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

Abstract

Precision feeding (PF) with the daily mixing of two diets with different lysine content (high (H) or low (L)) was previously reported for growing pigs to reduce protein intake and N excretion compared to a conventional feeding (CF) based on a single diet (C). Using a simulation approach based on farm data, the objective of the present paper was to describe and evaluate a decision support system (DSS) for the PF of gestating sows allowing the daily distribution of a tailored ration to each sow. Two datasets, one of 2511 gestations (farm A) and one of 2528 gestations (farm B), reporting sows’ characteristics at insemination and objectives at farrowing were used as inputs for a Python model. This model, mainly based on InraPorc, calculates the nutrient requirements of each sow over gestation and simulates the impact of PF in comparison to CF. Simulated diets L, H and C contained 3.0, 6.5, and 4.8 g/kg of standardized ileal digestible lysine (SID Lys) and 2.0, 3.3, and 2.5 g/kg of standardized total tract digestible phosphorus (STTD-P), respectively. The influence of farm, parity, gestation week, and their interactions, on calculated SID Lys and STTD-P requirements was analysed applying a mixed model. The calculated SID Lys and STTD-P requirements increased markedly in the last third of gestation (P < 0.01) and were higher for primiparous than for multiparous sows, unless after week 14 for STTD-P requirement. The calculated SID AA and mineral requirements were lower for farm B than farm A (respectively 2.94 vs. 3.08 g/kg for SID Lys and 1.30 vs. 1.35 g/kg for STTD-P, P < 0.01). On average, feed L represented 86% and 92% of the feed projected to be delivered by the PF strategy in farms A and B, respectively. Compared to CF, average calculated dietary SID Lys content was lowered by 27% and 32% with PF, for farms A and B, respectively, while average calculated dietary phosphorus content was lowered by 13% and 16%. The simulated proportions of sows in excess and deficient in SID Lys were reduced with PF. Compared to CF, the PF strategy allowed for a 3.6% reduction in simulated feed cost per sow during gestation, and reduced nitrogen and phosphorus intake (by 11.0% and 13.8%, respectively) and excretion (by 16.7% and 15.4%, respectively). To conclude, these simulations indicate that PF of gestating sow appears to be relevant to meet amino acid requirement while reducing feed cost, and supplies and excretion of nitrogen and phosphorus.

The effects of precisely meeting estimated daily energy and lysine requirements for gestating sows over three consecutive pregnancies on sow reproductive and lactation performance

“…Indeed, the estimated amount of excess N was not different between the PF and CON feeding programs in pregnancy 1, but in pregnancies 2 and 3, excess N was reduced for the sows that received the PF program. This supports the work of others which demonstrated that phase- or precision-feeding gestating sows can reduce both nitrogen intake and excretion, without negatively affecting sow performance ( Clowes et al, 2003a ; Gaillard et al, 2020 ). In addition, in the current study, excess P was greater for sows that received the PF vs. CON program, despite similar retention efficiencies that were comparable to those reported by others (e.g., van der Peet-Schwering et al, 1999 ; Buis, 2016 ).…”

“…The LP and HP diets contained the same P contents and since the PF program provided a greater feed allowance to sows, P intake and excretion were also greater. If P was provided more precisely (i.e., scaled with Lys in the HP and LP diets or by including a third diet to the blend), then there is also further opportunity to reduce feed costs as well as P excretion to the environment ( Gaillard et al, 2020 ). Finally, the cost of the PF program will also be largely influenced by commodity prices and ingredient selection.…”

Precision feeding of lactating sows: implementation and evaluation of a decision support system in farm conditions

“…These values may be compared to the 38% reduction in N and P excretion found in growing pigs ( Pomar et al, 2011 ). For a similar approach in gestating sows, Gaillard et al (2020) found a reduction in N and P excretion of 16.7% and 15.4%, respectively. The present study also reports an 11.7% reduction in feeding cost, which could confirm the economic benefits of precision feeding strategies reported for growing pigs (10.5%, Pomar et al, 2011 ) and gestating sows (3.6%, Gaillard et al, 2020 ).…”

A Novel Estimation of Unobserved Pig Growth Traits for the Purposes of Precision Feeding Methods

“…It was assumed that the current practise of blending high-nutrient and low-nutrient basal feeds would be largely compatible with such adjustments, although this is not fully guaranteed. To ensure universality, blending three basal feeds is likely to be needed ( 90 ).…”