Performance and Thermo-Physiological Responses to Heat Tolerance Coefficient of Sheep Offered Diets Supplemented with Lemon Seed Powder in Tropical Humid Zone of Nigeria
The study was carried out to determine the effect of dietary supplementation with lemon seed powder on growth, nutrient digestibility, blood indices with thermo-physiological parameters, heat stress and heat tolerances co-efficient of West African dwarf sheep. Two hundred West African dwarf male sheep aged etween 7 and 8 months old with initial average live body weight of 7.00 ± 0.15kg were used for the study. They were randomly allotted to four dietary treatments with fifty sheep per treatment in a completely randomized design. The prepared experimental diets that were offered to sheep comprised TD1 (60% guinea grass with 40% formulated diet that contained no lemon seed powder as control group), TD2 (60% guinea grass with 40% formulated diet that contained 0.50% lemon seed powder), TD3 (60% guinea grass with 40% formulated diet that contained 1.00% lemon seed powder) and TD4 (60% guinea grass with 40% formulated diet that contained 1.50% lemon seed powder). All parameters obtained in the study were subjected to one-way analyses of variance (ANOVA). Results showed that feed conversion ratio (4.28), digestibility of ether extract (70.13%), faecal with urinary nitrogen output (4.05 and 1.87g/day), total nitrogen output (5.92g/day), cholesterol (64.01mg/dl), creatinine (1.03mg/dl), urea (11.96mg/dl), relative humidity (morning 95.92%, midday 60.73% & evening 90.73%), rectal temperature (morning 38.70 0C, midday 39.76 0C & evening 38.960C), respiratory rate (morning 24.36 breaths/min, midday 25.43 breaths/min & evening 24.73 breaths/min), heart rate (morning 83.92 beats/min, midday 89.71 beats/min & evening 80.23 beats/min), skin surface (morning 29.01 0C, midday 32.46 0C & evening 30.670C), temperature humidity index (morning 73. 37, midday 80.94 & evening 73.33), black globe humidity index (morning 75.48, midday 79.82 & evening 77.34) and heat stress index (morning 79.55, midday 82.70 & evening 75.77) were significantly (p<0.05) higher in diet TD1 than diets TD2, TD3 and TD4. Sheep on diet TD4 were significantly (p<0.05) increased in daily feed intake (264.32g/day), final body weight (13.52kg), total with daily weight gain 6.39kg and 71.00g), digestibility of dry matter(71.02%), crude protein (72.04%), crude fiber (70.41%), ash (67.14%), nitrogen free extract(70.76%), neutral and acid detergent fiber (68.16 and 60.37%), nitrogen intake (14.06g/day), nitrogen balance (9.82g/day), nitrogen retention % intake (69.84%), packed cell volume (28.07%), haemoglobin (10.47g/dl), red blood cell (9.63 x106/ml), mean corpuscular value (34.37fl), mean corpuscular haemoglobin (10.46pg), mean corpuscular haemoglobin concentration (32.75%), white blood cell (11.02 x106/ml) lymphocytes (62.18%), neutrophils (32.87%), total protein (8.01g/dl), albumin (4.16g/dl), glucose (70.02 mg/dl), Benezra heat tolerance co-efficient (morning 1.86, midday 1.86, & evening 1.83), Iberia heat tolerance co-efficient (morning 135.10, midday 121.20 & evening 140.80), Rhoad heat tolerance index (morning 128.64 & evening 134.53), Singh physiological response index (morning 0.93, midday 0.94 & evening 0.92) and Davis heat tolerance coefficient (morning 0.90, midday 0.90, & evening 0.90) than those on other diets. Meanwhile, no significant differences (p>0.05) were found in initial body weight, nitrogen retained in gram per day, eosinophils, monocytes, basophils, globulin, triglycerides, dry bulb temperature, dew point temperature, black globe temperature, sweating rate, and midday Rhoad heat tolerance co-efficient index. It can be concluded that diets TD3 and TD4 that contained 1.00% and 1.50% lemon-seed powder improved performance, boost immunity and heat tolerance co-efficient with reduced heat stress in sheep.
