Dr. Kirby Krogstad, Assistant Professor, Department of Animal Sciences, The Ohio State University
Introduction
In part 1, we introduced the fundamentals of B-vitamin nutrition for dairy cows. Ruminants have a unique advantage when it comes to B-vitamins because the microbes in their rumen provide them with their own personal source of B-vitamins. When we consider that microbes supply dairy cattle with B-vitamins, it’s worth asking the question of whether supplementation of additional B-vitamins is needed, or beneficial, for dairy cows.
How to Supplement B-vitamins?
The rumen degradation of B-vitamins is different for each of the B-vitamins (Table 1). Previous research in beef and dairy cattle demonstrate that nearly all the riboflavin and niacin are degraded in the rumen before they reach the intestine. Folic acid is also extensively degraded in the rumen. Thiamin and cobalamin had intermediate rumen degradation, while biotin and pyridoxine had the least apparent rumen degradation.
Table 1. Apparent ruminal degradation (%) of B-vitamins.
| B-vitamin | Santschi et al. (2005) |
| Thiamin | 67.8 |
| Riboflavin | 99.3 |
| Niacin | 98.5 |
| Pyridoxine | 41.0 |
| Biotin | 45.2 |
| Folic Acid | 97.0 |
| Cobalamin | 62.9 |
Since most of the B-vitamins are extensively degraded in the rumen, they usually require rumen protection technology to deliver them to the small intestine in adequate quantities for intestinal absorption and use by the animal. There are many commercial sources of rumen protected B-vitamins for cattle (side note: if you’re considering rumen-protected B-vitamins, make sure that the rumen protection technology is effective). These rumen-protected supplements are often sold as B-vitamin blends, but some individual B-vitamin supplements are marketed as well.
The research on supplementing B-vitamins to dairy cattle is blurry and full of nuance. Some nutrients have been more thoroughly investigated than others, some B-vitamins have been provided by injection while some others have been fed through the bunk as a supplement, and some B-vitamins have been consistently effective while others have not.
What Does the Research Say?
Cobalamin and Folic Acid
In a 2017 experiment, injections of folic acid, cobalamin, or both were given to cows weekly from 3 weeks prior to calving until 7 weeks after calving. They did not observe any changes in milk yield or component yields due to treatment (Duplessis et al., 2017). Interestingly, this same research group observed that folic acid and cobalamin injections during this window around calving reduced days to first breeding (Duplessis et al., 2014). Other experiments have also observed improved fertility and reductions in culling when providing B-vitamins to dairy cattle through a rumen-protected supplement (Juchem et al., 2012). In this experiment, they did not observe changes in milk production from the B-vitamin blend supplement.
In general, cobalamin and folic acid have neutral results on milk production with possible health or fertility benefits for dairy cattle.
Biotin
Research has indicated that increasing biotin in the diet increases milk yield during lactation. Fortunately, there are enough data investigating the supplementation of biotin to dairy cattle that a meta-analysis was published on the topic. They summarized data from 11 experiments that included 238 cows (Chen et al., 2011). Their analysis concluded that 20 mg/day of biotin increased milk yield by 1.7 kg/day (3.7 lb/day) without any effect on milk component concentrations which resulted in greater milk component yields.
Niacin
Niacin, or vitamin B3, has very intriguing effects that could be beneficial for dairy cow health. Supplementing rumen-protected niacin reduces body fat mobilization after calving and has reduced ketones after calving. Recent research in dairy cattle has also shown that rumen-protected niacin is anti-inflammatory which may improve animal health during times of stress (Krogstad et al., 2024). In a recent abstract at the American Dairy Science Association meeting, the researchers suggest that rumen-protected niacin supplementation may increase milk yield throughout lactation as well, but it is the only experiment to monitor cows for a whole lactation when supplemented niacin during the transition period. Overall, the results for niacin are encouraging but require greater scrutiny to confirm the increased milk yield that was observed as a result of rumen-protected niacin supplementation
Bottomline on B-vitamins?
Supplementing B-vitamins to cows, in most cases, requires that they be rumen protected because they are extensively degraded by rumen microbes. The results of research from supplementing B-vitamins to dairy cattle depends on which B-vitamin was investigated. Biotin supplementation increases milk yield from dairy cattle, while supplementing folic acid and cobalamin has neutral effects on milk production. In some cases, providing folic acid and cobalamin improved fertility and reduced culling of dairy cows. Supplementing rumen protected niacin has increased milk yield in one instance and has demonstrated anti-inflammatory effects that require closer scrutiny. For your operation, look at the data, pencil out the costs, and calculate the benefits to determine which B-vitamin supplements may work best in your herd!
References
Chen, B., C. Wang, Y. M. Wang, and J. X. Liu. 2011. Effect of biotin on milk performance of dairy cattle: A meta-analysis. J. Dairy Sci. 94(7):3537-3546. https://doi.org/10.3168/jds.2010-3764
Duplessis, M., C. L. Girard, D. E. Santschi, J. P. Laforest, J. Durocher, and D. Pellerin. 2014. Effects of folic acid and vitamin B12 supplementation on culling rate, diseases, and reproduction in commercial dairy herds. J. Dairy Sci. 97(4):2346-2354. https://doi.org/10.3168/jds.2013-7369
Duplessis, M., H. Lapierre, D. Pellerin, J. P. Laforest, and C. L. Girard. 2017. Effects of intramuscular injections of folic acid, vitamin B12, or both, on lactational performance and energy status of multiparous dairy cows. J. Dairy Sci. 100(5):4051-4064. https://doi.org/10.3168/jds.2016-12381
Juchem, S. O., P. H. Robinson, and E. Evans. 2012. A fat based rumen protection technology post-ruminally delivers a B vitamin complex to impact performance of multiparous Holstein cows. Anim. Feed Sci. Technol. 174(1):68-78. https://doi.org/10.1016/j.anifeedsci.2012.03.004
Krogstad, K. C., J. F. Fehn, L. K. Mamedova, M. P. Bernard, and B. J. Bradford. 2024. Effects of rumen-protected niacin on inflammatory response to repeated intramammary lipopolysaccharide challenges. J. Dairy Sci. https://doi.org/10.3168/jds.2024-24974
Santschi, D. E., R. Berthiaume, J. J. Matte, A. F. Mustafa, and C. L. Girard. 2005. Fate of supplementary B-vitamins in the gastrointestinal tract of dairy cows. J. Dairy Sci. 88(6):2043-2054. https://doi.org/10.3168/jds.S0022-0302(05)72881-2