Active yeast products have the potential to increase milk yield of dairy cows in early lactation by improving rumen conditions. Greater milk yields, however, can sometimes be associated with poorer reproductive performance (Garnsworthy et al., 2008). This study aimed to assess the effect of an active yeast supplement on milk yield and reproduction indicators in high yielding dairy cows, using fifty Holstein-Friesian dairy cows were paired at calving according to parity, calving date, predicted milk yield and live weight, and allocated at random to two treatment groups (n = 25). Cows were fed ad libitum on a partial mixed ration (PMR; maize, grass and wheat silages (0.75), concentrate blend (0.25) supplying requirements for maintenance plus 30 L milk/day) with additional concentrates during milking at 0.45 kg/L milk yield above 30 L/day. Control PMR contained no yeast, and Yeast PMR contained live yeast (Actisaf Sc47, Phileo UK & Ireland) at 100 billion cfu / cow / day / 10 g. The trial lasted from 7 to 128 days in milk (DIM). Milk yield, live weight and feed intake were recorded daily. Milk samples were analysed for composition on two days per week and for progesterone on three days per week. Pregnancy was confirmed by rectal palpation. Whole-tract digestibility was determined in weeks 7 and 13 of lactation from ratios of acid-insoluble ash in feed and faeces. Data were analysed using Genstat (version 19) with generalised linear mixed models and appropriate error distributions (identity, Poisson, binomial). Fixed effects were treatment (Control, Yeast), calving month, and parity (1, 2, ≥3). Random effects were cow and a non-linear function for week of lactation. Cows offered Yeast had greater yields of energy corrected milk and milk fat than Control cows and tended to have greater milk protein yield (Table 1). Dry matter intake, feed efficiency, live weight (731 ± 9.5 kg) and live-weight change (-0.23 ± 0.19 kg/d to 42 DIM) were not affected by treatment, but dry matter digestibility was greater for Yeast than for Control. Intervals to first progesterone rise and conception, incidence of atypical cycles, and proportions of cows conceiving before 130 DIM and overall, did not differ between treatments. In conclusion, the feeding live yeast to high-yielding dairy cows in early lactation increased milk yield and milk fat yield without increasing dry matter intake by enhancing dry matter digestibility. Increased milk yield was achieved with no detrimental effect on reproductive performance.
Citation
Algherair, I., Saunders, N., Goodman, J., Margerison, J., Garnsworthy, P., & Mann, G. (2022). 42. Effect of live yeast (Saccharomyces cerevisiae) on milk yield, feed efficiency and reproduction of high-yielding dairy cows. Animal - Science proceedings, 13(1), 30-31. https://doi.org/10.1016/j.anscip.2022.03.043
Acknowledgement: The authors acknowledge funding from Phileo UK & Ireland, Shannon, Ireland. I.A. was sponsored by the government of the Kingdom of Saudi Arabia
