Variations in Composition, Antioxidant Profile, and Physical Traits of Goat Milk within the Semi-Intensive Production System in Mountainous Areas during the Post-Weaning to End-of-Lactation Period

SIMPLE SUMMARY: Dairy products derived from mountain-origin milk are recognized for their superior composition, which can positively impact sensory and nutritional attributes. This study delves into the alterations in milk composition, nutritional quality, and antioxidant properties within the context of semi-intensive goat farming in mountainous regions, specifically during the post-weaning to end-of-lactation phase. The research was conducted in Greece, a region known for its prevalent mountain livestock farming systems. The study unearthed noteworthy fluctuations in milk yield and gross composition over the data collection period. The composition of milk fatty acids, particularly polyunsaturated fatty acids, exhibited a discernible correlation with forage intake, leading to enhanced nutritional lipid quality indices with prolonged grazing duration. Additionally, the study identified an upswing in total phenolic content towards the study’s conclusion, suggesting potential health benefits. Importantly, milk physicochemical properties remained relatively stable throughout the study, with no significant changes observed. In summary, this research offers valuable insights into the dynamics of milk composition and quality within semi-intensive goat farming systems situated in mountainous regions. These findings can prove invaluable to cheese manufacturers and farmers striving to elevate the quality of milk produced in mountainous regions under semi-intensive management systems. ABSTRACT: Dairy products from mountain-origin milk are known for their superior composition and quality. This study aimed to examine changes in composition, nutritional quality, and antioxidant properties of milk from semi-intensively managed goats in mountainous regions during the post-weaning to end-of-lactation period. Bulk tank milk samples from 10 farms were collected bi-weekly in the period from March to September. The farms were situated in regions with an average altitude of 772.20 m above sea level. The results revealed significant variations in milk composition, with fluctuations in fat, protein, lactose, and total solids. Milk yield per doe showed seasonal differences, with the highest yield in April and the lowest in September. Fatty acid composition exhibited changes throughout the sampling period, with variations in polyunsaturated fatty acids. Nutritional indices, such as the atherogenicity index and thrombogenicity index, remained within the recommended values. Antioxidant properties, including total phenolic content, DPPH, FRAP, and ABTS, showed significant differences, with higher values toward the end of the study. Milk pH, electrical conductivity, brix value, and refractive index also exhibited variations, while density and freezing point remained relatively stable. The study provided valuable information that can be used to develop breeding and feeding plans to achieve uniform milk quality in mountainous regions.