Effects of varying the dietary valine : lysine ratios on the performance of lactating sows and their litters

A total of 18 sows with an average body weight (BW) of 211.6 kg (within 24 h after farrowing) were used for a 5-week experiment to determine the effects of the dietary valine : lysine (V : L) ratios on the performance and fecal score in lactating sows and litters. Sows were raised in individual pens and assigned to one of three experimental diets consisting of different V : L ratios (0.83, 0.85, and 0.88%). Sows BW was improved with the 0.85% V : L ratio compared to the 0.83 and 0.88%. However, no significant difference was observed for BW loss, average daily feed intake, back fat thickness and days to return to estrus among the three treatment groups during the experiment period. Furthermore, the growth performance of the piglets, the weaning weight, was improved in the group receiving the diet with the 0.85% V : L ratio compared to the 0.83 and 0.88%. Moreover, the average daily gain of the piglets was increased when the V : L ratio was 0.88% compared to 0.83 and 0.85%. The fecal score of the sows was better (p > 0.05) when the V : L ratio was 0.85% compared to the V : L ratio of 0.83%. In the piglets, the V : L ratios 0.88 and 0.85% had a better fecal score compared to the V : L ratio of 0.83% at day 14. In conclusion, the V : L ratio had no effect on the gut microflora shown by the fecal scores of the sows during lactation.