Influence of availability of shade on testicular characteristics of Santa Ines rams

The purpose of this study was to evaluate the effects of availability of artificial shading on testicular and seminal characteristics of Santa Ines crossbred rams. Twelve 8 month old rams at 38.1 ± 5.2 kg average weight, were used in a total random design with two treatments: areas with and without available artificial shading (black polyethylene mesh screen for a 50% reduction of solar radiation). The scrotal circumference, scrotal length, scrotal volume, rectal temperature and scrotal temperature were measured twice a week. Also a biweekly analysis of the semen was carried out, measuring the volume and spermatic concentration as well as the percentage of normal spermatozoa. The results show that available shading provided for lower scrotal temperatures and higher sperm concentration, without influencing the scrotal volume and the percentage of normal spermatozoa. The testicular measures, such as the scrotal circumference and length were higher in the rams that were subjected to the no available shading treatment. The absence of differences, in some of the analyzed variables, between the two treatments, with and without available shading, could be due to high adaptability of the animals

Características físicas dos ovos da perdiz vermelha (Alectoris rufa) criada em cativeiro

The objective of the present study was to evaluate the effects of female age (1, 2 and 3-year-old) and month of laying (March, April and May) on the physical characteristics of the red-legged partridge eggs reared in captivity. O objetivo do presente estudo foi avaliar os efeitos da idade das fêmeas (um, dois e três anos) e do mês de postura (março, abril e maio) sobre as características físicas dos ovos da perdiz vermelha (Alectoris rufa) criada em cativeiro. O peso (W), o comprimento máximo (L) e a largura máxima (B) de 2878 ovos foram determinados diretamente, enquanto o índice de forma (B/L), o volume (V) e a superfície (S) foram calculados com base nos parâmetros determinados diretamente. A análise mostrou diferenças significativas (P0,05). Observaram-se diferenças significativas (P<0,01) na largura máxima e no índice de forma do ovo entre as diferentes classes de idades, com valores mais elevados nas fêmeas mais velhas e no período de postura mais tardio. O volume dos ovos estimados por meio de V1 = 0,51LB2 e V2=0,913W foi afetado significativamente (P<0,01) pela idade e pelo mês de postura, bem como as áreas, S1=4.835W0,662, S2=4,951V10,666 e S3=4,951V20,666, as quais apresentaram os mesmos efeitos. Palavras-chave: perdiz vermelha, Alectoris rufa, características dos ovo

Kidney histological alterations and metallothionein and heat shock protein expression in Wistar rats after fungicide thiram exposure

The histological alterations and the expression of metallothionein (MTs) and heat shock protein (Hsp70) in the kidney of Wistar rats after thiram fungicide exposure were evaluated. Animals were distributed into three groups: standard diet group, standard diet + corn oil group and thiram group. Significant differences were found (P<0,05) in the evolution of body weight between rats in the thiram group and those in the control and corn oil groups, and no histological lesions were evident in the animals’ kidneys. Differences were found among animals in the group exposed to thiram and the control and oil groups regarding histomorphometric characteristics of the renal corpuscle – except for the proportion in the area of Bowman’s capsule: glomerulus area – and regarding the height of the epitelium in the distal tubules. In rats exposed to thiram, a positive moderate to strong immunoexpression was observed for MTs, in the cortical convulated tubules decreasing the cortex towards the medulla, and a strong immunoexpression for Hsp70 in the cortex and medulla areas, in the glomerulus and convulated tubules. The results suggest that thiram may have chronic toxicity in mammals affecting their growth, and that the expression of MTs and Hsp70, a probable cellular adaptive response to the oxidative stress caused by thiram, may be used as a biomarker of exposure to this chemical. Keywords: rat, kidney, thiram, histology, metallothioneins, heat shock proteins (Hsp70

In vivo and in vitro heat shock proteins gene expression in cattle.

The main purpose for this study was the quantification of the heat shock proteins HSPA1A and HSP90AA1, in cow lymphocytes, when subjected to heat stress directly - in vivo, or indirectly - in vitro. The aim was to identify differences between HSP expression in vitro and in vivo. The experiment was conducted in the Biometeorology and Ethology Laboratory of FZEA-USP. Were used three female Holstein Frisian, which were subjected to heat stress, by sun exposure. The blood samples were collected after sun exposure, with a temperature of 40 ± 2 º C, during three days. For in vitro tests, blood of the same animals was collected and placed for a period of 4 hours in a water bath at 40 º C, thus simulating the thermal stress. Total RNA of lymphocytes was extracted, treated with DNase I and submitted to cDNA synthesis for gene expression quantification of HSPA1A and HSP90AA1, by real time PCR (qRT-PCR). The data were tested for normality by Kolmogorov-Smirnov test and for homocedasticity by Levene test. Data were analyzed according to a general linear model procedure with 2 fixed factors treatment and genes expression. Significantly different means were submitted to post-hoc comparisons of means (LSD test) and regarded as significantly different when P<0.05. The results showed that there are no significant differences between the in vitro and the in vivo treatments

Effect of artificial shading on performance and reproductive parameters of semi-confined young Brangus bulls

Thirty Brangus bulls were used in a 90-d study to assess the effect of artificial shading on the performance and reproductive characteristics of semi-confined cattle. Animals were kept in four one-ha paddocks in two groups of eight for shade treatment (5 m²/animal of 80% solar block shade cloth) and two groups of seven animals in no-shade treatment. Each treatment had two homogeneous groups, each divided into heavy-bulls (351-450 kg) and light-bulls (300-350 kg). Time spent under shade, time standing, average daily gain, testicular development and sperm quality were investigated. Animals spent 24% of the daylight under the shade and no-shaded bulls spent more time standing (P 0.05) and testicular development between shaded and no-shaded animals. However, scrotal perimeter was higher for shaded light animals compared to no-shaded light bulls (P < 0.10). Sperm motility increase during the experimental period for shaded animals (P < 0.05) and sperm abnormalities were higher for the shaded ones (P < 0.05). Although the results did not indicate pronounced benefits on cattle performance, this resource was an important alternative because it appears to provide an improvement in some reproductive parameters and ensure a better thermal comfort to the animals

Central Santa Catarina coastal dunefields chronology and their relation to relative sea level and climatic changes

During the past decades, there have been contrarian explanations for the formation and stabilization of coastal dunefields: while many authors believe the dunes formation would be enhanced by falling sea level, others argue that a rising or stable sea level context would be favorable. For Brazilian coastal dunefields, the second hypothesis seems to be more consistent with the luminescence ages found so far; however, most of these data were obtained without using the SAR protocol. Another point of concern is the role of climate change in the aeolian system, which is still not very clear. The aim of this paper is to try to clarify these two questions. To this end, five coastal dunefields were selected in central Santa Catarina coast. The remote sensing and dating results allowed the discrimination and mapping of at least four aeolian generations. Their age distribution in relation to the global curve of relative sea level variation during the Late Pleistocene allows us to suggest that the formation of Aeolian dunefields in the coastal context is supported by stable relative sea level. However, relative sea level is not the only determinant for the formation and preservation of the aeolian coastal dunes. Evidences of climatic control indicate that the initiation of dunefields would be favored by periods of less humidity while their stabilization would occur preferably during the periods of rain intensification, connected to monsoon activity