Exploration of individual variability to better predict the nutrient requirements of gestating sows1

Abstract

Sows often receive the same feed during gestation even though their nutrient requirements vary during gestation and among sows. The objective of this study was to report the variability in nutrient requirement among sows and during gestation, in order to develop a precision feeding approach. A data set of 2,511 gestations reporting sow characteristics at insemination and their farrowing performance was used as an input for a Python model, adapted from InraPorc, predicting nutrient requirement during gestation. Total metabolizable energy (ME) requirement increased with increasing litter size, gestation weeks, and parity (30.6, 33.6, and 35.5 MJ/d for parity 1, 2, and 3 and beyond, respectively, P < 0.01). Standardized ileal digestible lysine (SID Lys) requirement per kg of diet increased from weeks 1 to 6 of gestation, remained stable from weeks 7 to 10, and increased again from week 11 until the end of gestation (P < 0.01). Average Lys requirement increased with increasing litter size (SID Lys: 3.00, 3.27, 3.50 g/kg for small, medium and large litters, P < 0.01) and decreased when parity increased (SID Lys: 3.61, 3.17, 2.84 g/kg for parity 1, 2, and 3++, P < 0.01). Standardized total tract digestible phosphorus (STTD-P) and total calcium (Total-Ca) requirements markedly increased after week 9, with litter size, and decreased when parity increased (STTD-P: 1.36 vs. 1.31 g/kg for parity 1 and parity 3 and beyond; Total-Ca: 4.28 vs. 4.10 g/kg for parity 1 and parity 3 and beyond, P < 0.01). Based on empirical cumulative distribution functions, a 4-diets strategy, varying in SID Lys and STTD-P content according to parity and gestation period (P1 from weeks 0 to 11, P2 from weeks 12 to 17), may be put forward to meet the requirements of 90% of the sows (2 diets for multiparous sows: P1: 2.8 g SID Lys/kg and 1.1 g STTD-P/kg; P2: 4.5 g SID Lys/kg and 2.3 g STTD-P/kg; and 2 diets for primiparous sows: P1: 3.4 g SID Lys/kg and 1.1g STTD-P/kg; P2: 5.0 g SID Lys/kg, 2.2 g STTD-P/kg). Better considering the high variability of sow requirement should thus make it possible to optimize their performance whilst reducing feeding cost and excretion. Feeding sows closer to their requirement may initially be achieved by grouping and feeding sows according to gestation week and parity, and ultimately by feeding sows individually using a smart feeder allowing the mixing of different feeds differing in their nutrient content.

Evaluation of a decision support system for precision feeding of gestating sows

“…As proposed by Gaillard et al (2019) , feeding the sows by parity group (primiparous and multiparous) and period (early vs. late gestation), with specific nutrient contents for each farm, might be the first step toward a better adjustment of AA supplies to requirements. In practice, this would require to group the sows according to their parity (primiparous and multiparous) and gestation stage (early and late) and use a specific diet for each group.…”

“…Nutritional model . The nutritional model included in the DSS is detailed in Gaillard et al (2019) . Three compartments are considered during gestation, i.e., body lipid, body protein, and conceptus.…”

“…There is a high variability in nutritional requirements among gestating sows, especially at the end of gestation when the requirements of amino acids ( AA ) and minerals increase and are affected by prolificacy ( Noblet et al, 1987 ; Jondreville and Dourmad, 2005 ; NRC, 2012 ). Nutritional requirements also vary regarding sow body condition at insemination ( Dourmad et al, 2008 ; NRC, 2012 ; Gaillard et al, 2019 ) and parity ( Noblet et al, 1993 ). In practice, all sows are generally fed the same standard gestation diet, and only the feeding level may be adjusted.…”

“…In practice, all sows are generally fed the same standard gestation diet, and only the feeding level may be adjusted. Most often, nutritional supplies are limiting in AA and minerals, mainly at the end of gestation for young sows, while excesses are observed at earlier stages ( Gaillard et al, 2019 ) and more frequently in older sows. New technologies have been developed to feed the group-housed sows, e.g., with automatic feeding stations that are sometimes designed to deliver several feeds.…”

“…More generally, the development of precision feeding ( PF ) gives new opportunities to better take into account, in real time, the factors influencing nutritional needs ( Brossard et al, 2016 ; Buis et al, 2016 ). In this context, models and decision support systems ( DSS ) have been developed to be integrated into automatic feeders for growing pigs ( Hauschild et al, 2012 ; Cloutier et al, 2015 ; Brossard et al, 2017 ) and more recently for sows ( Gaillard et al, 2019 ; Gauthier et al, 2019 ). These DSS are based on nutritional models that predict daily individual nutrient requirements, considering animals’ characteristics, physiological stage, and housing conditions.…”