Heritability Estimate and Genetic Correlations of Reproductive Features in Nellore Bulls, Offspring of Super Precocious, Precocious and Normal Cows Under Extensive Farming Conditions

The present work aimed to estimate heritability and genetic correlations of reproductive features of Nellore bulls, offspring of mothers classified as superprecocious (M1), precocious (M2) and normal (M3). Twenty one thousand hundred and eighty-six animals with average age of 21.29 months were used, evaluated through the breeding soundness evaluation from 1999 to 2008. The breeding soundness features included physical semen evaluation (progressive sperm motility and sperm vigour), semen morphology (major, minor and total sperm defects), scrotal circumference (SC), testicular volume (TV) and SC at 18 months of age (SC18). The components of variance, heritability and genetic correlations for and between the features were estimated simultaneously by restricted maximum likelihood, with the use of the vce software system vs 6. The heritability estimates were high for SC18, SC and TV (0.43, 0.63 and 0.54; 0.45, 0.45 and 0.44; 0.42, 0.45 and 0.41, respectively for the categories of mothers M1, M2 and M3) and low for physical and morphological semen aspects. The genetic correlations between SC18 and SC were high, as well as between these variables with TV. High and positive genetic correlations were recorded among SC18, SC and TV with the physical aspects of the semen, although no favourable association was verified with the morphological aspects, for the three categories of mothers. It can be concluded that the mothers sexual precocity did not affect the heritability of their offspring reproduction features.

Interannual variation in commercial oyster (Crassostrea gigas) farming in the sea (Florianopolis, Brazil, 27 degrees 44 ' S; 48 degrees 33 ' W) in relation to temperature, chlorophyll a and associated oceanographic conditions

Aquaculture of filter-feeding bivalve mollusks involves the fruitful conversion of marine particulate organic matter into premium protein of high nutritive value. Culture performance of bivalves is largely dependent on hydrological conditions and directly affected by e. g. temperature and chlorophyll levels. Accordingly, these parameters may be related with seasonality but also with oceanographic features combined with climate events. Yields of Pacific cupped oyster (Crassostrea gigas) reared at commercial procedures in suspended structures (long-lines) in a sheltered bay in Southern Brazil (Santa Catarina State, 27S 43'; 48 W 30') were evaluated in relation to local environmental conditions: sea surface temperature, chlorophyll a concentration, and associate effects of cold fronts events and El Nino and La Nina periods. Outputs from four consecutive commercial crop years were analyzed (2005/06, 2006/07, 2007/08, 2008/09) in terms of oyster survival and development time during the following grow-out phases of the culture cycle: seed to juvenile, juvenile to adult, adult to marketable. Since culture management and genetics were standardized significant differences verified among crop performance could be mostly related to environmental effects. Time series of temperature and chlorophyll a (remote sensing data) from crop periods displayed significant seasonal and interannual variation. As expected, performance during initial grow-out stages (seed to juvenile) was critical for final crop yield. Temperature was the main factor affecting survival in these initial stages with a trend of negative correlation, though not statistically significant. On the other hand, oyster development rate was significantly and positively affected by chlorophyll a concentration. Chlorophyll a values could be increased by upwelled cold nutrient-rich South Atlantic Central Water (SACW, related to predominant Northern winds) though further dependent on occurrence of Southern winds (cold fronts) to assist seawater penetration into the sheltered farming area. Lower salinity nutrient-rich northward drifted waters from La Plata River discharge may also result in chlorophyll a rise in the farming area. The El Nino period (July 2006 to February 2007) coincided with lower chlorophyll a levels in the farming site that may be related to both decreased number of cold fronts as well as predominance of Northern winds that retain northward spreading of La Plata River discharge waters. In contrast, the La Nina period (August 2007 to June 2008) corresponded to higher chlorophyll a values in the farming area by both upwelling of SACW and penetration of La Plata River discharge water assisted by increased occurrence of Southern winds and cold fronts. The recognition of the potentially changing climate and effects upon the environment will be an important step in planning future development of bivalve aquaculture.

Exogenous influences on plant secondary metabolite levels

Plant secondary metabolites are a group of naturally occurring compound classes biosynthesized by differing biochemical pathways whose plant content and regulation is strongly susceptible to environmental influences and to potential herbal predators. Such abiotic and biotic factors might be specifically induced by means of various mechanisms, which create variation in the accumulation or biogenesis of secondary metabolites. Hence the dynamic aspect of bioactive compound synthesis and accumulation enables plants to communicate and react in order to overcome imminent threats. This contribution aims to review the most important mechanisms of various abiotic and biotic interactions, such as pathogenic microorganisms and herbivory, by which plants respond to exogenous influences, and will also report on time-scale variable influences on secondary metabolite profiles. Transmission of signals in plants commonly occurs by 'semiochemicals', which are comprised of terpenes, phenylpropanoids, benzenoids and other volatile compounds. Due to the important functions of volatile terpenes in communication processes of living organisms, as well as its emission susceptibility relative to exogenous influences, we also present different scenarios of concentration and emission variations. Toxic effects of plants vary depending on the level and type of secondary metabolites. In farming and cattle raising scenarios, the toxicity of plant secondary metabolites and respective concentration shifts may have severe consequences on livestock production and health, culminating in adverse effects on crop yields and/or their human consumers, or have an adverse economic impact. From a wider perspective, herbal medicines, agrochemicals or other natural products are also associated with variability in plant metabolite levels, which can impact the safety and reliable efficacy of these products. We also present typical examples of toxic plants which influence livestock production using Brazilian examples of toxicity of sapogenins and alkaloids on livestock to highlight the problem. (c) 2012 Elsevier B.V. All rights reserved.

Molecular epidemiology of livestock rabies viruses isolated in the northeastern Brazilian states of Paraíba and Pernambuco from 2003 - 2009

Background Limited or no epidemiological information has been reported for rabies viruses (RABVs) isolated from livestock in the northeastern Brazilian states of Paraíba (PB) and Pernambuco (PE). The aim of this study was to clarify the molecular epidemiology of RABVs circulating in livestock, especially cattle, in these areas between 2003 and 2009. Findings Phylogenetic analysis based on 890 nt of the nucleoprotein (N) gene revealed that the 52 livestock-derived RABV isolates characterized here belonged to a single lineage. These isolates clustered with a vampire bat-related RABV lineage previously identified in other states in Brazil; within PB and PE, this lineage was divided between the previously characterized main lineage and a novel sub-lineage. Conclusions The occurrences of livestock rabies in PB and PE originated from vampire bat RABVs, and the causative RABV lineage has been circulating in this area of northeastern Brazil for at least 7 years. This distribution pattern may correlate to that of a vampire bat population isolated by geographic barriers.