Background
Supraventricular tachycardias (SVTs), despite having various anatomical substrates and pathophysiological mechanisms, frequently show similar electrocardiographic presentations.
Objectives
...To locate and characterize atrial deflections (ADs) on 12‐lead electrocardiograms in dogs with sustained rapid SVT and assess the utility of different electrocardiographic variables in differentiating types of tachycardia.
Animals
Ninety‐two dogs with orthodromic atrioventricular reciprocating tachycardia, 17 with atrial flutter, 33 with focal atrial tachycardia recorded and confirmed by electrophysiological study, and 40 dogs with sinus tachycardia.
Methods
Atrial deflection position on the 12‐lead surface electrocardiogram was assessed according to the sequence of intracardiac activation. Its features were evaluated together with the relationship between AD and QRS complex interval (AD‐R) and QRS complex and AD interval (R‐AD).
Results
Orthodromic atrioventricular reciprocating tachycardia was characterized by an AD‐AD interval of 213 ± 30 ms, mean electrical axis (MEA) of AD of −90 (−90/−78)°, R‐AD interval of 75 (65‐80) ms, and R‐AD/AD‐R of 0.54 (0.45‐0.64). Atrial flutter was characterized by an AD‐AD interval of 199 ± 57 ms, MEA of 76° (72/81), R‐AD of 120 (72‐144) ms, and R‐AD/AD‐R of 0.81 (0.63‐1.13). Focal atrial tachycardia was characterized by an AD‐AD interval of 270 ± 38 ms, MEA of 49 (−72/76)°, R‐AD of 160 (120‐200) ms, and R‐AD/AD‐R of 1.45 (0.92‐1.67). Sinus tachycardia was characterized by an AD‐AD interval of 292 ± 31 ms, MEA of 66° (52/73), R‐AD of 215 (192‐222) ms, and R‐AD/AD‐R of 2.68 (2.25‐3.08).
Conclusions and Clinical Importance
Analyzing AD on 12‐lead electrocardiogram is helpful in differentiating the most common SVTs in dogs.
Due to the climatic change, an increase in aflatoxin B1 (AFB1) maize contamination has been reported in Europe. As an alternative to mineral binders, natural phytogenic compounds are increasingly ...used to counteract the negative effects of AFB1 in farm animals. In cows, even low dietary AFB1 concentrations may result in the milk excretion of the genotoxic carcinogen metabolite aflatoxin M1 (AFM1). In this study, we tested the ability of dietary turmeric powder (TP), an extract from Curcuma longa (CL) rich in curcumin and curcuminoids, in reducing AFM1 mammary excretion in Holstein–Friesian cows. Both active principles are reported to inhibit AFM1 hepatic synthesis and interact with drug transporters involved in AFB1 absorption and excretion. A crossover design was applied to two groups of cows (n = 4 each) with a 4-day washout. Animals received a diet contaminated with low AFB1 levels (5 ± 1 µg/kg) for 10 days ± TP supplementation (20 g/head/day). TP treatment had no impact on milk yield, milk composition or somatic cell count. Despite a tendency toward a lower average AFM1 milk content in the last four days of the treatment (below EU limits), no statistically significant differences with the AFB1 group occurred. Since the bioavailability of TP active principles may be a major issue, further investigations with different CL preparations are warranted.
•Thermoregulatory mineral mixture did not show effect under moderate HS conditions•Other tools to mitigate HS may play a more important role than mineral supplement•Even mild and moderate HS can ...elevate respiratory rate and rectal temperature
Heat stress (HS) occurs when animals are enable to effectively dissipate excessive body heat, potentially affecting their welfare and productivity. Several tools can be used to mitigate HS in dairy cows. The aim of this study was to evaluate the effect of thermoregulatory mineral supplementation on dairy cows’ physiological response to HS and reproductive status. Thirty pluriparous Holstein dairy cows (2.8 ± 0.3 lactation), from a semi confinement production system (freestall barn), were enrolled in a 35 days duration experiment, and divided into two groups: 15 cows receiving a thermoregulatory mineral mixture containing calcium, sodium, chlorine, and potassium (200 g/day; TRT); and, 15 cows that did not receive any type of supplement (CON). Data on respiration rates (RR), rectal temperature (RT), milk yield, barn temperature, relative humidity, and temperature and humidity index (THI) were obtained on weekly evaluations (D7, D14, D21, D28, and D35). ANOVA and correlation analysis were used to compare variables between groups, and physiological and climate variables, regardless of group. Related to farm's protocols, on D0 and D35, all cows were submitted to US evaluation and categorized as inseminated, pregnant, and not pregnant, and this data analysed using Fisher's exact test. Cows in the TRT group had lower RT, compared to the CON group (38,8 °C and 39,0 °C, respectively; P = 0.0147), however both averages were within physiological range. As to physiological variables, stronger positive correlations were found between RR and RT with barn temperature and THI. In this study, the thermoregulatory mineral supplement did not significantly affect physiological responses to HS or reproductive status.
In rabbits' reproductive performance, litter size, birth weight, growth, and mortality rate are among the most important indicators to define the productive potential and they are associated with ...parity order. Birth weight and little size are valuable parameters as related to mortality and weaning weight. Thus, it is important to study individual newborn and intra-litter homogeneity parameters. This trial aimed to consider the litter homogeneity weight at birth, both within each litter and in the whole population, in order to suggest new proper within-litter homogenisation parameters. In this study, the 1st and 6th parity order had, respectively, the lowest and highest values in litter size (8.96 vs 12.39, n), born-alive (8.36 vs 12.22, n), litter weight (456.4 g vs 719.8, g), born-alive weight, and quartiles' homogeneity. These parameters decreased in greater parity orders. No significant effects on still-born numbers and mortality rates were evidenced. All these litter homogeneity evaluation parameters appeared interesting in describing differences between parity orders. The results confirmed that does parity order influences litter size and born-alive weight, but also the intra- and inter-litter homogenisation. Litter homogenisation is crucial to ensure a proportionate share of milk, more equal growth, and better productive performances. Based on these results, we suggest for the commercial genetic centres to equalise the litters according to the birth weight, by dividing the population into quartiles and rearing kits with light birth weight in smaller litters and those with heavier birth weight in larger litters.
HIGHLIGHTS
Does parity order influences litter size and born-alive weight
Kit's quartiles distribution is a useful tool for equalisation practice
Dairy cows are exposed to multiple stressors during the productive cycle, such as metabolic challenges, overcrowding, grouping change, environmental stress and dietary errors. Thus, it is essential ...to study reliable markers able to detect stress conditions in dairy farms. This study evaluates dairy cows' immunologic and metabolic markers after the sudden and combined exposition to a high‐grain diet (75% concentrates) and the abrupt change of the housing system (from free stall to tie stall). A group of twenty‐four Holstein cows were enrolled in a challenge study of 28 days duration. Several immunological and metabolic blood markers were evaluated over the trial. Blood samples were taken at day 0 (normal value) and day 1, 3, 7, 14, 21, and 28 (challenge). Data were submitted to a mixed model for repeated measures, including time as fixed and cows as random effects. The nutritional and environmental challenge had heavy effects on animal welfare and cows responded with a dramatic rumination drop. Our results suggest that the most responsive markers after abiotic stressors in cows were as follows: Serum Amyloid A and ROM in the acute response; Ceruloplasmin and GGT in the mid acute and Albumin, Paroxonase and FRAP in the chronic phase. Serum Amyloid A, Ceruloplasmin, Paraoxonase, GGT and ROM resulted as positive phase proteins, while, Albumin and FRAP resulted as negative phase proteins. Preliminary obtained results could concur to develop strategies able to mitigate stressor effects; moreover, the proposed design can be used as a model to test stress nutritional modulators.
The paper presents an overview of the usage of Instagram as a social media platform for teaching and engagement in the field of dairy cow nutrition and management. Our Instagram content, which ...includes posts, stories, hashtags, reels, and live videos, aims to educate and engage our followers and covers a wide range of topics, including research updates, student activities, and information on dairy cow health and welfare. This approach to education allows us to reach a larger audience while also providing a forum for interaction and discussion on essential dairy cow nutrition concerns.
Toxoplasmosis, caused by the protozoan parasite
Toxoplasma gondii
, is a globally distributed zoonotic infection with significant implications for human and animal health. This study investigated the ...prevalence of
T. gondii
infection in a population of beef cattle at three different stages of their productive lifespan and examined the impact of
T. gondii
serological status on blood parameters. A commercial beef fattening unit in Italy was the setting for this research, which involved a biosecurity assessment upon cattle arrival, blood sampling at three time points and
Toxoplasma
-specific serological testing using indirect fluorescent antibody tests (IFAT). Results revealed a dynamic pattern of
T. gondii
seropositivity in cattle, with an initial prevalence of 30.6% at arrival (T0) that increased to 44.6% at 14 days (T1) and then decreased slightly to 39.3% at slaughter after 5 months (T2). Interestingly, seroconversion was observed during the study, indicating ongoing infections, and antibody waning occurred in some animals. In terms of blood parameters, seropositive cattle exhibited significantly lower mean corpuscular volume (MCV) and a higher neutrophil–lymphocyte (N/L) ratio, suggesting an activation of the innate immune response. Furthermore, cattle with higher antibody titres displayed higher neutrophil counts. However, all blood parameters with a statistical significance were within the reference range. This study provides for the first time a longitudinal investigation on the serological status for
T. gondii
in naturally exposed beef cattle. These findings provide valuable insights into the clinico-pathological aspects of natural
T. gondii
exposure in cattle and underscore the importance of monitoring and managing
T. gondii
infection in livestock production systems.
The aim of this study was to evaluate the effects of a complete hay-based total mixed ration (TMR) for calves, focusing on their feed intake, animal growth performance, and fecal output, and to ...develop a preliminary estimation equation for solid feed intake and body weight in Holstein heifer calves. Twenty female Italian Holstein calves (37.14 ± 2.72 kg) born between February and July were studied from the day of birth until 77 days of age. From the fourth day of life, they were fed 3 L/day of pasteurized milk twice daily and supplemented with the same hay-based TMR. The data on feed intake, fecal characteristics, and growth performances were collected and showed that these calves had adequate parameters. Moreover, the data collected was used to create equations to predict body weight and solid feed intake using a mixed model. The goodness of fit of the developed equations was evaluated by coefficients of determinations (R2). The equation obtained shows high R2 (0.98 for solid feed intake and 0.99 for calf weight), indicating the satisfactory precision and accuracy needed to predict female calves’ body weight and solid feed intake.
Horses reared for meat production are generally fed a diet rich in starch with the aim of maximizing production performances. This study evaluated the effects of two feeding management systems on ...horse welfare by analysing the relative time spent engaged in different behavioural activities. Nineteen Bardigiano horses aged 14.3 ± 0.7 months were randomly assigned to one of two group pens: one group was fed high amounts of starch-rich concentrates (HCG; n = 10), the other was fed a fibre-based diet (HFG; n = 9). Behavioural activities performed by each horse were video-recorded over a 96-h period. A scan sampling process (n = 144 scans/horse/day; total n of scans sampled = 10,368) was used, and the scans were analysed according to a specific ethogram. The mean frequency (%/24 h) spent exhibiting each behavioural activity was calculated to obtain the time budget. After checking for normality (Shapiro–Wilk test), Student’s t tests (normally distributed data) and Mann–Whitney tests (not normally distributed data) were used to compare the time budgets of the two groups of horses (HCG vs. HFG). Principal Component Analysis (PCA) was applied to identify the components explaining the variability in behavioural activities between the two groups. K-means cluster analysis subsequently confirmed the PCA results. The behavioural activities associated with feeding horses a fibre-based diet correlated with better horse welfare compared with feeding horses a starch-based diet. Feeding horses a fibre-based diet resulted advantageous from both the welfare and economic perspective; it allowed horses to spend more time expressing feeding behaviours and reduced energy expenditure in the form of excitable, or “fizzy”, behaviours.
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