The effects of some environmental factors on animal welfare in different sized dairy cattle farms

This study was aimed to assess the compliance of dairy cattle farms in Izmir with the minimum requirements for dairy cow welfare and, to examine the effects of farm size, season and milking type on the welfare of dairy cows. The research was conducted in a total of 30 commercial dairy farms consisting of small (1-50 heads), medium (51-100 heads) and large (> 101 heads) sized farms that are members of İzmir Cattle Breeders Association and located in Bayındır District of İzmir Province. A measurement, observation and evaluation form including resource-based and management-based measures and the structural and herd characteristics of the farms were developed for the asses of dairy cattle farms in terms of animal welfare requirements. Animal-based measurements were repeated in winter, spring, summer and autumn seasons on a total of 229 dairy cows. Quality® Assessment Protocol For Dairy Cows that includes the principles of good feeding, good housing, good health and appropriate behavior was used to assess dairy cow welfare. Additionaly, some physiological stress responses were examined in blood serum taken before and after milking to evaluate the effect of milking type (mobile milking machine, stanchion barn milking system, traditional milking parlor system) on the welfare of dairy cows. The effects of farm size on the parameters evaluated within the scope of good feeding principle were generally nonsignificant. However it was determined in this farms that microbiological and chemical controls were not performed for newly purchased feeds and feedstuffs and, the all water points and feeders were functioning and appropriate for easy use by the animals. However, most drinkers and feeders were dirty or very dirty. It was determined that as the farm size increased, the number of animals per group drinker increased significantly (P <0.001). The highest rate of dairy cows with very lean body condition score was detected in summer. The effect of farm size on body condition score was statistically significant (P <0.01; P <0.05) in the spring and summer seasons and the rates of very lean dairy cows were higher in the spring season for small-sized farms and in the summer for medium and large-sized farms. Although the effect of farm size on resource-based measures evaluated for good housing principle was not statistically significant in general, it was determined that as the size of the farm increased, the width and height of the barns were increased significantly ( P<0,001; P<0,05). There was no bedding on the indoor resting areas (P <0.05) in the overwhelming majority of small and medium-sized farms. The farm size did not significantly affect the quality and cleanliness of floors of the barns and access to open areas, but the open area allovance per dairy cow decreased as farm size increased (P <0.05). Whereas there was no cooling in the barn in small and medium-sized farms only one-third of large-sized farms were cooling the barn with fans and sprinklers. Among the animal-based measures evaluated within the scope of good housing principle, lower leg, upper leg and udder cleanliness scores were significantly affected by farm size and, the dairy cows with the dirty and very dirty scores were higher in winter and autumn seasons(P<0,001; P<0,05). It was observed that the ratios of dairy cows with dirty and very dirty body scores were higher in medium and large-sized farms compared to small-sized farms. The farm size effects were generally meaningful for management-based measures evaluated concerning for good health principle. Clinical mastitis cases and rates of death or emergency slaughter in the farms during the last year have been significantly affected by the farm size(P<0,001; P<0,05). Mastitis rates were higher in small and medium-sized farms and the emergency slaughter and mortality rates were greater in medium and large-sized farms. Veterinary and other animal health costs and monthly manure removal frequency were higher in large-sized farms (P<0,001; P<0,05). According to assessments under the principle of good health, the lesions on the head, leg, joint and claws and the lameness score were significantly affected by season and farm size (P<0,05). The rates of dairy cows with body lesions and lameness observed to be higher in the winter season and in medium and large-sized farms. While the effect of farm size on milk composition was significant only for milk lactose level(P<0,001), the season and the interactions between season and farm size had significant impacts on milk parameters in general (P<0,05). Somatic cell counts in cow's milk were not affected by the farm size, however, the amount of milk somatic cells in autumn was significantly higher in large-sized farms comparing to other farm groups (P <0.05). Within the scope of management-based measurements in terms of the principle of performing natural behaviors, it was observed that as the farm size increased, the access to pasture of dairy cows increased (P <0.05). The detected variances among the different sized farms for total number od the staff and number of personnel trained in animal welfare were significant (P<0,01; P<0,05). In winter and summer seasons, the avoidance distance was affected significantly by farm size (P<0,05), the rates of dairy cows that the assessor can touch or approcah very closer were lower in medium and large- sized farms. The impact of farm size on blood serum cortisol, insulin and glauagon levels in dairy cows was found to be significant, the cortisol and glucagon increased and insulin decreased in the serums taken before and after milking as the farm size increased (P<0,05). Serum insulin and glucagon levels were not significantly affected by milking type but serum cortisol levels were higher (P<0,001) in the cows milked in stanchion barn comparing to the other two milking types.