{'fraction_non_alphanumeric': 0.020009095043201454, 'fraction_numerical': 0.01409731696225557, 'mean_word_length': 4.670103092783505, 'pattern_counts': {'":': 0, '<': 2, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Bromodialone reduces cell-mediated immunity in chickens

Qualitative analysis of fibre type composition demonstrated that in both lines and at all ages Pm had a uniform fibre type composition consisting almost entirely (> 99%) of glycolytic type IIb fibres. In contrast, Bf had a more heterogeneous distribution of fibre types with a large population of oxidative type I muscle fibres. The mean MFD of Pm and Bf increased significantly with age, and were significantly larger in the broilers compared to the layer line throughout the growth period studied (P < 0.001). In the broiler line, the mean MFD of Pm was significantly greater than the mean MFD of Bf at all ages (P < 0.001) except for the 20 week age group, which just failed to achieve significance (65 mm vs 46 mm, 41%: P1⁄4 0.064). In contrast in the laying line there was no significant difference in the mean MFD of Pm compared to Bf at any age. These results demonstrate that the muscle fibre diameters in both Pm and Bf are greater in meat type birds compared to layers throughout the growth period. This is true of the entirely glycolytic breast muscle and of the more oxidative leg muscle examined. The fact that the broiler muscle fibres are already significantly larger at 4 weeks of age may reflect increased rates of hypertrophy from hatch or before. Increases in fibre diameter continued until sexual maturity in both strains of bird and at comparable proportional rates. In consequence the final size was much greater in the rapidly growing birds. It also may be proposed that the genetic selection of broilers for increased breast yield is likely to be responsible for the divergence in Pm and Bf fibre size seen only in broiler birds. The commercially desirable high degree of muscle fibre hypertrophy observed in broiler chickens may be associated with a predisposition towards spontaneous and idiopathic myopathy as proposed by Mitchell et al. (2001) in turkeys. That study reported a critical fibre diameter of 65 mm above which, increased muscle damage was found. A selective hypertrophy of glycolytic fibres, as seen in the Pm muscle of the broiler, may contribute to the health disorders seen in modern meat chickens.