The Influence of Temperament on Body Temperature Response to Handling in Angus Cattle.

Previous studies have indicated that cattle with more excitable temperaments exhibit an increased stress response. The objective of this study was to investigate the relationship between temperament traits, handling, and stress-induced hyperthermia (SIH) in beef cattle. Rectal temperatures (TREC, °C) of 60 purebred Angus cattle (30 heifers, 30 steers; 235.2 ± 5.11 kg) were recorded at 20 s intervals from 30 min prior to handling until two hours post handling. All cattle were exposed to a standardized handling procedure consisting of (i) being restrained in a weighing box for 30 s; (ii) being held within the crush for 30 s; and then (iii) being restrained in a head bail for 60 s. Cattle temperaments were evaluated via three traits: (1) agitometer score (AG); (2) crush score (CS); and (3) flight speed (FS) during the handling procedure. Agitometer scores and FS measures were used to describe an AG category (AGCAT) and an FS category (FSCAT) that were used to classify animals into three temperament categories: 1, calm; 2, intermediate; and 3, temperamental. Pearson's correlation coefficients were used to evaluate the associations between (i) AG, CS, FS, and TREC 30 min prior to entry into the weighing box (T-30) and then at 1 min intervals between time of entry into the weighing box (T0) until 10 min post-weighing (T10); and (ii) the relationship between AG, CS, and FS. The relationship between TREC and temperament traits over the 2.5 h were modeled by using a first-order autoregressive repeated measures model. Flight speed had strong to moderate associations with TREC at T-30 (r ≥ 0.37; p ≤ 0.006) and between T0 and T10 (r ≥ 0.36; p ≤ 0.01). There were moderate associations amongst TREC between T0 and T10 and CS (r ≥ 0.31; p ≤ 0.01). A weak relationship existed with CS (r = 0.16; p = 0.16). There were no associations between AG and TREC at T-30 (r ≥ -0.15; p = 0.84) or between T0 and T10 (r ≤ 0.04; p ≥ 0.4). Rectal temperature, irrespective of sex and temperament traits, was influenced by time (p < 0.0001), and maximum TREC (39.3 ± 0.04 °C) occurred between 4 and 5.7 min after entry into the weighing box. In addition, CS (p = 0.007) influenced TREC in these cattle. There were also time × temperament trait × sex interactions with the CS (p = 0.0003) and FSCAT (p = 0.043) categories; however, time × temperament trait interactions were not statistically significant. Results from this study suggest that cattle with excitable temperaments, as evaluated by FS and CS, have a greater increase in TREC. In addition, these results suggest that a relationship exists between basal TREC and FS and CS. Together, these results highlight that temperament, as assessed by FS and CS, influences both basal TREC and the peak temperature recorded following handling but does not influence the magnitude of change in TREC post handling.

Relationship between Rectal Temperature and Vaginal Temperature in Grazing Bos taurus Heifers.

This study evaluated the relationship between rectal temperature (TREC, °C) and vaginal temperature (TVAG, °C) in grazing Bos taurus heifers, to develop an understanding of the reliability of these measures as estimates of core body temperature. Nineteen Angus heifers (BW = 232.2 ± 6.91 kg) were implanted with intra-rectal and intra-vaginal data loggers. Rectal temperature and TVAG were simultaneously recorded at 20 s intervals over 18.5 h. Heifers were housed as a singular cohort on grazing pastures for the duration of the study. A strong linear relationship (R² = 0.72, p < 0.0001) between the measurement sites was identified. The mean difference between TREC and TVAG was small, in which TVAG was on average 0.22 ± 0.01 °C lower than TREC. Individual twenty second TREC and TVAG data were used to determine the pooled mean TREC and TVAG and then to highlight the within measure variation over time. The coefficient of variation was, on average, lower (p < 0.001) for TVAG (0.38%) than TREC (0.44%), indicating that TVAG exhibited less variation. Overall, the results from the current study suggest that a strong relationship exists between TREC and TVAG, and that TVAG may be a more reliable estimate of core body temperature than TREC in grazing Bos taurus heifers.

Cognitive dysfunction in naturally occurring canine idiopathic epilepsy.

Globally, epilepsy is a common serious brain disorder. In addition to seizure activity, epilepsy is associated with cognitive impairments including static cognitive impairments present at onset, progressive seizure-induced impairments and co-morbid dementia. Epilepsy occurs naturally in domestic dogs but its impact on canine cognition has yet to be studied, despite canine cognitive dysfunction (CCD) recognised as a spontaneous model of dementia. Here we use data from a psychometrically validated tool, the canine cognitive dysfunction rating (CCDR) scale, to compare cognitive dysfunction in dogs diagnosed with idiopathic epilepsy (IE) with controls while accounting for age. An online cross-sectional study resulted in a sample of 4051 dogs, of which n = 286 had been diagnosed with IE. Four factors were significantly associated with a diagnosis of CCD (above the diagnostic cut-off of CCDR ≥50): (i) epilepsy diagnosis: dogs with epilepsy were at higher risk; (ii) age: older dogs were at higher risk; (iii) weight: lighter dogs (kg) were at higher risk; (iv) training history: dogs with more exposure to training activities were at lower risk. Impairments in memory were most common in dogs with IE, but progression of impairments was not observed compared to controls. A significant interaction between epilepsy and age was identified, with IE dogs exhibiting a higher risk of CCD at a young age, while control dogs followed the expected pattern of low-risk throughout middle age, with risk increasing exponentially in geriatric years. Within the IE sub-population, dogs with a history of cluster seizures and high seizure frequency had higher CCDR scores. The age of onset, nature and progression of cognitive impairment in the current IE dogs appear divergent from those classically seen in CCD. Longitudinal monitoring of cognitive function from seizure onset is required to further characterise these impairments.

Iron deficiency in blood donors: a national cross-sectional study.

BACKGROUND: Iron deficiency (ID) is an important consequence of blood donation. The epidemiology of this problem in the blood donor population was therefore studied to enable appropriate targeting of potential solutions to donor ID. STUDY DESIGN AND METHODS: A nationally representative, cluster-based cross-sectional study of Australian blood donors was performed. Donors were eligible for inclusion if they fulfilled criteria for blood donation or were deferred due to low or falling hemoglobin. Ferritin was measured and demographic and donation data were collected. RESULTS: A total of 3094 blood donors were recruited, of which samples were collected from 3049 donors; 1873 had exclusively donated whole blood (WB only), 242 had exclusively made apheresis donations, and 530 had not donated ("new" donors) in the previous 24 months. The prevalence of ID in new female donors was 12.0% compared with 1.3% in males. The prevalence of ID in female WB-only donors was 26.4%; it increased with donation frequency and decreased with age. The prevalence in male WB-only donors was 6.3% with no evident change with age or donation frequency. The prevalence of ID in apheresis-only donors (females 6.3%; males 2.2%) did not significantly exceed that of new donors nor did it change with donation frequency. Importantly, the risk of ID could not be satisfactorily predicted in an individual donor by his or her anemia status or with predictive modeling incorporating demographic and donation data. CONCLUSION: ID is especially prevalent in female, premenopausal, frequent WB donors. Strategies to combat ID should be implemented, specifically targeting this group.

The canine sand maze: an appetitive spatial memory paradigm sensitive to age-related change in dogs.

Aged dogs exhibit a spectrum of cognitive abilities including a syndrome similar to Alzheimer's disease. A major impediment to research so far has been the lack of a quick and accurate test of visuospatial memory appropriate for community-based animals. We therefore report on the development and validation of the Canine Sand Maze. A 4.5-m-diameter circular pool was filled with a sand and powdered food reward mix to a depth of 10 cm. Dogs were given 4 habituation and 16 learning trials which alternated a food reward being half (control trials) or fully-buried (acquisition trials) in a fixed location. After a 90-min break, a probe trial was conducted. Cognitively normal, aged (> 8 years, n  =  11) and young (1-4 years, n  =  11), breed-matched dogs were compared. After correction for differences in control trials, average probe times were 2.97 and 10.81 s for young and aged dogs, respectively. In the probe trial, both groups spent significantly more time in the target quadrant but there was a trend for young dogs to cross a 1 m(2) annulus zone around the buried reward more frequently (2.6 times) than aged dogs (1.5 times). Test-retest reliability in a subset of young dogs (n  =  5) was high. On the basis of these findings, the Canine Sand Maze is presented as a quick, sensitive and nonaversive tool for assessing spatial learning and reference memory in dogs.

The canine cognitive dysfunction rating scale (CCDR): a data-driven and ecologically relevant assessment tool.

Canine cognitive dysfunction (CCD) is an age-related neurobehavioural syndrome which, although common, is severely under-diagnosed in community-based dogs. Using data from a large cross-sectional survey of older dogs (n=957), this study aimed to develop a clinical scale for assessing CCD. Data-driven analytical techniques were used to distil 27 significant behavioural items (previously identified as relevant to CCD) into an assessment tool with maximal cognito-behavioural breadth whilst maintaining clinical utility. The resulting CCD rating scale (CCDR) comprised 13 behavioural items, of which three were sensitive to the severity of the disease stage. When tested on an independent survey sample, the CCDR had an overall 98.9% diagnostic accuracy with a 77.8% positive predictive value and a 99.3% negative predictive value. Test-re-test reliability of the CCDR over 2months was also high (r=0.73, P<0.0001). In conjunction with veterinary assessment, the CCDR could be a valuable tool in research and clinical settings for both the assessment and longitudinal tracking of cognitive change.

Effect of diet, energy balance and milk production on oxidative stress in early-lactating dairy cows grazing pasture.

The aim of this study was to determine the effect of diet, energy balance and milk production on oxidative stress in early-lactating, Holstein-Friesian dairy cows fed to produce either low or high levels of milk. Indicators of energy balance (non-esterified fatty acids, ß-hydroxybutyrate, glucose and insulin-like growth factor-1) and indicators of oxidative stress (reactive oxygen metabolites and biological antioxidants) were measured in the first 5 weeks of lactation. Energy balance indicators showed that high producing animals had a lower degree of negative energy balance. Diet was found to have an indirect effect on the level of oxidative stress. Factors associated with a high level of oxidative stress were severe negative energy balance (mean -71 ± 6.85 27 MJ/cow/day, P < 0.05) and lower levels of milk production (mean 26.4 ± 0.07 28 L/cow/day, P < 0 .05). Further studies will be required to more precisely determine the specific effects of diet, energy balance and milk production on such stress in dairy cows and to establish normal ranges for these biomarkers.

Under diagnosis of canine cognitive dysfunction: a cross-sectional survey of older companion dogs.

Canine cognitive dysfunction (CCD) is a neurobehavioural syndrome affecting aged dogs. Using a large cross-sectional epidemiological study of older dogs, this study aimed to estimate the prevalence of CCD amongst community based dogs (mean age 11.67years; range 8-19.75) and to determine the rate of veterinary diagnosis amongst affected dogs. An 84-item questionnaire was used to obtain information across six behavioural domains. Of the eligible survey responses obtained (n=957) a randomly selected one-half (n=497) was used for this study. Using a provisional diagnosis based on 27 significant behavioural items, the prevalence rate of CCD was estimated to be 14.2%. This was in contrast with only 1.9% diagnosed with CCD by a veterinarian. There was an exponential increase in prevalence of CCD with age (R2=0.9435), but prevalence did not differ by breed size or between longevity groups. The prevalence rate of CCD reported here is consistent with previous findings, and further supports the contention that the majority of these dogs do not receive a formal diagnosis.