For example, a cooperative study by researchers in Kentucky, Minnesota and Nebraska (Lewis et al., 1991) found that when sows had received 0.33 ppm of supplemental biotin, they averaged 9.4 pigs per litter at day 21, versus 8.7 for unsupplemented sows (P= 0.1).
Biotin levels higher than NRC values may be needed to permit optimum health and productivity under commercial conditions. The NRC recommends 182 mg per ton of complete ration, but this may be inadequate for gestating and lactating sows.
Complicating this is the fact that the biotin bioavailability has not been established for swine and must be extrapolated from chicken data, which suggest that the biotin bioavailability in various grains and protein sources is poor.
Based on these bioavailability data, Brooks (1978) estimates that the total dietary biotin requirement of the sow is 250 to 300 parts per billion (ppb) of bioavailable biotin. Because cereal grain-based diets usually supply from 90 to 170 ppb of total biotin, 100 to 200 ppb of supplemental biotin could be necessary.
Biotin's effects on foot, skin and hair conditions have also been documented. In numerous university studies, sows fed a biotin--supplemented ration had fewer heel cracks, white line hoof horn cracks, heel--horn junction cracks and sidewall cracks than sows fed an unsupplemented ration.
To help prevent hoof damage, early supplementation with biotin is important. Various studies have found that supplementation is more effective before hoof lesions and cracking develop than afterwards. And when hoof problems are due to or exacerbated by poorly designed floors, biotin supplementation by itself won't solve the problem.
Signs of biotin deficiency include loss of hair; dry, scaly skin; erosion of the soft heel; and extensive cracking of the toe heel and horn. Acute biotin deficiencies are fairly obvious, although they may be mistaken for other nutritional deficiencies. But marginal or subclinical deficiencies--which are most common in swine operations--are more difficult to detect.
Severity can vary, not all signs are always present, and there is no ready way to determine an animal's biotin status. Sows' hair coat and skin condition are the most important early signs of possible biotin deficiency. Action taken when these signs appear can prevent economic loss.
Various factors influence the level of supplemental biotin required in sow rations. More research is required in many of these areas before the full effect of biotin can be defined.
In the absence of this research, these factors should be considered when evaluating the need for supplemental biotin:
- Increase in total confinement housing, which reduces the opportunity for coprophagy
- Increase in number of farrowings per sow per year
- Reduction in daily feed intake during gestation, which increases the need for supplementation
- Strong genetic selection pressure for swine with faster growth rate, more efficient feed conversion, lower fat and higher muscle content
- Wide variation in the biotin content of feedstuffs and decreased use of such biotin-rich ingredients as alfalfa and distillers' solubles
- Deactivation or loss of biotin in feeds due to processing and storage, contact with rancid fats or oils, or the presence of biotin antagonists
- Limited bioavailability of biotin in various feedstuffs
- Reduction of biotin synthesis in the gastrointestinal tract by various diet components, especially antibiotics
- Disease or disorders that impair absorption of biotin.
References:
- Bryant, K.L., et al. 1985. Supplemental Biotin for Swine: Influence of Supplementation to Corn and Wheat Based Diets on Reproductive Performance and Various Biochemical Criteria of Sows During Four Parities. J. Anim. Sci 60:145.
- Brooks, P.H. 1978. The Effect of Dietary Biotin on the Incidence of Foot Lesions and on the Reproductive Performance of the Sow. Proc. Vitamin Day Symp. Roche, Paris.
- Lewis, A.J., et al. 1991. Effects of Supplemental Biotin during Gestation and Lactation on Reproductive Performance of Sows. J. Anim. Sci. 69:207.
- Kornegay, ET. 1985. Biotin in Swine Production: a Review. Livestock Production Science. 14:65.
