Maternal Behavior in Beef Cattle: The Physiology, Assessment and Future Directions-A Review.

Bovine maternal behavior is known to be influenced by a variety of factors including hormonal mediation, breed, age, parity, host genetics and general management practices. Following centuries of varying levels of domestication processes, the behavior of the bovine cow has altered from that of her original wild ungulate ancestors, although many maternal instincts have remained unchanged. The influence of maternal behavior on calf health and performance is of interest to cow-calf beef production operations, as in most instances, the cow is solely responsible for rearing the calf until weaning. However, investigating the magnitude of this influence is challenging, in part because objective measurement of behavioral traits is difficult, particularly in extensive settings. In recent years, while a number of remote monitoring devices have been developed that afford opportunities for objective measurement of behavioral traits in livestock, characterization of physiological mechanisms that underlie superior maternal behavior, including identification of potential biomarkers remains elusive in cattle. Hormonal profiles during the periparturient period have been shown to influence behavioral patterns in both current and future generations in other mammalian species and may provide insights into the physiology of bovine maternal behavior. Therefore, the aim of this review is to describe general characteristics of bovine maternal behavior and the factors known to influence it, including hormonal drivers, through which cross-reference to other species is made. Current methods of measuring and assessing behavior that may also be applicable to most production settings have also been reviewed. At present, there is no known hormonal assay that can be used to measure and/or reliably predict bovine maternal behavior post-calving or across generations. Being able to objectively assess superior maternal behavior, whether that be through remote monitoring, hormonal profiling or indirectly through measuring calf performance will be beneficial to livestock industries in the future.

Increasing the value and efficiency of herbicide resistance surveys.

The scale of herbicide resistance within a cropping region can be estimated and monitored using surveys of weed populations. The current approach to herbicide resistance surveys is time-consuming, logistically challenging and costly. Here we review past and current approaches used in herbicide resistance surveys with the aims of (i) defining effective survey methodologies, (ii) highlighting opportunities for improving efficiencies through the use of new technologies and (iii) identifying the value of repeated region-wide herbicide resistance surveys. One of the most extensively surveyed areas of the world's cropping regions is the Australian grain production region, with >2900 fields randomly surveyed in each of three surveys conducted over the past 15 years. Consequently, recommended methodologies are based on what has been learned from the Australian experience. Traditional seedling-based herbicide screening assays remain the most reliable and widely applicable method for characterizing resistance in weed populations. The use of satellite or aerial imagery to plan collections and image analysis to rapidly quantify screening results could complement traditional resistance assays by increasing survey efficiency and sampling accuracy. Global management of herbicide-resistant weeds would benefit from repeated and standardized surveys that track herbicide resistance evolution within and across cropping regions. © 2021 Society of Chemical Industry.

Opportunities and challenges for harvest weed seed control in global cropping systems.

The opportunity to target weed seeds during grain harvest was established many decades ago following the introduction of mechanical harvesting and the recognition of high weed-seed retention levels at crop maturity; however, this opportunity remained largely neglected until more recently. The introduction and adoption of harvest weed seed control (HWSC) systems in Australia has been in response to widespread occurrence of herbicide-resistant weed populations. With diminishing herbicide resources and the need to maintain highly productive reduced tillage and stubble-retention practices, growers began to develop systems that targeted weed seeds during crop harvest. Research and development efforts over the past two decades have established the efficacy of HWSC systems in Australian cropping systems, where widespread adoption is now occurring. With similarly dramatic herbicide resistance issues now present across many of the world's cropping regions, it is timely for HWSC systems to be considered for inclusion in weed-management programs in these areas. This review describes HWSC systems and establishing the potential for this approach to weed control in several cropping regions. As observed in Australia, the inclusion of HWSC systems can reduce weed populations substantially reducing the potential for weed adaptation and resistance evolution. © 2017 Society of Chemical Industry.

Temperament, age and weather predict social interaction in the sheep flock.

The aim of the current study was to investigate the social relationships between individual sheep, and factors that influence this, through the novel application of the statistical multiple membership multiple classification (MMMC) model. In study one 49 ewes (ranging between 1 and 8 years old) were fitted with data loggers, which recorded when pairs of sheep were within 4m or less of each other, within a social group, for a total of 6days. In study two proximity data were collected from 45 ewes over 17days, as were measures of ewe temperament, weight and weather. In study 1 age difference significantly influenced daily contact time, with sheep of the same age spending an average of 20min 43s together per day, whereas pairs with the greatest difference in age spent 16min 33s together. Maximum daily temperature also significantly affected contact time, being longer on hotter days (34min 40s hottest day vs. 18min 17s coolest day), as did precipitation (29min 33s wettest day vs. 10min 32s no rain). Vocalisation in isolation, as a measure of temperament, also affected contacts, with sheep with the same frequency of vocalisations spending more time together (27min 16s) than those with the greatest difference in vocalisations (19min 36s). Sheep behaviour in the isolation box test (IBT) was also correlated over time, but vocalisations and movement were not correlated. Influences of age, temperature and rain on social contact are all well-established and so indicate that MMMC modelling is a useful way to analyse social structures of the flock. While it has been demonstrated that personality factors affect social relationships in non-human animals, the finding that vocalisation in isolation influences pair social contact in sheep is a novel one.