The Nigerian local chicken hormonal functional status as influenced by age and sex factors
A study was conducted to investigate the effect of age and sex on the hormonal status of the Nigerian Local Chicken raised in the Teaching and Research Farm of the Rivers State University Nkpolu-Oroworukwo, Port Harcourt. A total of forty (40) heterogeneous population of the Nigerian Local Chickens were used in a Completely Randomized Block Design (CRBD). Blood samples were collected from 10 males and 10 females from two different age groups (21 and 72 weeks). Hormonal assay was conducted to ascertain the values of some growth and reproductive hormones. These includes; thyroxin (T4), Triiodothyroxine (T3), Thyroid stimulating hormone (TSH). Prolactin (PRL), testosterone (TET), estrogen (E), luteinizing hormone (LH), follicle stimulating hormone (FSH) and progesterone (PROG). PRL, FSH, PROG and TET were significantly (p<0.05) affected by age while others were not significant (p<0.05). Prolactin had higher value for birds under the ages of 21 weeks than 72 weeks of age with a corresponding value of 28.35ng/mL and 8.64ng/mL respectively. Sex effect on hormones showed that, all hormones studied were significant except Tri-iodothyronine (T3). Testosterone as observed in this study was also influenced by age. Male birds unlike their female counterparts at 72 weeks of age recorded higher means value of 4.14 ± 0.52 than those of 21 weeks of age (1.11 ± 0.07). Therefore, the study was able to demonstrate the influence of age and sex on the status of hormones in the Nigerian Local Chicken.
Keywords: Local chicken, age, sex, growth hormones, reproductive hormones