Performance of near-infrared (NIR) spectroscopy in pork shoulder as a predictor for pork belly softness

Pork belly quality indicators are economically relevant in the pork industry. Near-infrared (NIR) spectroscopy of the pork shoulder outer subcutaneous fat layer, belly flop angle and subjective softness scores of the pork belly were measured (n=144) to determine the accuracy of pork shoulder NIR spectroscopy as a predictor of pork belly softness. The NIR spectra hot carcass estimates explained over 80.0% variability in pork belly softness (80.5–90.8%), with low prediction error, suggesting that NIR spectroscopy measured in the pork shoulder is an efficient and accurate indicator of pork belly softness to classify pork bellies for specific market demands

Effect of porcine reproductive and respiratory syndrome virus infection and soy isoflavone supplementation on carcass cutability and meat quality of pigs

The objective was to evaluate the effects of porcine reproductive and respiratory syndrome virus (PRRSV) infection and dietary soy isoflavone (ISF) supplementation on carcass cutability and meat quality of commercial pigs. Barrows (21 d of age) were randomly allotted to experimental treatments that were maintained throughout the study: noninfected pigs received an ISF-devoid control diet (CON, n = 22) and infected pigs received either the control diet (PRRSV–CON, n = 20) or that supplemented with total ISF in excess of 1,500 mg/kg (PRRSV–ISF, n = 25). Pigs were penned by treatment, with six pigs within a pen. Following a 7-d adaptation, weanling pigs were inoculated once intranasally with either a sham-control (phosphate buffered saline [PBS]) or live PRRSV (1 × 105 tissue culture infective dose [TCID]50/mL, strain NADC20). Pigs were maintained on experimental diets for 166 d after inoculation and then slaughtered (192 or 194 d of age; approximately 120 kg body weight [BW]). At 1-d postmortem, left sides were separated between the 10th and 11th rib for the determination of loin eye area (LEA), backfat (BF) thickness, and loin quality (ultimate pH, instrumental color, drip loss, visual color, marbling, and firmness). Loin chops were aged 14 d postmortem prior to Warner–Bratzler shear force (WBSF) determination. Belly width, length, thickness, and flop distance were determined. Data were analyzed as a one-way ANOVA with pig as the experimental unit. Carcass yield, LEA, BF, and estimated lean percentage did not differ (P > 0.26) among treatments. Loins from CON pigs had increased ultimate pH (P = 0.01), reduced L* scores (P = 0.005) coupled with darker visual color scores (P = 0.004), were firmer (P < 0.0001), and exhibited reduced drip loss (P = 0.01) compared with PRRSV–CON and PRRSV–ISF pigs. However, WBSF did not differ (P = 0.51) among treatments after 14 d of aging. Bellies from CON pigs were more firm compared with bellies from PRRSV–CON and ISF pigs (P < 0.01). These data suggest PRRSV infection did not alter carcass characteristics but may have marginally reduced loin and belly quality. Supplementation with dietary soy isoflavones did nothing to mitigate the detrimental effects of PRRSV infection.

74 Effects of dietary soy isoflavone supplementation on carcass cutability and meat quality of pigs infected with porcine reproductive and respiratory virus

The objective was to evaluate the effects of porcine respiratory and reproductive syndrome virus (PRRSV) infection and dietary soy isoflavone supplementation on carcass cutability and meat quality of commercial pigs. Barrows were randomly allotted to experimental treatments that were maintained throughout the study: non-infected pigs received an isoflavone-devoid control diet (NC, n = 22), and infected pigs received either the control diet (PC, n = 20) or that supplemented with total ISF in excess of 1,600 mg/kg (ISF, n = 25). Following a 7-d adaptation, weanling pigs were inoculated intranasally with either a sham-control (PBS) or live PRRSV (1×105 TCID50/mL, strain NADC20). At 1 d postmortem (192–194 days of age; approximately 120kg BW), left sides were separated between the 10th and 11th rib for determination of loin eye area (LEA), backfat thickness (BF), and loin quality (ultimate pH, instrumental color, drip loss, visual color, marbling, and firmness). Loin chops were aged 14 d postmortem prior to Warner-Bratzler shear force (WBSF) determination. Belly width, length, thickness, and flop distance were determined. Data were analyzed as a one-way ANOVA with a model including effects of PRRSV status and dietary treatment, and also with single-df pre-determined contrasts to compare NC and PC (infection status) and PC and ISF (ISF effect within infected pigs). Carcass yield, LEA, BF, and estimated lean percentage did not differ (P > 0.26) among treatments. Loins from NC pigs had increased ultimate pH (P = 0.01), reduced L* scores (P = 0.005) coupled with darker visual color scores (P = 0.004), were firmer (P < 0.0001), and reduced drip loss (P = 0.01) compared with PC and ISF pigs. However, WBSF did not differ (P = 0.51) among treatments after 14 d of aging. Bellies from NC pigs were more firm compared with bellies from PC and ISF pigs (P < 0.01). These data suggest PRRSV infection and soy isoflavone supplementation do not alter carcass characteristics but may marginally reduce loin and belly quality.