Physicochemical and microbiological characteristics of goat milk from animals grown in a mountainous area in Bulgaria

D. Pamukova1, N. Rusenova2, T. Kolev3, S. Chobanova4, N. Naydenova1*

1Department of Animal husbandry – Ruminants and Dairy farming, Faculty of Agriculture, Trakia University, 6015 Stara Zagora, Bulgaria
2Department of Veterinary Microbiology, Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, Trakia University, 6015 Stara Zagora, Bulgaria
3Agricultural Academy, Agricultural Institute, 6000 Stara Zagora, Bulgaria
4Department of Morphology, Physiology and Animal Nutrition, Faculty of Agriculture, Trakia University, 6015 Stara Zagora, Bulgaria

(Manuscript received 20 June 2020; accepted for publication 4 August 2020)

Abstract. The aim of the study was to determine the goat milk quality from animals grown in a mountainous area in Bulgaria based on physicochemical and microbiological parameters. The study was carried out in a farm that breeds local goats and goats of the Bulgarian White Dairy Goat (BWD). Individual milk samples were taken on a monthly basis from morning milking. A total of 100 individual and 10 bulk milk samples were examined for fat, solids non fat, protein and density. A total of 62 samples were collected at a time to determine the microbiological characteristics of milk. For the period May-September 2017, the percentage of fat in the milk of local goats averaged 3.61% and of goats from BWD goat – 3.54%. The solids non fat were 8.27% and 8.19%, total protein – 3.13% and 3.10%, and the dry matter – 11.89% and 11.74%, respectively. For the period May-August 2017 the individual constituents of milk changed to varying degrees with the most variable being milk fat (decrease of 0.97% in local goats’ milk and 1.09% in milk from BWD goat) followed by solids non fat (0.56% and 0.7%, respectively). The slightest change was in protein – 0.21% and 0.26%, respectively. Coagulase-negative staphylococci were the predominant bacterial species in the goats’ milk samples.