GROWTH PERFORMANCE AND CALCIUM RETENTION OF BROILER CHICKENS FED DIETARY OILS

Abstract

Dietary Oils (DO) are used in poultry feeding without considering their effects on nutrient digestion, absorption and utilisation. Oils rich in Saturated Fatty Acids (SFA) may interfere with uptake of minerals especially calcium in chickens’ gut, resulting in the formation of indigestible soaps which reduce absorption of nutrients. Characterisation of DO is imperative to ascertain the likely effects on nutrients uptake. However, there is dearth of information on the effects of different DO on performance, serum biochemical indices and calcium retention in Broiler Chickens (BC). Therefore, effects of DO and varying Dietary Calcium (DC) levels on performance and calcium retention in BC were investigated. Five DO: Shea butter-Sb, Soybean Oil-SO, Groundnut Oil-GO, Coconut Oil-CO and Palm Kernel Oil-PKO were analysed for Arachidonic, Oleic, palmitic, total carotene and α-tocopherol concentration (μ/mL) using standard procedures. Nine diets with three DO based on degrees of unsaturation containing 1%, 2%, 3% each of Sb (T1, T2 and T3), PKO (T4, T5 and T6) and CO (T7, T8 and T9) were formulated. Arbor Acre BC (n=360) were fed the diets for six weeks. Weight Gain-WG (g/bird) and Feed Conversion Ratio (FCR) were calculated. At day 21, blood (3 mL) was sampled from two BC/replicate for serum biochemical assay using standard procedures. Another 540 BC were allotted to nine dietary treatments comprising 2% PKO and DC at 0.75 (TA), 1.00 (TB)and 1.25% (TC); 2% Sb and DC at 0.75 (TD), 1.00 (TE), 1.25% (TF); 2% CO and 0.75 (TG), 1.00 (TH), and 1.25% (TI), for six weeks. Two BC/replicate were housed in metabolic cages from day 35 to 42 for the determination of calcium retention and left tibia ash using standard procedures. The experiments were 3x3 factorial arrangements in a completely randomised design. Data were analysed using descriptive statistics and ANOVA at α0.05. Arachidonic acid concentration in GO (0.07±0.01) and Sb (0.08±0.02) were significantly lower than SO (2.33±0.05), PKO (2.10±0.03) and CO (2.25±0.15). Oleic acid in CO (26.95±2.57) and Sb (26.93±1.78) were significantly lower than 42.15±1.35 (GO), 38.65±4.17 (PKO) and 37.67±2.30 (SO). Palmitic acid ranged from 3.45±0.57 (Sb) to 8.83±0.89 (SO). Total carotene in Sb (8550.26±280.00) and CO (8345.06±203.00) were significantly higher than 3396.54±133.86 (PKO), 1641.48±72.50 (SO) and 4372.67±165.17 (GO). The α-tocopherol ranged from 25.59±0.35 (PKO) to 53.37±2.18 (Sb). The WG of BC fed T1 (924.38±57.25) T2 (881.38±40.77), T5 (936.50±60.13), T6 (882.25±44.65), T8 (959.50±58.02) and T9 (904.38±50.01) were significantly higher than 788.13±34.20 (T3), 756.00±20.25 (T4)and 856.75±32.05 (T7). The FCR ranged from 2.37±0.05 (T1) to 2.55±0.04 (T5). Superoxide dismutase (μL) was highest in BC fed T9 (174.00±0.14) and least in T1 (147.75±19.20). Serum calcium (mg/dL) ranged from 12.88±0.04 (T1) to 14.40±0.46 (T7). The BC on TI (92.62±4.02) had highest calcium retention and in TE (49.55±1.85) was least. Tibia ash (%) was highest in BC fed TH (86.38±5.75) and least in TB (77.86±3.25). Inclusion of shea butter at 1%, palm kernel and coconut oils at 2% enhanced weight gain. Combined dietary inclusion of 1.25% calcium and 2% coconut oil improved calcium retention in broiler chicken.