Long bones can grow in length by 1 to 1.5 mm per day, and the physical stress of large muscles or nutritional deficiencies could predispose to the development of leg problems later in life. The leg tendons ossify as the birds mature. Presumably, these late hatching poults suffer from leg malposition during incubation time. Avian muscles are a mixture of red and white fibres or group of muscle are predominantly one variety or the other. Red fibres have abundant blood supply, high myoglobin content, high fat content and low glycogen content.
White fibres are the opposite.
Red fibre metabolizes fat directly and has sustained activity and slow contraction. White fibres metabolize glycogen, and have rapid activity and fast contraction, for short rapid flight. Crooked toes Spraddle legs 2. Rickets Chondrodystrophy Curled toes 3. Mycoplasma infections Bacterial arthritis, tendinitis and osteomyelitis Foot pad dermatitis Avian Encephalomyelitis 4.