Technical Note:Evaluation of extent of water adulteration of milk produced and marketed in Morogoro Municipality, Taniania

Tanzania Journal of Agricultural Sciences 2005, Vol.6(2) : 104- 107A study was conducted to evaluate the extent of water adulteration of milk produced and marketed in Morogoro municipality in Tanzania. A total of 90 milk samples were collected from institutional, private and smallholder farms and milk vendors, The samples were analysed for lactometer reading (LR), butterfat (BF), solids-not-fat (SNF) and total solids (TS). Overall adulteration (AD) was calculated as the difference between SNF of standard/genuine milk obtained at the farm gate and respective milk samples, It was observed that lactometer reading for the farm milk ranged from 25: 32 to 26.75 and was significantly higher (P<0, 05) than vendors' milk, which ranged from 23.01 to 23.58 L. The butter fat content for farm milk which ranged from 3.56 to 4.12 % was significantly higher (P<0.05) than that of the vendors' milk that ranged from 2.86 to 3.03%. The SNF content for farm milk ranged from 7.18 to 7.67 % and was significantly higher (P<0.05) than that of vendors' milk, which ranged from 6.47 to 6.63 %. Furthermore, TS of farm milk which ranged from 10.81 to 11.87% was significantly higher (P<0.05) than vendors' milk, which ranged from 9.38 to 9.74% The overall adulteration for farm milk ranged from 6.57 to 9.48% and was significantly lower than that of vendors 'milk, which ranged from 19.28 to 21.13 %. It was concluded that water adulteration of milk in Morogoro municipality was rampant and starts from the farm level. Therefore, there is a need for the Government to educate dairy farmers, milk vendors and the consumers on the importance of producing, selling and consuming respectively un-adulterated mil

Optimisation of activity and storage stability of crude pepsin extracted from adult cattle Abomasa for cheese making

Tanzania Journal of Agricultural Sciences 2001, Vol. 4(1) : 29-36The study conducted to investigate the activity and storage stability of crude pepsin extract for use as rennet substitute in cheese processing. The conditions tested were regions of the abomasa, fresh versus dry abomasa drying methods, maceration temperatures (37oC, 24-28oC or 15oC); maceration pH 1-6 for 6 days; activation pH (pH 1-4) and clarification by centrifugation or use of chemicals. The shelf life of the extract was evaluated under storage temperatures ranging from deep freezing at -20oC refrigeration temperatures (<10 oC) and room temperature. Results showed that fundic region of the abomasa had 70.8% pepsin while the pyloric region had only 27% pepsin. Milk clotting activity (MCA) was 1978 and 1800 pepsin units per ml (PU/ml) for sun and shade-dried abomasa respectively. Concentrations of 5, 10, 15, 20, 25% NaCl gave 1845, 2189, 1596, 1021, 462 MCA respectively. Maceration at pH 3 for 3 days at 37 oC gave the highest enzymatic activity (5536 PU/ml). Clearing of the extract by centrifugation at 3000g/15 min gave an extract with 902.3 PU/ml. Clarification by use of di-sodium phosphate (Na2HSO4) gave extract of 1679.1 PU/ml. The enzyme activity of the extract stored under deep freezer temperature was sibnificantly higher (p < 0.05) than ambient and refrigeration temperatures. However, they were significantly lower (p< 0. 001) than the activity of the extract before storage. Therefore, the best pepsin extraction conditions were found to be the use of fundic region of sundried abomasa, macerated at 37oC in an extraction solution containing 5-10% salt at pH 3 for 3 days and clarified after activation at pH2 for 20 min followed by centrifugation of sediment at 3000g/15 min or by use of anhydrous disodium phosphate. The clarified extract could retain its activity for 16 weeks when stored at - 20oC in single use portion

Optimisation of activity and storage stability of crude pepsin extracted from adult cattle Abomasa for cheese making

Tanzania Journal of Agricultural Sciences 2001, Vol. 4(1) : 29-36The study conducted to investigate the activity and storage stability of crude pepsin extract for use as rennet substitute in cheese processing. The conditions tested were regions of the abomasa, fresh versus dry abomasa drying methods, maceration temperatures (37oC, 24-28oC or 15oC); maceration pH 1-6 for 6 days; activation pH (pH 1-4) and clarification by centrifugation or use of chemicals. The shelf life of the extract was evaluated under storage temperatures ranging from deep freezing at -20oC refrigeration temperatures (<10 oC) and room temperature. Results showed that fundic region of the abomasa had 70.8% pepsin while the pyloric region had only 27% pepsin. Milk clotting activity (MCA) was 1978 and 1800 pepsin units per ml (PU/ml) for sun and shade-dried abomasa respectively. Concentrations of 5, 10, 15, 20, 25% NaCl gave 1845, 2189, 1596, 1021, 462 MCA respectively. Maceration at pH 3 for 3 days at 37 oC gave the highest enzymatic activity (5536 PU/ml). Clearing of the extract by centrifugation at 3000g/15 min gave an extract with 902.3 PU/ml. Clarification by use of di-sodium phosphate (Na2HSO4) gave extract of 1679.1 PU/ml. The enzyme activity of the extract stored under deep freezer temperature was sibnificantly higher (p < 0.05) than ambient and refrigeration temperatures. However, they were significantly lower (p< 0. 001) than the activity of the extract before storage. Therefore, the best pepsin extraction conditions were found to be the use of fundic region of sundried abomasa, macerated at 37oC in an extraction solution containing 5-10% salt at pH 3 for 3 days and clarified after activation at pH2 for 20 min followed by centrifugation of sediment at 3000g/15 min or by use of anhydrous disodium phosphate. The clarified extract could retain its activity for 16 weeks when stored at - 20oC in single use portion

Assessment of raw cow milk quality in smallholder dairy farms in Pemba Island Zanzibar, Tanzania

Veterinary Medicine International Volume 2018, Article ID 1031726, 9 pagesMilk quality depends on the physicochemical characteristics, hygienic standards, and nutritional quality; however, animal husbandry practices, unhygienic harvesting and processing, may affect its quality. A cross-sectional study was conducted between August 2010 and July 2011 to assess the hygiene of cow milk production environment, raw cow milk physicochemical characteristics, and microbial quality and estimate the prevalence of antimicrobial residues using standard methods in Pemba Island. A total of 98 raw cow milk samples from selected smallholder dairy farms were analyzed, and the judgement on the quality used the East African Standards. Generally, the milk production chain was done under the unhygienic condition, and dirty plastic containers were used for collection and storage of milk under room temperature. Some milk samples had abnormal colour (2.1%), abnormal smell (7.1%), and pH below normal (35.7%), clotted on alcohol test (9.2%), and had the specific gravity below normal (13.3%). All the milk samples had mineral contents within the recommended range. Milk samples with butterfat below normal were 29.6%, while 14.3% had total solids below recommended values. The mean total viable count (TVC) of milk container surfaces was  log CFU/100 cm2, while total coliform count (TCC) was  log CFU/100 cm2. Up to 55.1% of milk had TVC beyond the recommended levels. The milk mean TVC was  log CFU/ml and TCC was  log CFU/ml. Up to 26.5% of milk samples had the TCC beyond levels. Results on physicochemical characteristics and nutritional analysis show that the raw cow milk in Pemba Island is of inferior quality. Microbiological results of this study imply heavy contaminations of milk. Antimicrobial residues were detected in 83% of the samples and most of them were from Wete District. Unhygienic milk production chain accelerates microbial contaminations, and antimicrobial residues in milk are a big problem that needs urgent attention from the responsible authority

Assessment of raw cow milk quality in smallholder dairy farms in Pemba Island Zanzibar, Tanzania

Veterinary Medicine International Volume 2018, Article ID 1031726, 9 pagesMilk quality depends on the physicochemical characteristics, hygienic standards, and nutritional quality; however, animal husbandry practices, unhygienic harvesting and processing, may affect its quality. A cross-sectional study was conducted between August 2010 and July 2011 to assess the hygiene of cow milk production environment, raw cow milk physicochemical characteristics, and microbial quality and estimate the prevalence of antimicrobial residues using standard methods in Pemba Island. A total of 98 raw cow milk samples from selected smallholder dairy farms were analyzed, and the judgement on the quality used the East African Standards. Generally, the milk production chain was done under the unhygienic condition, and dirty plastic containers were used for collection and storage of milk under room temperature. Some milk samples had abnormal colour (2.1%), abnormal smell (7.1%), and pH below normal (35.7%), clotted on alcohol test (9.2%), and had the specific gravity below normal (13.3%). All the milk samples had mineral contents within the recommended range. Milk samples with butterfat below normal were 29.6%, while 14.3% had total solids below recommended values. The mean total viable count (TVC) of milk container surfaces was  log CFU/100 cm2, while total coliform count (TCC) was  log CFU/100 cm2. Up to 55.1% of milk had TVC beyond the recommended levels. The milk mean TVC was  log CFU/ml and TCC was  log CFU/ml. Up to 26.5% of milk samples had the TCC beyond levels. Results on physicochemical characteristics and nutritional analysis show that the raw cow milk in Pemba Island is of inferior quality. Microbiological results of this study imply heavy contaminations of milk. Antimicrobial residues were detected in 83% of the samples and most of them were from Wete District. Unhygienic milk production chain accelerates microbial contaminations, and antimicrobial residues in milk are a big problem that needs urgent attention from the responsible authority

Prevalence of clinical and subclinical mastitis and quality of milk on smallholder dairy farms in Tanzania

A cross sectional study was conducted during October and November 2006 on 69 smallholder dairy farms with lactating cows in Mvomero and Njombe districts Tanzania, to determine the prevalence of mastitis and to assess the milk quality on the study farms. Clinical mastitis was investigated using clinical changes of udder and milk at animal level. Cow-side California Mastitis Test (CMT) and microbiological cultures were used to assess subclinical mastitis at quarter level. Milk quality was determined on bulk milk samples at herd level using alcohol and acidity tests, butter fat content, total solids, ash content as well as Delvotest® for antimicrobial residues. Overall prevalence of clinical mastitis at herd level in both districts was 21.7 % (n = 69). Based on CMT, prevalence of subclinical mastitis at animal level was 51.6 % (n = 91). Prevalence of bacterial isolates at animal level was 35.2 % (n = 91) while for fungal it was 16.7 % (n = 90). Based on CMT results, prevalence of subclinical mastitis at quarter level was 30 % (n = 353), while for bacteria and fungi it was 16 % and 6 % respectively. Contamination of milk with antimicrobial residues was 4.5 % (n =67). The milk quality parameters for most of the milk samples were within acceptable levels. Findings in this study have demonstrated high prevalence of subclinical mastitis that may contribute to low productivity of dairy cattle in both districts. About 20 % of CMT subclinical cases had no involvement of microbial pathogens that suggested the need for minimal interventions with antimicrobial agents. These findings call for use of udder disinfectants and improved milking hygiene as intervention strategies to control mastitis on the smallholder dairy farms in Tanzania

Forage availability and its quality in the dry season on smallholder dairy farms in Tanzania

Acta Agriculturae Scand Section A, 2008, 58: 196 - 204The study was conducted on smallholder dairy farmers in Tanzania. A number of forage species and feed supplements were collected and analysed. Panicum maximum and P. purpureum constituted the bulky forage in about 20 and 11 households, respectively. The crude protein (CP) content of P. maximum and P. purpureum ranged from 6.5 to 8.5% and 7.8 to 10.2% while in vitro dry matter digestibility ranged from 44 to 50 and 48 to 51%, respectively. The mineral content of these two grasses were adequate for Ca but 95% of the forages were deficient in Cu and Zn and 84% in P. The CP content of multipurpose tree leaf was 3 4 times higher than that of grasses. In conclusion, the study revealed that dairy farmers depended solely on natural grasses and crop residues, which are low in CP, digestibility and mineral content

Forage availability and its quality in the dry season on smallholder dairy farms in Tanzania

Acta Agriculturae Scand Section A, 2008, 58: 196 - 204The study was conducted on smallholder dairy farmers in Tanzania. A number of forage species and feed supplements were collected and analysed. Panicum maximum and P. purpureum constituted the bulky forage in about 20 and 11 households, respectively. The crude protein (CP) content of P. maximum and P. purpureum ranged from 6.5 to 8.5% and 7.8 to 10.2% while in vitro dry matter digestibility ranged from 44 to 50 and 48 to 51%, respectively. The mineral content of these two grasses were adequate for Ca but 95% of the forages were deficient in Cu and Zn and 84% in P. The CP content of multipurpose tree leaf was 3 4 times higher than that of grasses. In conclusion, the study revealed that dairy farmers depended solely on natural grasses and crop residues, which are low in CP, digestibility and mineral content