Investigating novelty traits to improve cow-calf efficiency in South African Afrikaner, Angus and Charolais for climate-smart production

The aim is of the study was to identify novelty traits that could be used as breeding objectives to improve cow-calf efficiency and describe cow efficiency in extensive systems in support of climate-smart production in beef cattle. The traits that were investigated were ‘weaning weight of the calf as a trait of the dam’ (K205) and ‘kilogram calf weaned per large stock unit’ (KgC/LSU. The latter trait is a value that expresses performance (calf weaning weight) per constant unit, namely per LSU. This may be a useful breeding objective or goal to increase production efficiency, which may reduce the carbon footprint of extensive beef cow-calf production systems. The investigation of the novel traits was conducted on three diverse breeds, namely Afrikaner, Angus and Charolais, with 6104, 7581 and 2291 complete cow-calf records, respectively. Only cows with all three first parities recorded were used to investigate KgC/LSU and K205, as breeding objectives to improve cow-calf efficiency. The heritabilities for KgC/LSU were 0.52, 0.24 and 0.21 for the Afrikaner, Angus and Charolais, respectively, and for K205 were 0.40, 0.17 and 0.13 respectively. The genetic relationship between KgC/LSU and K205 for Angus and Charolais varied substantially. In Charolais cows a strong negative correlation (-0.75) was found, while a strong positive correlation (+0.84) was estimated in Angus cows. These results indicate that a ‘cow efficiency index’ in which several traits (production, fertility and efficiency) are included may be a more effective alternative breeding strategy. Breeding strategies and production systems to improve the production efficiency of beef cattle could play a significant role in reducing the carbon footprint and would enhance climate-smart beef production.Keywords: breeding objective, calf weight, cow weigh

Alternative approaches to evaluation of cow efficiency

The purpose of this study was to evaluate alternative expressions of genetic merit for cow efficiency. Weights of Pinzgauer cattle taken at birth, weaning, and maturity were extracted from the South African National Database. Average daily gain from birth to weaning (ADG) and cow weight (CWT) were analyzed with a multi-trait mixed model. The model included direct and maternal genetic effects, a permanent environmental effect attributable to dams on ADG, a direct genetic effect and a permanent environmental effect attributable to there being multiple observations from the same cow on CWT as random effects. Heritability estimates for direct and maternal additive effects on ADG were 0.27 ± 0.04 and 0.06 ± 0.02, respectively. The estimated heritability for CWT was 0.45 ± 0.06. Estimates of repeatability for ADG and CWT were 0.42 and 0.67, respectively. Estimated breeding values based on the preceding results and using the maternal genetic effect on ADG as a proxy for the direct genetic effect on milk production were combined in six indexes of cow efficiency. These indexes sought to increase output and decrease input simultaneously, to increase output holding input constantly, and to hold input constant while decreasing input. The diversity of emphasis applied across these indexes suggests the need for due diligence in developing breeding objectives for improvement of cow efficiency. Indexes that are consistent with the econometric definition of efficiency and seek to simultaneously increase output and reduce input are recommended.______________________________________________________________________________________Keywords: genetic parameters, multiple trait selection, Pinzgauer, selection inde

A South African perspective on livestock production in relation to greenhouse gases and water usage

This work is based on research supported in part by Red Meat Research and Development South Africa and the National Research Foundation of South Africa, under grants UID 75123 and 85281.http://www.sasas.co.za/am201

Crypto-unitary forms of quantum evolution operators

For the description of quantum evolution, the use of a manifestly time-dependent quantum Hamiltonian $\mathfrak{h}(t) =\mathfrak{h}^\dagger(t)$ is shown equivalent to the work with its simplified, time-independent alternative $G\neq G^\dagger$. A tradeoff analysis is performed recommending the latter option. The physical unitarity requirement is shown fulfilled in a suitable ad hoc representation of Hilbert space.Comment: 15 p

Semiclassical and quantum description of motion on noncommutative plane

We study the canonical and the coherent state quantization of a particle moving in a magnetic field on a non-commutative plane. Starting from the so called \theta-modified action, we perform the canonical quantization and analyze the gauge dependence of the obtained quantum theory. We construct the Malkin-Man'ko coherent states of the system in question, and the corresponding quantization. On this base, we study the relation between the coherent states and the "classical" trajectories predicted by the \theta-modified action. In addition, we construct different semiclassical states, making use of special properties of circular squeezed states. With the help of these states, we perform the Berezin-Klauder-Toeplitz quantization and present a numerical exploration of the semiclassical behavior of physical quantities in these states.Comment: 20 page

Fostering accessible online education using Galaxy as an e-learning platform

The COVID-19 pandemic is shifting teaching to an online setting all over the world. The Galaxy framework facilitates the online learning process and makes it accessible by providing a library of high-quality community-curated training materials, enabling easy access to data and tools, and facilitates sharing achievements and progress between students and instructors. By combining Galaxy with robust communication channels, effective instruction can be designed inclusively, regardless of the students’ environments

Negative effects of urbanisation on the physical condition of an endemic dung beetle from a neotropical hotspot

1. Urbanisation causes important losses in biodiversity and ecosystem of animals. To test whether these negative effects are preceded by unhealthy individuals in urban populations, we evaluated the effects of urbanisation on the abundance and physical condition of the dung beetle Dichotomius guaribensis, an endemic species of the Brazilian Atlantic Forest. 2. We sampled beetles in nine forest fragments with different urbanisation degrees, embedded in the urban matrix of the city of João Pessoa. Besides testing the abundance in each fragment, we quantified four indicators of physical condition in males and females: body size, body mass, energetic condition, and mite load. 3. Females tended to be larger, and to have less lipid mass and more mites than males. Urbanisation had no effect on beetle abundance, but it negatively affected body mass and lipid content in males, but not females, revealing different sensitivities for both sexes. Body size and mite load were not affected by urbanisation in males or females. Fragment size had no effect on beetle abundance and physical condition in both sexes, suggesting that urbanisation has a greater impact than fragment size on beetle individual condition. 4. In this study, we show that individual deterioration precedes population declines in disturbed environments, and our study opens new insights into the proximate causes that leads to the loss of biodiversity and ecosystem services in urbanised regions. © 2020 The Royal Entomological Societ