MATERIALS AND METHODS
Experimental site
The study was carried out at the Teaching and Research Farm of the Department of Animal Science, Faculty of
Agriculture and Forestry, Obubra Campus, Cross River University of Technology (CRUTEH), Cross River State Nigeria. The
Experimental treatments and design
The experiment comprised three treatments each of which was replicated four times in a Complete Randomized
Design (CRD). The treatments are as follows: T1 (control): Methionine and Lysine; T2: Lysine only; T3: Methionine only.
Experimental diets
The feed ingredients used for the diets were based on availability and cost. The cheapest and most available
ingredients were used in formulation of the diets. They include; maize, Soybean meal, wheat offal, bone meal,
mineral/vitamin premix, synthetic lysine and methionine and common salt. The diets were formulated according to NRC
1994 specification. The experimental diets and their calculated chemical composition are presented in table 1. The
chemical composition of the rations was obtained by calculation. The calculation was carried out using the spreadsheet
Table 1 - Experimental diets and their calculated nutrient composition
T1 (control)
Methionine + Lysine
T2
Lysine
T3
Ingredients (%)
Methionine
Maize
48.94
36.56
10.00
3.25
0.25
0.50
49.26
36.49
10.00
3.25
0.25
0.50
0
49.26
36.49
10.00
3.25
0.25
0.50
0.25
0
Soybean meal
Wheat offal
Bone meal
Common salt
Vitamin premix*
DL-methionine
Lysine – Hcl
0.25
0.25
0.25
Total
100.00
100.00
100.00
Calculated composition of experimental diets.
Crude protein (%)
20.00
3073.10
3.99
20.00
3081.77
4.00
20.00
3081.77
4.00
ME (Kcal/kg)
Crude fibre (%)
Methionine (%)
0.98
0.32
0.57
Lysine (%)
1.58
1.33
1.08
* Each 2.5 kg of premix contained: Vitamin A, 8,000,000 IU; Vitamin D1,,600,000 IU; Vitamin E, 20,000 IU; Vitamin K, 2,000mg; Vitamin B1,
1,5000mg; Vitamin B2, 4,000mg; Vitamin B6, 2,000mg; Vit. B12, 10mg; Niacin, 15,000mg; Panthotenic Acid, 5,000mg; Folic Acid, 500mg;
Biotin, 20mg; Choline Chloride, 200,000mg; Manganese, 80,000mg; Zinc, 50,000mg; Iron, 20,000mg; Copper, 5,000mg; Iodine, 1,000mg;
Selenium, 200mg; Cobalt, 500mg; Antioxidant, 120,000mg.
Management of experimental animals
One hundred and twenty finisher broilers were used for the feeding trial which lasted for twenty-eight days. The birds
were selected after brooding and randomly allotted to the twelve experimental units (10 birds per unit). They were housed
in deep litter house partitioned into experimental units of 8ft × 12ft (width × length). Feed and water were given ad
libitum. The birds were managed using standard husbandry practices for rearing broilers.
Data collection
The birds were weighed at the beginning of the experiment to get their initial body weight. They were weighed
thereafter on weekly basis. Weight gain and feed conversion ratio were deduced from the weekly body weights. Feed
offered daily was weighed and the left over weighed the following morning. Feed intakes were obtained by subtracting the
leftover from the quantity supplied the previous day. At the end of the experiment at eight weeks of age, four birds were
randomly selected from each treatment for carcass analysis. The birds were starved of feed but not water for twelve hours
before slaughtering. The slaughtering and dressing of the birds were carried out using standard practices for processing
broilers.
Statistical analysis
Data collected were subjected to analysis of variance (ANOVA) using Minitab Statistical Package. Significant means
were separated using the Fisher Least Significant Difference (FLSD) that is containing in the statistical software.
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Citation: Meremikwu VN and Gboshe PN (2021). Comparative effects of synthetic lysine and methionine supplements on performance and carcass characteristics of