Effect of Phase Feeding, Space Allowance and Mixing on Productive Performance of Grower-Finisher Pigs

This study investigates the effects of space allowance (SA), mixing and phase feeding (PF) on performance of grower-finisher pigs. Three trials (T) were conducted. In T1 and T2, 345 pigs/trial were moved to finisher stage at 11 weeks of age and assigned to two SAs: 0.96 (n = 15 pens; 10 pigs/pen) and 0.78 (n = 15; 13 pigs/pen) m²/pig. Mixing was applied to 5 pens of each SA leading to a 2 × 2 factorial arrangement (SA × Mixing). For PF, 2 diets with 0.95 and 0.82 g SID Lys/MJ NE were applied to 5 pens of each SA (not mixed) leading to another 2 × 2 factorial arrangement (SA × PF). In T3, 230 pigs were moved to the grower-finisher stage at 11 weeks of age, mixed, and assigned to 4 treatments (SA × PF; n = 5 pens). Data were analyzed using general linear mixed models. SA did not affect performance (p > 0.05). Non-mixed pigs were 5.40 (T1) and 5.25 (T2) kg heavier than mixed pigs at 21 weeks of age (p < 0.001). PF reduced performance of pigs by 3.45 (T1) and 4.05 (T2) kg at 21 weeks of age (p < 0.001). In conclusion, mixing and reducing SID Lys:NE ratio from 0.95 to 0.82 g/MJ at 15-16 weeks of age, have a more marked impact on performance than reducing SA from 0.96 to 0.78 m²/pig.

Phase-feeding strategies based on lysine specifications for grow-finish pigs1

Four experiments were conducted using 1,100 to 1,188 pigs each (PIC 359 × 1,050) from ~27 to 127 kg BW to evaluate phase-feeding strategies based on Lys specifications and number of dietary phases for grow-finish pigs. Different phase-feeding strategies were used in each experiment with treatments consisting of a combination of 3 Lys specifications at 96%, 98%, or 100% of estimated requirement for growth rate and 4 phase-feeding strategies with 1, 2, 3, or 4 dietary phases. A single-phase-feeding strategy reduced (P < 0.05) overall growth performance, live BW, and HCW whether Lys specifications were at 98% or 100% of estimated requirements compared with multi-phase-feeding strategies. Lysine specifications at 96% of estimated requirements in a 4-phase-feeding strategy reduced (P < 0.05) overall growth performance compared with feeding strategies with Lys at 100% of estimated requirements, unless Lys specifications were increased to 100% of estimated requirements in the late finishing phase. Lysine specifications at 98% or 100% of estimated requirements in a 2-, 3- or 4-phase feeding strategy led to similar (P < 0.05) overall growth rate, live BW, and HCW of grow-finish pigs. Pigs fed 1, 2, or 3-phase feeding strategies or feeding strategies with Lys below the requirements in early grow finish had improved growth performance driven by improved feed efficiency in the period following low Lys levels, indicating the occurrence of compensatory growth. For carcass characteristics, there was no evidence (P > 0.10) for differences in carcass yield, back fat, loin depth, or lean percentage across feeding strategies in any of the experiments. In conclusion, phase-feeding strategies provide performance advantages over feeding a single dietary phase throughout the grow-finish period. Simplification of feeding strategies from 4 to 3 or 2 dietary phases with Lys specifications at 98% to 100% of estimated requirements for growth rate does not compromise overall growth performance and carcass characteristics of grow-finish pigs from 27 to 127 kg BW. Although, using feeding programs with fewer dietary phases and Lys set slightly below the requirements can compromise growth performance if initial BW and feed intake in the grow-finish period are lower than expected.

pH: a promising indicator of feed waste in piggery effluent?

Feed waste in pork production sheds can amount to substantial economic losses. No simple methods exist to quantify this waste, which commonly ends up in the effluent stream. Monitoring piggery effluent might offer producers a practical alert solution for feed waste losses. We investigated piggery effluent pH as a potential marker of feed waste, given that most feed substrates and breakdown products are acidic whereas effluent is alkaline. To explore this prospective relationship, we constructed simulated effluent streams comprising faeces, urine and feed. These waste components were acquired from a commercial batch grower shed, at four different times over the 12-week growth cycle. In laboratory settings (25°C) we used the collected wastes to simulate the two stages of typical flushing piggery effluent systems: (1) Faeces + urine + feed waste accumulation in flushing channels, and (2) flush water mixing with these wastes in an effluent collection sump. We repeated the exercise for a one-off sampling event at a sow facility. For all events, at the grower and sow facility, the pH of the simulated effluents yielded exponentially decreasing relationships with increasing feed waste level (P &lt; 0.05). For the grower facility we applied each of the four laboratory-derived relationships to the farm’s sump effluent pH, which was measured during each of these sampling events. The predicted feed waste levels were commensurate with estimates of feed waste for the same facility derived from alternative, time intensive approaches reported in other studies. Further work is needed to transition the promising results uncovered here into an alert system to help farmers improve profitability and minimise waste.