Begum Fatema Zohara*
Department of Medicine, Surgery and Obstetrics, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh
Azizunnesa
Department of Medicine and Surgery , Chittagong Veterinary and animal Sciences University, Chittagong, Bangladesh
Md. Faruk Islam
Department of Medicine, Surgery and Obstetrics, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh
Md. Golam Shahi Alam
Department of Surgery and Obstetrics, Bangladesh Agricultural University, Mymensingh, Bangladesh
Farida Yeasmin Bari
Department of Surgery and Obstetrics, Bangladesh Agricultural University, Mymensingh, Bangladesh
Reproductive performances, Supplementation, Indigenous ewes.
Department of Surgery and Obstetrics, Bangladesh Agricultural University, Mymensingh.
Animal Health and Management
2.1 Study area: The study was carried out at the Department of Surgery and Obstetrics, Bangladesh Agricultural University, Mymensingh. The research units are located on N 24.73 and E 90.44 latitude and longitude, respectively and elevated 9 m above sea level. The area receives on average 174 mm of rainfall. Mean annual minimum and maximum temperatures experienced at the site are 16.46 and 29.13° C, respectively. 2.2 Study design The study was conducted between January to December, 2011. A total of 24 clinically healthy indigenous ewes of 2- 3 months old and 6-8kg body weight were selected from the local market. After preliminary acclimatization, all the animals were dewarmed and vaccinated for rabies and tetanus. Two grown up rams were vasectomized in the laboratory to be used as teasure. Indigenous experienced rams were used for natural service. The ewes randomly divided in to either controlled or supplemented group. The controlled group was maintained on natural grazing with traditional feeding practice used by the farmer and the supplemented group was maintained with supplemented feeding ration along with natural grazing. All ewes in the supplemented group received the supplemental diet (composed of concentrate mixture 25% Crushed Maize, 50% Wheat Bran, 20% Soybean meal, 1% Fish meal, 2% DCP Powder, 1.5% salt and 0.5% vitamin- mineral premix) for a minimum of 120 days prior to collecting data. The supplementation was at the rate of 300g/head /day. Water was supplied ad labium. Proximate composition analysis of the supplements were carried out to measure the content of Crude Protein, Crude fiber, Ash, Lipid, Carbohydrate and Moisture according to methodologies recommended by AOAC [16]. The compositions of diets are presented in Table 1.
2.3 Measurement of growth rate, age and body weight at puberty of ewes Body weight was recorded weekly by a balance scale. Daily weight gain was calculated by dividing the total weight gain by the total days of feeding period. Age at puberty was recorded by the onset of first behavioral estrus. 2.4 Measurement of Estrus cycle length, duration and stages of ewes Estrous detection in ewes was carried out twice a day for 1 h period of observation using vasectomized ram. Estrus duration was defined as the time interval between the onset of estrus and when a ewe no longer stood to be mounted while estrous cycle length was defined as the number of days between the onsets of two consecutive estrous periods. The stages of the cycle were determined by vaginal cytology. Ovulation response and cyclical stages was further confirmed by the measurement of serum progesterone concentration. Blood sample (5ml) was collected from each ewe of both groups on every 5th day for Day 16 of the cycle. Serum was recovered by centrifugation (15 minutes at 3000 rpm) and stored at -20ºC until assayed for serum progesterone concentrations using commercially available sheep progesterone (PROG) ELISA kit (Cusabio Biotech Co., Ltd.). Each ewe was considered to have ovulated when progesterone concentration was ≥0.5 ng/ml. 2.5 Detection of estrus and natural service Ewes and vasectomized rams were kept together in a paddock for one hour twice a day for observing the behavioral signs. The behaviors of animals were noted on individual sheets prepared for each ewe. Each ewe was considered to be in estrus when she was directly observed to accept a mount from the ram. The ewes were hand mated/ NS twice at 12hrs interval.
2.6 Pregnancy, gestation length and post partum onset of oestrus Pregnancy was determined by transabdomial ultrasonography, using B-mode diagnostic ultrasound scanner (DRAMI'SKI, Poland) at 50 days of natural service. Gestation length was counted from the day of service to the day of onset of labor. Post partum onset of estrus was determined by the first observed estrus after parturition and by observing the vaginal cytology. Pregnancy rate, Lambing and fertility rate, litter size was calculated by the following formula [20]. Pregnancy rate (%) = (number of ewes pregnant / ewes present to rams) x 100. Lambing rate (%) = (number of ewes lambing /number of ewes mated) x 100. Lamb survival rate (%) = Number of offspring weaned/ Number of offspring produced x 100 Litter size (prolificacy) = Number of lambs / number of ewes lambing 2.7 Lamb birth weight, weaning weight and pre-weaning average daily weight gain of lamb Within 24 hours of the new born, date of birth, birth weight, type of birth, sex of lamb was taken. The numbers of lambs born per ewe were recorded daily during lambing. Weaning weight was recorded on 60th day by the following formula: Pre-weaning Average Daily Gain = (weaning weight - birth weight) / weaning age.
2.8 Data analysis Data analysis was carried out to evaluate the differences in results between supplemented and control animals using students “t” test. Sexual behaviors were compared by Chi-Square test. Pregnancy, lambing and lamb survival rate was expressed in percentage. The mean progesterone concentrations between groups were analyzed by ANOVA-repeated measures (GLM procedure of (SPSS.), Version 17.0). All significant differences were set at P<0.05.
IOSR Journal of Agriculture and Veterinary Science (IOSR-JAVS) e-ISSN: 2319-2380, p-ISSN: 2319-2372. Volume 7, Issue 5 Ver. I (May. 2014), PP 64-72 www.iosrjournals.org
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