Comparative Evaluation of effect of selenium sources on growth, production and reproduction in different varieties of indigenous Aseel chicken

Abstract

This study was planned to evaluate the influence of selenium (Se) supplementation on growth, production and reproduction in Lakha, Mushki, Peshaweri, and Mianwali varieties of Aseel at Indigenous Chicken Genetic Resource Centre, University of Veterinary and Animal Sciences (UVAS), Lahore. The study was comprised of two main experiments. In the 1st experiment, 400 d-old birds, 100/variety (50 males and 50 females) were procured from Avian Research and Training center, UVAS, Lahore. The birds were given an adjustment period of 21 days. From the base population of 400 birds, a total of 240 birds were then selected randomly, divided into 4 groups, 60/variety (30 males and 30 females). The birds of either sex in each group were further subdivided into three treatment groups A, B, and C, 10/treatment. Each treatment was replicated 10 times with one bird/replicate. In this experiment, each bird was regarded as an experimental unit. Groups A and B were experimental, while C was control. Se-enriched yeast (SY) and sodium selenite (SS) were supplemented @ 0.3 ppm (mg/kg) in basal diets of group A and B, respectively, while, group C was fed without additional selenium. Birds were maintained individually in cages under uniform husbandry conditions from 4-21 weeks. Statistical analysis of data through Analysis of Variance procedures in a Randomized Complete Block Design under factorial arrangements and comparison of means through Duncan’s Multiple Range test showed the reduced feed intake, enhanced nutrient utilization for dry matter, crude protein, crude fiber, crude fat and ash; superior feed conversion ratio; higher live final body weight; lower mortality and rearing cost in SY fed birds, especially in the males of Lakha variety than the rest of the treatments. The dietary supplementation with SY increased the values of glucose, triglyceride, globulin, glutathione peroxidase (GPX) in blood serum but decreased the levels of urea, creatinine, uric acid, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol, and thyroxin (T4), especially in the birds of Lakha and Peshaweri varieties. Significant variations in slaughtering traits were observed. SY inclusion presented improved live final body weight, dressing weight, dressing%, eviscerated weight, eviscerated% and giblet weight. Selenium accumulation in the chest and thigh muscles was also significantly enhanced, especially in the birds of Lakha and Mushki exposed to SY supplemented diet. This study concluded that SY had a major influence in improving the overall growth performance of indigenous Aseel chicken. In the 2nd experiment, a total of 96 selenium-treated twenty-one-weeks-aged birds (84 females and 12 breeding males) from Lakha, Mushki, Peshaweri and Mianwali varieties of Aseel were selected randomly and distributed into four groups (21 females and 3 breeding males from each variety), subdivided into three treatment groups A, B and C with seven replicates and 7 females and 1 breeding male in each treatment. Each treatment was replicated 7 times with one bird in each replicate. Groups A and B were the experimental, while C was control group. Ration for the birds of group A and B was supplemented @ 0.3 ppm with SY and SS, while group C was fed the ration without Se additional supplement. The birds were maintained separately in battery cages from 22 to 42 weeks. Stud mating system was practiced for breeding by providing access to each of 7 females to respective males in which SY treated males were offered for mating to SY treated females, SS treated males were offered to SS treated females and non-treated males were offered to non-treated females once a week to obtain fertile eggs from hens. Results showed that SY fed Mianwali females exhibited higher feed intake, enhanced body weight and gained sexual maturity earlier, better egg production, higher egg weight and egg mass. FCR/dozen eggs, FCR/kg egg mass were observed higher in Peshaweri. Higher egg Se concentration was recorded in SY fed group compared to SS and control groups. Non-significant variations were observed in Haugh unit scores among all the four varieties. Interaction presented improvement in egg breadth, egg length, egg volume, egg weight, egg shape index, egg shell thickness, yolk index and Huagh unit scores of the eggs in all varieties with significantly higher values in SY-fed Mianwali females. The SY-fed females of Peshaweri showed decreased dead germ%, dead in shell% and clear egg% compared with the females receiving other treatments. Improved hatchability% and hatch of fertile% was also noticed in females of SY-fed group; the highest increase was recorded in Peshaweri. Similarly, superior body weights of the hatched chicks (next progeny) of Peshaweri and Mianwali varieties were detected on SY supplemented ration. It was therefore concluded that SY is the superior supplement that can improve the production and reproduction traits of Aseel as well as assist in manufacturing a quality functional food in the form of Se-enriched eggs.