Effects of feeding increasing levels of a proprietary yeast blend on sow reproductive performance over a two-parity period

Abstract Text: This study evaluated the effects of feeding increasing levels of yeast blend (Evosure^TM) on sow reproductive performance over a two-parity period at a commercial sow facility designed and staffed to conduct research. A total of 401 sows (PIC 1050; parity 1 to 9) randomly selected from the commercial herd were allotted randomly to one of four dietary treatments containing 0 (CON), 0.25, 0.375 or 0.50 g/kg yeast blend in both gestation and lactation diets resulting in approximately 100 sows per treatment. Experimental diets were fed from day 3 of gestation until weaning over two successive parities with sows remaining on the same treatment. Analysis of variance was conducted to analyze the data using the MIXED procedure of SAS. Parity was used as covariate in the model for all parameters if it was significant (P < 0.05). Weaning age was used as covariate for analyzing pig weaning weight. Orthogonal polynomial contrasts were used to determine the linear effect of dietary yeast blend. Feeding increasing levels of yeast blend linearly increased litter birth weight (P < 0.05) and pig birth weight (P < 0.08) in both parity periods. Specifically, feeding yeast blend at 0.50 g/kg resulted in 8.2% greater litter birth weight (18.3 vs. 16.9 kg, P = 0.003), 8.0% greater pig birth weight (1.32 vs. 1.22 kg, P < 0.001) in Parity 1 period, and 4.4% greater pig birth weight (1.31 vs. 1.26 kg, P = 0.004) in Parity 2 period relative to feeding CON. In addition, percentage of small pigs at birth (BW≤1.13 kg) was also significantly reduced (P < 0.003 ) in sows fed 0.50 g/kg yeast blend in both parity periods. Moreover, percentage of pre-weaning mortality was significantly lower in sows fed 0.50 g/kg yeast blend in Parity 2 period (10.8 vs. 14.4%, P = 0.03). Furthermore, feeding increasing levels of yeast blend linearly increased pig weaning weight in both parity periods (P < 0.05). Compared to sows fed CON, sows fed 0.50 g/kg yeast blend showed 4.1% greater pig weaning weight in Parity 1 period (5.71 vs. 5.49 kg, P = 0.03), and 5.6% greater pig weaning weight in Parity 2 period (4.83 vs. 4.57 kg, P= 0.01). Total born, born alive, sow BW change during lactation and wean-estrus intervals were not affected by dietary treatments in any parity period. These results indicate that feeding a proprietary yeast blend to sows in gestation and lactation will positively affect pig birth weight, weaning weight and pre-weaning mortality, and these effects seem to be consistent over a two-parity period.

Keywords: reproductive performance, sows, yeast blend