Ivo Walter dos Santos

Comparison between deep intracornual artificial insemination (dIAI) and conventional artificial insemination (AI) using low concentration of spermatozoa in beef cattle

This study aimed to compare the pregnancy rate using the conventional artificial insemination (AI) or deep intracornual artificial insemination (DIAI), with low number of spermatozoa (4.0 million sperm) in 270 Nelore cows. The animals were divided in two groups (G: G1 (135 cows) conventional AI was performed (=semen deposition in the uterine body) and in G2 (135 cows) to DIAI, in ipsilateral horn where the dominant follicle in the ovary had previously been detected, by ultrasound examinations. For both the methods, a single artificial insemination was carried out after visual estrus observation, checked three times a day (morning, afternoon and evening). The pregnancy diagnosis after 45 days was conducted by ultrasound. Results showed a better pregnancy rate in the DIAI group (67.4% - p<0.01), when compared to conventional AI (48.8%) with low spermatozoa concentration.

PUERPÉRIO DA VACA PELA ULTRA-SONOGRAFIA

The aim of this study was to investigate uterus involution and ovarian activity by ultrasonography. The puerperium of fifteen charolais cows was observed from the 8th to 40th day, with interval of 3 days. A Pie Medicai Inc. Scanner Mod. 450 with a 5MHz linear array transducer and a printer were used for ecographic purposes. The uterus complete involution, was detected on the 28.12±1.55 days in the cows with normal parturition and on the 32.57±1.13 days in the cows with dystocia and the lochia was not visualized on the 18.87±1.12 days and 25.28±1.13 day respectively postpartum. The puerperium period was tested by linear and quadratic regression. A high significance was observed, between normal and dystocic parturition on the uterino horn involution (p < 0.0001) and the cervix (p < 0.01). On the 10th day, great follicles was detected and on the 13th day ovulation was observed without estrous manifestation. The correct monitoration of uterus involution, as well as the lochia and resumption of ovarian function, during the puerperium, is feasible through ultrasonography.

Temporary Calf Removal and Equine Chorionic Gonadotropin (Ecg) Administration after Progesterone-Based Protocol Improves the Reproductive Performance of Beef Cattle

This study aimed to evaluate the effects of equine chorionic gonadotropin (eCG) administration and the temporary 48-h calf removal (CR) in a long-term progesterone (P4)based protocol in suckled Nelore cows. In all, 150 cows were randomly submitted to P4 protocol as follows. At day 0 (d 0), an intravaginal device containing 1.9 g P4 was inserted, and 1 mg estradiol benzoate (EB) was injected intramuscularly (im). On d 8, the P4 device was removed, and cows were im injected 500 µg of prostaglandin F group 2 alpha (PGF 2α ). On the same day, 75 cows (eCGCR group) received 400 IU im of eCG and were separated from their calves for 48 h. The other 75 cows (NoeCGCR group) stayed with the calves and did not receive eCG. On d 10, the calves were returned to the eCGCR group. After 8 days, all the cows were observed for estrus. The ovulatory follicle size was measured using ultrasonography at the day estrus was detected, and artificial insemination (AI) was performed 12 h later. Pregnancy was diagnosed 35 days after AI. The respective parameters for the eCGCR and NoeCGCR groups were as follows: pregnancy rate, 74.6% and 50.6% ( p 0.05). Thus, eCGCR after a long-term P4 protocol markedly improved pregnancy rates and estrus induction.

SINCRONIZAÇÃO DO ESTRO EM VACAS DE CORTE

O objetivo desse trabalho foi o de comparar a eficiencia do cloprostenol aplicado isoladamente e do acetato de medroxiprogesterona (MGA) mais cloprostenol para sincronizar o estro de vacas. Cento e sessenta vacas secas, meio sangue Nelore x Charoles, foram selecionadas em dois grupos: G1 - composto por 80 vacas recebeu 0,5 mg de cloprostenol (IM), com previa identificacao do corpo luteo por palpacao retal; G2 com 80 vacas foram submetidas a aplicacao de Progesterone Releasing Intravaginal Device (PRID), em forma de pessario, impregnado com 200 mg de acetato de medroxiprogesterona por via intravaginal, permanecendo por 9 dias, sendo que no 8o dia foi aplicado 0,5 mg de cloprostenol (IM). As vacas de ambos os grupos apresentaram estro a partir de 48 horas da aplicacao do cloprostenol, sendo 87,5% das vacas do G1 e 95% dos animais do G2 (P Estrus synchronization in beef cows Abstract A comparative study between coprostenol alone or associated with progesterone to synchronize estrus has been carried out in 160 unsuckled beef cows of the Nelore x Charoles crossbreed. For the experiment, all cows were divided into two groups = G1 and G2 = of 80 animals each. By means of rectal palpation, the presence of a salient corpus luteum has been established in all animals of group G1. Each cow of this group received by intramuscular injection 0.5 mg of coprostenol. To the G2 group of cows, a progesterone releasing intravaginal device (PRID) containing 200 mg of medroxiprogesterone acetate, was applied during 9 days. At the 8th day, to each animal of this group, 0.5 mg of coprostenol was also administered by intramuscular injection. Within 48 to 72 hours after this treatment, estrus has been detected in 87.5% of cows from G1 and 95% from G2 (P

DIAGNÓSTICO DE GESTAÇÃO NA VACA PELA ULTRA-SONOGRAFIA

SUMMARY The aim of this study was to investigate the embryonic development and the age of the pregnancy, in which may firstly be detected by ultrasound. One hundred and forty two cows, performing two groups were submitted to echographic examination for pregnancy diagnosis. A Pie Medical Inc. scanner Mod. 450 with a 5MHz linear array transducer and a printer were used for echographic purposes. In the first group constituted of 12 charolais cows were studied some characteristics of the fetal anatomy from the 10th to the 50th day. The first detection of the subsequent structures was made in the following days: embryonic vesicle (18.0 ± 0.7); embryo proper (24.1 ± 0.5); heartbeat (26.2 ± 0.6); amnion (30.7 ± 0.7); limbs (32.7 ± 0.6); vertebres (40.2 ± 0.7); fetal movements(45.6 ± 0.5). In the second group constituted of 130 cross bred charolais cows the embryonic development from the 23rd to the 50th day of gestation was observed. In this period the embryonic vesicle reached a diameter of 46.4mm with a daily growth of 38mm and the embryo, a length (crown-rump) of 36.4rnm with a daily increase of 1.15mm (P<0.0001). The eariy pregnancy diagnosis as well as the monitoring of gestation, is feasible through uttrasonography.