Effect of a lysine depletion–repletionprotocol on the compensatory growth of growing-finishing pigs
L. Cloutier, M.-P. Létourneau-Montminy,J. F. Bernier, J. Pomar and C. Pomar
The effect of Lys restriction followedby a repletion period on the performance of growing pigs was studied during 3feeding phases, each lasting 28 d. A total of 47 castrated male pigs (GPerformer 8.0 × Fertilis 25 pigs; Genetiporc Inc., Saint-Bernard, QC, Canada;initial BW of 26.7 ± 2.7 kg) were given each d 70% or 100% of their Lys requirementsaccording to 1 of the following 5 sequences: 70–70–70, 70–70–100, 70–100–70,70–100–100, or 100–100–100 (for each sequence, numbers indicate the Lys supplypercentage in phase 1, 2, and 3, respectively). Individual Lys requirementswere estimated daily on the basis of each pig’s actual BW and feed intake andBW gain patterns obtained by regression using each pig’s historical data. Atthe end of phase 1, the pigs given 100% of their Lys requirements had higherADFI (P = 0.01), ADG (P < 0.01), and average daily protein deposition (P< 0.01) than did the pigs given 70% of their requirements. Similar resultswere observed during phases 2 and 3. At the end of phase 2, the pigs in the70–100 sequence did not display any compensatory response, given that theirADFI, ADG, and average daily protein deposition did not differ from those ofthe pigs in the 100–100 sequence. Similar results were observed during phase 3.Although no compensatory growth was observed during the growing phases, thefact that the pigs in the 70–100–100 treatment were able to catch up in termsof BW and body protein mass to the pigs in the 100–100–100 sequence couldindicate that a small degree of compensation did occur; these research resultscannot ascertain that any compensatory growth occurred.
