How Immunological Castration Affects Belly Quality and Bacon Yields in Pigs08 November 2014
Generally, fresh belly characteristics in immunologically castrated barrows were similar to those of surgically castrated males and gilts, an Ohio State University study has found, however, bacon slicing yield was lower from the former group.
The fresh belly characteristics, further processed belly characteristics and commercial bacon slicing yields of immunologically castrated (IC) barrows, IC barrows fed ractopamine hydrochloride (IC+RAC), physically castrated (PC) barrows, intact males and gilts have been investigated by D.D. Boler and reported in Journal of Animal Science.
In a study with Zoetis and Sugar Creek Packing Co., researchers at Ohio State University used 188 bellies from pigs housed in single sex pens (n=48) slaughtered at 130kg ending live weight. The bellies were evaluated for flop distance, length, width, thickness and fatty acid composition.
Bellies were injected, thermally processed and sliced according to standard protocols at a USDA federally inspected facility. Complete slices were sorted by trained plant personnel. Then, sliced bellies were individually packaged to maintain anatomical orientation.
The effects of treatments were analysed as a generalised linear mixed model with pen of pigs serving as the experimental unit for all comparisons.
Belly thickness was not different (P≥0.11) in bellies from IC barrows (3.74cm) when compared with bellies from IC+RAC (3.60cm), PC barrows (3.94cm) or gilts (3.64cm); however, bellies were 0.42cm thicker (P<0.01) in IC barrows than intact males.
Iodine value was not different (P≥0.06) in bellies from IC barrows (68.26) from bellies from IC+RAC (69.78), PC barrows (67.55) or gilts (69.45). However, iodine value was 2.32 units less (P<0.01) in IC barrows than intact males.
Green weight was not different (P≥0.09) in bellies from IC barrows (4.88 kg) from bellies from IC+RAC (5.11kg), PC barrows (5.10kg) or gilts (4.79kg). However, green weight was 0.56kg greater (P<0.0001) in IC barrows than intact males.
Pump uptake and cooked yield was not different (P≥0.15) among treatment groups.
Slicing yield (as a percentage of green weight) was lower (P≤0.01) in bellies from IC barrows (93.61 per cent) than those from PC barrows (98.42 per cent) or gilts (98.19 per cent). Slicing yield was not different (P≥0.11), however, among bellies from IC barrows, IC+RAC or intact males.
Boler and co-authors concluded that overall, fresh belly characteristics of IC barrows were analogous to PC barrows and gilts but that commercial slicing yields of bacon manufactured from IC barrows were lower than both PC barrows and gilts.
Kyle J.M., B.M. Bohrer, A.L. Schroeder, R.J. Matulis and D.D. Boler. 2014. Effects of immunological castration (Improvest) on further processed belly characteristics and commercial bacon slicing yields of finishing pigs. J. Anim. Sci. 92:4223-4233. doi: 10.2527/jas.2014-7988
You can view the full report (fee payable) by clicking here.