Genetic selection for temperament traits in dairy and beef cattle

Animal temperament can be defined as a response to environmental or social stimuli. There are a number of temperament traits in cattle that contribute to their welfare, including their response to handling or milking, response to challenge such as human approach or intervention at calving, and response to conspecifics. In a number of these areas, the genetic basis of the trait has been studied. Heritabilities have been estimated and in some cases quantitative trait loci (QTL) have been identified. The variation is sometimes considerable and moderate heritabilities have been found for the major handling temperament traits, making them amenable to selection. Studies have also investigated the correlations between temperament and other traits, such as productivity and meat quality. Despite this, there are relatively few examples of temperament traits being used in selection programmes. Most often, animals are screened for aggression or excessive fear during handling or milking, with extreme animals being culled, or EBVs for temperament are estimated, but these traits are not commonly included routinely in selection indices, despite there being economic, welfare and human safety drivers for their. There may be a number of constraints and barriers. For some traits and breeds, there may be difficulties in collecting behavioral data on sufficiently large populations of animals to estimate genetic parameters. Most selection indices require estimates of economic values, and it is often difficult to assign an economic value to a temperament trait. The effects of selection primarily for productivity traits on temperament and welfare are discussed. Future opportunities include automated data collection methods and the wider use of genomic information in selection

Evaluation of a standard provision versus an autonomy promotive exercise referral programme: rationale and study design

Background The National Institute of Clinical Excellence in the UK has recommended that the effectiveness of ongoing exercise referral schemes to promote physical activity should be examined in research trials. Recent empirical evidence in health care and physical activity promotion contexts provides a foundation for testing the utility of a Self Determination Theory (SDT) -based exercise referral consultation. Methods/Design Design: An exploratory cluster randomised controlled trial comparing standard provision exercise on prescription with a Self Determination Theory-based (SDT) exercise on prescription intervention. Participants: 347 people referred to the Birmingham Exercise on Prescription scheme between November 2007 and July 2008. The 13 exercise on prescription sites in Birmingham were randomised to current practice (n=7) or to the SDT-based intervention (n=6). Outcomes measured at 3 and 6-months: Minutes of moderate or vigorous physical activity per week assessed using the 7-day Physical Activity Recall; physical health: blood pressure and weight; health status measured using the Dartmouth CO-OP charts; anxiety and depression measured by the Hospital Anxiety and Depression Scale and vitality measured by the subjective vitality score; motivation and processes of change: perceptions of autonomy support from the advisor, satisfaction of the needs for competence, autonomy, and relatedness via physical activity, and motivational regulations for exercise. Discussion This trial will determine whether an exercise referral programme based on Self Determination Theory increases physical activity and other health outcomes compared to a standard programme and will test the underlying SDT-based process model (perceived autonomy support, need satisfaction, motivation regulations, outcomes) via structural equation modelling. Trial registration The trial is registered as Current Controlled trials ISRCTN07682833

Relationships between feeding behaviour, activity, dominance and feed efficiency in finishing beef steers

To increase the profitability and sustainability of beef production systems, the use of animals with high feed efficiency is preferred. Efficient animals eat less than their peers for the same or better growth. This efficiency can be measured using feed conversion ratios (FCR) and residual feed intake (RFI) parameters. However, the biological mechanisms, particularly those related to the animal’s behaviour and personality, are poorly understood. An individual animal’s behaviour, such as its activity levels, may contribute to efficiency. Feed intake is also a factor in efficiency, and therefore, social dominance rank may also indirectly affect efficiency through its influence on feeding behaviour. This experiment investigated the effects of dominance on feeding behaviour, as well as of dominance and activity on average daily gain (ADG), FCR and RFI in two breeds of beef cattle. The study used a 2 × 2 design with 80 cattle of two breed-types (Charolais-cross (CHx) (n = 41) and Luing (n = 39)) and two diets (a concentrate-based diet (CONC) and a mixed forage and concentrate diet (MIXED)). For each individual steer, FCR and RFI were measured over a 56-day performance test. Feed intake, patterns of feeding behaviour, activity and dominance were also measured. Feed intake was affected by dominance, with more dominant steers having significantly higher dry matter intakes (P = 0.001) and feeding rates (P = 0.006) suggesting that dominant animals had priority of access to the feeders. Steers with higher ADG had higher intakes and performed more standing bouts. Steers with better FCR values performed more standing bouts and younger animals had better FCR. For RFI there was also an interaction between breed and variation in length of the feeding events, showing that Luing steers with more consistent feed bout lengths had better RFI, with no association shown for CHx steers. There was no direct effect of dominance on ADG, FCR or RFI. However, the effect of dominance on feed intake suggests that measures of performance in any study may be affected by feeder-space allocation. The associations between standing bouts and feeding bouts with efficiency measures also suggest that individual animal behavioural characteristics influence efficiency and that overall efficiency of all animals may be improved by allowing animals to express individual patterns of behaviour

Current available strategies to mitigate greenhouse gas emissions in livestock systems: an animal welfare perspective

Livestock production is a major contributor to greenhouse gas (GHG) emissions, so will play a significant role in the mitigation effort. Recent literature highlights different strategies to mitigate GHG emissions in the livestock sector. Animal welfare is a criterion of sustainability and any strategy designed to reduce the carbon footprint of livestock production should consider animal welfare amongst other sustainability metrics. We discuss and tabulate the likely relationships and trade-offs between the GHG mitigation potential of mitigation strategies and their welfare consequences, focusing on ruminant species and on cattle in particular. The major livestock GHG mitigation strategies were classified according to their mitigation approach as reducing total emissions (inhibiting methane production in the rumen), or reducing emissions intensity (Ei; reducing CH4 per output unit without directly targeting methanogenesis). Strategies classified as antimethanogenic included chemical inhibitors, electron acceptors (i.e. nitrates), ionophores (i.e. Monensin) and dietary lipids. Increasing diet digestibility, intensive housing, improving health and welfare, increasing reproductive efficiency and breeding for higher productivity were categorized as strategies that reduce Ei. Strategies that increase productivity are very promising ways to reduce the livestock carbon footprint, though in intensive systems this is likely to be achieved at the cost of welfare. Other strategies can effectively reduce GHG emissions whilst simultaneously improving animal welfare (e.g. feed supplementation or improving health). These win–win strategies should be strongly supported as they address both environmental and ethical sustainability. In order to identify the most cost-effective measures for improving environmental sustainability of livestock production, the consequences of current and future strategies for animal welfare must be scrutinized and contrasted against their effectiveness in mitigating climate change

Ecological implications of a flower size/number trade-off in tropical forest trees

Peer reviewedPublisher PD

QCD and strongly coupled gauge theories : challenges and perspectives

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe

Temperament and dominance relate to feeding behaviour and activity in beef cattle: implications for performance and methane emissions

In beef cattle, feeding behaviour and activity are associated with feed efficiency and methane (CH4) emissions. This study aimed to understand the underlying traits responsible for the contribution of cattle behaviour to individual differences in feed efficiency, performance and CH4 emissions. Eighty-four steers (530±114 kg body weight) of two different breeds (crossbreed Charolais and Luing) were used. The experiment was a 2×2×3 factorial design with breed, basal diets (concentrate vs. mixed) and dietary treatments (no additive, calcium nitrate, or rapeseed cake) as the main factors. The individual dry matter intake (DMI; kg) was recorded daily and the body weight was measured weekly over a 56-day period. Ultrasound fat depth was measured on day 56. Based on the previous data, the indexes average daily gain, food conversion and residual feed intake (RFI) were calculated. The frequency of meals, the duration per visit and the time spent feeding per day were taken as feeding behaviour measures. Daily activity was measured using the number of steps, the number of standing bouts and the time standing per day. Agonistic interactions (including the number of contacts, aggressive interactions, and displacements per day) between steers at the feeders were assessed as indicators of dominance. Temperament was assessed using the crush score test (which measures restlessness when restrained) and the flight speed on release from restraint. Statistical analysis was performed using multivariate regression models. Steers that spent more time eating showed better feed efficiency (P=0.039), which can be due to greater secretion of saliva. Feeding time was longer with the mixed diet (P<0.001), Luings (P=0.009) and dominant steers (P=0.032). Higher activity (more steps) in the pen was associated with poorer RFI, possibly because of higher energy expenditure for muscle activity. Frequent meals contributed to a reduction in CH4 emissions per kg DMI. The meal frequency was higher with a mixed diet (P<0.001) and increased in more temperamental (P=0.003) and dominant (P=0.017) steers. In addition, feed intake was lower (P=0.032) in more temperamental steers. This study reveals that efficiency increases with a longer feeding time and CH4 emissions decrease with more frequent meals. As dominant steers eat more frequently and for longer, a reduction in competition at the feeder would improve both feed efficiency and CH4 emissions. Feed efficiency can also be improved through a reduction in activity. Selection for calmer cattle would reduce activity and increase feed intake, which may improve feed efficiency and promote growth, respectively

Changes in feed intake during isolation stress in respiration chambers may impact methane emissions assessment

Respiration chambers are considered the ‘gold standard’ technique for measuring in vivo methane (CH4) emissions in live animals. However, the imposed isolation required may alter feeding behaviour and intake, which ultimately impact CH4 emissions. The aim of this study was to assess the impact of isolation within respiration chambers on feed intake and CH4 emissions with two different diets and breeds of beef cattle. In addition, a routine stressor (transport) was used to examine the relationship between individual stress responsiveness and changes in feed intake during isolation. Eighty-four steers (castrated males) (569 ± 5.7 kg bodyweight, BW) were divided into two groups and each group fed with one of two basal diets consisting of (g/kg dry matter, DM) either 50 : 50 (Mixed) or 8 : 92 (Concentrate) forage to concentrate ratios. Within each basal diet there were three supplementation treatments: (1) control, (2) calcium nitrate, and (3) rapeseed cake. The stress biomarkers plasma cortisol, creatine kinase (CK), and free fatty acids (FFA) were determined before (0 h) and after (30 min, 3 h, 6 h and 9 h) a 30-min journey, when steers were transported to the respiration chamber facilities. Methane emissions were measured over a 3-day period using individual respiration chambers. Dry matter intake (DMI) was assessed within the group-housed pens (4 weeks before entry to training pen), in the training pens and the chambers. Cortisol, FFA and CK increased (P < 0.05) after transport confirming a stress response. DMI (g/kg BW) decreased (P < 0.001) during isolation in the training pens (14.7 ± 0.28) and the chambers (14.3 ± 0.26) compared with that of the same animals in the group pens (16.8 ± 0.23). DMI during isolation decreased more in those animals which had an increased (P < 0.05) stress response during transport as measured by cortisol, FFA and CK. With the Mixed diet, the decline in DMI was estimated to result in an increase in CH4 (g/kg DMI) (r = 0.25, P = 0.001), which did not occur with the Concentrate diet. According to the results of this experiment, the stress associated with isolation reduces the DMI resulting in an increase in g CH4/kg DMI in fibrous diets. Habituation to isolation needs refinement in order to reduce the impact of stress on intake and therefore achieve more accurate estimates of CH4 emissions. Alternatively, modelling CH4 estimations according to behavioural and physiological changes associated with isolation stress would improve accuracy of CH4 estimations

Association of temperament and acute stress responsiveness with productivity, feed efficiency, and methane emissions in beef cattle: an observational study

The aim of this study was to assess individual differences in temperament and stress response and quantify their impact on feed efficiency, performance, and methane (CH(4)) emissions in beef cattle. Eighty-four steers (castrated males) (Charolais or Luing) were used. Temperament was assessed using two standardized tests: restlessness when restrained [crush score (CS)] and flight speed (FS) on release from restraint. Over a 56-day period individual animal dry matter intake (DMI) and weekly body weight was measured. Ultrasound fat depth was measured at the end of 56 days. Average daily gain (ADG), feed conversion ratio (FCR), and residual feed intake (RFI) were calculated. After the 56-day test period, animals were transported in groups of six/week to respiration chamber facilities. Blood samples were taken before and 0, 3, 6, and 9 h after transport. Plasma cortisol, creatine kinase (CK), glucose, and free fatty acids (FFA) were determined to assess physiological stress response. Subsequently, CH(4) emissions were measured over a 3-day period in individual respiration chambers. CS (1.7 ± 0.09) and FS (1.6 ± 0.60 m/s) were repeatable (0.63 and 0.51, respectively) and correlated (r = 0.36, P < 0.001). Plasma cortisol, CK, and FFA concentrations increased after transport (P = 0.038, P = 0.006, and P < 0.001, respectively). Temperament (CS) and CK concentration were correlated (r = 0.29; P = 0.015). The extreme group analysis reveals that excitable animals (FS; P = 0.032) and higher stress response (cortisol, P = 0.007; FFA, P = 0.007; and CK, P = 0.003) were associated with lower DMI. ADG was lower in more temperamental animals (CS, P = 0.097, and FS, P = 0.030). Fat depth was greater in steers showing calmer CS (P = 0.026) and lower plasma CK (P = 0.058). Temperament did not show any relationship with RFI or CH(4) emissions. However, steers with higher cortisol showed improved feed efficiency (lower FCR and RFI) (P < 0.05) and greater CH(4) emissions (P = 0.017). In conclusion, agitated temperament and higher stress responsiveness is detrimental to productivity. A greater stress response is associated with a reduction in feed intake that may both increase the efficiency of consumed feed and the ratio of CH(4) emissions/unit of feed. Therefore, temperament and stress response should be considered when designing strategies to improve efficiency and mitigate CH(4) emissions in beef cattle

Carbogen-induced changes in rat mammary tumour oxygenation reported by near infrared spectroscopy

We have evaluated the ability of steady-state, radially-resolved, broad-band near infrared diffuse reflectance spectroscopy to measure carbogen-induced changes in haemoglobin oxygen saturation (SO2) and total haemoglobin concentration in a rat R3230 mammary adenocarcinoma model in vivo. Detectable shifts toward higher saturations were evident in all tumours (n = 16) immediately after the onset of carbogen breathing. The SO2 reached a new equilibrium within 1 min and remained approximately constant during 200–300 s of administration. The return to baseline saturation was more gradual when carbogen delivery was stopped. The degree to which carbogen increased SO2 was variable among tumours, with a tendency for tumours with lower initial SO2 to exhibit larger changes. Tumour haemoglobin concentrations at the time of peak enhancement were also variable. In the majority of cases, haemoglobin concentration decreased in response to carbogen, indicating that increased tumour blood volume was not responsible for the observed elevation in SO2. We observed no apparent relationship between the extent of the change in tumour haemoglobin concentration and the magnitude of the change in the saturation. Near infrared diffuse reflectance spectroscopy provides a rapid, non-invasive means of monitoring spatially averaged changes in tumour haemoglobin oxygen saturation induced by oxygen modifiers. © 1999 Cancer Research Campaig