Effect of Different Pasture Species on Performance, Behaviour, Welfare, Meat Quality and Some Blood Parameters in Free Range Broiler Production

This study was aimed to investigated the effect of various pasture species on welfare and behavior, growth performance, carcass characteristics, internal organ weights, and meat quality of slow growing broiler chickens in the free-range production system. The animal materials comprised of mixed-sex Hubbard ISA Red JA, which were reared in the deep litter system for the first 3 weeks and thereafter, the pop hole in each of the indoor pens was opened to allow birds access to the range containing one of the above pasture treatments. After 21 days completely indoor, the birds were permitted access to outdoor pens cultivated with one of the following pasture treatments: Medicago sativa (A), Trifolium repens (WC), Lolium perenne(PR) and a mixture (Mix, A + WC + PR). The range availability was restricted between 08.30 am to 16.30 pm daily. It was found that pasture type had a significant effect (P<0.05) on the fluctuating asymmetry of the face and radius length. Tonic immobility and blood parameters did not differ among the pasture species and between sexes at 11 weeks of broiler age (P>0.05). Pasture treatment had no significant effect on broiler behaviors (P>0.05). However, the age of broilers had a significant effect on pecking, dustbathing, and scratching (P<0.01). Pecking behavior was affected by the time of the day; morning and afternoon (P<0.01). Location had a significant effect on pecking and stretching behaviors (P<0.01). In the study, dustbathing behavior was significantly affected by the interaction between location. age (P<0.01), age and time of the day (P<0.01), and location, age, and time of the day (P<0.05). Scratching behavior was significantly affected by the interaction between location and time of the day (P<0.05) and location, age and time of the day (P<0.01). Stretching behavior was significantly affected by the interaction between location and age (P<0.05) and location, age and time of the day (P<0.05). Furthermoe, distribution of birds on the range significantly decreased with the increasing distance from the poultry house (P<0.01).The results also indicated no significant difference in broiler live body weight, feed conversion ratio, and livability between 28 and 77 days among the pasture treatments (P>0.05). No significant variations were observed in the carcass and internal organ weights among pasture types (P>0.05). Additionally, while the dry matter content (P<0.01), TBA value (P<0.05) and fatty acid profiles differed (P<0.01), the protein, ash, water holding capacity, and oxidation stability of broiler breast meat did not differ among pasture groups (P>0.05). Moreover, while the values of breast meat lightness (L*) and brightness (b*) differed (P<0.05), redness and pH did not differ between sexes (P>0.05). Furthermore, sex significantly affected ash, protein content (P<0.05) and TBA value (P<0.01) of breast meat but, did not affect dry matter, water holding capacity and peroxide value of breast meat. Also, there was a significant difference in the weight of the neck, breast, thigh, live weight, hot carcass yield, heart, liver, abdominal fat, and digestive system between sexes (P<0.05). However, breast meat fat content and fatty acid profiles were not influenced by the sex of the broilers (P>0.05). It was concluded that giving an access to the studied pasture species does not affect the evaluated welfare traits and observed behaviors. Also, giving an access to the studied pasture species has no effect (P>0.05) on the growth performance traits but results in notable variations in the fatty acid profiles in broiler breast meat. Therefore, it is suggested that other pasture species should be investigated to identify their effect on slow growing strains in the free-range production system.