MATERIAL AND METHODS

Transcription

1 MATERIAL AND METHODS

2 III. MATERIAL AND METHODS The experimental procedures adopted in the biological trial to study the Economic impact of variation in dietary profile and duration of early feed restriction in broilers are described below. 3.1 Location The experiment was designed and carried out at the University Poultry Farm, Department of Poultry Science, Veterinary College, Hebbal, Bangalore. 3.2 Biological experiment Period of study The experiment was conducted for six weeks period in broilers from day old to six weeks of age Experimental design and birds Eight hundred day old sexed commercial broiler chicks belonging to single hatch were procured from a local hatchery, wing banded and randomly allotted into five feeding schedules with four diets in each feeding schedule. Each diet having male and female chicks of 20 each, reared separately. All the chicks were reared up to six weeks under standard management conditions in deep litter system. Quantitative feed restriction was done based on the previous day total feed consumption of full fed control group. The design of the experiment was as follows (Fig. 2): S1: Ad libitum feeding (control) with four diets S2: Ten per cent feed restriction (8 th day to 14 th day) with four diets

3 S3: Twenty per cent feed restriction (8 th day to 14 th day) with four diets S4: Ten per cent feed restriction ( th day to 21 st day) with four diets S: Twenty per cent feed restriction ( th day to 21 st day) with four diets Experimental feed The experimental diets were formulated in each stage of feeding (pre-starter, starter and finisher ration) with four dietary profiles i.e., low energy high protein (D1), low energy low protein (D2), high energy-high protein (D3) and high energy-low protein (D4). The four dietary profiles were made by slightly varying protein and energy in the standards prescribed by Bureau of Indian Standards (BIS, 1992). Dietary profile schedule has been presented in the Table 1. Ingredients and nutrient composition of the experimental broiler prestarter, starter and finisher ration is presented in Table 2, 3 and 4, respectively. Broiler pre-starter ration was fed to chicks from 0 to 14 days, starter ration from to 28 days and finisher ration was used thereafter Management Broiler chicks were reared in deep litter system in an even span, asbestoes sheet roofed, open sided house. All the chicks were provided with uniform floor, feeder and waterer space and were reared under standard management conditions throughout the experimental period Health care The experimental broilers were vaccinated against Ranikhet disease and Infectious bursal disease.

4 7 th day - Ranikhet disease vaccine (RDVF) 14 th day - Infectious bursal disease vaccine (Intramediate strain) 21 st day - Ranikhet disease vaccine (RDV Lasota) 28 th day - Infectious bursal disease vaccine (Intramediate plus strain) 3.3 Parameters studied Body weight Weekly body weight of individual birds was recorded to evaluate the growth rate during the experimental period Feed Consumption Average weekly feed consumption was recorded for each replicate and was added to proceeding weeks feed consumption for calculation of cumulative feed consumption Feed efficiency The weekly feed efficiency was calculated on cumulative basis for each replicate, every week to observe the change in feed efficiency from 1 st to 6 th week Livability Mortality, if any, were recorded in the different treatment groups at occurrence and postmortem examination was carried out to identify the cause of death.

5 3.3. Carcass characteristics At the end of 42 days of age two males and two females were randomly picked up from their respective replicate (totally 16 birds per feeding schedule) and slaughtered as per Arumugam and Panda (1970). The pre-slaughter weight, dressing percentage and giblet weights were recorded Abdominal fat weight After recording carcass characteristics, the abdominal fat pad was dissected and weighed Skeletal deformities Skeletal deformities, if any, were recorded in different treatment groups at occurrence Economics Relative economics of broilers reared under different levels of feed restriction was worked out to evaluate the cost effectiveness using the prevailing market rates. 3.4 Statistical analysis Live birds data were subjected to standard statistical procedure. For testing significance of main and interaction effect, a test developed by Tukey (1949) was made use of. The procedure assumed that the interaction is of a particularly simple form: namely ( )ij = i i where is an unknown constant. Data on feed consumption and feed conversion ratio is not available for individual birds since all the birds are reared in single pen. The average data collected was subjected to analysis.

6 Duration of Feed Restriction 8-14 Days Feed Restriction - 21 Days Feed Restriction Feeding schedules S 1 S 2 S 3 S 4 S Diets D 1 D 2 D 3 D 4 D 1 D 2 D 3 D 4 D 1 D 2 D 3 D 4 D 1 D 2 D 3 D 4 D 1 D 2 D 3 D 4 Birds M Fig 2: Experimental design Note: M : Males S 1 : Adlibitum feeding (control) F : Females S 2 : Ten per cent feed restriction during 8 14 days of age D 1 : Low energy - High protein S 3 : Twenty per cent feed restriction during 8 14 days of age D 2 : Low energy - Low protein S 4 : Ten per cent feed restriction during 21 days of age D 3 : High energy - High protein S : Twenty per cent feed restriction during 21 days of age D 4 : High energy - Low protein

7 Table 1: Dietary profile schedule Diets 0-14 days - 28 days days % CP Kcal ME/kg % CP Kcal ME/kg % CP Kcal ME/kg D D D D

8 Table 2: Ingredients and nutrient composition of broiler pre-starter ration Maize (%) Soybean meal (%) Ingredients Diet 1 Diet 2 Diet 3 Diet 4 Groundnut extraction (%) De-oiled rice bran (%) Oil (%) Mineral mixture 1 (%) Salt (g) Vit AB2D3K 2 (g) Ventrimix BE 3 (g) DL-Methionine 4 (g) Monocox (g) Furazolidone 6 (g) Calculated composition Protein (%) ME, Kcal/kg Calcium (%) Available P (%) Ether extract (%) Crude fibre (%) Lysine (%) Methionine (%) Provides per kg: Calcium-8.4 g, phosphorus-2.7 g, iodine-3 mg, cobalt-2 mg, zinc-78 mg, copper-13 mg, iron-30 mg, selenium-2 mg and mangannese-80 mg 2 Provides per kg diet: A-1237 IU, D IU, B 2-7. mg and K-1. mg 3 Provides per kg diet: B-4 mg, B 6-7 mg, B g, E-20 mg, niacin-60 mg and calcium pantothenate-12. mg 4 Provides per g: DL-Methionine-980 mg Provide per g: Maduramycin- 10 mg 6 Provides per g: Furazolidone 980 mg

9 Table 3: Ingredients and nutrient composition of broiler starter ration Maize (%) Ingredients Diet 1 Diet 2 Diet 3 Diet 4 Soybean meal (%) Groundnut extraction (%) De-oiled rice bran (%) Oil (%) Mineral mixture 1 (%) Salt (g) Vit AB2D3K 2 (g) Ventrimix BE 3 (g) DL-Methionine 4 (g) Monocox (g) Furazolidone 6 (g) Calculated composition Protein (%) ME, Kcal/kg Calcium (%) Available P (%) Ether extract (%) Crude fibre (%) Lysine (%) Methionine (%) Provides per kg: Calcium-8.4 g, phosphorus-2.7 g, iodine-3 mg, cobalt-3 mg, zinc-78 mg, copper-13 mg, iron-30 mg, selenium-2 mg and mangannese-80 mg 2 Provides per kg diet: A-1237 IU, D IU, B 2-7. mg and K-1. mg 3 Provides per kg diet: B-4 mg, B 6-8 mg, B g, E-20 mg, niacin-60 mg and calcium pantothenate-12. mg 4 Provides per g: DL-Methionine-980 mg Provide per g: Maduramycin- 10 mg 6 Provides per g: Furazolidone 980 mg

10 Table 4: Ingredients and nutrient composition of broiler finisher ration Maize (%) Ingredients Diet 1 Diet 2 Diet 3 Diet 4 Soybean meal (%) Groundnut extraction (%) De-oiled rice bran (%) Oil (%) Mineral mixture 1 (%) Salt (g) Vit AB2D3K 2 (g) Ventrimix BE 3 (g) DL-Methionine 4 (g) Monocox (g) Furazolidone 6 (g) Calculated composition Protein (%) ME, Kcal/kg Calcium (%) Available P (%) Ether extract (%) Crude fibre (%) Lysine (%) Methionine (%) Provides per kg: Calcium-8.4 g, phosphorus-2.7 g, iodine-3 mg, cobalt-3 mg, zinc-78 mg, copper-13 mg, iron-30 mg, selenium-2 mg and manganese-80 mg 2 Provides per kg diet: A-1237 IU, D IU, B 2-7. mg and K-1. mg 3 Provides per kg diet: B-4 mg, B 6-8 mg, B g, E-20 mg, niacin-60 mg and calcium pantothenate-12. mg 4 Provides per g: DL-Methionine-980 mg Provide per g: Maduramycin-10 mg 6 Provides per g: Furazolidone-980 mg