Balance and serum concentration of biotin in sheep fed alfalfa meal-based diets with increasing level of concentrate

The objective of this study was to test the hypothesis that serum biotin concentration and biotin balance (consumed - [urinary output + fecal output]) measured as total avidin-binding substances (biotin + biotin metabolites) are responsive to changes in the proportions of dietary alfalfa meal and concentrate fed to sheep. Eight sheep (initial BW = 40 kg) consumed a pelleted alfalfa meal-based diet that had 95:5, 48:52, 23:77, or 9:91% alfalfa meal:concentrate ratios (DM basis) in a replicated 4 x 4 Latin square design with 20-d periods (10 d of acclimation, 7 d of adaptation, and a 3-d collection period with jugular blood drawn on the last day). Replacing alfalfa meal with concentrate in the pelleted diets decreased dietary concentrations of biotin proportionally. As the percentage of alfalfa meal in the diet decreased, there was a linear decrease in daily DM intake (1,128 to 901 g of DMI/d; P < 0.01), with a linear (P < 0.01) and quadratic (P < 0.01) increase in the apparent total-tract DM digestibility of diets (51.0 to 80.0%). The biotin consumed decreased with alfalfa meal proportion in the diet (linear, P < 0.01). Both fecal biotin concentration (linear, P < 0.01) and fecal biotin output (quadratic, P < 0.05) increased, reaching peaks at 23% alfalfa meal. Fecal biotin output was not correlated with biotin intake, DMI, or intake of digestible DM. Mean urinary output, urinary biotin concentration, urinary biotin output, and serum biotin concentration were not affected by treatments. Means of biotin balance were negative and revealed the same trends among treatments as did fecal output. Biotin balance was a quadratic (P < 0.05) function of decreasing alfalfa meal in the diet, with more negative values at the alfalfa meal:concentrate ratio of 23:77. Results suggest that the greatest synthesis of biotin in the total digestive tract occurs with diets of either 52 or 77% concentrate for sheep; however, research addressing the significance of biotin metabolites on biotin balance and plasma biotin pool is needed.     

Biotin in swine production: A review

Biotin, an essential water-soluble vitamin, is a cofactor of a number of enzyme systems responsible for carboxylation and transcarboxylation reactions. These reactions play a major role in the metabolism of carbohydrates and nucleic acids, in the synthesis of fatty acids, proteins and purines, and in the deamination of amino acids. In the past, it was believed that supplemental biotin was not required in swine diets because of its wide distribution in feedstuffs generally used in the formulation of swine diets, and its known synthesis by the pig's intestinal microflora. Interest in biotin nutrition for swine, however, was rekindled when several field reports in the mid-1970s described disease conditions similar to those reported for experimentally induced biotin deficiencies (poor growth in young pigs, low plasma biotin levels, alopecia and pustule formation in the skin and lesions of the hoof and sole of the toes). These conditions were reported to be responsive to biotin supplementation in many cases, but control treatments were usually not included so that definitive conclusions could not be made. Results from properly controlled research are now available, especially from long-term sow studies (three to four parities), which suggest that supplemental biotin may improve one or more of the following: poor litter size, conception rate or weaning to estrus interval, toe lesions and poor haircoat condition. Milk biotin concentration and plasma biotin concentration of sows and piglets were reported to be elevated when supplemental biotin was fed. The amount of biotin in feedstuffs varies from 20 to 2600 parts per billion (p.p.b.), but availability values have not been determined for pigs, although chick bioavailability values suggest that biotin in commonly used grain and protein sources is poorly available. Numerous environmental and nutritional factors may influence the occurrence of a biotin deficiency in swine or alter the level of biotin required in the diet to meet the animal's needs. Using presently available feedstuffs and under modern swine production conditions, a marginal biotin deficiency is possible. There are, however, many unanswered questions and a need for more research to better understand the role of biotin in swine nutrition. Swine producers experiencing poor reproductive performance in their sow herds, associated with excessive loss of hair and severe foot lesions, should evaluate the biotin content of their sow diet and consider supplemental biotin.     

Effect of biotin supplementation of a barley-wheat diet on restoration of healthy feet, legs and skin of biotin deficient sows

Sixteen sows with induced biotin deficiency were divided into groups of four and fed an egg-white-free barley-wheat based diet without added biotin (control) or supplemented with one of three levels of synthetic d-biotin (100, 200 or 400 micrograms kg-1) for two parities in order to determine the optimal level required to reverse symptoms of the deficiency and to evaluate the relationship among dietary biotin levels, stage of recovery and serum biotin concentrations. Biotin supplementation significantly reduced (P less than 0.05) the incidence of lesions (on the foot pads, above the dew claws and on the skin) and also dry skin, but had no effect (P greater than 0.05) on hoof cracks, hair score or hair density. Time after supplementation had significant effects on reversal of most biotin deficiency symptoms. Interactions between biotin supplementation and time after supplementation suggested that these symptoms were reversed more quickly when higher levels of biotin were fed. Serum biotin concentrations of biotin-supplemented sows were increased with time and exceeded 600 ng litre-1 after 0.5, 1.0 and 1.5 months following biotin supplementation of the basal diet with 400, 200 and 100 micrograms kg-1. In contrast, serum biotin concentrations of the control sows remained low and peaked at 411 ng litre-1 after 2.5 months. The data suggested that supplementation of a barley-wheat diet to provide 147 to 217 micrograms available biotin kg-1 might be adequate to restore healthy feet, legs and skin and concurrently maintain high serum biotin concentrations.     

The digestibility of biotin in protein supplements and cereal grains for growing pigs

Studies were carried out with six growing barrows fitted with a simple T-cannula 5 to 10 cm anterior to the ileo-cecal sphincter. In Exp. 1, the digestibility of biotin was determined in three cornstarch-based diets formulated to contain 16% CP by supplementation with soybean meal (SBM), meat and bone meal (MBM) and canola meal (CM). In Exp. 2 the digestibility of biotin was determined in three diets that contained 96.8% barley, corn or wheat. Experiments 1 and 2 were conducted according to a replicated 3 X 3 latin square design. In Exp. 3 pigs were fed a cornstarch-based diet supplemented with 12% vitamin-free casein to determine the amount of endogenous biotin. In Exp. 4 the digestibility of supplemental biotin was determined. There was a small amount of endogenous biotin in ileal digesta, 11 micrograms/kg DMI. Digestibilities of biotin determined at the distal ileum (apparent digestibilities corrected for endogenous biotin) were 55.4, 2.7 and 3.9% in SBM, MBM and CM, respectively, and 4.8, 4.0 and 21.6% in barley, corn and wheat, respectively. The digestibility of supplemental biotin was 93.5%. There was a large increase in the level of biotin between digesta collected from the distal ileum and in feces, ranging from 138 to 324 micrograms/kg DMI. With the exception of the CM diet, this increase exceeded dietary biotin intake. Biotin in many feedstuffs was not available in the small intestine.     

Research note: effect of increasing dietary concentrate levels on microbial biotin metabolism in the artificial rumen simulation system (RUSITEC).

The effect of varying hay/barley-proportions in the feed ration on biotin metabolism of rumen microbes was studied by means of the rumen simulation technique RUSITEC. The stepwise replacement of hay by barley decreased dietary biotin and the net output of biotin by the microbial metabolism. It is concluded that rumen microbes utilise more and/or synthesize less biotin with increasing proportions of dietary barley. These results indicate that a critical reconsideration of current views with regard to the supply and requirement of the high yielding dairy cow for biotin is necessary.     

不同水平生物素对鸡生产性能的影响

生物素在动物的生长、繁殖、生产以及疾病防治等方面发挥着重大作用。本文主要研究了生物素与肉仔鸡增重和料肉比之间的关系、生物素与产蛋鸡产蛋率之间的关系以及生物素与生长鸡屠宰性能之间的关系,并提出了各种鸡日粮中生物素的最适添加量。     

Physiological Changes in the Concentrations of Biotin in the Serum and Milk and in the Physical Properties of the Claw Horn in Holstein Cows

Physiological changes in the concentrations of biotin in the serum and milk and in the physical properties of the claw horn were examined in Holstein cows. A lower concentration of biotin in the serum and a higher concentration of biotin in milk were found during early and late lactation and during the dry period, and a significant (p<0.05) inverse correlation was found between serum and milk biotin concentrations. A high moisture content and a low level of hardness of the claw horn were found during mid-lactation. Our results indicate that change in the serum biotin concentration probably results from the loss of biotin in the milk of cows during each stage of lactation and also confirm that the moisture content and hardness of the claw horn undergo physiological changes.     

Development of a system for clinical evaluation of the biotin status of sows

Sixteen test gilts were fed an egg white-fortified practical diet and four control gilts an egg white-free diet over a two-parity period in order to monitor changes in the serum biotin levels as induced biotin deficiency progressed. Gilts were individually housed in metal crates with slatted floors. Serum biotin (ng/L) of test animals declined from 1490 (initially) to 610 (month 3), remained stable (months 4-8) and thereafter approached 400, 135 and 30 after months 9, 13 and 15, respectively. Early clinical symptoms, i.e. lesions (on the feet, legs and skin), hoof cracks, hair loss and dry skin, were first observed after six months and became progressively more pronounced with time. After nine months, the induced symptoms resembled those characteristic of biotin deficiency. In contrast, serum biotin remained high in the control animals which did not develop symptoms. The data are interpreted to mean that serum biotin might be used as a sensitive index of biotin deficiency development in sows. On the basis of these observations, a system is proposed for evaluation of the sow's biotin status. Adequate biotin may be indicated by serum biotin level (ng/L) > 700; marginal, > 600 < 700; inadequate, > 400 < 600; and deficient, < 400. Alternatively, several concurrent clinical symptoms (i.e. alopecia, hoof cracks and lesions on the feet, legs and skin) may aid in the diagnosis of inadequate biotin status of sow herds reared under field conditions.     

鸡生物素缺乏症研究进展

生物素缺乏导致体内三大物质代谢紊乱,从而影响鸡的生长和生产性能。生物素缺乏症的病鸡免疫机能下降,影响肝脏中的丙酮酸羧化酶活性以及血清碱性磷酸酶活性,影响葡萄糖和血清总磷水平,造成神经内分泌功能紊乱等。分析鸡对生物素吸收利用的因素,总结生物素缺乏症的诊断指标和临床症状,以及在饲料中适宜添加量,可为进一步研究该病提供理论依据。     

Effect of biotin supplementation on the vLa4 of thoroughbred horses

Thoroughbred horses in racing condition were supplemented twice daily with 25 mg biotin (biotin group), while control horses received an equivalent amount of maltodextrose as a placebo (placebo group). Changes of v_fLa4 (running speed necessary for producing a lactate concentration of 4 mmol/l in the blood) were determined with an incremental step test within three days and after two, three and four months after the beginning of supplementation. The mean v_fLa4 of both the biotin and the placebo groups (5 horses each) did not change significantly within three days of supplementation, but the mean plasma biotin concentration increased in the biotin group from 1.3±0.4 to 47±22 nmol/l (p<0.01), while remaining below 3 nmol/1 in the placebo group. There was no significantly different development of the v_fLa4 between groups over four months of supplementation. But, while the mean v_fLa4 of Thoroughbreds supplemented with biotin over this period of time did not show any changes, the v_fLa4 of the placebo group horses showed a tendency to decrease. In the biotin group, the mean plasma biotin levels varied between 38 and 64 nmol/l over the four months, while the biotin concentration of the placebo group never exceeded 3 nmol/1.     

Response of sows and litters to added dietary biotin in environmentally regulated facilities

A 3-yr study was conducted to evaluate the effects of biotin on sow longevity, reproductive performance and piglet performance to weaning utilizing 161 sows and 414 litters. Sows and gilts were fed a basal corn-soybean meal diet (without any antibiotic or chemotherapeutic compounds) during gestation and lactation containing either 0 or .55 ppm added biotin. The basal diet contained .17 ppm total dietary biotin based on microbiological assay. Results indicated sow culling rates and weight gains, number of live pigs at birth, pig weights at birth and weaning, and the interval from weaning to rebreeding were similar for both treatment groups. However, sows fed the diet with added biotin weaned more (P less than .05) pigs/litter overall and at gestation-lactation period 1 than did sows fed the basal diet without added biotin, although biotin did not increase (P greater than .10) the number of pigs weaned at gestation-lactation periods 2 through 5. The incidence of dermatitis, hair loss and soundness of feet and legs did not appear to be affected by adding biotin to the diet. Thus, the addition of .55 ppm biotin to a corn-soybean meal diet fed during gestation and lactation did not improve any of the criteria measured except number of pigs weaned overall.     

The influence of administration of biotin and zinc chelate (Zn-methionine) to cows in the first and second trimester of lactation on their health and productivity

In cattle, the prevention of diseases might be possible using dietary methods, with nutritional optimization of feed rations. For years significant influence has been associated with the addition of biotin, methionine and zinc (each given individually, or as chelate - Zn-methionine). The aim of this study was to evaluate the influence of biotin or biotin + Zn-methionine additives on the health and performance of cows, in the first and second trimester of lactation. This study was carried out in 3 groups of cows, 30 animals in each group. In the first group cows were fed the usual fodder used on the farm. In the second group biotin at 10 mg/day/cow was added. In the third group both biotin at 10 mg/day/cow and Zn-methionine at 5 g/day/cow were added. The administration of biotin increased the milk yield and reduced the occurrence of retained placenta, as well as endometritis puerperalis. However, the high doses of biotin suppressed ovulation and oestrus symptoms in the investigated cows (low progesterone levels on days 15, 21 and 45 after calving). Zn-methionine in comparison to biotin had a lower effect on the milk yield in the cows. Moreover, its supplementation improved the milk content, as well as some of the blood parameters; it also decreased the number of somatic cells in milk. The concurrent administration of biotin and zinc-methionine seemed to be a good method for the prophylaxis of subacute mastitis and for the improvement of the high yielding dairy cows' productivity.     

Pharmacologic effects of biotin on epidermal cells]

Biotin deficiency in animals causes pathological changes of the skin and its appendages including, for example, exfoliative dermatitis, depigmentation, and alopecia. The hooves of biotin-deficient swine are weak, brittle, and often necrotic. These changes disappear after dietary biotin supplementation. Biotin supplementation also noticeably improves the hoof quality of horses, cattle and swine having no apparent biotin deficiency. In order to elucidate the molecular basis of these effects, the influence of biotin on cytokeratin expression in a keratinocyte cell line (Ha-CaT) was investigated using electrophoretic and immunological techniques. Pharmacological biotin concentrations of 1 microM, and 100 microM in the culture medium caused a specific increase in cytokeratins, which are normally induced upon terminal differentiation of epidermal cells in vivo. The expression of cytokeratins occurring in stratified epithelia independent of differentiation were not affected. These findings show that biotin directly stimulates the differentiation of epidermal cells. Such a molecular mechanism revealed in cell culture could provide an explanation for the therapeutic effects of pharmacological doses of biotin on hoof quality in farm animals.     

Effects of biotin supplementation on serum biotin levels and physical properties of samples of solar horn of Holstein cows

Effects of dietary biotin supplementation on serum biotin levels and physical properties of sole horn of 40 Holstein cows were evaluated. The mean serum biotin level in biotin-supplemented cows after 10 mo of biotin supplementation (1163.2 +/- 76.2 pg/mL) was significantly higher (P = 0.007) than that in control cows (382.0 +/- 76.2 pg/mL). The sole horn of biotin-supplemented cows was significantly harder (P = 0.026) and had a significantly lower moisture content (P = 0.021) than that of control cows. No morphologic differences in horn tubules or intertubular horn were found between the biotin-supplemented and control cows. The total lipid content of sole horn was significantly higher (P = 0.030) in the biotin-supplemented cows than in the control cows. These results suggest that dietary biotin supplementation causes increases in serum biotin levels and changes in physical properties and fat content of sole horn.     

An immunohistochemical study of the distribution of biotin in tissues of pigs and chickens

An optimised indirect peroxidase-anti-peroxidase immunohistochemical technique was used to detect endogenous biotin in frozen tissue sections from biotin-supplemented and biotin-depleted pigs and chickens. A monoclonal anti-biotin antibody was used as primary antibody in this technique. Immunoreactive biotin was detected in many tissues of both species including liver, kidney, pancreas, adipose tissue, adrenal gland, testis, brain, choroid plexus, cardiac and skeletal muscle, epithelium of the respiratory and digestive systems, skin and lymphoid tissues. The specificity of immunostaining for biotin was confirmed by the finding of reduced staining intensities in tissues of biotin-depleted animals compared to those of biotin-supplemented animals. The results of this study suggest that biotin has metabolic functions in a wider range of tissues than previously known. They also indicate that endogenous tissue biotin should be considered as a source of false-positive staining when immunohistochemical or histochemical techniques which use avidin or streptavidin reagents or anti-biotin antibodies as components of the detection system, are applied to tissue sections.     

Effects of supplemental biotin during gestation and lactation on reproductive performance of sows: a cooperative study

A cooperative experiment to evaluate biotin addition to sow diets was conducted at three research stations using 303 litters. Primiparous and multiparous sows (overall average parity 2.8) were fed a 14% CP corn-soybean meal diet (140 micrograms/kg biotin), with or without supplemental biotin (330 micrograms added biotin per kg feed), throughout gestation and lactation. As many sows as possible were fed their respective diets through three successive parities. During gestation, sows were given from 1.82 to 2.27 kg of feed per day, depending on environmental conditions; during lactation sows had ad libitum access to feed. Supplemental biotin had no effect (P greater than .35) on sow weights at breeding, at d 109 of gestation, at farrowing or at weaning. No differences were found in litter size at birth (P greater than .18), but at d 21 of lactation, sows fed the diet containing supplemental biotin had larger litters than sows fed the unsupplemented diet (9.4 vs 8.7 pigs, respectively; P = .01). Pig weights at birth and d 21 of lactation were not affected (P greater than .20) by dietary treatment. Biotin supplementation did not affect (P greater than .28) the length of the interval from weaning to estrus. No evidence was found that feet cracks or bruises were reduced by biotin supplementation. The results indicate that biotin supplementation of a corn-soybean meal diet during gestation and lactation increased the number of pigs at d 21 of lactation, but it did not decrease the incidence of foot lesions.     

Field experience with d‐biotin supplementation to gilt and sow feeds

At a pig breeding farm with 130 sows, the culling rate in respect of the young replacement stock was more than 50% and was in particular caused by lameness.

The effect was investigated of d‐biotin supplementation of the feed on culling percentage, reproduction, claw lesions and lameness of gills (young replacement stock) and sows, and piglet mortality. The young pigs were divided into a group of 23 young replacement pigs aged 2.5 months (12 controls and 11 treated) and a group of 47 gilts aged 7 months (23 controls and 24 treated). Both treatment groups received feed supplemented with 1250 mcg / kg d‐biotin. Furthermore, all sows received feed supplemented with 500 mcg / kg d‐biotin. The basic feed contained 175 mcg / kg biotin, of which about 100 mcg / kg was biologically available biotin.

Biotin supplementation resulted in an increase in the plasma biotin levels from the critical deficiency level of about 50 ng / 100 ml to about 300 ng / 100 ml in young replacement stock, to about 179 ng / 100 ml in the gilts, and to about 123 ng / 100 ml in the sows.

After 2.5 months of biotin supplementation the claw lesion score of the gilts had decreased by 28% (p < 0.001). In the young replacement stock a reduction of the claw lesion score by 52% (p<0.001) was found after 4 months supplementation.

The effect of biotin supplementation was greatest in the soft heel region (improved by 35%) and somewhat less on the claw wall (improved by 23%).

After 11 months’ supplementation with 500 mcg / kg biotin the effects on production performance of the sows compared to the previous year can be summarized as follows: - the overall culling rate dropped from 54.0% tot 30.8%,

- the culling rate due to lameness decreased by 11% from 25% to 14%,

- the culling as a result of ‘insufficient production’ was reduced from 11% to 4%,

- a positive trend in piglet mortality was observed (17.7% compared to 19.2%).

An increase of the biotin content of Dutch pig feeds and regular monitoring of its biotin content would appear to be advisable.     

Effect of dietary biotin supplement on equine hoof horn growth rate and hardness.

Over a 10-month period, 24 randomly selected riding horses were fed various amounts of biotin. Statistically significant improvements in growth rates and hardness of hooves were produced by biotin supplementation. Greater growth rates and hardness were achieved at a daily dose of 15 mg than at 7.5 mg. Increased hoof hardness was greatest in the hoof quarters and toe. No ring formation occurred in hooves of horses fed biotin intermittently.     

Biotin requirements of broiler breeders fed diets of different protein content and effect of insufficient biotin on the viability of progeny

Production of eggs or normal chicks was depressed when practical diets containing 168 g or 137 g of crude protein (CP)/kg were not supplemented with synthetic biotin. Overall egg production and hatchability of fertile eggs was significantly (P less than 0.05) higher with the diets containing 137 g CP/kg. Biotin requirement was higher with the diet containing 168 g CP/kg and was estimated to be about 100 micrograms of available biotin/kg, equivalent to a daily intake of 16 micrograms for food-restricted hens. Biotin concentrations in egg yolk and chick plasma were related to maternal intake and increased with maternal age. The minimum yolk biotin concentration indicative of adequate maternal status was about 550 micrograms/g. Chicks from young hens fed insufficient biotin had the poorest biotin status at hatching and their growth potential and viability were reduced.     

The effects of dietary biotin supplementation on vertical fissures of the claw wall in beef cattle

A clinical field trial was performed on a herd of Hereford beef cows in central Saskatchewan. The herd had a history of being severely affected with vertical fissures. The objective of the study was to determine the effects of supplemental dietary biotin on the prevalence of vertical fissures in beef cows. In June 1994 and June 1995, 1- and 2-year-old heifers were randomly allocated into 2 treatment groups, each composed of 79 animals. One group received a 10 mg/head/day biotin-supplemented free-choice mineral supplement, while the other groups received an identical free-choice mineral without the biotin supplementation. The claws from these animals were evaluated in June 1994, October 1994, June 1995, October 1995, and June 1996 for the presence of vertical fissures. Supplemental dietary biotin significantly increased serum levels of biotin and significantly increased claw hardness in supplemented cows. Both groups of heifers started the trial without vertical fissures. After 18 months, 15% of the cows fed supplemental dietary biotin had vertical fissures compared with 33% in the nonsupplemented group. The difference was statistically significant (P = 0.01).