Evaluation of the causes of infertility in dairy cattle on smallholder farms in Tanzania : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, School of Veterinary Science, Manawatu

Abstract

Smallholder dairy cattle farming plays a crucial socio-economic role for many households across rural, peri-urban and urban areas in Tanzania. Despite its importance, the sector faces numerous challenges, with reproductive issues, particularly infertility, being among the major barriers to productivity and sustainability. This study explored farmer demographics and their knowledge, attitudes and practices (KAP) regarding infertility in dairy cattle, alongside an assessment of reproductive performance in cows and heifers. A cross-sectional survey was conducted on 301 smallholder farms across 13 districts in six key dairy-producing regions: Arusha, Kilimanjaro, Mbeya, Morogoro, Njombe and Tanga. Despite the shared similarities in demographics depicted by farmers, regional differences were notable. For instance, men dominated most regions except Njombe, where gender representation was more balanced. Education levels varied, with Morogoro farmers having higher education levels than others, while a higher proportion of farmers in Morogoro and Tanga had herds >4 animals. Acquisition of the first cattle beast also differed; cash purchases dominated, except in Mbeya, where cattle were often received as gifts (referred to as ‘kufufya’). The top-reported farming constraints included high input costs (93%), feed unavailability (71%), insufficient land (68%), and livestock diseases (62%). Overall, 95% of farmers reported having infertility in their herds, with the key reported causes being poor nutrition and housing (93%), livestock disease (89%), poor farm record keeping (85%) and poor heat detection (83%). Nearly all farmers (98%) considered infertility as having a major impact, with repeat breeding (95%) and failure to produce a calf in a year (69%) having the most impact. Reproductive performance was poor, with only 46% of animals pregnant and a median inter-calving interval of 468 days (despite excluding cows that were sold or culled before getting pregnant). Analysis of influencing factors showed that region was an important predictor of reproductive performance, followed by herd size and farmer experience. Larger herds were linked with better performance, while less experienced farmers surprisingly reported more pregnant animals, with better ability to recognise infertility signs. These findings highlight the need for regionally tailored strategies to improve reproductive outcomes and sustain smallholder dairy cattle farming in Tanzania.