Effect of free-range days on a local chicken breed: Growth performance, carcass yield, meat quality, and lymphoid organ index

Abstract

An experiment was conducted to evaluate the effect of free-range days on growth performance, carcass yield, meat quality, and lymphoid organ index of a local chicken breed. In total, 1,000 one-day-old male Suqin yellow chickens were raised for 21 d. On d 21, 720 birds with similar BW (536 ± 36 g) were selected and randomly assigned to free-range treatment at 21, 28, 35, and 42 d of age (assigned to free-range treatment for 21, 14, 7, and 0 d, respectively). Each treatment was represented by 5 replicates (pens) containing 36 birds (180 birds per treatment). All the birds were raised in indoor floor pens measuring 1.42 × 1.42 m (2 m(2), 18 birds/m(2)) in conventional poultry research houses before free-range treatment. In the free-range treatment, the chickens were raised in indoor floor houses measuring 3 × 5 m (15 m(2), 2.4 birds/m(2)). In addition, they also had an outdoor free-range paddock measuring 3 × 8 m (24 m(2), 1.5 birds/m(2)). The BW of birds after being assigned to free-range treatment for 7 d decreased significantly compared with that in the conventional treatment (P < 0.05). However, there was no effect of the free-range days on the BW at 42 d of age (P > 0.05). The daily weight gain, feed per gain, daily feed intake, and mortality from 21 to 42 d of age were unaffected by free-range days (P > 0.05). At 42 d of age, the breast yield increased linearly with increasing free-range days (P < 0.05), whereas the thigh, leg, thigh bone, and foot yields decreased linearly (P < 0.05). The lung yield showed a significant increasing and then decreasing quadratic response to increasing free-range days (P < 0.05). The water-holding capacity of the thigh muscle decreased linearly with increasing free-range days (P < 0.05), whereas there was no significant difference in the meat color, shear force, and muscle pH (P > 0.05). The absolute thymus weight and thymus:BW ratio showed a significant increasing and then decreasing quadratic response to increasing free-range days (P < 0.05). The findings of this study suggest that increasing free-range days advantageously affects breast yield, but decreases thigh, leg, thigh bone, and foot yields as well as the water-holding capacity of thigh. No evidence was found that increasing free-range days caused changes in growth performance, meat quality, and lymphoid organs except for changes in water-holding capacity and thymus.

Effects of rearing systems on growth performance, carcass yield, meat quality, lymphoid organ indices, and serum biochemistry of Wannan Yellow chickens

“…Our observations revealed that thymus weight and the thymus weight to BW ratio of FRS birds were significantly higher than those of CRS birds. This was consistent with the findings of a previous study, which found that the thymus was the only lymphoid organ showing a significant difference among different free‐range days (Tong et al., ), indicating that birds had gradually adapted to the environment as the number of free‐range days increased.…”

Dietary supplementation with pioglitazone hydrochloride improves intramuscular fat, fatty acid profile, and antioxidant ability of thigh muscle in yellow‐feathered chickens

“…Importantly, the spleen index was also improved by PGZ supplementation, especially in the 7.5 mg kg −1 PGZ group. These data suggest that the immune capacity of chickens was elevated …”

Effects of free-range access on production parameters and meat quality, composition and taste in slow-growing broiler chickens

“…A possible reason is that as free-range chickens get more exercise, they will have a lower BW at slaughter and a higher FCR, which is confirmed by several studies (e.g., Castellini et al, 2002;Wang et al, 2009). However, others found no differences (e.g., Fanatico et al, 2005b;Tong et al, 2014) or even better productive performance in the free-range groups (e.g., Ponte et al, 2008a;Ponte et al, 2008b).…”