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.

Studies on the tryptophan requirement of lactating sows. Part 1: Estimation of the tryptophan requirement by performance.

Mature sows were evenly assigned to six dietary treatments, which differed only in the concentration of total (apparent ileal digestible, AID) tryptophan (Trp) amounting per kg feed to 1.2 g (0.8 g) to 4.2 g (3.8 g) in diets 1-6. For a total of 72 lactations (28 days) sows' feed intake was measured daily and body weight was measured on day 110 of pregnancy and on days 1 and 28 of lactation. Litter size was standardized to 10-12 piglets within 1 week after farrowing. The piglets were weighed at days 1, 21 and 28. Milk yield was recorded by the weigh-suckle-weigh method on days 20 and 21. Concentrations of milk fat and protein were measured in manually drawn samples (days 20 and 21) by infrared spectroscopy. Average daily feed intake of the sows was 3.4, 4.7, 4.7, 6.1, 5.1 and 4.7 kg (diets 1-6 respectively, p < 0.001). Body weight losses of the sows during lactation were 30.8, 16.9, 19.2, 9.5, 14.1 and 13.1 kg (diets 1-6 respectively, p < 0.05). Milk output in the average of days 20 and 21 was 6840, 8192, 8362, 9035, 8618 and 8140 g/day, respectively (p < 0.01). There were no differences in milk fat or protein contents. Daily weight gain of the piglets in the average of lactation was 157, 184, 184, 187, 185 and 177 g, respectively (p < 0.10). Based on the results of this study the estimated Trp requirement of lactating sows for optimal performance was calculated with 1.9 g AID Trp/kg in the lactation diet (according to 2.0 g true ileal digestible Trp and approximately 2.6 g Trp on total basis).

Studies on the tryptophan requirement of lactating sows. Part 2: Estimation of the tryptophan requirement by physiological criteria.

Mature sows were fed for a total of 72 lactations with diets which provided an adequate supply of energy and nutrients except for tryptophan (Trp). By supplementing a basal diet [native 1.2 g Trp/kg, equivalent to 0.8 g apparent ileal digestible (AID) Trp or 0.9 g true ileal digestible (TID) Trp] with L-Trp, five further diets (2-6) containing 1.5-4.2 g Trp/kg were formulated. The dietary Trp content had no effect on amino acid contents in milk on days 20 and 21 of lactation, but Trp in blood plasma on day 28 of lactation reflected the alimentary Trp supply with an increase from 2.74 +/- 1.14 mg/l (diet 1) to 23.91 +/- 7.53 mg/l (diet 6; p < 0.001). There were no directional differences between the diets with regard to the other amino acids. Concentrations of urea in milk and blood were higher with diet 1 (211 and 272 mg/l, respectively) than with diets 3-6 (183 and 227 mg/l, respectively). Serotonin levels in the blood serum were lower with diet 1 (304 ng/ml) than the average of diets 4-6 (540 ng/ml). This study confirms previously given recommendations for the Trp content in the diet of lactating sows, estimated by means of performance, of 1.9 g AID Trp (equivalent to 2.0 g TID Trp; approximately 2.6 g gross Trp) per kg diet.

Dietary probiotic supplementation and resulting effects on performance, health status, and microbial characteristics of primiparous sows.

In an experiment with 33 first-litter sows from day 90 of pregnancy to day 28 of lactation, the influence of a probiotic supplementation on weight performance, feed intake, litter sizes, litter weights, health status and microbiological profile was tested. Enterococcus faecium DSM 7134 was supplemented in a concentration of 5 x 10(8) CFU/kg feed to the gestation and lactation diets of gilts. The supplemented sows showed a significant higher improvement of feed intake (4.16 vs. 3.71 kg/day), litter size (9.2 vs. 7.7 piglets) and weight performance. The average live weight of the probiotic sows at day 28 of lactation was 11 kg higher than of the controls. The bacterial counts/g faeces (lactobacilli, Gram-positive anaerobes, Gram-negative anaerobes, Escherichia coli and enterococci) and the incidence of adhesive and haemolytic E. coli organisms revealed no significant differences between the sows of the two groups or their piglets. While the litter size cannot necessarily be assumed as a primary effect of the probiotic supplementation, the significantly better feed intake and weight performance might be partly due to the probiotic use and can prevent "starvation sterility" of young sows after their first litter caused by reduced feed intake during lactation with high mobilization of body tissue accompanied with lack of energy.

Efficiency of Echinacea purpurea on performance and immune status in pigs.

The aim of the present investigation was to examine the inclusion of the dried herb Echinacea purpurea (L.) MOENCH as feed additive in diets of sows, piglets, and grower/finisher pigs on growth performance, blood picture, plasma enzymes including proliferation of lymphocytes, antibody status, and protein and immune globulin content of colostrum. The control groups were supplemented with alfalfa meal. The sows (total 36) received 0%, 1.2%, or 3.6% Echinacea cobs in the diet from day 85 to day 110 of gestation and 0%, 0.5%, or 1.5% Echinacea cobs up to day 28 of lactation. No significant differences were found for growth performance, weight loss, blood picture, plasma enzymes, and colostrum composition. Performance of the sucking piglets was not impaired either during lactation or during a 4 week observation period after weaning. The health status was similar in all treatment groups. In a second experiment, lasting 6 weeks, with 36 piglets (5.8-22.1 kg body weight), 1.8% Echinacea cobs, or 20 mg/kg feed Flavomycin were supplemented. No significant differences were found for the recorded parameters. Feed conversion ratio (kg feed/kg gain) of the Echinacea group was slightly (4%) increased (1.54 vs. 1.60). In a third trial, 48 grower/finisher pigs were used during a 9-week experimental period with two supplementation phases (weeks 1-3 and weeks 7-9). The experimental groups received 0%, 1.5% cobs or 4-6 ml pressed juice (commercial standard) per day respectively. Vaccination with Swine erysipelas was implemented in weeks 1 and 5 to determine the specific immune response. Growth performance and blood picture for all groups were similar, however, feed conversion of both Echinacea supplemented groups was significantly (p < 0.03) better than of the unsupplemented control group (2.44 vs. 2.51). In addition, the Swine erysipelas antibodies showed a marked significance (p < 0.05) in regard of altitude in both supplemented groups. It is concluded, that E. purpurea might be used as a feed additive to achieve immune stimulating efficiency in pig production and increase feed-to-gain-conversion. The efficiency of cobs is comparable to a commercial juice product.

Precaecal and faecal digestibility of inulin (DP 10-12) or an inulin/Enterococcus faecium mix and effects on nutrient digestibility and microbial gut flora.

The aim of the present study was to investigate the precaecal and faecal digestibility of inulin (DP 10-12) and inulin/Enterococcus faecium mix, and the effects of these substances on nutrient digestibility and microbial gut flora. For the experiment four of eight male pigs were fitted with an end-to-end ileo-rectal anastomosis (IRA) with preserved ileo-caeco-colic valve. The residual pigs were used as intact partner (IN). The animals received 1.5 kg/day of a diet based on corn, wheat, barley and soybean meal, supplemented with either 8 x 10(9) CFU E. faecium/kg, 2% inulin or a mixture of both substances. The digestibility trial was carried out from weeks 4 to 8 after surgery. Precaecal digestibility of inulin was assessed to be 57%. The addition of E. faecium to the diet resulted in a similar precaecal digestibility of inulin of 55%. Supplementation of E. faecium, inulin, and a mixture of E. faecium and inulin did not affect precaecal and faecal nutrient digestibility with the exception of the precaecal digestibility of CF which increased when inulin alone was supplemented. Bacterial population in the digesta of IRA and IN pigs were not affected by the experimental diets except the concentration of bifidobacteria and lactobacilli. The supplementation of E. faecium to the diet significantly decreased the concentration of bifidobacteria and the population of lactobacilli inclined to decrease when IN pigs received the probiotic diet. The combination of E. faecium and inulin prevented a reduction of enterococci in faeces of IN pigs. The daily digesta excretion (DM) tended to decrease in IRA and IN pigs when inulin was supplemented. The results indicate that inulin (DP 10-12) in pig nutrition did partly react as a prebiotic as has been confirmed for humans. A combination of E. faecium and inulin improves the survival of the probiotic strain through the upper intestinal tract and allocates the synbiotic effect. Furthermore inulin might be able to show positive effects on precaecal and faecal microbial characteristics.

Requirement of true ileal digestible threonine of growing and finishing pigs.

Ninety-six crossbred barrows and gilts were used to investigate the optimum supply of true ileal digestible threonine for growing (approximately 35-65 kg body weight) and finishing (approximately 65-110 kg body weight) pigs. For this purpose, according to a bifactorial arrangement in the grower as well as in the finisher phase four dietary threonine levels were combined with two dietary levels of lysine. Measurement criteria were body weight gain, feed intake, feed conversion rate and carcass characteristics. In the grower stage at the lower lysine level daily gain increased numerically (p < 0.1) and the feed to gain ratio decreased significantly with an increasing dietary true ileal digestible threonine concentration. Increasing the true ileal digestible lysine concentration of the diet from 7.8 to 9.2 g/kg increased average daily gain in the grower stage significantly from 815 to 855 g and decreased the feed to gain ratio significantly. In finishing pigs, daily gain and feed to gain ratio were significantly improved by an increasing dietary true ileal digestible threonine concentration from 821 to 902 g and from 3.14 to 2.94 kg/kg, respectively, but not by the differing lysine supply. As in the grower stage, barrows consumed more feed than gilts at similar growth rates and this resulted in a significantly reduced feed to gain ratio in gilts compared with barrows. The requirements of true ileal digestible threonine for optimize both, daily gain and feed to gain ratio, as derived by the broken-line model were 10.3 g/animal and day for growing and 10.7 g/animal and day for finishing pigs respectively.

Effects of the level of dietary valine supply on amino acids and urea concentration in milk and blood plasma of lactating sows.

In order to determine the valine (Val) requirement, suckling sows with 10-12 piglets were supplied with feed mixtures, which contained various levels of Val derived by adding crystalline L-Val to the native diet (0.45% = native, 0.55, 0.65, 0.85, 1.05 and 1.45%) during a total of 72 lactations. Milk and blood plasma, taken after 3 weeks of lactation, was examined on the concentration of amino acids (total amino acids in milk, free amino acids in plasma) and urea by ion exchange chromatography or autoanalyzer, respectively. The contents of almost all amino acids in milk were significantly higher compared with the native diet, when Val was supplemented, reflecting increasing milk protein concentrations. Highest amino acid concentrations were observed with 0.85% dietary Val. Amino acid pattern in milk was not affected by the Val supply. In blood plasma the concentration of free Val rose with the dietary Val from 9 mg/l (0.45% dietary Val) to 132 mg/l (1.45% dietary Val). Several other amino acid contents were also higher when Val was added to the native diet, but there was no dose-response. Urea concentrations in milk and blood plasma were lowest with 0.65% and 0.85% dietary Val, respectively. Conclusively, for sows nursing litters with 10-12 piglets a dietary valine supply of 0.85% (0.75% apparent ileal digestible Val) can be recommended with a minimum requirement of 0.65% (0.55% apparent ileal digestible Val).

Performance of lactating sows in response to the dietary valine supply.

In order to determine the requirement of lactating sows for valine (Val) the effects of graded Val supplementations on feed intake, milk yield and changes of body weight of sows and piglets were examined using 54 multiparous sows over a total of 72 lactations (35 days). The sows were randomly assigned to six treatments (1-6). Each group received the same basic diet, covering the requirements of energy and nutrients except Val (4.5 g native Val, i.e. 3.5 g apparent ileal digestible Val). Adding crystalline l-Val dietary Val concentrations of 5.5, 6.5, 8.5, 10.5 and 14.5 g/kg, respectively, were realized. Feed intake of the sows was determined daily, body weight was determined on day 110 of gestation and day 1, 22 and 35 of lactation. The piglets were weighed on day 1, 21 and 35. The intake of piglet feed, which was offered from day 21, was determined at day 35 for each litter. Milk yield was determined using the weigh-suckle-weigh-method at day 13, 14, 20 and 21, fat and protein contents were analysed in hand-milked samples with infrared spectroscopy. Feed intake (kg/day) of the sows during lactation averaged 2.9, 4.3, 4.6, 4.6, 4.9 and 5.1 for treatments 1-6, respectively. For treatments 1 and 2 body weight losses of the sows during lactation were higher (1207 and 805 g/day, respectively) and milk production was lower (7076 and 8686 g/day, respectively), compared with the average of treatments 3-6 (625 g/day body weight loss; 9263 g milk/day). Daily weight gain of the piglets was also lower (146 and 171 g/day vs. 200 g/day) leading to lower weaning weights of 6.6 and 7.5 vs. 8.5 kg. As a consistent growth depression of the piglets in Val deficiency must be assumed, at least 6.5 g Val corresponding to 5.5 g apparent ileal digestible Val per kg lactation feed must be recommended.

Effect of apparent ileal digestible lysine to energy ratio on performance of finishing pigs at different dietary metabolizable energy levels.

A study with a total of 96 crossbred barrows and gilts fed ad libitum in a body weight range of 56-110 kg was carried out in order to investigate whether the optimum ratio of apparent ileal digestible lysine : energy (ME) depends on the energy density of the diet. Dietary treatments were ratios of 0.34, 0.42, 0.50 and 0.58 g digestible lysine/MJ ME either at an energy density of 13 or 14 MJ ME. Body weight gain as well as feed and ME conversion rate were improved when lysine : ME ratio increased from 0.34 to 0.50, whereby all parameters showed a significant ratio x sex interaction. Feed intake and feed conversion rate were higher at a dietary energy density of 13 MJ ME than at an energy density of 14 MJ ME but energy density did not influence daily growth rate, ME intake and ME conversion rate. Fat area above eye muscle and meat : fat ratio were lower and eye muscle area and lean percentage were higher at a ratio of 0.42 compared with a ratio of 0.34. Daily feed intake, body weight gain, feed conversion rate and parameters of fatness were higher in barrows than in gilts. Conversely, gilts had higher eye muscle area and lean percentage. Optimum ratio for body weight gain, feed and ME conversion rate calculated by exponential regression analysis were 0.42-0.43 in barrows. In gilts, feed and ME conversion rate were optimized at a ratio of 0.53 and 0.54. Because growth showed a linear response to increasing digestible lysine : ME ratios, optimum ratio for daily gain in gilts is considered to be at least 0.58.

The effects of conjugated linoleic acids or an alpha-glucosidase inhibitor on tissue lipid concentrations and fatty acid composition of broiler chicks fed a low-protein diet.

The effects of dietary conjugated linoleic acid (CLA) and an alpha-glucosidase inhibitor--Bay g 5421--on tissue lipid concentrations and fatty acid composition were investigated in male broiler chicks fed a low-protein diet. The trial comprised six isoenergetic broiler diets. One diet (high-protein diet) was used as a control diet and contained 230 g crude protein per kilogram. The other five diets were low-protein diets (180 g crude protein/kg) without additional supplement, or supplemented with 20 or 40 g/kg of a CLA-enriched oil, or supplemented with 50 or 100 mg of Bay g 5421/kg. Broilers fed the low-protein diets had higher concentrations of triglycerides and cholesterol in the liver than broilers fed the high-protein diet. Broilers fed low-protein diets supplemented with CLA had a higher cholesterol concentration in plasma, lower hepatic triglyceride concentrations, higher relative concentrations of saturated fatty acids (SFA), and lower relative concentrations of monounsaturated fatty acids (MUFA) in lipids of liver, thigh muscle, and adipose than broilers fed low-protein diets without CLA supplement. Broilers fed the low-protein diets supplemented with Bay g 5421 had lower concentrations of triglycerides and cholesterol in the liver and lower concentrations of triglycerides in plasma than broilers fed the low-protein diet without supplementation. Moreover, broilers fed diets with Bay g 5421 had higher relative concentrations of polyunsaturated fatty acids and lower relative concentrations of MUFA in lipids of liver, muscle, and adipose tissue. The results show that supplementation of the low-protein diets with CLA and Bay g 5421 affected tissue lipid concentrations and fatty acid composition in broilers, which are of practical relevance with regards to meat quality.

Vitamin B-12 deficiency and hyperhomocysteinemia are partly ameliorated by cobalt and nickel supplementation in pigs.

Vitamin B-12 deficiency and hyperhomocysteinemia alter the metabolism of trace elements. This study tested the hypothesis that there is a reverse relationship in which diets high in iron, copper, nickel and cobalt would influence vitamin B-12 deficiency outcomes including hyperhomocysteinemia. Piglets (German Landrace x Pietrain) were assigned to six groups of 8 and fed one of the following diets for 166 d: a vitamin B-12-adequate and folate-fortified diet (30 microg/kg vitamin B-12 and 0.5 mg/kg folate) with normal trace element concentrations or one of five vitamin B-12-free, folate nonsupplemented diets (0.36 mg/kg), with either normal trace element concentrations or high concentrations of iron (300 mg/kg), copper (30 mg/kg), cobalt (1 mg/kg) or nickel (6 mg/kg). Feed intake and weight gain did not differ significantly among the groups. Vitamin B-12-deficient pigs developed diminished serum and liver concentrations of vitamin B-12 and folate, an accumulation of iron in the liver and hyperhomocysteinemia. The magnitude of changes differed among vitamin B-12-deficient groups. Vitamin B-12-deficient pigs fed 6 mg/kg nickel had distinctly higher vitamin B-12 concentrations in liver and serum and 45% lower serum concentration of homocysteine than the corresponding deficiency group fed 1 mg/kg nickel; iron concentration in liver was completely normalized. Vitamin B-12-deficient pigs fed 1 mg/kg cobalt had 47% lower homocysteine concentrations in serum than the vitamin B-12-deficient group fed 0.13 mg/kg cobalt, but the vitamin B-12 status was unaffected. Supplementation of iron and copper did not affect these variables. The dietary manipulations had no detrimental effects on variables symptomatic of oxidative stress. The findings indicate a collaborative relationship between vitamin B-12 metabolism and the trace elements nickel and cobalt.

Effects of vitamin B6 supplementation in rats during lactation on vitamin B6 concentration and transaminase activities in the offspring.

The aim of the present investigation was to study the effect of a varying maternal vitamin B6 supplementation during lactation period on vitamin B6 levels in blood, liver and total body, and on the activity of two transaminase enzymes in the offspring. Therefore, eighty female Sprague-Dawley rats were fed a semi-synthetic diet (0.2 mg vitamin B6 per kg) which was supplemented during gravidity with 5 mg vitamin B6 per kg diet. During the following lactation period the rats were assigned to one of 10 vitamin B6 treatment groups (supplementation of 0, 3, 6, 9, 12, 15, 18, 36, 360, 3600 mg vitamin B6 per kg diet). At day 14 of lactation the pubs of all dams were decapitated and blood, liver, and carcass were used for analysis of vitamin B6 concentration, activities of two transaminases, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in plasma, erythrocytes, and liver, and of haematological parameters. While the liver and total body wet weights as well as the haematological parameters (red blood cells, haemoglobin concentration, hematocrit, middle corpuscular cell volume, middle corpuscular haemoglobin, middle corpuscular haemoglobin concentration) did not differ within the experimental groups, the present data clearly show that in blood, liver and total body of the offspring exists a slight dose-response relationship between the maternal dietary vitamin B6 supplementation and the vitamin B6 concentration. Concerning the activities of the transaminases a dietary supplementation above 3 mg vitamin B6 per kg diet had no influence on the AST and ALT activities in offspring plasma. In the erythrocytes no statistical significant influence of the vitamin B6 supplementation during lactation on the activities of AST and ALT was found. The activities of ALT and AST in liver were not consistently altered by the vitamin B6 supplementation of the dams during lactation. In conclusion these results indicate that a minimal maternal dietary vitamin B6 supply of 3.1 mg per kg diet is necessary with regard to health and development of their offspring. But not all of the analysed parameters as the liver and total body weights, the activities of AST and ALT in the erythrocytes, and the haematological parameters were influenced by a deficient maternal dietary vitamin B6 supply.

Precaecal digestibility of niacin and pantothenic acid from different foods.

This study was conducted to investigate the apparent precaecal digestibilities of niacin and pantothenic acid from human nutrient related foods including wheat, coarse whole-meal bread, boiled potatoes and boiled pork and beef. Therefore, pigs were subjected to an end-to-end ileo-rectal anastomosis, so digesta passed straight from ileum to rectum, eliminating endogenous vitamin synthesis. Excreted chyme was collected over 5-days periods, and concentrations of niacin, and pantothenic acid in the food and chyme samples were determined microbiologically. The intestinal bioavailability of niacin and pantothenic acid was affected differently by the food administered. The digestibility values of niacin deriving from the wheat-, potato- and the meat-based meals ranged from 59 to 69%. Wholemeal bread exerted a nutritionally important negative effect on the apparent intestinal availability of dietary niacin relative to the other foods, which averaged by 40%. Food-related differences of the pantothenic acid digestibility values were greater than that observed with niacin. The digestibility values of pantothenic acid from wheat, potatoes and the meat meals ranged between 65 and 81% and were of the order wheat diet > pork diet > potato diet > beef diet, although differences were not statistically significant. The digestibility of pantothenic acid from the coarse wholemeal bread diet was lower than 30%.

Investigations on the intestinal availability of native thiamin in selected foods and feedstuffs.

The aim of the present study was to investigate the precaecal digestibility as a quantitative measure for the intestinal availability of naturally occurring thiamin from selected foods and feedstuffs. Therefore, three experiments were conducted to examine the following foods and feedstuffs: Eggs, bananas, white cabbage, corn, milk, fish, barley, soybeans, rice, wheat bran, brewer's yeast, rye and soybean meal. The foods and food processing procedures were made with regard to their relevance in human and animal nutrition. For all experiments male pigs with an initial live weight between 33 and 40 kg were fitted with an end-to-end ileo-rectal anastomosis with preserved ileo-caeco-colicvalve. Three weeks after surgery, the digestibility trials were carried out from week 4 to week 9 and week 12 to week 17 after surgery. The animals were fed the individual experimental diets for a period of 12 days while digesta were collected twice a day quantitatively during the final 5 days of this period. Precaecal digestibility for thiamin from all tested foods and feedstuffs was within a range from 73% to 94% with the highest values from boiled soybeans, boiled rice and barley, and the lowest value from steamed fish. In comparison with the animal products the plant products show on average a nearly equal precaecal digestibility for thiamin (87.3% versus 83.5%). Moreover, all tested foods and feedstuffs exhibit a relatively good intestinal availability of thiamin.

Dietary thiamin supply during lactation influences thiamin status in lactating rats and their offspring and the thiamin level in milk.

This study was conducted to examine the effect of dietary thiamin, ranging from deficient to excessive supplies, on thiamin status of lactating rats and their offspring, and the thiamin level in milk. Therefore, after parturition, rat dams were divided into eight groups of 10 each, and were fed diets with 0, 2, 4, 6, 7, 40, 350 and 3500 mg/kg thiamin over a total of 13 days during lactation. Milk for determining the thiamin concentration was obtained from day 6 and 13 of lactation. At day 14 of lactation rat dams and their offspring were used to ascertain the thiamin status including transketolase activity of blood, liver and brain, and thiamin concentration in body. Thiamin supplies ranging from deficient to excessive dietary concentrations influenced both the thiamin levels of the lactating dams and their offspring within 13 days. Lactating rat dams fed a thiamin-free diet and their offspring were classified as thiamin-deficient on the basis of growth retardation and a lower activity of transketolase in blood, liver and brain. Within these variables transketolase in blood has been shown to be most sensitive, and reached a plateau feeding 6 mg/kg thiamin. The concentration of thiamin in milk ranged between 0.1 and 19 mg/kg. The findings also show that dietary thiamin had the strongest effect on thiamin in milk obtained from day 6 and 13 of lactation, and a deficient or suboptimal supply with thiamin was therefore not compensated for an intensified transfer of reserved body thiamin into milk. Also thiamin levels in tissues and carcass, which did not show any clear-cut saturation characteristic, increased with increasing dietary thiamin, and this dose-dependence was more marked in blood and liver than in carcass.

[Effect of various riboflavin supplementations during lactation on riboflavin levels in milk, liver and carcass in lactating rats]. / Untersuchungen zum Einfluss einer unterschiedlichen Riboflavinversorgung während der Laktation auf den Riboflavingehalt von Milch, Leber und Restkörper laktierender Ratten.

The present study investigated the effect of various dietary riboflavin supplementations (0 to 4000 mg/kg) during lactation on riboflavin concentrations of liver, carcass (bled body without intestine and liver), and milk in the rat. The experiment was conducted until the 14th day of lactation; milk samples were drawn on the 7th and 13th day of lactation. Riboflavin concentrations of milk raised continuously with increasing riboflavin supplementation; in the range between 0 and 10 mg/kg riboflavin supplementation, there was a linear relationship, and in the range between 12 and 4000 mg/kg there was a logarithmic relationship between riboflavin supplementation and riboflavin concentration in the milk. Maximum riboflavin concentration of milk obtained by supplementation with 4000 mg/kg was twelve-fold higher than without riboflavin supplementation. For riboflavin supplementation up to 12 mg/kg, riboflavin concentrations in milk on the 7th day of lactation and that on the 13th day of lactation were not different. In contrast, in rats fed diets with higher riboflavin supplementation, riboflavin concentrations were higher by 25% in average in milk on the 13th day of lactation than in milk on the 7th day of lactation. Contrary to the milk, riboflavin concentrations in liver and carcass exhibited a saturation, which was achieved at a supplementation of 6 mg/kg (liver) and 10 mg/kg (carcass), respectively. Maximum riboflavin concentrations obtained at a supplementation of 4000 mg/ kg were 1.9- and 2.3-fold higher for liver and carcass, respectively, than concentrations obtained without riboflavin supplementation. The dose-response relationship using riboflavin concentrations of liver and carcass as response factors indicates a riboflavin requirement of 8 to 9 mg/kg for lactating rats fed a semisynthetic diet with 17.4 MJ ME/kg dry matter and 20.8% protein in dry matter.

[The effect of different high riboflavin supplements during pregnancy and lactation on performance and erythrocyte glutathione reductase activity of rats]. / Zum Einfluss einer Unterschiedlich hohen Riboflavinversorgung in der Gravidität und Laktation auf Leistungsparameter und die Aktivität der erythrozytären Glutathion-Reduktase von Ratten.

In two experiments with 160 female Sprague-Dawley rats the influence of various dietary riboflavin supplementations during lactation and during pregnancy and lactation were examined on food intake, body mass, reproduction, hematologic profile and the erythrocyte glutathione reductase activity coefficient (EGR-AC). In the first trial rats were fed a semisynthetic, riboflavin-deficient diet, based on casein and corn starch with various riboflavin supplementations during lactation (0, 2, 4, 6, 8, 10, 12, 40, 400, 4000 mg riboflavin/kg diet). In the second experiment the rats received supplements of 1 and 20 mg riboflavin/kg diet, respectively, during pregnancy. After parturition each group was divided into three sub-groups with riboflavin supplementations during lactation of 1, 5 and 20 mg/kg diet, respectively. Both investigations ended at the 14th day of lactation. Food intake was decreased significantly by 25% and 11% in the groups without riboflavin supplementation or 1 mg riboflavin/kg diet. In the same groups body mass was reduced by 11% and 4%, respectively. With regard to the reproduction parameters the riboflavin supply influenced only the litter mass at the 14th day of lactation and only lactational supply was relevant. In both trials the results of the hematologic profile showed no differences. In riboflavin deficiency (0 or 1 mg riboflavin/kg diet, respectively) the EGR-AC was increased significantly to 1.9 and 1.8, respectively. At the supplementation of 4-5 mg riboflavin/kg diet EGR-AC reached a plateau of 1.45, which was not improved by higher supplements. Concerning the whole reproduction cycle (trial II) there was a stronger influence of the actual lactation-supply on EGR-AC, on the other hand a riboflavin deficiency in pregnancy could be compensated only partially by an optimal supply in lactation. Therefore, based on the parameter EGR-AC an optimal riboflavin supply is recommended for each part of the reproduction cycle. By means of EGR-AC also the riboflavin requirement for lactating rats was derived. Feeding a semisynthetic diet (17.4 MJ ME/kg DM, 20.8% crude protein in DM) a supplementation of 5-6 mg riboflavin/kg or a total content of 6-7 mg/kg diet is recommended.

Dietary thiamin supply during gestation effects thiamin status of lactating rats and their suckling offspring.

This investigation was designed to examine the effect of dietary thiamin supply during gestation on body thiamin status of lactating rats and their suckling offspring, and thiamin in milk from 1 to 13 days postpartum. Therefore, a study over two generations was conducted feeding 2, 6.7 and 20 mg/kg thiamin during gestation and 8 mg/kg thiamin during lactation. Rat dams receiving inadequate thiamin during gestation and their offspring were thiamin-deficient on the basis of reduced activity of transketolase in blood and erythrocytes, which did not reach completely the control level even two weeks postpartum. The thiamin intake during gestation influenced significantly the thiamin levels in tissues of the dams and their offspring. However, the observed dose-dependence remained only for the first days of lactation. The thiamin concentration in milk two days postpartum also reflected the nutritional thiamin status from the pregnant rats, in which the thiamin concentration raised continuously with the duration of the lactation cycle. The data indicate that an adequate thiamin supply during lactation can not completely compensate for an inadequate thiamin supply during gestation, and that necessitates a constant thiamin intake.

[The effect of wheat bran and green meal supplements on vitamin B6 metabolism of sows fed suboptimal vitamin B6 supply]. / Zum Einfluss von Weizenkleie- und Grünmehlzulagen auf den Vitamin-B6-Stoffwechsel von Sauen mit suboptimaler Vitamin-B6-Versorgung.

The aim of these investigations was to examine the influence of "natural fibrous feedstuffs" as wheat bran and alfalfa meal on criteria of vitamin B6 metabolism of adult sows subjected to a low vitamin B6 supply. Two experiments were conducted in two periods with 12 sows (180 kg BW) and 3 groups each. The supplements were in the first experiment 0 g, 225 g and 675 g wheat bran, and in the second experiment 0 g, 575 g and 1150 g alfalfa meal to a compound feed, low in vitamin B6 content. The criteria were fecal and urinary vitamin B6 concentration and excretion, vitamin B6 concentration in blood, hematological criteria, activity of aspartate aminotransferase in erythrocytes (EAST) and xanthurenic acid excretion in the tryptophan load test. Vitamin B6 concentration in feces amounted 10-12 micrograms/g DM and was neither influenced by quality or amount of the fibrous products. Vitamin B6 excretion was increased by each supplement and 60-70% of vitamin B6 was excreted via feces. Fecal vitamin B6 excretion was enlarged linearly by increasing fibrous supplementation. Bacterially fermentable substrates from wheat bran induced a higher bacterial vitamin B6 synthesis compared to cellulose.