Effects of increased energy and amino acid intake in late gestation on reproductive performance, milk composition, metabolic, and redox status of sows1

The objective of this study was to determine the effects of increased AA and energy intake during late gestation on reproductive performance, milk composition, and metabolic and redox status of sows. A total of 118 Yorkshire sows (third through sixth parity) were randomly assigned to dietary treatments from day 90 of gestation until farrowing. Dietary treatments consisted of combinations of 2 standardized ileal digestible (SID) AA levels [14.7 or 20.6 g/d SID Lys, SID Lys and other AA met or exceeded the NRC (2012) recommendations] and 2 energy levels (28.24 or 33.78 MJ/d intake of NE) in a 2 × 2 factorial design. After parturition, all sows were fed a standard lactation diet. Blood samples were collected and analyzed for parameters on metabolism, redox status, and amino acid profile. The data were analyzed using the generalized linear mixed models to reveal the impact of dietary levels of energy, AA, and their interaction. Sows with increased intake of AA had greater BW gain (P < 0.01) during late gestation. Furthermore, the BW loss during lactation was increased in sows with increasing intake of energy (P < 0.05) or AA (P < 0.05). Sows fed high energy had higher total litter birth weights (20.2 kg vs. 18.4 kg, P < 0.05) and shorter duration of farrowing (261 min vs. 215 min, P < 0.05), compared with those fed low energy, which likely was due to higher (P < 0.05) plasma glucose and lower (P < 0.05) plasma lactate prior to parturition. High AA intake in late gestation increased the ADG of piglets during the following lactation (P < 0.05), and increased the concentrations of plasma urea, and the following AA: Lys, Met, Thr, Val, Ile, Leu, Phe, Asp, Ser, and Arg at farrowing (P < 0.05). In conclusion, the increased intake of energy increased total litter weight of newborns and shortened the farrowing duration, which likely was due to improved energy status at farrowing. Furthermore, sows with increased intake of AA led to higher growth rate of piglets during the following lactation, accompanying with the increasing levels of plasma urea and amino acids. Therefore, the higher energy intake in late gestation appeared to improve litter weight and farrowing duration, while higher AA intake may have positive effect on piglets performance in lactation.