FACTORS AFFECTING QUALITY AND QUANTITY OF MILK PRODUCED FROM COMMERCIAL DAIRYING AT CHITTAGONG OF BANGLADESH

Abstract

Chittagong is one of the milk pocket areas and the second largest city of Bangladesh. But the commercial dairy farms of Chittagong can’t fulfill the demand of milk of this area. The Government of Bangladesh has a vision 2021 where importance has given for the universal food production and food security. It emphasizes that the country needs to be self-sufficient not only in terms of food production but also equitable distribution of nutritious food amongst the people.

TheDepartment of Livestock Services has registered commercial dairy farms of the Chittagong areas, and they have divided the farms into four categories. These are A, B, C and D categories. Each category of dairy farm has different number of dairy cows. The A, B, C and D farm has ≥50, 31-<50, 11-30 and 3-10 number of dairy cows, respectively. Though many problems exist in the dairy farms of Bangladesh, quality is one of them. Similar problems are facing by the Chittagong dairy sector, which also exist in the other dairy farms of Bangladesh. It is observed thatquality of milk produced by these farms is not satisfactory. That is why the aim of this study was to explore the important factorsthat influence the quality and quantity of milk production in the different categories of commercial dairy farms at Chittagong, Bangladesh. From the observed data it was revealed that the commercial dairy sector of Chittagong is facing a lot of problems regarding the quality and quantity of milk production. Among those, selection of appropriate crossbreds under different categories of farm, imbalanced feed and seasonal effects etc., being the most important constraints for milk quality and quantity of milk production. The baseline survey showed that the quality and quantity of milk production of different category of farms (A, B, C) varied significantly due to differing in socio economic conditions of the farmers. From the survey, it also observed that five types of crossbreds were available in different category of farms, of which Holstein Friesian(HF) bloodwas common in four crossbreds (50%HF×50%L(Local), 75%HF×25%L, 50%HF×50%S(Sahiwal), 50%HF×25%S×25%L) and only one crossbred without HF blood was 50%S×50%L. According to the number, the 50%HF×50%L genotype being the highest, and 50%S×50%L crossbred was the lowest in different category of farms. There were significant differences (p<0.05) in milk yield and quality among different category of farms, crossbreds and different seasons. The daily average milk yield/cow was higher in category A farms, and the gross composition of milk except lactose was also rich in the same category of farms. The highest milk yield was observed in monsoon season in compared to summer and winter. The highest daily average milk yield was found in case of 75%HF×25%L compared to other crossbreeds, and the rearing percentage of 75%HF×25%L cow was found to be the highest in category A farms. The lowest daily milk yield/cow was observed in case of 50%S×50%L crossbred. The milk yield and milk constituents of HF 50%×L50% were more or less similar under different category of farms with different feeding and management conditions, whereas performance of 75%HF×25%L and 50%HF×50%S crossbreds were decreased significantly with inferior management and feeding under category B and category C farms compared to category A farms. The average milk urea nitrogen (MUN) differs significantly(p<0.05) among different category of farms and seasons.MUN was the lowest in category A (21.67±4.130) and the highest in category C (26.30±3.976) farms.Theconcentration of MUN in dairy herd of Chittagong was ranged from 18.6mg/dl to 31.03mg/dl which was higher than suggested MUN level of the dairy herd. The MUN level was highest in winter than in summer and the lowest MUN were observed in rainy season. The important finding was observed by the correlation with MUN and milk yield. The negativecorrelations were observed in winter and summer. Positive correlation was observed in monsoon. This finding could be used for minimizing feed costs while maximizing production in commercial dairying at Chittagong. Grading-up of local cattle by temperate breeds for greater performance results to increase the sensitivity to heat stress in tropical environment.The average temperature humidity index (THI) of the stanchion barn were 70.83± 0.535 and 83.87± 0.375 in cool and hot period, respectively. The differences of THI of cool and hot season was significant (p<0.05). At the same THI level the 75%HF×25%L genotypes were suffered more from heat stress than the 50%HF×50%L genotype, which was reflected at their rectal temperature. The average rectal temperature (0F) of 75%HF×25%L and 50%HF×50%L genotype being the 102.15±0.049 and 102.5±0.052, respectively in hot period. The average milk yield (liter/day), fat% and protein% of both genotypes were significantly (p>0.05) lower at heat stressed condition compared to cool period.It was also seen that the declining trend of milk yield was more prominent in 75%HF×25%L genotype compared to 50%HF×50%L above optimum(72) level of THIduring heat stressed period. From the results it can be concluded that genotype 50%HF×50%L might be the better option for all category of farmers considering existing management system, whereas 75%HF×25%Lwould also be a promising for the category B and C farmers through improving overall management and feeding system of the farms.