Effects of season, parity and stage of lactation on yield, composition and microbial quality of milk from camels raised in Tsabong, Botswana

Abstract

Background: Introduced to Botswana in the early 20th century, dromedaries remain little exploited for milk production. In Tsabong, the herd is mainly used for tourism, and no study has yet assessed influencing factors on milk yield or composition. Aim: This study was conducted to assess the effects of season, parity, and stage of lactation on the yield, composition, and quality of camel milk at the Tsabong Ecotourism Camel Park. Methods: Twenty lactating camels, averaging eight years old and at various lactation stages (early, mid, and late) and parities (2–6), were studied. They browsed freely during the day and received 3 kg of a 1:1 saltbush–sorghum bran supplement at night, with unlimited access to water and salt. Milk yield was measured every three days over six weeks. A total of 560 records were collected during the dry season and 640 during the wet season. Milk samples for chemical and microbiological analysis were collected six times over a two-week period. Data were analysed using SAS for non-balanced data. Results: Milk yields were significantly higher during the wet season (1,340 ml/day) than during the dry season (781 ml/day). In the dry season, milk yield decreased as parity increased, while in the wet season, milk yield increased up to the fifth parity before declining. The stage of lactation significantly influenced fat, protein, solids-not-fat (SNF), and density in the dry season. Early lactation milk had higher protein, SNF, and density, while fat content peaked in mid lactation. In the wet season, only the protein content varied significantly across lactation stages. Parity significantly affected titratable acidity, protein, and lactose in the dry season, and protein, lactose, total solids, SNF, and pH in the wet season. The highest values were observed in camels at their second parity during the wet season. Fat and total solids were higher in the wet season overall. Coliform counts were generally higher in samples collected during the wet season. Salmonella was detected in 3.42% of dry season samples and 1.7% of wet season samples, highlighting public health concerns. Conclusions: These findings highlight the need for improve