Risposta riproduttiva al trattamento con melatonina in bufale sottoposte a sincronizzazione degli estri e inseminazione artificiale.

Aim of the present study was to increase fertility in adult buffalo cows subjected to oestrus synchronization and Artificial Insemination (AI), by melatonin administration in spring. Thirtysix pluriparous buffalo cows, aged 5.4 ± 1.2 years, were selected. On April 8, eighteen animals were treated with 3 implants each of 18 mg melatonin, while the others 18 buffalo cows were untreated (control group). All the animals received oestrus synchronization treatment (April, 28 100 mcg of gonadorelin diacetate tetra hydrate equivalent to 2m of Cystoreline®, 2ml; May 5, 10 mg of alfaprostol equivalent to 5ml of Gabbrostim®; May, 7, 28 100 mcg of gonadorelin diacetate tetra hydrate equivalent to 2m of Cystoreline). On May, 8, all the animals were examined and the cyclic buffalo cows were subjected to AI. Thirty days after AI, pregnancy status was determined by rectal examination and/or ultrasonography. On May, 8, fourteen buffalo cows treated with melatonin were cyclic vs 11/18 subjects of the control group. Also for pregnancy rate, treated group showed 13/18 animals vs 8/18 of the control group. Results show that in buffalo cows melatonin implants can stimulate reproductive activity in spring. By this way, lambing rate could be distributed throughout the year, thus streamlining the production.