Prepartum Magnesium Butyrate Supplementation of Dairy Cows Improves Colostrum Yield, Calving Ease, Fertility, Early Lactation Performance and Neonatal Vitality

Simple Summary Butyrate is an established feed additive for supporting gut health in pigs and poultry and also young ruminants where it is used to promote rumen development. However, the effect of supplementing dairy cows with butyrate ahead of calving has been less extensively studied, and it is not known what effect precalving butyrate supplementation has on the calf. The purpose of this on-farm study was to investigate the effect of magnesium butyrate (MgB) fed daily for the last 3 weeks before the expected time of calving on dairy cow and calf-related parameters. The study findings showed that prepartum MgB enhanced colostrum yield and the total yield of immunglobulin G, protein and lactose. Improved early lactation performance, calving ease, fertility and body condition score were observed in the cows of the MgB-supplemented group, and their calves had increased vitality at birth. These findings highlight that prepartum MgB supplementation of dairy cows gives a wide range of benefits, which also extend to the calf. Butyrate promotes rumen epithelium growth and function; however, the effect of prepartum butyrate supplementation on dairy cow productivity, health and their offspring has not been extensively studied. Furthermore, no studies have investigated the effect of magnesium butyrate (MgB), which is also a source of magnesium. A trial was performed to test the hypothesis that prepartum MgB supplementation (105 g/cow/day) would increase colostrum quality and improve calving, newborn calf vitality and cow health. Multiparous Holstein cows were randomly assigned to MgB supplemented (n = 107) and Control groups (n = 112). Colostrum yield and the total yield of IgG, protein and lactose were higher (p <= 0.05) in the supplemented group. The calving assistance rate was lower (p <= 0.012), and the neonatal vitality score was higher (p <= 0.001) in the MgB group. Improved parameters related to cow health and fertility were observed in the supplemented group. The MgB group also had higher milk yield during the first week of lactation (p <= 0.001), and a higher (p <= 0.05) body condition score from 3 to 9 weeks after calving. In conclusion, prepartum MgB supplementation provides a wide range of benefits for dairy cows, as well as their newborn calves.