Production performance and nutrient digestibility of lactating dairy cows fed low-forage diets with and without the addition of a live-yeast supplement

Abstract

We aimed to evaluate the use of a live-yeast product as a means to attenuate plausible nutritional disturbances when feeding relatively low-forage diets containing rapidly fermentable carbohydrates (i.e., wheat) to high-producing cows in early to mid lactation. Eight primiparous [mean ± SD; 569 ± 35 kg of body weight (BW) and 80 ± 29 d in milk (DIM) at the beginning of the experiment] and 16 multiparous (665 ± 67 kg of BW and 64 ± 10 DIM at the beginning of the experiment) Holstein cows were blocked by parity and DIM, and randomly assigned to 1 of 2 diets (control vs. yeast) for a 12-wk-long period according to randomized complete block design. The formulated diets contained 36.7% corn silage, 8.3% alfalfa hay, and 55% concentrate. The yeast diet was formulated to provide approximately 5.4 × 10 11 cfu/d of Saccharomyces cerevisiae (BeneSacc; Global Nutritech Biotechnology LLC, Richmond, VA). Total-tract nutrient digestibility was estimated using 240-h undigested neutral detergent fiber (NDF) as an internal marker. Dry matter intake, milk yield, and milk component concentrations and yields were analyzed using repeated measures. The statistical model for these variables included the effects of block, treatment, the block by treatment interaction, week, the treatment by week interaction, and the random residual error. The statistical model for analyzing BW gain, body condition score gain, and dry matter and nutrient digestibilities included the effects of block, treatment, and the random residual error. Supplementing live yeast to lactating dairy cows did not affect dry matter intake (26.0 kg/d), milk yield (48.1 kg/d), milk fat concentration (3.61%), milk fat yield (1.72 kg/d), milk protein concentration (2.96%), milk protein yield (1.43 kg/d), milk lactose concentration (4.84%), milk lactose yield (2.35 kg/d), milk urea nitrogen (7.99 mg/dL), body weight gain (0.62 kg/d), and body condition score gain (0.02 units; all averages of the 2 treatments). The digestibilities of dry matter (70.2%), crude protein (71.4%), NDF (36.4%), and starch (99.8%) were not affected by treatments. In conclusion, the supplementation of the live yeast did not affect production performance and nutrient digestibility of high-producing dairy cows. A potential interaction between live-yeast supplementation and NDF passage rate, which may have hindered the beneficial effects of live-yeast supplementation on production performance and nutrient utilization, deserves further research.

Effects of yeast culture supplementation on lactation performance and rumen fermentation profile and microbial abundance in mid-lactation Holstein dairy cows

“…Dietary treatments did not affect BW or BCS in the current study (Table 2), which agrees with previous studies with live yeast (Ambriz-Vilchis et al, 2017;Ferreira et al, 2019) and yeast culture (Dias et al, 2018b). Yeast supplementation effects on BCS and BW are seldomly reported in adult dairy cows and seem to have a more consistent effect when supplemented to young ruminants (Alugongo et al, 2017).…”

Effects of live yeast on the rumen fermentation parameters and milk performance of Simmental dairy cows during the hot season

“…Bitencourt et al [31] reported that dietary NDF digestibility increased by 11.3% with the use of 10 10 cfu/day of LY and milk yield increased by 0.9 kg/day, which supports the proposition in the previous sentence. However, Ferreira et al [32] reported no significant difference in milk yield in lactating dairy cows due to yeast use. Moreover, the addition of 60 g yeast/ day to the diet of Holstein dairy cows for 84 days in midlactation during a period of heat stress did not enhance milk production or affect its components [8].…”

Short communication: Production performance and nutrient digestibility of lactating dairy cows fed diets with and without addition of a live-yeast supplement

“…In a recent study, Ferreira et al (2019) evaluated the use of a live-yeast product when feeding relatively low-forage diets containing rapidly fermentable carbohydrates to high-producing cows and found no differences in production performance or nutrient utilization. Based on the low NDF digestibility coefficients, the authors suggested that conditions for fiber digestion may not have been optimal and that the potential benefit of supplementing the live-yeast product may have been hindered by the rapid rate of passage of fiber particles attributed to the low concentration of forage NDF (14.3% forage NDF), the low proportion of forage in the diet (~45% forage), or their combination.…”

“…Two nonpelleted concentrates (control and yeast) were prepared at a commercial feed mill (Big Spring Mill Inc., Elliston, VA). The live-yeast product (BeneSacc; Global Nutritech Biotechnology, LLC, Richmond, VA), which contained 4.5 × 10 −9 cfu/g of Saccharomyces cerevisiae, was delivered through a premix that was prepared onfarm by mixing 7.5 kg of live-yeast product with 625 kg of soybean meal (Ferreira et al, 2019). The resulting premix was bagged and submitted to the feed mill, where it was included in the nonpelleted concentrate to provide 12 g of product for every 24 kg of DM.…”

“…Total-tract nutrient digestibility was estimated using 240-h undigested NDF (uNDF) as an internal marker and as described by Ferreira et al (2019). Once uNDF concentrations were determined in both TMR and fecal samples, DM and nutrient digestibilities were determined using equations [1] and [2], respectively:…”