M.A. Rashid
Department of General Animal Science and Animal Nutrition, Patuakhali Science and Technology University, Khanpura Campus, Barisal-8210, Bangladesh
M.J. Khan
Department of Animal Nutrition, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh.
M.A.M.Y. Khandoker
Department of Animal Breeding and Genetics, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh.
M.A. Akbar
Department of Animal Nutrition, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh.
M.M. Monir
Department of General Animal Science and Animal Nutrition, Patuakhali Science and Technology University, Khanpura Campus, Barisal-8210, Bangladesh
Goats, Performance, Digestibility, Compound pellet, Pellet diameter
Animal Nutrition Laboratory, Bangladesh Agricultural University, Mymensingh
Animal Health and Management
2.1 Experimental goats Fifteen castrated male Black Bengal goats of about six months of age and average body weight 9.98 kg to 10.20 kg were collected from local farm. The goats were randomly divided into three equal groups, tagged and housed in a well ventilated shed and allowed two weeks to adapt with the housing conditions and experimental diets. The goats were vaccinated against Peste des petits ruminants (PPR) after allowing seven days of quarantined. After ten days of PPR vaccination, the animals were treated with antihelmintic to control gastrointestinal parasites. The initial live weight of each goat was taken at the beginning of the experiment for three consecutive days before offering feed at morning and the mean weight of individual goat was recorded as initial weight. Thereafter, goats were weighed individually prior morning feeding in every 7 days interval throughout the experimental period. Final live weight of each goat was also taken for three consecutive days at the ending point of the experiment. Live weight gain was calculated from the data. The experimental goats were reared for 100 days under identical care and management and thereafter slaughtered to know the dressing percentage.
2.2 Experimental diets Napier grass (Pennisetum purpureum), cultivated in fodder field of Animal Nutrition Department of Bangladesh Agricultural University, was selected as basal feed. The green grass was cut, chopped, dried and ground by an electric grinder using a 1mm diameter sieve. Concentrate feed ingredients were purchased from local market. The sample of grass and other ingredients were analyzed for proximate components before using for pellet preparation. Compound pellets of three different diameters (D10, 10 mm; D8, 8 mm and D6, 6 mm), according to the NRC (1981) nutrient requirements, were prepared for goats belonging to three groups with the ground grass and concentrate feed ingredients in a ratio of 60:40.
2.3 Feeding the goats Fifty percent of the allocated (@ 3% of the body weight) compound pellet for a day was supplied to the respective group at every 8:00 am and the goats were allowed for grazing from 9:30 am to 11:30 am and then confined in pen. The rest of the portion of pellet was supplied at 4:00 pm. Grazing length was shortened and feed allocation increased gradually. After seven days grazing was fully stopped and experimental diet was supplied @ 5kg DM/100kg body weight. In the whole experimental period goats were kept in a paddock for exercise at 6:30 am and returned to pen at 8:00 am. One half of compound pellets were supplied to the goats of respective group at every 8.00 am and another portion at 4.00 pm. Every morning before supply of feed, leftovers of all groups, if any, were collected, weighed and daily feed intake was calculated. Fresh drinking water was supplied for 24 hours.
2.4 Metabolic trial A conventional metabolic trial was conducted for a period of 10 days at the ending point of feeding trial to know the digestibility of feed nutrients and nitrogen balance. The goats were placed in metabolic crate at 84th day of experiment and allowed for 7 days for adaptation. Then a conventional metabolic trial was performed for a period of 10 days. Amount of daily feed intake, voided feces and excretion of urine were recorded and sample was taken for proximate analysis. 2.5 Proximate analysis The samples of feed, left-over and feces were analyzed for nutrient content following the methods of AOAC (2012). Digestible crude protein (DCP) was calculated according to the methods of McDonald et al.
2.6 Slaughtering and carcass weight of the goats Goats were individually weighed after overnight fasting and slaughtered according to Mohammadian (Halal) method at 100th day of experiment. Worm carcass weight was recorded immediately after complete dressing (removal of head and skin with feet) and evisceration. The dressing percentage was calculated from the carcass weight divided by the slaughtered weight then multiplied by 100 (Devendra, 1988).
2.7 Statistical analysis Data were analyzed by completely randomized design using the GLM procedure of SAS version 9.1 (SAS Institute Inc., Cary, N.C.) to determine the effect of diameter of pellet on performance of Black Bengal goat.
IOSR Journal of Agriculture and Veterinary Science (IOSR-JAVS) e-ISSN: 2319-2380, p-ISSN: 2319-2372. Volume 9, Issue 4 Ver. I (Apr. 2016), PP 18-23 www.iosrjournals.org
Journal