Physicochemical and Nutritional Changes in Milk Composition of Indigenous Goats During Different Lactation Stages in Swat Valley, Pakistan

Abstract

Goat milk plays a significant role in nutrition and rural livelihoods in mountainous regions of Pakistan. However, limited data are available regarding compositional changes of milk from local goats across different lactation stages under field conditions in Swat Valley. Understanding these variations is essential for improving feeding strategies and dairy product utilization. A total of 120 clinically healthy local goats were selected from smallholder farms in Swat. Animals were categorized into early (0–40 days), mid (41–80 days), and late lactation (81–120 days), with 40 goats per group. Milk samples were collected weekly and analyzed for fat, protein, lactose, total solids (TS), and solid-not-fat (SNF) using standard milk analyzer machine. Data were analyzed using one-way ANOVA, and differences among means were considered significant at p < 0.05. Significant variations (p < 0.05) were observed across lactation stages. Fat percentage increased from early (3.84 ± 0.41%) to late lactation (4.92 ± 0.38%). Protein content followed a similar increasing trend (3.21 ± 0.27% to 3.78 ± 0.30%). Lactose concentration decreased significantly from early (4.52 ± 0.19%) to late lactation (4.21 ± 0.23%). Total solids increased progressively from 12.10 ± 0.62% to 13.74 ± 0.71%. Milk from late lactation contained higher fat and protein levels, suggesting improved suitability for cheese and processed dairy products, while early lactation milk had relatively higher lactose concentration. These findings provide baseline compositional data for indigenous goats in Swat and may assist in developing stage-specific feeding and milk utilization strategies.