High numbers of antral follicles are positively associated with in vitro embryo production but not the conception rate for FTAI in Nelore cattle.

The objective was to compare the conception rates for FTAI and in vitro embryo production between Nelore cows with different antral follicle counts (AFC=number of follicles ≤3mm in diameter in the ovaries). Nelore cows (n=547) were subjected to ovulation synchronization. Randomly during the estrous cycle (D0), cows received an intravaginal device containing 1.9g P4 (CIDR(®)) and 2mg BE (Estrogin(®)), IM. When the device was removed (D8), the cows received 500µg PGF2α (Ciosin(®)), 300IU eCG (Novormon(®)) and 1mg EC (ECP(®)), IM. All cows were inseminated 48h after P4 device removal. Antral follicles ≥3mm were counted using an intravaginal microconvex transducer (D0), and the cows were assigned to high (G-High, ≥25 follicles, n=183), intermediate (G-Intermediate, 16-20 follicles, n=183) or low AFC groups (G-Low, ≤10 follicles, n=181). In another experiment, COCs were retrieved by OPU from Nelore cows (n=66), which were assigned to groups according to oocyte production: G-High (n=22, ≥40 oocytes), G-Intermediate (n=25, 18-25 oocytes) or G-Low (n=19, ≤7 oocytes). All COCs from the same cow were cultured individually (maximum of 25 COCs per drop) and then in vitro fertilized using thawed frozen sperm (2×10(8)/dose) from a Nelore sire of known fertility. The data were analyzed using a Kruskal-Wallis and a Chi-square test (P≤0.05). There was no difference in the conception rates after FTAI between Nelore cows with high, intermediate or low AFC (51.9 vs. 48.6 vs. 58.6%). The number of viable embryos was 18.4±6.7 (G-High), 6.1±3.6 (G-Intermediate) and 0.6±0.7 (G-Low; P<0.05). Therefore, AFC had no influence on the conception rates for FTAI; however, Nelore cows with high oocyte production exhibited better in vitro embryo production.

Effects of progestagen exposure duration on estrus synchronization and conception rates of crossbreed ewes undergoing fixed time artificial insemination.

Synchronization of estrus and ovulation are of paramount importance in modern livestock improvement programs. These methods are critical for assisted reproduction technologies, including artificial insemination and embryo transfer, that can increase productivity. In the current study, subcutaneous implants containing norgestomet were placed for long (14 days), medium (9 days), and short (5 days) periods of time in 70 crossbred ewes undergoing fixed-time artificial insemination. The resulting effects on estrus synchronization and conception rates were subsequently evaluated. Among the synchronized ewes, 85.7% (60/70) underwent estrus over a period of 72 h after progestagen treatment ceased. The shortest mean interval between withdrawal of the device and onset of estrus (34.2 ± 8.9 h) was observed in the G14 days of P4 group (p < 0.05). The conception rate of the G14 days of P4 group was statistically higher than that of the other groups (83.3% vs. 60.9% vs. 47.8%; p < 0.05). In conclusion, 14 days of norgestomet treatment produced higher conception rates and a greater number of pregnancies at the beginning of the breeding season.

Parâmetros obtidos no exame andrológico de touros da raça bonsmara / Parameters obtained on andrologic examination of bonsmara bulls

Objetivou-se com este estudo demonstrar os resultados obtidos no exame andrológico de touros da raça Bonsmara e classificá-los por meio da Classificação Andrológica por Pontos (CAP). Foram utilizados 39 touros da raça Bonsmara, criados extensivamente, com idade entre 33 a 74 meses. Os animais foram submetidos ao exame clínico geral, exame interno e externo do sistema genital, medições da circunferência escrotal e coleta do sêmen por meio de eletroejaculação, para avaliação das características físicas e morfológicas. Os resultados foram submetidos à análise estatística descritiva. Os valores médios obtidos para circunferência escrotal, motilidade espermática e vigor, foram respectivamente 40,96 ± 3,06 cm, 63,08 ± 23,41 % e 2,92 ± 0,98 (0-5) e os encontrados para defeitos espermáticos maiores e totais foram 4,25 ± 4,29 % e 21,10 ± 12,49 %. A média da Classificação Andrológica por Pontos (CAP) de 78,88 ± 18,19 (0-100) foi considerada satisfatória.

The objective of this study was to demonstrate the results obtained on andrologic examination and Andrologic Points Classification (CAP) of Bonsmara bulls. 39 Bonsmara bulls raised extensively, with ages between 33 and 74 months were submitted to general clinical examination, internal and external examination of the genital system, measurement of scrotal circumference and semen collection by electroejaculation for the evaluation of physical and morphological seminal characteristics. The results were submitted to the descriptive statistical analysis. The average values for scrotal circumference, sperm motility and vigor were respectively 40.96 ± 3.06 cm, 63.08 ± 23.41 % and 2.92 ± 0.98 (0-5) and those found for higher defects and total sperm were 4,25 ± 4.29 % and 21.10 ± 12.49 %. The average for Andrologic Points Classification (CAP) 78.88 ± 18.19 (0-100) was considered satisfactory.

Enzootic bovine leucosis ­ a case report / Leucose enzoótica bovina ­ relato de caso

Enzootic bovine leucosis is an infectious disease of cattle caused by the bovine leukemia virus that results in lymphoma within target tissues. Cattle might demonstrate four clinicopathological age-related manifestations of the disease: juvenile, adult, thymic, and cutaneous form. This article describes the unusual manifestation of this disease in a 4-yr-old cow. Regional lymph nodes were enlarged during clinical examination. Peripheral and internal lymph nodes, as well as the vagina, uterus, spleen, liver, heart, thoracic vertebrae, eye and the thoracic and abdominal cavities demonstrated lymphoma at necropsy. Bovine enzootic leucosis was confirmed by histopathology and agar gel immunodifusion.

A leucose enzoótica bovina é uma doença infecciosa de bovinos causada pelo vírus da leucemia bovina que produz linfoma em tecidos alvos. Bovinos podem demonstrar quatro manifestações clínico-patológicas da doença relacionadas à idade: forma juvenil, adulta, tímica e cutânea. Esse artigo descreve a manifestação incomum dessa doença em uma vaca de quatro anos de idade. Os linfonodos regionais apresentaram-se aumentados no exame clínico. Linfoma foi observado nos linfonodos periféricos e internos bem como na vagina, útero, baço, fígado, coração, vértebras torácicas, olho e nas cavidades torácica e abdominal durante a necropsia. A leucose enzoótica bovina foi confirmada na histopatologia e pela imunodifusão em gel de ágar.

Comparação das taxas de prenhez entre receptoras com corpos lúteos cavitários ou compactos após protocolo de sincronização com cloprostenol ou transferência de embriões em tempo fixo / Comparison tge pregnancy rates between bovine recipients with cavitary or compact corpus luteum after cloprostenol or fixed time embryo transfer

O objetivo deste experimento foi avaliar as taxas de prenhez em receptoras com corpo lúteo (CL) compacto ou cavitário, submetidas a protocolos com cloprostenol ou transferência em tempo fixo. Foram utilizadas 203 novilhas mestiças. No primeiro grupo (G-PGF, n=103), os animais com CL previamente detectados por ultra-sonografia transretal receberam 500mg de Cloprostenol (Sincrocio, Ouro fino, Brasil), por via IM e permaneceram sob observação de cio por 72 horas. No segundo grupo (G-P4, n=100), as novilhas receberam um dispositivo intravaginal de progesterona (CIDR, Pfizer, Brasil) simultaneamente à aplicação IM de 2 mg de benzoato de estradiol (BE); (Estrogin, Farmavet, Brasil). No oitavo dia, os dispositivos foram retirados e os animais receberam 500 mg de Cloprostenol (Sincrocio, Ouro fino, Brasil) por via IM. Após 24 horas, os animais receberam uma aplicação IM de 1 mg de BE. A avaliação ultra-sonográfica do CL foi realizada 10 dias e 17 dias após o início dos tratamentos, respectivamente para os grupos G-PGF e G-P4. Todas as receptoras com CL receberam embriões produzidos in vitro. O diagnóstico de gestação foi realizado 23 dias depois, por ultra-sonografia. Os resultados foram analisados pelo testo do Qui-quadrado. Não houve diferença significativa nas taxas de aproveitamento de receptoras entre os grupos G-PGF e G-P4 (72,8; 75/103; 79; 79/100). Detectou-se CL cavitário em 21,3 (16/75) das receptoras do G-PGF e 22,7 (18/79) para o grupo G-P4 (P>0,05). Entre as receptoras com CL cavitário ou compacto, não houve diferença na taxa de prenhez 41,1 (14/34) e 38,3 (46/120), respectivamente. Os resultados demonstraram que não houve diferença nas taxas de prenhez de receptoras com corpos lúteos cavitários, em comparação às receptoras com CL compactos, independentemente dos tratamentos realizados.

The aim of this work was to evaluate pregnancy rates in bovine embryo recipients with compact andcavitary corpus luteum. Two hundred and three crossbred heifers were divided in two groups. In the firstgroup (G-PGF, n=103), the animals received 500 mg de Cloprostenol IM (Sincrocio, Ouro fino, Brasil) afterCL identification by ultrasonography. After that, heifers were detected for heat the next 72 hours. Theanimals from second group (G-P4, n=100) received an intravaginal progesterone device (CIDR, Pfizer,Brasil) and 2 mg estradiol benzoate (Estrogin, Farmavet, Brasil) IM, in random stages from estrus cycle.On the 8th day the devices were removed and the animals received 500 mg of Cloprostenol IM. After 24hall animals received 1 mg BE, IM. The CL was identified and evaluated at 10 and 17 days after thebeginning of the treatmentin G-PGF and G-P4, respectively. All the heifers with CL received IVP embryos.The pregnancy diagnosis was made by transrectal ultrasonography after 23 days. The results wereanalyzed by Chi-square. There were no significant difference in number of heifers ready to embryotransfer in G-PGF and G-P4, respectively 72.8% (75/103) e 79% (79/100); (P>0.05)Twenty one percent (16/75) had cavitary CL in G-PGF and 22.7% (18/79) in G-P4 (P>0.05). Among all embryo recipients with acavitary or compact CL there was no difference on pregnancy rates(41.1% 14/34 and 38.3% 46/120,respectively, P>0.05), regardless of protocol treatment