Circulating progesterone at insemination and accessory spermatozoa are associated with fertilization and embryo quality five or six days post insemination in dairy cattle.

This study aimed to evaluate animal and ovarian parameters that affected fertilization and embryo development up to the morula stage. The data were combined from four studies in which cows were inseminated between 46 and 60 days in milk, following a synchronization protocol, and flushed for embryo collection five or six days later. Parity and body condition score on the day of insemination were recorded. Cyclicity, ovarian structures, and circulating hormone concentrations before and on the day of insemination were also assessed. The recovered structures were graded on a 5-point scale (excellent-good quality, fair quality, poor quality, degenerated, and not fertilized). For recovered embryos, the total number of blastomeres, the number of nonviable blastomeres, and the number of accessory spermatozoa were assessed by epifluorescence microscopy. The risk factors for fertilization and embryo quality were identified using cumulative link mixed models. A total of 418 structures from 389 lactating Holstein cows (34% primiparous and 66% multiparous) were recovered. Thirty-five percent of the recovered structures were excellent-good quality embryos, 21% were fair quality embryos, 11% were poor quality embryos, 16% were degenerated embryos, and 17% were unfertilized oocytes. Structures from primiparous cows, from those with greater progesterone concentration at insemination, and from cows with seven or less accessory spermatozoa were less likely to be fertilized or of better quality than structures from multiparous cows, from those with lower progesterone concentration in plasma, and from those with more than seven accessory spermatozoa, respectively. Embryos with more blastomeres or without nonviable blastomeres were more likely to be of better quality than embryos with fewer blastomeres or with nonviable blastomeres. The results of this analysis highlight the importance of low circulating concentrations of progesterone near artificial insemination and potential positive association with number of accessory spermatozoa reaching the embryo and improvement of embryo development up to the morula stage.

Milk lymphocyte profile and macrophage functions: new insights into the immunity of the mammary gland in quarters infected with Corynebacterium bovis.

BACKGROUNDS: The present study explored the viability of bovine milk macrophages, their intracellular production of reactive oxygen and nitrogen species (RONS), and their phagocytosis of Staphylococcus aureus, as well as the profile of lymphocytes, from healthy udder quarters and udder quarters infected by Corynebacterium bovis. The study included 28 healthy udder quarters from 12 dairy cows and 20 udder quarters infected by C. bovis from 10 dairy cows. The percentages of macrophages and lymphocytes were identified by flow cytometry using monoclonal antibodies. Macrophage viability, RONS production, and S. aureus phagocytosis were evaluated by flow cytometry. RESULTS: Milk samples from quarters infected with C. bovis showed a lower percentage of macrophages but an increased number of milk macrophages per mL and a higher percentage of macrophages that produced intracellular RONS and phagocytosed S. aureus. No effect of C. bovis infection on macrophage viability was found. Udder quarters infected by C. bovis showed a higher percentage of T cells and CD4+ T lymphocytes, but no effect was found on the percentage of CD8+ CD4- T, CD8- CD4- T, or B lymphocytes. CONCLUSIONS: Thus, our results corroborate, at least in part, the finding that intramammary infections by C. bovis may offer protection against intramammary infections by major pathogens.

Ocorrência e caracterização da tuberculose em caprinos leiteiros criados no estado de Pernambuco / Occurrence and characterization of tuberculosis in dairy goats bred in the state of Pernambuco, Brazil

Acreditou-se durante muito tempo que a espécie caprina era resistente à infecção por Mycobacterium bovis, porém tal hipótese foi desconsiderada quando relatos da enfermidade surgiram em vários países. No entanto, ainda permanecem desconhecidas certas características da tuberculose em caprinos e suas implicações na saúde pública e caprinocultura nacional. Objetivou-se com este trabalho descrever os aspectos nosológicos, radiológicos, anátomo-histopatológicos, baciloscópicos e biomoleculares da tuberculose em caprinos leiteiros com doença respiratória, naturalmente infectados e procedentes do estado de Pernambuco. Para isso foram tuberculinizadas 442 cabras com sintomas respiratórios e, destas, 3,4% (15/442) foram consideradas positivas ao teste. Dos animais positivos, sete foram monitorados clinicamente durante 12 meses, descrevendo-se os achados obtidos. O agente etiológico foi identificado através da reação em cadeia da polimerase, por amplificação de sequências genômicas do Complexo Mycobacterium tuberculosis e posteriormente de Mycobacterium bovis. Este é o primeiro diagnóstico molecular com caracterização do envolvimento do Mycobacterium bovis na tuberculose caprina no Brasil.

For a long time, it was believed that the goat species is resistant to infection by Mycobacterium bovis; however, this hypothesis changed when reports of the disease became apparent in various countries. Nevertheless, certain characteristics of tuberculosis in goats and its impact on public health are still unknown. The objective of this study was to describe nosologic, radiologic, anatomo-histopathological, bacilloscopic and biomolecular aspects of tuberculosis in dairy goats with respiratory disease naturally infected, from the state of Pernambuco, Brazil. When we tuberculinized 442 goats with respiratory symptoms, 3.4% (15/442) of these were considered positive in the test. From the positive goats, seven were monitored clinically for 12 months. The etiological agent was identified through the polymerase chain reaction, by amplification of genomic sequences of the Mycobacterium tuberculosis complex and later Mycobacterium bovis. This is the first molecular diagnosis which characterizes the involvement of Mycobacterium bovis in goat tuberculosis in Brazil.