Application of melatonin implants to induce cyclicity in buffalos in seasonal anoestrus in northeastern Argentina

KONRAD, J.L.; GARRIDO, M.J.; CRUDELI, G.; DE AL SOTA, R.L.

Cartagena de Indias

Congreso; 11th World Buffalo Congress; 2016

Asociación Colombiana de Criadores de Búfalos

Buffaloes show higher melatonin plasma concentrations during breeding season, in winter, when nights are longer. Continuous-release melatonin implants are used for induction of ovary activity and trigger estrus in spring-summer. The aim of this work was to assess the efficiency of use of melatonin implants in induction of cyclicity in buffaloes in seasonal anoestrus. Twenty adult buffaloes in seasonal anoestrus were used. Ovarian structures were determined by ultrasonography, and blood samples were taken by jugular puncture for Progesterone (P4) dosage. Animals were randomly assigned into one of three treatments (TRT). TRT1 (n=10), on D0 (566.8±76.7pv), buffaloes received melatonin implants (11.2±1.62 implants of 18 mg) and on D9 0.1mg of gonadorelin acetate. TRT2 (n=5), an ovulation synchronization protocol was applied (D0, 2 mg of estradiol benzoate; placement of a P4 intravaginal device until D7, 250.ug cloprostenol; 1mg of estradiol cypionate; D9, 0,1 mg of gonadorelin acetate), and TRT3 (n=5) or control group. Ultrasound monitoring was made, and ovulation was determined by the disappearance of dominant follicle and subsequent corpus luteum formation. P4 concentration on D0 and D17 was stablished by RIA. Categorical data was analyzed with GENMOD procedure and continuous data with MIXED procedure of SAS. At the beginning of treatments all buffaloes were in anoestrus, they had follicles