M. M. Alam
Char Livelihood Programme, CLP Secretariat, Rural Development Academy Campus, Sherpur,
Bogra-5842, Bangladesh
M. J. U. Sarder
Department of Animal Husbandry and Veterinary Science, Faculty of Agriculture,
Rajshahi University, Rajshahi-6205, Bangladesh
Nutrition , Production, Reproduction , Dairy cows
Bogra sadar Uupazila (Sub-district)
Animal Health and Management
Site selection and selection of dairy farms: The study was conducted between March and December, 2008 in Bogra sadar Uupazila (Sub-district). The farms selected had 8-20 crossbred cows. Artificial insemination was practiced. In order to handle the animals systematically the number of farms was restricted to 24. Identification number was given to each farm. Cow selection and grouping: The randomly selected animals were local, or crosses animal was local, or crosses between lLocal and Sahiwal (L × SL), Llocal and Friesian (L × F) or lLocal, Friesian and Sahiwal (L × F × SL). A total of 200 cows were selected. Among them 60 were Llocal, 80 were L × F, 42 were L × SL and 18 were L × F × SL. Farms were categorized in three groups (A = 68 cows; B = 66 cows , C = 66 cows) according to current feeding method. Factors studied: Services per pregnancy, calving to first service interval and milk yield per day were recorded. Breed, age, parity, body condition score (BCS) and body weight were measured. Considering age, cows were divided into up to 4 years, 4.1 to 5.5 years, 5.6 to 7.5 years and ≥ 7.6 years. Considering parity, cows were divided into Parity-1, Parity-2, Parity-3, Parity-4 and over. Considering BCS, cows were divided into up to 2.5, 2.6 to 3.0, 3.1 to 3.5 and 3.6 or over. Considering body weight, cows were divided into up to 200 kg, 201 to 250 kg, 251 to 300 kg and 301 kg or over. Feeding intervention: The usual feeding practice in the area was rice straw, Napier grass as green roughage, and concentrate mixture, fed in the morning, noon and evening. The rice straw was the major source of feed for the animals. All farmers supplied Napier grass, but amount varied between farms. Crushed rice, wheat bran, rice bran and mustard oil cake were common ingredients in the concentrate mixture. Some farmers supplied concentrate that included crushed maize, lentil bran, pea bran and gram bran. Collection of feed samples and chemical analysis Representative samples of feed in each group were collected in polythene bags containing 200 - 250g, and taken to laboratory for chemical analysis. The roughage samples were dried and ground to pass through two mm sieve and kept in the polythene bags for chemical analysis. Chemical composition for dry matter (DM), crude protein (CP), crude fibre (CF), ether extract (EE) and total ash (TA) were determined following the methods of AOAC (1995). Organic matter (OM) digestibility and metabolizable energy (ME) were estimated following the methods of Menke and Steingass (1988). Nutrient requirements and feeding intervention The daily nutrient requirements such as digestible crude protein (DCP) and ME were estimated based on the ARC (1980) standard considering body weight and milk production. Supply of DCP and ME were calculated from amount of supplied feed ingredients and results of chemical analysis. Data collection Reproductive data were collected for 10 months. A formatted register was supplied to each farmer and closely and frequently monitored by visits. Farmers were given suggestion on management of reproduction and data recording. Services per pregnancy, calving to first service interval and milk yield per day were recorded. Pregnancy diagnosis was performed by rectal palpation of genital tract. The data were entered into MS Excel spreadsheet, and transferred to analytical software SPSS for descriptive analysis. General Linear Model analysis was done to measure the strength of association between the potential influencing factors. Duncan Multiple Range Test (DMRT) was used for test of significance of means with unequal subclass number (Kramer, 1956). The outcome variables were services per conception, calving to first service interval and milk yield per day. Univariate Analysis of Variance was used to test significance of effect of breed, parity, age, BCS and body weight on pregnancy rate.
The Bangladesh Veterinarian (2010) 27(1) : 8 – 17
Journal