Relationship of knob morphometric analysis with production performance and meat quality in Yangzhou goose ( Anser cygnoides)

To evaluate factors affecting pork color, the gluteus medius (GM), longissimus lumborumetthoracis (LT), semimembranosus (SM), biceps femoris (BF), and triceps brachii (TRI) muscles from pork carcasses of varying ultimate pHs were allowed to bloom for 30 min. L*, a*, and b* values, hue angle, chroma and visual color were determined. Color was evaluated using HunterLab (illuminants A, C, D(65) and F) and Minolta (illuminants C and D(65)) Spectrocolorimeters. LT had the highest L* value (51.31; TR=39.93) and hue angle (59.36; TR=46.94), and the lowest a* (7.52; TR=12.88) value. L* value was unaffected by bloom time; hue angle stabilized after 5 min, a* and b* values after 10 min and chroma after 20 min. Using the Minolta/illuminant D65, visual color best correlated with b* and L* values (r=-0.94 and -0.89) of LT. Using the Hunter/illuminant C, visual color correlated with L* value of LT, GM, BF and SM (r >-0.90 for each). Overall, the instrumental measure that best related to visual color was L* value.

An experiment was conducted using a total of 540 one-day-old Yangzhou geese to study the effect of rearing system on growth performance, carcass traits, and meat quality of male and female Yangzhou geese. The birds were divided into homogeneous groups according to initial BW and sex. The male and female geese were raised in separate pens under 5 different treatments, with 3 replicate pens of 18 male or 18 female geese per pen for each treatment. This experiment included 2 stages, with geese at 1 to 28 d of age (the first stage) and 29 to 70 d of age (the second stage). The 5 different treatments were 1) system A (geese raised on a wire floor), 2) system B (geese raised on the floor), 3) system C (geese raised on the floor and transferred to to a wire floor), 4) system D (geese raised on a wire floor and transferred to the floor), and 5) system E (geese raised on the floor and transferred to a free range). Results showed that feed conversion rate, BW, and BW gain were significantly affected by rearing system and sex (P 0.05). Differences between sexes, but not rearing systems, were observed for only breast yield, thigh yield, and liver yield (P 0.05) by the rearing system, and only water, protein, and pH of the meat were affected by sex (P < 0.05). This study indicates that rearing system A, in which Yangzhou geese were raised on a wire floor, improved growth performance but had little effect on meat quality, implying that the use of rearing system A, using a wire floor, might be feasible and effective for Yangzhou geese.