Farm factors associated with milk rejection at dairy cooperatives in Peri-Urban Nairobi
Within the cooperative milk market chain, milk loss is estimated at between 1-5% on average, but can go up to 10% in the wet season when delivery rejections are common. In Kenya, most studies on milk losses have focused on milk spoilage along the milk market chain. This study was therefore conducted to identify practices at the farm level that contributed to milk spoilage hence rejection at the peri-urban dairy cooperative societies around Nairobi area. The objectives of the study were; to assess the main reasons of milk rejection at the dairy cooperatives, to determine milk quality control, tests at the dairy cooperatives and the implications of milk rejection at 80% ethanol and to determine the farm level factors associated with milk rejection at the dairy cooperatives in peri-urban Nairobi. Four dairy cooperative societies were purposively selected for the study. A questionnaire was administered with the aim of identifying the main reasons for milk rejection at the cooperative societies. Smallholder farms having :S 10 dairy cattle were selected in the study. Dairy farmers who met this selection criterion were randomly selected from the records of the dairy cooperatives. A total of 181 farms were selected for the study. These farms were proportionately distributed in the four dairy societies and in the different collection centers based on the number of active members in the dairy societies. Milk samples were collected both at the collection centers and at the farms. During the farm visits questionnaires were administered and relevant data collected. The XlI samples collected were subjected to 68% alcohol test, 80% alcohol test and mastitis testing using California Mastitis Test (CMT). Data were analysed using descriptive statistic, Chi square statistic and logistic regression analysis. Comparison and level of agreement between the two tests (68% and 80% alcohol test) was determined using the Kappa Test. Prevalence for subclinical mastitis was also determined. Tests routinely done by the dairy societies included organoleptic test, alcohol test and lactometer test. Milk rejection was mostly done after failing the alcohol and lactometer tests. The milk processing plants dictated the alcohol (ethanol) concentration used in all the dairy societies most of them using 80% as compared to 68% alcohol concentration recommended by the Kenya Bureau of Standards (KEBS). Comparisons were made between 68% ethanol and 80% ethanol test results. Kappa test was used to determine the usefulness and level of agreement between the two tests. The test result revealed a test comparison of 0.48 indicating that the two tests are agreeable and can be used for milk quality assessment as indicated by the KEBS. However, it should be noted that milk being rejected based on 80% alcohol test is not necessarily of bad quality but the need to use 80% should be addressed by the processing firms to the cooperatives and faremers. The main reasons for milk rejection at the dairy societies were poor hygiene, subclinical mastitis and adulteration. Other causes were delay by the processors in collecting milk and lack of refrigeration facilities. Farmers who used plastic containers for milking were approximately two times more likely to have their Xlll milk rejected compared to those who used aluminum/stainless steel containers (p< 0.027; Odds ratio =2.12). Those farmers who provided bedding to their animals reduced the chances of milk rejection by 45% compared to those who did not provide bedding (p< 0.02; Odds ratio =0.45). Farmers who did teat dipping reduced the chances of milk rejection by 10% as compared to those who did not do teat dipping (p<0.026; Odds ratio =0.1). Farmers whose bulk milk was CMT positive were three times more likely to have their milk rejected (p<0.002; O.R = 2.9) as compared to those whose milk was CMT negative. The apparent prevalence of sub-clinical mastitis from the bulk milk samples was 52%, while that of quarter sampling was 40%. This study found that the use of 80% alcohol was more sensitive than 68% in determining milk of high keeping quality. For the milk to pass the 80% alcohol test, hygienic practices both at the farm level and at the cooperative societies should be improved to meet the standards set by the processors and hence reduce rate of milk rejection and improve quality of milk. There is therefore need to formulate and implement education and training on milk quality control targeting the cooperative societies, farmers and other stakeholders.