Milk composition and mastitis diagnosis in goats

Background: Milk is one of the most used foodstuffs by humans in their diet. The quality of goat milk is already regulated by Law, which takes into consideration its physical-chemical and microbiological composition parameters. Several factors contribute for the alteration of the physical-chemical and microbiological parameters of caprine milk. These include breed, age, lactation phase and diet, among others. The health status of animals may interfere in the quality of the milk produced, both regarding food safety and milk processing and, for that reason, the identification of mastitis-causing agents is important, so that prevention and control measures can be implemented. The present study aimed at analyzing the occurrence of mastitis and the milk composition of dairy goats in a semi-intensive production system. Materials, Methods & Results: In a private goat farm with a flock composed of 32 female animals of breeds such as Saanen and Anglo-Nubian, raised on a semi-confined system, the diagnosis of mastitis was made through methods such as California Mastitis Test (CMT), Somatic Cells Count (SCC) and bacterial isolation. A total of 136 milk samples were analyzed, which were individualized per teat. Additionally, the study determined the volume of milk produced individually and the chemical composition of milk samples (fat, raw protein, lactose and total solids). In 37 (27.2%) samples, subclinical mastitis caused by CNS was identified. A negative response to CMT was observed in 125 (91.92%) samples. Only four samples presented a coincidence (OR =1.239) between CMT and bacterial isolation (P =0.7470). It was observed that the daily milk production ranged between 207.90 mL and 2.68 L. Moreover, it became clear that the milk production in half of the teats with subclinical mastitis was smaller (P =0.0026). A tendency to a significant reduction (P <0.001) in the percentage of fat and total solids was verified. The lactose percentage remained stable during the four months, and that of protein showed a tendency to reduction (P <0.001). A great variability in SCC was observed (23,000 to 9,999,000 cel.mL-1) during the sampling months. A significant concordance (P