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Abstract Two experiments evaluated the effects of precision feeding lactating sows. In both experiments, sows were blocked by parity and allotted to treatment on d 2 of lactation. The first experiment included a total of 95 mixed parity sows and litters. Treatments included a control, NRC (2012), or INRA (2009) treatment curve. Sows on the NRC or INRA treatment curves received a blend of a low (0.25% SID Lys) and high (1.10% SID Lys) Lys diet using the Gestal Quattro Opti Feeder (Jyga Technologies, St-Lambert-de-Lauzon, Quebec, Canada) to target specific SID Lys intake/d based on parity and litter size according to NRC and INRA models. Control sows received only the high Lys diet. Blend of the high and low Lys diets were adjusted every 2 d based on actual Lys intake to more closely meet target Lys intake (NRC and INRA curves). Control sows had greater (P 0.05) average Lys intake (76.7 g/d) compared with sows fed either NRC (53.1 g/d) or INRA (42.8 g/d) curves (Table). Pigs from sows fed the high Lys diet had greater (P 0.05) body weight at weaning and average daily gain (ADG) compared with pigs from sows fed INRA treatment, with NRC curve fed sows intermediate. Nitrogen excretion, estimated from NRC equations, was greatest (P 0.05) in sows fed the high Lys diet, followed by sows fed the NRC curve, and INRA curve sows the least. In Exp. 2, 56 mixed parity sows and litters were used. Treatments included a control where sows were provided a high Lys (1.10% SID Lys) diet and two treatments where sows were fed either a static or dynamic blend of a low (0.40 % SID Lys) and high Lys diet to target a specific SID Lys intake/d based on parity and litter size. The dynamic curve blend was adjusted based on actual Lys intake every 2 d to reach target Lys intake while the static curve was not adjusted. Lysine intake curves were based on the NRC (2012), but targets were increased by 20% to reach an average Lys intake of 60 g/d across parities. Control sows had greater Lys intake (P 0.05; 77.7 g/d) compared with sows fed the blend curves, with no differences between the two blend curves (P 0.05; 60.1 vs. 59.7 g/d). There were no differences (P 0.05) observed in litter size, piglet or litter weight at weaning, or ADG. Estimated nitrogen excretion was greater (P 0.05) for sows on the control diet compared with both blend curves. These data would suggest that 60 g/d of SID Lys is sufficient to maximize litter weight gain for litter sizes of 13.5 weaned piglets. Overall, feed blending can be used to decrease N excretion while achieving similar performance compared with feeding a standard high Lys diet.
Spinler et al. (Wed,) studied this question.