80 Exploratory Animal and Medical Research, Vol.6, Issue 1, June, 2016 ISSN 2277- 470X (Print), ISSN 2319-247X (Online) Website: www.animalmedicalresearch.org Explor Anim Med Res, Vol.6, Issue - 1, 2016, p. 80-88 Research Article EFFECT OF GnRH AND PHOSPHORUS IN DELAYED PUBERTAL SURTI BUFFALO HEIFERS H.B. Dhamsaniya 1 , Sanjay C. Parmar 2 *, S.J. Jadav 3 , D.V. Pansuriya 1 , A.S. Patel Received 10 February 2016, revised 15 May 2016 1 Sabarmati Ashram Gaushala, Ahmedabad region, H.Q. Bidaj, Kheda – 387 120, Gujarat, India. 2 College of Veterinary Science & Animal Husbandry, Anand Agricultural University, Anand – 388 001, Gujarat, India. 3 Dairy Vigyan Kendra, Anand Agricultural University, Anand – 388 001, Gujarat, India. *Corresponding author. e-mail: dr.sanjayparmar@yahoo.in. ABSTRACT: The study was conducted on eighteen delayed pubertal Surti buffalo heifers, divided into three equal groups (6 in each) to evaluate the efficacy of GnRH alone and in combination of phosphorus. The buffalo heifers in Group-I and Group-II were treated with Buserelin acetate (5 ml, IM). Buffalo heifers in Group-II also received additional injection of Toldimphos sodium (10 ml, IM) at 3 day interval for 4 times, while buffalo heifers in Group-III served as control. The percentage of induced estrus was highest (83.33%) in each treated groups as compared to control group (50%). The mean estrus induction intervals were significantly (P<0.05) shorter in Group-I (20.20 ± 2.18 days) and Group-II (18.80 ± 2.32 days) as compared to control group (30.24 ± 0.81 days). The conception rate at induced estrus was highest in Group-II (50%) followed by Group-I (33.33%). The plasma progesterone levels being significantly lowest on the day of estrus (less than 0.5 ng/ml) as compared to pre-treatment days in all groups. The mean total protein and triglycerides levels were differed significantly between the groups on the day of estrus and being significantly higher in Group-II as compared to Group-I and III on that day. A significantly higher level of cholesterol in both treatment groups as compared to the control group during different intervals and also being higher on the day of estrus as compared to pre-treatment days. The mean plasma glucose levels were differed non- significantly between and within the treatment and control groups. It is concluded that estrus can be successfully induced in delayed pubertal heifers with the use of GnRH alone and in combination with phosphorus. Key words: Buffalo heifers, GnRH, Phosphorus, Estrus, Hormonal, Metabolic profile. INTRODUCTION The ovarian activity in buffalo begins with puberty. Puberty is complex physiological phenomenon whose origins are the neuro- endocrine mechanisms that determine the first ovulation and changes in primary and secondary sexual characters in the female. Follicle stimulating hormone (FSH) and luteinizing