Induction and synchronization of estrus in dairy cows using a single injection of PGF2α and GnRH

Abstract

The aim of this study was to examine the effects of treatment with a single injection of GnRH and PGF2α on estrous response, fertility and service period. A total of 120 lactating Simmental cows were divided into four groups of 30 cows each: group PGF2α 40 was treated on the 40th day post partum with a single injection of 2 mL prostaglandin analogue (Estrumate), group PGF2α 50 was treated in the same way on the 50th day, group GnRH was treated on the 40th day post partum with a single injection of 2 mL GnRH analogue (Receptal), and the fourth group (control) was not hormonally treated. Fertility of cows was not significantly different (p>0.05). The difference in the estrous response and service-period between the control group and experimental groups was statistically significant (p lt 0.01).

Cilj ovog rada bio je da se ispita uticaj tretmana sa PGF2α i GnRH na estrusno reagovanje, fertilitet i trajanje servis-perioda krava simentalske rase u laktaciji. Ukupno 120 krava bilo je podijeljeno u četiri grupe po 30 krava: prva grupa (PGF2α 40) je tretirana 40 dana post partum sa jednom injekcijom 2 ml analoga prostaglandina (Estrumate), dok je druga grupa (PGF2α 50) tretirana na isti način 50 dana, treća grupa (GnRH) tretirana je 40 dana post partum sa jednom injekcijom 2ml GnRH analoga (Receptal), a četvrta grupa nije hormonalno tretirana. Fertilitet krava nije se statistički značajno razlikovao između grupa (p>0.05), dok je kod estrusnog reagovanja krava i dužine trajanja servis-perioda između oglednih grupa i kontrolne grupe ustanovljena statistički značajna razlika (p lt 0.01).