The association of medroxyprogesterone to the Ovsynch protocol for the fixed time artificial insemination of cyclic buffaloes (Bubalus bubalis) in the Eastern Amazon

O presente estudo visou avaliar os efeitos da associação da medroxiprogesterona (análogo sintético da progesterona) ao protocolo Ovsynch sobre o crescimento folicular, a ovulação e a taxa de concepção de búfalas criadas na Amazônia Oriental (Tracuateua-PA). Vinte e sete fêmeas adultas (G1 n=14 e G2 n=13), cíclicas, sem bezerro ao pé e com ECC 3,5 foram submetidas a Ovsynch. Os animais do G2 receberam 60 mg de medroxiprogesterona entre D0 e D7 (D0=início do tratamento). A ultra-sonografia ovariana foi realizada nos D 0, 7, 9 e 10. O contingente de folículos pequenos diferiu no D7 (G1: 4,57±0,60 versus G2: 6,54±0,67; P=0,05). Tempo e tratamento influenciaram o diâmetro folicular no D7. O crescimento do folículo dominante entre D7 e D9 foi maior nos animais tratados (G1: 2,05±0,49 mm/dia versus 3,48±0,41 mm/dia; P<0,05). Mais animais do G1 ovularam precocemente (35,71% versus 30,77%), porém isso não afetou as taxas de concepção (G1: 50,00% e G2: 30,77%; P>0,05). Os achados sugerem que a medroxiprogesterona (1) aumenta recrutamento folicular e retarda o crescimento dos folículos com diâmetro maior que 5,0 mm entre D0 e D7; (2) sua retirada incrementa em 1,7 vezes o crescimento folicular do D7 ao D9; (3) pode contribuir para a ovulação de folículos maiores e, em tese, para maior formação de tecido luteínico; (4) não promove ovulação precoce após o Ovsynch; (5) não eleva as taxas de concepção após sincronização de fêmeas cíclicas e com bom escore corporal, devendo ser avaliada para uso em fêmeas acíclicas ou com ECC mais baixo.The aim of this study was to evaluate the effect of the association of medroxyprogesterone with the Ovsynch protocol on the follicular growth, ovulation, and conception rate of buffaloes in the Eastern Amazon (Tracuateua-PA). Twenty-seven cyclic, non-lactating females (G1 n=14 and G2 n=13) with a 3.5 BCS were synchronized with the Ovsynch. Animals from G2 received a supplementation of 60 mg of medroxyprogesterone from D0 to D7 (D0=starting day of treatment). Ultrasonography evaluation on ovaries was realized on Days 0, 7, 9, and 10. A significant effect of treatment on follicle number was observed on D7 (G1: 4.57±0.60 versus G2: 6.54±0.67; P=0.05). Time and treatment influenced follicular diameter on D7. The growth of the dominant follicular was increased from D7 to D9 on treated females (G1: 2.05±0.49 mm/day versus 3.48±0.41 mm/day; P<0.05). G1 animals (35.71% versus 30.77%) ovulated comparatively earlier than their G2 counterparts, but this did not affect the conception rates (G1: 50,00% and G2: 30,77%; P>0,05). The findings suggest that medroxyprogesterone: (1) increases follicular recruitment and inhibits the growth of follicles whose diameter was larger than 5.0mm from D0 to D7; (2) the withdrawal of medroxyprogesterone speeds up follicular growth 1.7 fold from D7 to D9; (3) would probably contribute to the ovulation of larger follicles thereby forming more luteal tissue; (4) does not stimulate early ovulation after Ovsynch; and (5) does not elevate the conception rate after the synchronization of cyclic females with good body condition, and should be evaluated for the utilization in acyclic/reduced BCS females.Embrapa Amazônia OrientalBanco da Amazôni

Comparison between Tris, Lactose/Tris, Ringer- Lactate and Skim Milk as extenders to deep freezing buffalo semen

ABSTRACT. Miyasaki M.Y.A., Vale W.G., Baía F.A.C., Minervino A.H.H., Ribeiro, H.F.L. & Miyasaki M.T.A. [Comparison between Tris, Lactose/Tris, Ringer- Lactate and Skim Milk as extenders to deep freezing buffalo semen.] Comparação entre o Tris, Lactose/Tris, Ringer-Lactato e Leite Desnatado como diluidores na criopreservação do sêmen bubalino. Revista Brasileira de Medicina Veterinária, 36(1):1-10, 2014. Instituto de Biodiversidade e Florestas, Universidade Federal do Oeste do Pará, Campus Tapajós, Rua Vera Paz, s/n, Santarém, PA 68035-110, Brasil. E-mail: [email protected] The objective of the present experiment was to test the effectiveness of different extenders, as TRIS (hydroxymethyl-amino-methil-methan), Lactose/ TRIS, Ringer-Lactate and Skim Milk, for deep freezing and cryopreservation of buffalo semen. Three male Murrah buffaloes were submitted to semen collection through artificial vagina, totaling 71 ejaculates. After collection, each sample was subjected to analysis of physical and morphological characteristics of semen. The ejaculates were fractionated, diluted and frozen in four diluents. After deep freezing process the frozen semen were thawed at 40°C for 30 seconds and sequentially evaluated for motility, vigor, acrosome damage, and percentage of sperm abnormalities. The thermo-resistance test (TCT) was used to evaluate the post-thawing of motility and sperm vigor characteristics at 3-5 minutes, 30 minutes, 1 hour, 2 hours and 3 hours of incubation. After thawing the spermatic vigor decreased significantly (p 0.05), however no statistical differences were observed when compared with each other (p>0. 05). In the post-Thermo Resistance Test, after three hours of incubation, motility and sperm vigor showed no statistical difference between treatments (p 0.05). Notwithstanding, the observed results allowed to be concluded that the four extenders used have demonstrated satisfactory function when used in deep freezing of buffalo semen, with adequate technical and economic feasibility for this biotechnology applied to animal species used