22 research outputs found
Validating attention bias as a novel measure of affect in sheep
To facilitate the understanding and enhancement of animal well-being in livestock production systems, there is a need to develop robust methods which can assess the emotional or affective states of animals, as an aspect of their welfare.
Chapter 1 of this thesis discusses some current methods used for the assessment of animal affect, highlighting the key limitations of each approach. The potential role of cognitive methods for welfare assessment is introduced, with a particular focus on attention bias tests. The aim of this thesis was to further develop and validate a novel attention bias test for the assessment of affective states in sheep.
Chapter 2 examines the impact of pharmacologically-induced stress on judgement bias and attention bias in sheep. The study finds no clear indication that elevated cortisol concentrations impacted on cognitive biases in sheep.
Chapter 3 refines the attention bias test methodology to remove a habituation period, improving the practical application of the test. The study demonstrates that pharmacologically-induced anxiety-like and calm-like states impact on attention bias in sheep.
Chapter 4 introduces a modified method for the assessment of attention bias, which is shown to assess and differentiate pharmacologically-induced anxiety-like and depression-like states in sheep.
Chapter 5 examines the potential influence of pharmacologically induced positive affective states on the modified attention bias test, finding no clear effect of positive states on attention bias in sheep. It is suggested that external factors may have confounded results of this study.
Chapter 6 examines repeatability of the attention bias test to gain insight into the factors influencing animal behaviour during the attention bias test. Key measures of attention had low repeatability and are suggested to be readily influenced by emotions and moods. Measures of vigilance and zones crossed had moderate repeatability and are suggested to be more heavily influenced by temperament or personality traits.
Finally, chapter 7 concludes that the attention bias test developed throughout this thesis may be a useful and practical tool for the assessment of negative affective states in sheep
Does Sex Trade with Violence among Genotypes in Drosophila melanogaster?
The evolutionary forces shaping the ability to win competitive interactions, such as aggressive encounters, are still poorly understood. Given a fitness advantage for competitive success, variance in aggressive and sexual display traits should be depleted, but a great deal of variation in these traits is consistently found. While life history tradeoffs have been commonly cited as a mechanism for the maintenance of variation, the variability of competing strategies of conspecifics may mean there is no single optimum strategy. We measured the genetically determined outcomes of aggressive interactions, and the resulting effects on mating success, in a panel of diverse inbred lines representing both natural variation and artificially selected genotypes. Males of one genotype which consistently lost territorial encounters with other genotypes were nonetheless successful against males that were artificially selected for supernormal aggression and dominated all other lines. Intransitive patterns of territorial success could maintain variation in aggressive strategies if there is a preference for territorial males. Territorial success was not always associated with male mating success however and females preferred âwinnersâ among some male genotypes, and âlosersâ among other male genotypes. This suggests that studying behaviour from the perspective of population means may provide limited evolutionary and genetic insight. Overall patterns of competitive success among males and mating transactions between the sexes are consistent with mechanisms proposed for the maintenance of genetic variation due to nonlinear outcomes of competitive interactions
Keratin and S100 calcium-binding proteins are major constituents of the bovine teat canal lining
The bovine teat canal provides the first-line of defence against pathogenic bacteria infecting the mammary gland, yet the protein composition and host-defence functionality of the teat canal lining (TCL) are not well characterised. In this study, TCL collected from six healthy lactating dairy cows was subjected to two-dimensional electrophoresis (2-DE) and mass spectrometry. The abundance and location of selected identified proteins were determined by western blotting and fluorescence immunohistochemistry. The variability of abundance among individual cows was also investigated. Two dominant clusters of proteins were detected in the TCL, comprising members of the keratin and S100 families of proteins. The S100 proteins were localised to the teat canal keratinocytes and were particularly predominant in the cornified outermost layer of the teat canal epithelium. Significant between-animal variation in the abundance of the S100 proteins in the TCL was demonstrated. Four of the six identified S100 proteins have been reported to have antimicrobial activity, suggesting that the TCL has additional functionality beyond being a physical barrier to invading microorganisms. These findings provide new insights into understanding host-defence of the teat canal and resistance of cows to mastitis
The impacts of Ascaridia galli on performance, health, and immune responses of laying hens: new insights into an old problem
Gastrointestinal nematodes are re-emerging in countries where the popularity of free-range poultry production systems is increasing. Amongst all gastrointestinal nematodes, Ascaridia galli is of significant concern due to the parasite's direct life cycle and ability to survive extreme environmental conditions. In laying hens, A. galli parasites have been associated with reduced health, welfare, immunity, and egg production. Direct losses are caused by obstruction and damage of the intestinal tract in hens when high worm burdens are present. These result in reduction in egg production and body weight of infected laying hens, consequently leading to significant economic losses for farmers. Furthermore, heavy infections with A. galli may lead to increased mortality within the flock. Indirect losses are due to suppression of immune system function which can increase susceptibility to secondary infections. Infection with A. galli can also alter nutrient utilization and absorption. Levels of anti- A. galli serum and egg yolk antibodies increase following A. galli infection. Elevated antibodies can be used as an indicator of current or previous infections and therefore can be used as a diagnostic tool. The impact of A. galli on hen health and welfare manifests through the depletion of liver lipid reserves and increased use of energy reserves to mount immune responses against the parasite. This review highlights the variable effects of A. galli infection on the performance, health, egg quality, and emphasizes especially on immune responses of free-range laying hens as well as it evaluates various potential detection methods and preventive and control measures of this parasitic disease
A Novel Protocol to Assess Acclimation Rate in Bos taurus Heifers during Yard Weaning
The speed with which animals acclimate to a new environment could be an important measure of ability to cope with management induced stress. This study developed a measure of acclimation rate in a group of 50 Bos taurus heifers during yard weaning over nine days. We recorded the time and order in which heifers moved through a novel funnel structure into a feeding yard daily. We hypothesised that addition of an obstacle at the entrance would increase the time it took heifers to move through the funnel, but that they would acclimate to the obstacle over a three-day period. The change in latency to move through could then be used as a measure of acclimation rate. We hypothesised that individuals which acclimated to obstacles at a faster rate might display favourable temperament as assessed by flight time. All heifers took longer to move through the funnel after a novel object was introduced, then latency decreased over the following two days while the object was present. This indicates the protocol could be useful for measuring acclimation rate at a group level. Individual acclimation rate variables, measured as change in times and orders of heifers between test days, did not appear to have any consistent relationships with flight time or weight change during or post-weaning (p > 0.05). We concluded that the protocol was inappropriate for assessing acclimation rate at an individual level, due to social effects while testing heifers as a group. Heifers which were consistently one of the first 20 to move through the funnel had a significantly greater average weight 5 and 10 months post-weaning (345 ± 9 kg and 518 ± 10 kg respectively) than heifers which were consistently one of the last 20 through the funnel (311 ± 8 kg and 484 ± 8 kg respectively" 0.05). We concluded that the protocol was inappropriate for assessing acclimation rate at an individual level, due to social effects while testing heifers as a group. Heifers which were consistently one of the first 20 to move through the funnel had a significantly greater average weight 5 and 10 months post-weaning (345 ± 9 kg and 518 ± 10 kg respectively) than heifers which were consistently one of the last 20 through the funnel (311 ± 8 kg and 484 ± 8 kg respectively"
A Novel Protocol to Assess Acclimation Rate in Bos taurus Heifers during Yard Weaning
The speed with which animals acclimate to a new environment could be an important measure of ability to cope with management induced stress. This study developed a measure of acclimation rate in a group of 50 Bos taurus heifers during yard weaning over nine days. We recorded the time and order in which heifers moved through a novel funnel structure into a feeding yard daily. We hypothesised that addition of an obstacle at the entrance would increase the time it took heifers to move through the funnel, but that they would acclimate to the obstacle over a three-day period. The change in latency to move through could then be used as a measure of acclimation rate. We hypothesised that individuals which acclimated to obstacles at a faster rate might display favourable temperament as assessed by flight time. All heifers took longer to move through the funnel after a novel object was introduced, then latency decreased over the following two days while the object was present. This indicates the protocol could be useful for measuring acclimation rate at a group level. Individual acclimation rate variables, measured as change in times and orders of heifers between test days, did not appear to have any consistent relationships with flight time or weight change during or post-weaning (p > 0.05). We concluded that the protocol was inappropriate for assessing acclimation rate at an individual level, due to social effects while testing heifers as a group. Heifers which were consistently one of the first 20 to move through the funnel had a significantly greater average weight 5 and 10 months post-weaning (345 ± 9 kg and 518 ± 10 kg respectively) than heifers which were consistently one of the last 20 through the funnel (311 ± 8 kg and 484 ± 8 kg respectively; p < 0.001). This may indicate order of movement through the funnel was related to feeding motivation or another aspect of temperament not reflected by flight time
Proteomics data in support of the quantification of the changes of bovine milk proteins during mammary gland involution
Here we provide data from three proteomics techniques; two-dimensional electrophoresis (2-DE) followed by identification of selected spots using PSD MALDI-TOF MS/MS, one-dimensional gel electrophoresis followed by LC-MS/MS analysis of gel slices (GeLC) and dimethyl isotopic labelling of tryptic peptides followed by Orbitrap MS/MS (DML), to quantify the changes in the repertoire of bovine milk proteins that occurs after drying off. We analysed skim milk and whey sampled at day 0 and either day 3 or day 8 after drying off. These analyses identified 45 spots by MALDI-TOF, 51 proteins by GeLC and 161 proteins by DML, for which the detailed data work-up is presented as three Excel files. The data supplied in this article supports the accompanying publication âChanges in the repertoire of bovine milk proteins during mammary involutionâ (Boggs et al., 2015) [1]. Data are available via ProteomeXchange with identifiers ProteomeXchange: PXD003110 and ProteomeXchange: PXD003011. Keywords: Host defence, Dairy, Drying off, Proteomic
Validating attention bias as a novel measure of affect in sheep
These datasets were generated during the PhD candidature of Jessica Monk between 2016 to 2019. Data were generated across 5 experiments, each of which aimed to further develop, refine and validate a novel method for assessing emotional states in sheep as a measure of animal welfare. The attention bias test is a 3 min test which records behavioural responses of sheep to a potential predator threat. Key behaviours recorded included duration of vigilance, looking behaviours and latency to feed. The first experiment examined the impact of pharmacologically-induced stress on judgement bias and attention bias in sheep. The study found no clear indication that elevated cortisol concentrations impacted on cognitive biases in sheep. The second experiment examined the impact of pharmacologically induced anxiety-like and calm-like states on a refined attention bias test in sheep, finding that the test can be shortened, a habituation period removed and that it is sensitive to anxiety-like and calm-like states. The third experiment introduced a modified method for the assessment of attention bias, and examined the impact of pharmacologically-induced anxiety-like and depression-like states in sheep. The modified method could differentiate these states. The fourth experiment examined the influence of pharmacologically induced positive affective states on the modified attention bias test but found no clear effect on attention bias. The final experiment examined the repeatability of the attention bias test across 3 time periods using the same animals from the Sheep CRC information nucleus flock. Key measures of attention had low repeatability and are suggested to be readily influenced by emotions and moods. Measures of vigilance and zones crossed had moderate repeatability and are suggested to be more heavily influenced by temperament or personality traits
The Relationship Between Anti-Ascaridia Galli Antibody Levels in the Egg Yolk and Number of Excreta Worm Eggs by ELISA Test
Ascaridia galli is one of the most abundant nematode parasites of poultry. This study aimed at determining the relationship between the levels of anti-A. galli in the egg yolks and number of worm eggs in the hens' excreta, which can then be used to develop a new method to detect A. galli infection in layer hens. The procedures to optimize the performance of enzyme-linked immunosorbent assay (ELISA) for detection of anti-A. galli antibodies in egg yolks were also examined. The results showed that blocking buffer with BSA (99%) diluted at 0.5%, secondary antibodies diluted at 1/15,000 and egg yolk samples diluted at 1/3,000 and 1/12,000 were optimal to maximize the performance of ELISA assay. Although anti-A. galli antibody levels in the egg yolk was not highly correlated with worm egg counts, ELISA test is still a potential method to detect A. galli infection in laying hens
Ascaridia galli challenge model in laying hens
Ascaridia galli is one of the most prevalent helminths in free-range laying hens. This study was conducted to establish a reliable infection model for A. galli in laying hens. Materials and methods : A total of 20 Lohmann brown hens of 19 weeks age were assigned to 4 treatment groups (n=5 per group). Hens of group 1 were orally inoculated with 1000 A. galli eggs stored at 26°C, group 2 with 1000 A. galli eggs stored at 4°C and transferred to 26°C prior to inoculation. Hens were infected 3 times over a week period. Hens of group 3 were orally inoculated with 500 A. galli eggs stored at 26°C, 6 times over 2 week period. Hens in group 4 were infected with adult A. galli via cloaca. Intestinal immature worms were counted from 2 hens from each group after slaughter at 2 weeks post infection (p.i).Excreta was collected and analysed for A. galli eggs at 8 and 14 weeks p.i.. Blood was collected to examine A. galli specific antibodies and intestinal A. galli worms were counted at 16 weeks p.i. results: Hens in group 3 had the highest A. galli worm counts (