Effects of Inclusion of Opuntia Stricta (Erect Prickly Pear) in the Diet of Lactating Camels on Milk Production and Quality in Kenya

Abstract

There are increasing numbers of pastoralist communities rearing camels in the Arid and Semi-Arid Lands of Kenya, whose population in the country was estimated to be 3.22 million in 2016. The camel keepers experience shortage of fodder especially during prolonged drought. Within these ASALs, Opuntia is regarded as an invasive species. Opuntia is drought-resilient, tolerates severe utilization and provide large quantities of succulent fodder to camels during prolonged drought. The study therefore evaluated the effects of inclusion of Opuntia stricta (erect prickly pear) in diets of lactating camels on milk production and milk composition. Eight lactating dromedary Somali camels were kept under traditional management conditions and supplemented with Opuntia stricta and cotton seed cake in a double Latin Square experimental design for 84 days. The four treatments were: grazing only (control); grazing supplemented with Opuntia stricta only; grazing supplemented with Opuntia stricta plus Cotton seed cake; grazing supplemented with Cotton seed cake only. Specific objectives were to determine the most preferred forage species by camels and their nutritional value, evaluate the chemical composition and in vitro dry matter digestibility of Opuntia stricta as well as explore the effects of supplementing lactating grazing camels with Opuntia stricta and cotton seed cake on milk yield, composition and sensory characteristics. The most preferred browsed and grazed forage species were; Acacia nubica (22.6%), Acacia seyal (47.3%), Cucumis aculeatus (7.2%), Euclea divinorum (11.1%), Hibiscus parrifolia (11.9%) during wet season. Additionally, Barleria acanthoides (22.9%), Balanites aegyptiaca (15.5%), Cynodon dactycon (11.7%), Lycium europium (32%), Pollichia campestris (17.8%) were the most browsed and grazed forages in the dry season. Among camels fed on the supplemental diets, there was a highly significant difference (P<0.001) in crude protein intake with camels fed on the cotton seed cake diet having

the highest (0.414±0.018 kg) and Opuntia stricta diet having the least (0.061±0.003 kg) crude protein intake per day respectively. There was no difference in dry matter intake between camels fed on different supplemental diets (P >0.05) and ranged between 1.416±0.055-1.626±0.051 kg/day. Milk yield ranged between 4.49 and 4.82 L/day and there were no differences among treatments. Similarly, Milk composition () was also not affected by the treatments (P > 0.05). On sensory attributes, appearance, flavor, mouth feel and smell were not significantly different (P > 0.05) while there were significant differences in acceptability and preference among camels on different treatments (P<0.05). Milk from camels supplemented with Opuntia stricta and cotton seed cake was more preferred and acceptable among panelists than other treatments. The study concluded that camels preferred the forage species that had high crude protein and low neutral detergent fibre. Young cladodes were nutritious than the mature ones and Opuntia stricta was highly digestible. The study recommended further research should be done on optimal level of Opuntia stricta supplementation to grazing lactating camels. Keywords: Opuntia stricta; milk yield; Cotton seed cake; preferred forages; lactating camels