Novel physiological data needed for progress in global change ecology

Studies examining the underlying causes of the distributions of species and their future trajectories under climate change have benefitted from the accumulation of measurements of thermal tolerance across the tree of life. However, gaps in the global coverage of heat-tolerance data for ectotherms persist on four critical fronts. First, most large-scale analyses treat heat tolerance as a fixed species trait despite that population-level variation can equal or exceed cross-species variation. Second, terrestrial non-arthropod invertebrates and aquatic ectotherms other than bony fish have been poorly sampled, particularly in boreal and tropical regions, the Indian Ocean and the mesopelagic-deep ocean. Third, the study of climate impacts on the heat tolerance of terrestrial ectotherms has often neglected the interaction of environmental temperatures with water availability. And fourth, the mechanisms driving the dependence of heat tolerance on oxygen supply-demand remain largely unknown. We contend that filling those data and knowledge gaps requires novel strategies for the ecophysiological sampling of the range of understudied populations and species that occupy the length of climatic gradients globally. Such developments are essential for comprehensively predicting species responses to climate change across aquatic and terrestrial biomes

Incorporating oldman saltbush hay and prickly pear in diets for red Sindhi calves

This study was designed to evaluate the nutrient intake, digestibility, degradability, and ruminal characteristics of Sindhi heifers fed diets that contained a combined total of 75% oldman saltbush hay (hereafter saltbush hay) and prickly pear cactus. Eight 12-month old intact male red Sindhi calves (four fistulated and four non-fistulated) with an initial mean weight of 170 ± 5 kg were assigned to 4 × 4 Latin squares, where factors consisted of four diets, namely 15% hay and 60% cactus; 30% hay and 45% cactus; 45% hay and 30% cactus; and 60% hay and 15% cactus, and four times at which rumen fluid was collected. Neutral detergent fibre (NDF) and acid detergent fibre (ADF) intakes in kg/day and NDF in percentage live weight (LW), water intake, salinity, and conductivity increased with hay level. Intake and digestibility of non-fibrous carbohydrates were curvilinear with higher values in diets containing 30% saltbush hay. The apparent digestibility of dry matter (DM) and organic matter decreased linearly as the concentration of saltbush hay increased in the diet. The pH of the rumen fluid was within the acceptable range for favourable microbial growth. The low temperature and high salinity and conductivity indices in the diets should be viewed with caution at higher concentrations of saltbush hay, because of a possible decrease in nutrient absorption and the development of health problems in the animals. Apparent degradability coefficients of DM and NDF were affected significantly by inclusion of prickly pear and saltbush hay in the diets.Keywords: animal nutrition, apparent digestibility, Atriplex nummularia Lindl, Opuntia ficus, ruminal degradation, semi-arid environmen

Desempenho de cabras em lactação alimentadas com dietas com diferentes níveis de fibra oriundas de forragem com maturidade avançada

Objetivou-se com este trabalho avaliar o efeito de diferentes teores de fibra em detergente neutro oriunda da forragem com maturidade avançada sobre o consumo, a digestibilidade da matéria seca e de nutrientes, o balanço de nitrogênio, a produção de leite, a eficiência de utilização da energia metabolizável e o comportamento ingestivo de cabras em lactação. Foram distribuídas cinco cabras em delineamento em quadrado latino 5 × 5 utilizando-se teores crescentes de fibra em detergente neutro oriunda da forragem como variável independente. As concentrações de fibra em detergente neutro oriunda da foragem utilizadas foram 20, 28, 35, 43 e 49%. Os consumos de matéria seca, de nutrientes e de energia líquida reduziram com o aumento de fibra na ração. No entanto, o consumo de fibra em detergente foi crescente, indicando capacidade de acomodação desse componente nutritivo pelos animais. O teor de fibra influenciou os coeficientes de digestibilidade da matéria seca, matéria orgânica, proteína bruta e dos carboidratos não-fibrosos, contudo, a digestibilidade da fibra em detergente neutro não foi influenciada pelas dietas. O nível de fibra em detergente neutro oriunda da forragem não influenciou os constituintes do leite (gordura, proteína e lactose). O teor de fibra oriunda da forragem teve efeito quadrático sobre a produção de leite (corrigida e não corrigida para 4% de gordura), em kg/dia, com maiores produções obtidas com o teor de 28% de fibra. A eficiência de utilização da energia metabolizável não foi influenciada pelas variações nas dietas. O teor de fibra em detergente neutro oriunda da forragem influencia o comportamento ingestivo de cabras em lactação, aumentando os tempos de ruminação e mastigação e diminuindo o tempo em ócio dos animais.The objective of this study was to evaluate the different contents of neutral detergent fiber from forage at advanced maturity on intake, digestibility of the dry matter and of nutrients, nitrogen balance, milk production, efficiency metabolizable energy use and the ingestive behavior of lactating goats. Five dairy goats were distributed in 5 × 5 Latin square by using increasing contents of neutral detergent fiber from forage as independent variable. Concentrations of neutral detergent fiber from forage used were 20, 28, 35, 43 and 49%. The intakes of dry matter, of nutrients and of net energy were reduced with the increase of fiber to the ration. However the intake of neutral detergent fiber was increasing, indicating the capacity of accommodation of this nutrient by the animals. Fiber content influenced digestibility coefficients of dry matter, organic matter, crude protein and non-fibrous carbohydrates but digestibility of neutral detergent fiber was not influenced by the diets. Level of neutral detergent fiber from forage did not influence milk constituents (fat, protein and lactose). Content of fiber from the forage had a quadratic effect on milk production (corrected and not corrected for 4% of fat) in kg.day-1, with greater productions obtained with the content of 28% of fiber. Efficiency of use of the metabolizable energy was not influenced by the variations of the diets. Content of neutral detergent fiber from forage influences ingestive behavior of goats in lactation, increasing the time of rumination and chewing and reducing iddle time of the animals

The ZEPLIN-III dark matter detector: performance study using an end-to-end simulation tool

We present results from a GEANT4-based Monte Carlo tool for end-to-end simulations of the ZEPLIN-III dark matter experiment. ZEPLIN-III is a two-phase detector which measures both the scintillation light and the ionisation charge generated in liquid xenon by interacting particles and radiation. The software models the instrument response to radioactive backgrounds and calibration sources, including the generation, ray-tracing and detection of the primary and secondary scintillations in liquid and gaseous xenon, and subsequent processing by data acquisition electronics. A flexible user interface allows easy modification of detector parameters at run time. Realistic datasets can be produced to help with data analysis, an example of which is the position reconstruction algorithm developed from simulated data. We present a range of simulation results confirming the original design sensitivity of a few times $10^{-8}$ pb to the WIMP-nucleon cross-section.Comment: Submitted to Astroparticle Physic

Genetic parameters for milk yield, lactation length and calving intervals of Murrah buffaloes from Brazil

The major objective of this study was to estimate heritability and genetic correlations between milk yield (MY) and calving interval (CI) and lactation length (LL) in Murrah buffaloes using Bayesian inference. The database used belongs to the genetic improvement program of four buffalo herds from Brazil. To obtain the estimates of variance and covariance, bivariate analyses were performed with the Gibbs sampler, using the program MTGSAM. The heritability coefficient estimates were 0.28, 0.03 and 0.15 for MY, CI and LL, respectively. The genetic correlations between MY and LL was moderate (0.48). However, the genetic correlation between MY and CI showed large HPD regions (highest posterior density interval). Milk yield was the only trait with clear potential for genetic improvement by direct mass selection. The genetic correlation between MY and LL indicates that indirect selection using milk yield is a potentially beneficialstrategy.Theinterpretation of the estimated genetic correlation between MY and CI is difficult and could be spurious. ©2013 Sociedade Brasileira de Zootecnia.Universidade Estadual do Sudoeste da BahiaUniversidade Federal do AlagoasUniversidade Estadual PaulistaUniversidade Federal do Mato Grosso do SulCanakkale Onsekiz Mart University Ziraat FakUniversidade Estadual Paulist