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Inclusion of a hydrolyzed yeast product in grow/finish pig diets reduced mortality
CELMANAX SCP is an enzymatically hydrolyzed yeast product containing yeast culture and other complex carbohydrates. A performance study (142 d) was conducted to assess dietary inclusion level of CELMANAX SCP in grow/finish pig diets based on growth performance, loadout variability (i.e. BW variation at first cut) and carcass characteristics at slaughter (loin and backfat depth, lean percent) . A total of 1344 grower pigs (30.3 ± 0.6 kg BW) were randomly divided among 64 pens (n = 16 pens/treatment) in a commercial wean-to-finish facility. Pens were assigned to one of 4 dietary levels of CELMANAX SCP (0.0, 0.01, 0.02, and 0.04%) in a 5-phase feeding program with phase changes occurring on d 28, 57, 84 and 114. Tylan was included at 40 g/ton in Phase 1 – 4 and the first 28.4 kg feed/pig in Phase 5. For the remainder of Phase 5, Tylan inclusion was 100 g/ton. Pigs were weighed on a pen basis at the start of each phase as well as individually on d 0 and d 114, which corresponded with first cut. Pens were observed daily and any deaths or removals were recorded. Data were analyzed with the Proc MIXED procedure in SAS with pen as the experimental unit. Differences among treatments was based on Tukey’s adjusted means test. There were no differences in pig performance within each phase, across the overall experiment, or for carcass characteristics of all pigs marketed. Body weight at first pull was 123.2 ± 1.3 kg and overall performance (gain, feed disappearance, and gain:feed) was 0.85 ± 0.01 kg/d, 2.40 ± 0.05 kg/d, and 0.34 ± 0.01, respectively. During the trial, there were 2 disease outbreaks (PRRS positive test in Phase 2 and ileitis incident in Phase 4) where an increase in mortality occurred. However, during both periods, pigs fed 0.02% CELMANAX SCP recorded the lowest mortality resulting in a lower (P = 0.02; Chi squared test) overall mortality at 2.8% compared to 7.5, 6.7, and 4.3% in pigs fed 0.0, 0.01, and 0.04% CELMANAX SCP, respectively. This resulted in a net return over feed cost ($/pig started) of $55.82, 56.01, 59.64, 57.20 in pigs fed 0.0, 0.01, 0.02, and 0.04% CELMANAX SCP, respectively; a $3.82 gain in net return over feed cost in pigs fed 0.02% CELMANAX SCP. Dietary inclusion of CELMANAX SCP had no impact on growth performance or loadout variability but reduced overall mortality resulting in improvement in net return.
Keywords: growth performance, grow/finish pigs, hydrolyzed yeast, mortality