Effects of feeding live yeast at 2 dosages on performance and feeding behavior of dairy cows under heat stress

Abstract

The objectives were to evaluate the effects of feeding different amounts of supplemental live yeast (LY) on performance and digestion of cows under heat stress. Sixty Holstein cows, 27 multiparous and 33 primiparous, were blocked by parity and milk yield in the first 20 d in milk (DIM) and randomly assigned to receive 0, 0.5, or 1.0 g/d of LY, resulting in daily intakes of 0, 14.2, and 37.6 billion cells, respectively, of Saccharomyces cerevisiae strain CNCM I-1077 from 30 to 107 DIM. Cows were milked twice daily, dry matter intake (DMI) and milk yield were measured daily, and milk components, body weight, and body condition were measured weekly. Blood was sampled weekly and plasma analyzed for concentrations of glucose, fatty acids, urea N, haptoglobin, serum amyloid A, and acid-soluble protein. Digestibility of nutrients was measured in the last 2 wk of the experiment. Ruminal fluid was collected on 2 consecutive days 6 h after the morning feeding for measurements of pH, concentrations of short chain fatty acids, and NH 3-N. Feeding behavior was observed for 48 h on experiment d 21 and 63. The mean ambient temperature was 26.8°C, humidity was 83.2%, and the temperature and humidity index ranged from 73 to 81. Treatment did not affect rectal temperature (38.9 ± 0.04°C) or DMI but increased yield of energy-corrected milk (ECM; 35.2 vs. 36.1 vs. 37.2 kg/d for 0, 0.5, and 1.0 g/d, respectively) and efficiency of conversion of DM into ECM (1.70, 1.79, and 1.83 for 0, 0.5, and 1 g/d, respectively). Feeding LY increased digestibility of crude protein (65.1 vs. 68.8 vs. 70.4%) and neutral detergent fiber (NDF; 47.5 vs. 49.2 vs. 55.2%), and concentration of acetate (64.7 vs. 69.1 vs. 72.2 mM), which resulted in increased concentration of total short chain fatty acids in ruminal fluid (110.3 vs. 117.7 vs. 121.4 mM). Mean ruminal pH increased (5.99 vs. 6.03 vs. 6.26), and proportion of cows with pH <5.8 decreased linearly (42.9 vs. 34.9 vs. 7.7%) with increasing inclusion of LY. Concentrations of acute-phase proteins decreased with increasing amount of LY. Some aspects of feeding behavior were altered by LY, and meal size reduced quadratically (3.2, 3.5, and 2.9 kg of DM, respectively), whereas interval between rumination bouts tended to reduce linearly (122, 96.5, and 90.7 min, respectively) with increasing dose of LY. Chewing time per kilogram of NDF tended to increase linearly (71.6, 71.3, and 81.6 min/kg, respectively) with increasing dose of LY. The estimated net energy for lactation of the diet increased 5.2%, from 1.72 Mcal/kg of DM for 0 g of LY to 1.81 Mcal/kg for 1 g of LY. Feeding 1 g of LY/d to cows under heat stress increased yield of ECM and efficiency of feed conversion into ECM, improved diet digestibility, and increased ruminal fluid pH; these responses might be related either to direct effects of LY on ruminal microbial activity or to changes in feeding behavior that improved digestion of cows in heat stress.

Saccharomyces cerevisiae boulardii CNCM I-1079 supplementation in finishing male pigs helps to cope with heat stress through feeding behaviour and gut microbiota modulation

“…In dairy cows, LY supplementation has been shown to induce an increased meal frequency and a decreased meal size (11) , that may limit the increase in HP shortly after a meal (by decreasing the amount of nutrients and energy consumed at each meal). Moreover, in dairy cows submitted to heat stress, LY dietary supplementation induces changes in feeding behavior associated with improved lactation performance (12) . Another study furthermore evidenced a decrease in rectal temperature of 0.2 °C (13) in LY supplemented cows that may increase the temperature difference between the animal and its environment, thus helping them to face heat stress.…”

Effects of peripartal yeast culture supplementation on lactation performance, blood biomarkers, rumen fermentation, and rumen bacteria species in dairy cows

“…Yeast culture supplementation has been observed to improve milk fat yield in early and mid-lactation dairy cows (Dias et al, 2018;Perdomo et al, 2020). Olagaray et al ( 2019) observed a 0.13-kg/d increase in milk fat yield at 4 and 5 wk postpartum, feeding 19 g/d of yeast culture during the peripartal period, which was similar to the 0.16-kg/d increase in milk fat yield observed in YC cows compared with control.…”

The effect of Saccharomyces cerevisiae additive to cattle ration on milk yield of dairy cows

“…Bruno et al (2009) report a rise in milk yield of 1.2 kg/day in dairy cows within first 130 days of lactation fed with the yeast additive. Perdomo et al (2020) recorded that milk yield tended (p = 0.10) to increase linearly, a 1.4 kg/day difference between 0 and 3.76 10 10 cfu/head/day treatments, with incremental feeding of live yeast. Desnoyers et al (2009) in a meta-analysis on S. cerevisiae supplementation to ruminants, estimated a mean milk yield response to yeast of +0.78 kg/day, for a 650-kg cow-equivalent.…”

“…Similarly, De Vries and Chevaux (2014) record an increasing trend in fat content -rise by 0.16%, and milk fat yield -rise by 0.07 kg/day, in cows which had yeast added to their ration by the dosage 1 • 10 10 cfu/head/day, however, no effect on milk protein content or milk fat content was noted in their study. Perdomo et al (2020) evaluated the effect of different doses of live yeast on the performance of dairy cows (0, 1.42 and 3.76 • 10 10 cfu/head/day). They found that protein tended (p = 0.08) to increase with increasing dose of live yeast.…”

“…Thus, rumen ecosystem plays a key role in ruminants' responses to their diet (Desnoyers et al, 2009). Saccharomyces cerevisiae is a single-celled fungus capable of fermenting carbohydrates that is commonly used as a feed additive in diets of ruminant livestock (Perdomo et al, 2020). Live Saccharomyces cerevisiae scavenges ruminal oxygen (Newbold et al, 1996), which reduces ruminal redox potential, favouring the activity of cellulolytic bacteria and lactate-utilizing bacteria (Marden et al, 2008).…”