Response of lactating cows to live yeast supplementation during summer

Abstract

Dairy cows experiencing heat stress have reduced intake and increased reliance on glucose, making feeding strategies capable of improving diet digestibility plausible for improving postrumen nutrient flow and performance. The effect of yeast on digestion and performance of lactating cows during the warm summer months of southeastern Brazil was evaluated. Cows were individually fed in tie stalls and temperature-humidity index was above 68 during 75.6% of the experiment. Twenty-eight Holstein cows (207±87 d in milk) received a standard diet for 14 d and then a treatment for 70 d, in a covariate-adjusted, randomized block design with repeated measures over time. Treatments were yeast (Saccharomyces cerevisiae) or control. Yeast was top dressed to the diet in the morning, equivalent to 25×10(10) cfu of live cells and 5×10(10) cfu of dead cells. The diet contained corn silage (37.7%), Tifton silage (7.1%), raw soybeans (4.1%), soybean meal (16.5%), finely ground corn (20.7%), and citrus pulp (11.9%). Yeast increased milk (26.7 vs. 25.4 kg/d) and solids yield (3.06 vs. 2.92 kg/d), especially lactose. Response in milk yield was consistent over time and started at d 5. The daily intake of digestible OM, total-tract digestibility of nutrients, urinary allantoin excretion, chewing pattern throughout the day, and dry matter intake did not respond to yeast. A trend was observed for increased plasma glucose with yeast (62.9 vs. 57.3mg/dL), lowered respiratory frequency (48 vs. 56 breaths/min), and increased plasma niacin content (1.31 vs. 1.22 µg/mL), though cows had similar rectal temperature. Ruminal lactate and butyrate as proportions of ruminal organic acids were reduced by yeast, but no effects on other organic acids, ruminal pH, or protozoa content were detected. Plasma urea N over 24h was increased by yeast. On d 72 to 74, citrus pulp was abruptly replaced with finely ground corn to induce acidosis. The increased load of starch increased dry matter intake between 0700 and 1300 h, jugular blood partial pressure of CO2, HCO3-, and base excess, and decreased blood pH for both treatments. The yeast treatment had a higher blood pH compared with the control, 7.34, and 7.31, respectively. Yeast supplementation improved lactation performance of dairy cows under heat stress. Improvement in lactation performance apparently involved the regulation of body homeothermia, rather than improved digestibility.

The Effect of Live Yeast Supplementation on Beef Cattle Performance: A Systematic Review and Meta-Analysis

“…A systematic literature search identified peer-reviewed publications published through January 2015. The server of the Federal University of Rio Grande do Sul (UFRGS, Brazil) was used to perform the search in the ISI Web of Science (Thomson Reuters, 1900-2015, Scopus (Elsevier, 1960(Elsevier, -2015, and Science Direct (Elsevier, 1823(Elsevier, -2015 databases.…”

Positive effects of dietary supplementation of three probiotics on milk yield, milk composition and intestinal flora in Sannan dairy goats varied in kind of probiotics

“…Intestinal microbiota affect the nutrient utilization efficiency, health and production characteristics of host animals (Kritas, Govaris, Christodoulopoulos, & Burriel, 2010;Wang, Jin, Xue, Wang, & Peng, 2019). For example, studies of cows indicate that supplementation with probiotics may increase milk yield (Piva, Belladonna, Fusconi & Sicbaldi, 1993;Salvati et al, 2015). For dairy livestock, these factors all act on lactation directly or indirectly.…”

“…For dairy livestock, these factors all act on lactation directly or indirectly. For example, studies of cows indicate that supplementation with probiotics may increase milk yield (Piva, Belladonna, Fusconi & Sicbaldi, 1993;Salvati et al, 2015). Furthermore, Dailidaviciene et al (2018) reported that dairy cows fed probiotic additives had significantly higher milk fat than control group animals.…”

Technical note: use of internal transcribed spacer for ruminal yeast identification in dairy cows

“…Mendes et al (2012) suggested that yeasts are able to degrade simple carbohydrates, which could favor the growth of yeast populations, and also contribute to the regulation of ruminal pH. Both live and dead yeast (Saccharomyces) are used as feed additives for dairy cows (Salvati et al, 2015); however, their precise role in improving rumen function is still unclear. Because yeast is involved in the oxygen utilization, fiber digestion and pH regulation (Salvati et al, 2015) in the rumen, data from this study are relevant for a wide range of scientists, animal nutritionists and enterprises.…”

“…Both live and dead yeast (Saccharomyces) are used as feed additives for dairy cows (Salvati et al, 2015); however, their precise role in improving rumen function is still unclear. Because yeast is involved in the oxygen utilization, fiber digestion and pH regulation (Salvati et al, 2015) in the rumen, data from this study are relevant for a wide range of scientists, animal nutritionists and enterprises. Despite the fact that the effects of dietary supplementation of ruminants with yeast has been extensively studied, there is little information on the identification, quantification and function of these fungi in the rumen.…”