Effects of dietary valine:lysine ratios on lactation performance of primiparous sows nursing large litters

Abstract

-Eighteen sows were used to determine the effect of dietary valine:lysine (val:lys) ratios on lactation performance in primiparous sows and litter performance. Sows, raised in individual pens, were randomly assigned to 1 of 2 experimental diets containing different standardized ileal digestibility (SID) val:lys ratios of 0.80 or 0.85. Corn-soybeanwheat-based diets were formulated to achieve the dietary treatments (0.86% or 0.87% SID lysine, and 0.69% or 0.74% SID valine). All diets were formulated to have 3,450 kcal metabolizable energy/kg. The experiment lasted 24 d. At the end of the experiment, body weight loss, backfat loss, average daily feed intake, and days to return to estrus were not affected by the different dietary val:lys ratios. Furthermore, no difference was observed in number of piglets weaned, piglet survival rate, weaning litter weight, litter weight gain, piglet weaning body weight, piglet gain, or piglet daily gain between the two dietary treatments. However, increasing the dietary val:lys ratio increased arginine and threonine concentrations in the milk. Dietary val:lys ratios of 0.80 and 0.85 do not affect the lactation performance of primiparous sows nursing large litters, but increase the arginine and threonine concentrations in milk as the dietary val:lys ratio are increased.

A review of branched-chain amino acids in lactation diets on sow and litter growth performance

“…In summary, some studies that evaluated Val:Lys requirement for lactating sows concluded that total Val concentrations above 120% of Lys optimized litter weaning weights and average daily gain ( Richert et al, 1996 ; 1997a , b; Moser et al, 2000 ; Xu et al, 2017 ). In contrast, others determined that increasing SID Val:Lys ratios from 55% to 136% did not improve piglet growth performance ( Carter et al, 2000 ; Gaines et al, 2006 ; Devi et al, 2015 ; Craig et al, 2016 ; Strathe et al, 2016 ; Greiner et al, 2019 ). Within some these studies, it is important to note that dietary BCAA content, namely, Leu:Lys ratios, was not controlled across the treatments evaluated ( Moser et al, 2000 ; Gaines et al, 2006 ; Craig et al, 2016 ).…”

“…Within the last few years, re-evaluation of Val:Lys ratios in lactation diets with modern high producing females also yielded inconsistent responses in sow reproductive performance and litter growth rates when dietary SID Val:Lys ratios ranged from 55% to 105% ( Devi et al, 2015 ; Strathe et al, 2016 ; Xu et al, 2017 ; Greiner et al, 2019 ). Xu et al (2017) observed linear improvements in litter ADG when increasing SID Val:Lys ratios from 74% to 133% across a small sample size of sows ( n = 24 sows).…”