To test the hypothesis that poor maternal nutrition during gestation would alter offspring muscle shear force and adipogenesis, fibrogenesis, and myogenesis mRNA expression, Dorset ewes (n=46) pregnant with twins were fed 100%, 60% or 140% of NRC requirements from d30±0.02 of gestation until parturition. Male offspring from CON (n=12), OVER (n=13), and RES (n=21) ewes were euthanized at d284±1.82 and longissimus muscle (LM) was harvested for shear force and gene expression. Vacuum-sealed LM steaks were aged for 10 d postmortem (4℃) and tenderness was measured using Warner-Bratzler shear force (WBSF) methodology. RNA was isolated from the LM to quantify mRNA expression of genes related to adipogenesis (fatty acid binding protein 4, CCAAT/enhancer-binding protein α, and peroxisome proliferator-activated receptor γ), fibrogenesis [collagen A1A (COLA1A), COL3A1, cystain-c, fibronectin (FN1), and lysyl oxidase (LOX)], and myogenesis [bone-morphogenic protein (BMP)-1, myostatin, myogenin, and myogenic differentiation 1). The WBSF decreased by 21% and 18% in OVER relative to CON (P=0.01) and RES (P=0.03), respectively, but CON and RES were not different (P=0.60). Expression of BMP1 was 1.5- and 1.8-fold greater in RES than OVER and CON, respectively (P≤0.03). Expression of FN1 was 1.6-fold greater in RES than OVER (P=0.02). Expression of COL1A1 was 2.2-fold greater in RES than CON (P=0.05) and was 1.6-fold greater in RES than OVER (P=0.07). Expression of LOX was decreased 37% in OVER compared with CON (P=0.04) and decreased 21% compared with RES (P=0.08). An effect of diet was not observed for other genes (P≥0.18). In summary, RES offspring had greater expression of genes related to fibrogenesis, but no observed difference in tenderness relative to CON. Over-feeding during gestation increased meat tenderness, which may be due to reduced collagen cross-linking by LOX.

The objective was to collect and quantify three-axis acceleration data from locations within commercial transport trailers shipping market weight pigs during summer. Two trucks and straight-deck trailers, owned and operated by a single producer, were observed during two loads per day for five consecutive days. Three-axis accelerometers were placed under top and bottom deck floors in the center of the fore, center, and aft compartments. Z-axis and combined x- and y-axis data were processed to generate root-mean-square (RMS) values and vibration dose values (VDV) during loading, trailer movement, and unloading. At all periods of the trip and both sets of axis data, there were no Deck × Area interactions (P > 0.11) for RMS and VDV values. During loading and movement, the bottom deck had greater z-axis RMS and VDV values than the top deck (P < 0.01), but there was no difference (P = 0.07) during unloading. There were no Area effects for z-axis RMS and VDV values during all time periods (P > 0.06). During all periods, the top deck had greater x,y-axis RMS values than the bottom deck (P < 0.02). During loading and movement, the bottom deck had greater x,y-axis VDV values than the top deck (P < 0.03), but there was no difference (P = 0.52) during unloading. There were no Area effects for x,y-axis RMS and VDV values during all time periods (P > 0.07). Individual trip RMS and VDV values were compared with exposure action values (EAV; injury possible) and exposure limit values (ELV; injury likely). At all parts of the trip, trailer RMS and VDV violated between 51% and 99% EAV and ELV thresholds. These data indicate top and bottom decks vibrate differently and pigs experience vibrations that may contribute to fatigued pig syndrome or the non-ambulatory condition.