Abstract

URIBE VALDERRAMA, Rubén  and  ROBLEDO VELEZ, Eliana. Using nogestomet ear devices fixed-time insemination artificial in cattle double purpose, permanent nursing calf. Ces. Med. Vet. Zootec. [online]. 2012, vol.7, n.1, pp.63-72. ISSN 1900-9607.

To evaluate the effectiveness of progesterone ear devices new and second use, rates were determined estrus and pregnancy rates in cycling and anestrous animals by breastfeeding. We used 69 dual-purpose cows (Bos taurus by Bos indicus) with calf at foot and 60 to 80 days postpartum, a livestock farm, located in the municipality of Cimitarra, Santander. The animals were implanted for 9 days with 3 mg of norgestomet (Crestar^® MSD), and were divided randomly into two groups, Group 1 (n=35) cows with new devices, Group 2 (n=34) cows with implants headset reused, and artificial insemination was performed at fixed time at 56 hours after removal of the devices. The data obtained were tested in a simple ANOVA (ANOVA) with a reliability of 95%. For the variable estrus no differences (p>0.05) between group 1 and 2 (66.4% and 53.4%), respectively. The variables pregnancy and ovarian structures (Dominant follicles and corpus luteum), upon synchronization, yielded significant differences (p<0.05) between groups 1 devices new group (53.9,%) vs group 2 devices reused (38,3%), ovarian structures and between group 1 devices new (56,6%) vs. group 2 devices reused (33.2%) respectively, with ovaries without structures. We conclude that progesterone ear devices new and reused, generate similar rates of estrus. Also, pregnancy rates are higher in cows cycling versus anestrus cows.

Keywords : Anestrus; FTAI; pregnancy rate; progestogen estrus synchronization.

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