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The illegal use of glucocorticoids (GCs) as growth-promoters (GPs) is prohibited in farm animals in the European Union because the strong pharmacological activity of most synthetic GCs produces residues that are dangerous for human consumption. Among the alternative methods proposed to increase the efficacy of official controls, histology was the technique of choice in Italy on account of its high performance level. The aim of this study was to evaluate the reliability of immunohistochemistry (IHC) using anti-cleaved-Lamin A antibody to enhance the performance of the histological test applied to GC-related microscopic changes in the thymus. Veal calves (VC) and beef cattle (BC) were raised and both underwent different growth-promoting protocols or were left untreated. The morphology of the thymus parenchyma was evaluated for cortical atrophy with concurrent adipose tissue infiltration, and a score of 1 to 3 was attributed. A semi-quantitative IHC analysis was also performed by counting the number of positive thymocytes in 5 randomly selected high-power fields (HPFs). The distribution of the thymus atrophy scores was significantly different among the subgroups in both BC and VC. The IHC values were higher in untreated than in treated animals, for both BC and VC. The association between thymus atrophy score and IHC positivity showed higher median values in control than in treated animals (independently of the treatment protocol), for both BC and VC. Our data shows that IHC against anti-cleaved-Lamin A antibody is a reliable marker to detect illegal GC treatments, administered either alone or in association with other growth promoters, in both BC and VC. Combining IHC with the thymus atrophy score improves the accuracy of the histological method in correctly identifying treated animals and could represent a valuable, reproducible method to be applied to large-scale screening programmes. [ABSTRACT FROM AUTHOR]

Contents High-yielding dairy cows are struggling with a high incidence of embryonic loss, among others caused by an insufficient peripheral progesterone concentration which for its part might be associated with an impaired luteal progesterone production. This impaired capacity to produce progesterone might be reflected in the histology of the gland. The aim of the present pilot study was the assessment of the variation in cell density within a bovine luteal gland ( LG), to examine whether it is possible to analyse histologically the functionality of the gland based on one single tissue sample. Six LGs (stage II or III) were harvested out of just as many healthy cows at the slaughterhouse. The luteal cell density was assessed by calculating the nuclear density ( ND) of the different luteal cell types on haematoxylin-eosin-stained histological sections from a number of topographic regions evenly spread throughout the glands, to give an overview of the pattern of cellular distribution within the whole gland. Cells were differentiated into 'large luteal cells', 'small luteal cells' and 'non-steroidogenic cells'. Results show that the cellular density, within a tissue sample is not significantly influenced by its location in relation to the gland's equatorial plane. However, the position with respect to the polar axis of the gland has a decisive effect, as the ND is significantly higher (p < 0.05) in the peripheral regions (outer zone) when compared with the central regions (inner zone) of the gland, and this counts for all three cell types. [ABSTRACT FROM AUTHOR]

Abstract: The placenta of mammals is a structure formed by the juxtaposition of the fetal membranes and the maternal tissues. The main function of the placenta is to regulate the physiological interchange between the fetus and the mother as well as to operate as an important endocrine organ during the gestation. The placentomal fusions were characterized throughout gestation of cattle using macroscopic, histological and flow cytometry analyses. Analyzing the cell cycle phases with a flow cytometry, a balance between the G2M phase and apoptosis was observed, suggesting that the placentomal fusions do not interfere in the placentary maturation process, which is a pre-requirement for the fetal-maternal disconnection and the release of fetal membrane. [Copyright &y& Elsevier]

Abstract: Studies of postpartum endometrial physiologic and immune mechanisms in cows are compromised by the difficulty in acquiring tissue of suitable quality and in sufficient quantity (Bos taurus). Endometrial biopsy sampling has attracted concern regarding potential animal ill-health and perturbed subsequent fertility. Here, we describe a method of endometrial biopsy that obtains high-quality tissue samples and does not compromise fertility. Using a Hauptner instrument, endometrial biopsies were taken at 15, 30, and 60 d postpartum from 13 mixed-breed beef cows. The effects of repeat biopsy on health (heart rate, respiration rate, color of mucous membranes, rectal temperature), onset of estrous cyclicity, and first service conception rate were monitored. Extensive daily clinical examinations revealed no signs of ill-health. All cows had resumed estrous cyclicity at 60 d postpartum. A conception rate of 77% was achieved after estrus synchronization and artificial insemination. Each biopsy yielded intact endometrial tissue and nucleic acid suitable for extensive histologic and molecular analysis, respectively. We conclude that when carried out appropriately, bovine endometrial biopsy is a safe and reliable technique for assessing postpartum uterine function or health. [Copyright &y& Elsevier]

The article presents information of a study which aims to characterize physiological and histological responses to heat stress in imported Bos taurus, native Bos taurus, and native Bos indicus cattle. It found that native Bos indicus cattle were environmentally adapted and differed in skin histology and sweat gland histometry.