Determination of protein and amino acid requirements of lactating sows using a population-based factorial approach

Abstract

Determination of appropriate nutritional requirements is essential to optimize the productivity and longevity of lactating sows. The current recommendations for requirements do not consider the large variation between animals. Therefore, the aim of this study was to determine the amino acid recommendations for lactating sows using a stochastic modeling approach that integrates population variation and uncertainty of key parameters into establishing nutritional recommendations for lactating sows. The requirement for individual sows was calculated using a factorial approach by adding the requirement for maintenance and milk. The energy balance of the sows was either negative or zero depending on feed intake being a limiting factor. Some parameters in the model were sow-specific and others were population-specific, depending on state of knowledge. Each simulation was for 1000 sows repeated 100 times using Monte Carlo simulation techniques. BW, back fat thickness of the sow, litter size (LS), average litter gain (LG), dietary energy density and feed intake were inputs to the model. The model was tested using results from the literature, and the values were all within ±1 s.d. of the estimated requirements. Simulations were made for a group of low-(LS = 10 (s.d. = 1), LG = 2 kg/day (s.d. = 0.6)), medium-(LS = 12 (s.d. = 1), LG = 2.5 kg/day (s.d. = 0.6)) and high-producing (LS = 14 (s.d. = 1), LG = 3.5 kg/day (s.d. = 0.6)) sows, where the average requirement was the result. In another simulation, the requirements were estimated for each week of lactation. The results were given as the median and s.d. The average daily standardized ileal digestible (SID) protein and lysine requirements for low-, medium-and high-producing sows were 623 (CV = 2.5%) and 45.1 (CV = 4.8%); 765 (CV = 4.9%) and 54.7 (CV = 7.0%); and 996 (CV = 8.5%) and 70.8 g/day (CV = 9.6%), respectively. The SID protein and lysine requirements were lowest at week 1, intermediate at week 2 and 4 and the highest at week 3 of lactation. The model is a valuable tool to develop new feeding strategies by taking into account the variable requirement between groups of sows and changes during lactation. The inclusion of between-sow variation gives information on safety margins when developing new dietary recommendations of amino acids and protein for lactating sows.

Increased dietary protein for lactating sows affects body composition, blood metabolites and milk production

“…Based on the average feed intake and the SID CP concentration of 135 g/kg (Strathe et al, 2017a), the daily requirement for optimal litter ADG was estimated to be 850 g SID CP/day. The 850 g SID CP/day found in the current study was considerably higher than the 700 g SID CP/day estimated in the NRC model (National Research Council, 2012) and slightly lower than the 880 g SID CP/day (±70 g/day) estimated in the requirement model by Strathe et al (2015). The largest difference between the two models is the equation used to determine milk production: the one used by NRC (2012) is based on weigh-suckle-weigh data, which underestimates milk yield and thereby estimates a lower requirement (Hansen et al, 2012).…”

Sows with high milk production had both a high feed intake and high body mobilization

“…The ADFI in individual weeks of lactation also had a positive correlation to the ADG of the litter, especially in weeks 3 and 4 even though the effect of the total ADFI for the entire lactation period was more pronounced. This makes sense because around days 16 to 18 postpartum the sows reach their maximum milk production and therefore has the highest energy and nutrient requirement (Strathe et al, 2015); Koketsu et al, (1997) also investigated the effect of ADFI in individual weeks of lactation on litter weight at weaning; and similarly found that ADFI of weeks 2 and 3 had a higher impact than ADFI in week 1. It is nevertheless important to mention that the sows in the current study did not have ad libitum access to feed, but an upper limit was set on the feed allowance.…”

Arginine for gestating sows and foetal development: A systematic review

“…However, studies evaluating the effects of arginine supplementation for gestating sows on the intrauterine development of the litter have conflicting results (Li et al., ; Novak et al., ; Quesnel et al., ). It is known that, in addition to dietary levels of arginine, lysine, and protein (Li et al., ), gestational age for supplementation (Li et al., ), the parity of the sow (Li et al., ), the litter size (Strathe, Strathe, Theil, Hansen, & Kebreab, ), and environmental conditions (Laspiur & Trottier, ) may also influence the results. To date, there is no consensus about the best way to use this amino acid in diets of gestating sows.…”