreover, the biological significance of such concentrations of cyanocobalamin needs to be validated with performance criteria by using greater numbers of animals during several parities.     

复合植物精油对脂多糖刺激仔猪肝脏的保护作用

试验旨在研究复合植物精油(OCT)对脂多糖(LPS)刺激仔猪肝脏的保护作用。选取18头仔猪,随机分为对照组、LPS组和OCT+LPS组,每组6个重复。对照组与LPS组饲喂基础日粮,OCT+LPS组在基础日粮中添加50 mg/kg OCT。试验期21 d。于试验第21天,LPS组与OCT+LPS组仔猪腹腔注射LPS,对照组注射等量的生理盐水,3 h后采血,6 h后屠宰。结果表明:与对照组相比,LPS刺激提高了血浆谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(ALP)、谷酰转肽酶(GGT)、肝脏诱导型一氧化氮合酶(i-NOS)的活力(P0.05),肝脏热休克蛋白70(HSP70)基因的相对表达量显著提高(P0.05);仔猪肝脏表皮生长因子(EGF)、白细胞介素10(IL-10)、胰岛素样因子(IGF-1)、丝氨酸蛋白激酶(mTOR)基因的相对表达量显著降低(P0.05)。在日粮中添加50 mg/kg的OCT,可缓解LPS导致的仔猪血浆ALT、AST、GGT活力的升高以及肝脏i-NOS活力的升高(P0.05),且有缓解LPS导致的仔猪肝脏MPO活力升高的趋势(P0.1),另外可缓解LPS导致的仔猪肝脏HSP70基因相对表达量的升高以及EGF、IL-10、IGF-1、mTOR等基因相对表达量的降低(P0.05)。综上可知,日粮中添加50 mg/kg的OCT可缓解LPS刺激引起的肝脏炎症反应,提高仔猪肝脏细胞的生长和增殖,进而缓解LPS刺激导致的仔猪肝脏氧化应激损伤。     

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。