Trait sensitivity to stress and cognitive bias processes in fish: A brief overview.

Like other animals, fish have unique personalities that can affect their cognition and responses to environmental stressors. These individual personality differences are often referred to as "behavioural syndromes" or "stress coping styles" and can include personality traits such as boldness, shyness, aggression, exploration, locomotor activity, and sociability. For example, bolder or proactive fish may be more likely to take risks and present lower hypothalamo-pituitary-adrenal/interrenal axis reactivity as compared to shy or reactive individuals. Likewise, learning and memory differ between fish personalities. Reactive or shy individuals tend to have faster learning and better association recall with aversive stimuli, while proactive or bold individuals tend to learn more quickly when presented with appetitive incentives. However, the influence of personality on cognitive processes other than cognitive achievement in fish has been scarcely explored. Cognitive bias tests have been employed to investigate the interplay between emotion and cognition in both humans and animals. Fish present cognitive bias processes (CBP) in which fish's interpretation of stimuli could be influenced by its current emotional state and open to environmental modulation. However, no study in fish has explored whether CBP, like in other species, can be interpreted as long-lasting traits and whether other individual characteristics may explain its variation. We hold the perspective that CBP could serve as a vulnerability factor for the onset, persistence, and recurrence of stress-related disorders. Therefore, studying fish's CBP as a state or trait and its interactions with individual variations may be valuable in future efforts to enhance our understanding of anxiety and stress neurobiology in animal models and humans.

Case-control study of behavior data from automated milk feeders in healthy or diseased dairy calves.

Group housing of preweaning dairy calves is increasing in popularity throughout the dairy industry. However, it can be more difficult to individually monitor calves to identify disease in these group systems. Automated milk feeders (AMF) not only provide producers with the opportunity to increase the milk allowance offered to preweaning calves but they can also monitor individual feeding behaviors that could identify calves at increased risk of disease. The objective of this retrospective case-control study was to determine how feeding behaviors change in preweaning calves leading up to and during a disease bout. This study was conducted between fall 2015 and fall 2016 on 2 commercial dairy farms in Ontario, Canada. Producers' treatment records for respiratory or enteric illness were used to identify cases. Control calves were selected from calves not treated for disease and matched on the days on the AMF. Both farms housed calves in dynamic groups of 9 to 11 calves with an AMF and fed milk replacer. Differences in feeding behaviors, including milk consumption, drinking speed, rewarded visits, unrewarded visits, and total visits to the AMF per day, were analyzed by mixed models accounting for repeated measures. Data were analyzed for the 7 d before, the day of, and 7 d after treatment. A total of 28 cases and 28 control calves (n = 56) were analyzed. Calves with disease consumed significantly less milk than their healthy counterparts, beginning 5 d before disease and until 3 d after disease detection. Sick calves had fewer unrewarded visits starting 3 d before until 2 d after illness detection. Sick calves drank significantly more slowly starting 4 d before illness detection until the day after illness detection compared with healthy controls. No differences were found between cases and controls for rewarded visits. Calves on a high plane of milk nutrition significantly alter feeding behaviors before illness detection. Data from AMF on feeding behaviors may help to detect disease earlier in preweaning dairy calves.

Associations between Feeding Behaviors Collected from an Automated Milk Feeder and Neonatal Calf Diarrhea in Group Housed Dairy Calves: A Case-Control Study.

The objective of this case-control study was to determine if feeding behavior data collected from an automated milk feeder (AMF) could be used to predict neonatal calf diarrhea (NCD) in the days surrounding diagnosis in pre-weaned group housed dairy calves. Data were collected from two research farms in Ontario between 2017 and 2020 where calves fed using an AMF were health scored daily and feeding behavior data (milk intake (mL/d), drinking speed (mL/min), number of rewarded or unrewarded visits) was collected. Calves with NCD were pair matched to healthy controls (31 pairs) by farm, gender, and age at case diagnosis to assess for differences in feeding behavior between case and control calves. Calves were first diagnosed with NCD on day 0, and a NCD case was defined as calves with a fecal score of ≥2 for 2 consecutive days, where control calves remained healthy. Repeated measure mixed linear regression models were used to determine if there were differences between case and control calves in their daily AMF feeding behavior data in the days surrounding diagnosis of NCD (-3 to +5 days). Calves with NCD consumed less milk on day 0, day 1, day 3, day 4 and day 5 following diagnosis compared to control calves. Calves with NCD also had fewer rewarded visits to the AMF on day -1, and day 0 compared to control calves. However, while there was a NCD status x day interaction for unrewarded visits, there was only a tendency for differences between NCD and control calves on day 0. In this study, feeding behaviors were not clinically useful to make diagnosis of NCD due to insufficient diagnostic ability. However, feeding behaviors are a useful screening tool for producers to identify calves requiring further attention.

Evaluación de bienestar animal en fincas bovinas lecheras basadas en pastoreo en la Sabana de Bogotá, Colombia / Animal welfare assessment on pasture-based dairy farms in Savanna of Bogota, Colombia

RESUMEN Objetivos. Determinar un puntaje de bienestar animal (PBA) a nivel de hato para ganaderías lecheras utilizando un protocolo que involucrara variables basadas en los animales y en manejo/recursos, e identificar las variables que más contribuyen a la varianza del PBA. Materiales y métodos. Veinticinco fincas lecheras basadas en pastoreo (Sabana de Bogotá - trópico alto colombiano) fueron visitadas dos veces. Durante cada visita, 15 variables basadas en el animal y 13 basadas en manejo/ recursos fueron evaluadas. Para cada variable se estableció un punto de corte negativo a nivel de hato para determinar el cumplimiento. En función del cumplimiento, se determinó un PBA (de 0 a 100) y las fincas se clasificaron como 'excelente', 'buena', 'aceptable' o 'no-aceptable'. Se usó una regresión lineal para evaluar la asociación entre variables a nivel de hato con PBA. Resultados. La mediana de PBA fue de 82 (mín = 67; máx = 97). Dos fincas fueron clasificadas como "excelentes" (PBA=94.5), 20 como "buenas" (PBA = 82.5) y 3 como "aceptables" (PBA = 68). Entre todas las variables, el incumplimiento con respecto a mastitis subclínica, calificación de suciedad (patas y ubre), heridas en la línea ventral, recuentos de mosca Haematobia ¡rritans y condición/limpieza del área de espera pre-ordeño se asociaron significativamente con 5.6; 3.6; 6.7; 5.1; 6.5 y 6.1 puntos de reducción en el PBA, respectivamente (R2 = 0.84). Conclusiones. El nivel de bienestar encontrado fue bueno y alentador. No obstante, se identificaron seis variables que contribuyeron a un resultado desfavorable. Las estrategias de mejora podrían centrarse en estas variables para alcanzar un buen nivel de bienestar.

ABSTRACT Objectives. The aim of this study was to determine an overall on-farm animal welfare score (WS) for dairy farms using a protocol involving animal- and management/resource-based variables; and to identify the variables that contributed the most to the variance for the WS. Materials and methods. Twenty-five pasture-based dairy farms in Savanna of Bogota - Colombian high tropic, were visited twice. During each visit, a total of 15 animal- and 13 management/resource-based variables were evaluated. For each variable, a herd-level negative cut-off point was established to determine compliance. Based on compliance, a WS was determined (from 0 to 100) and farms were classified as 'excellent', 'enhanced', 'acceptable', or 'non-acceptable'. A linear regression model was used to evaluate the association between variables at the herd-level with the WS. Results. Overall, median WS was 82 (min=67; max=97). Two farms were classified as 'excellent' (WS=94.5), 20 as 'enhanced' (WS=82.5), and 3 as 'acceptable' (WS=68). Among all variables, the noncompliance regarding subclinical mastitis, hind-legs and udder dirtiness score, ventral line wounds, Haematobia ¡rritans fly counts, and condition/cleanliness of pre-milking holding area was significantly associated with a 5.6, 3.6, 6.7, 5.1, 6.5, and 6.1 points reduction in the WS, respectively (R2 = 0.84). Conclusions. Welfare level found across farms was good and encouraging. Nonetheless, six variables were identified as the main contributors to an unfavorable result. Strategies for improvement could focus on these variables to be able to reach a welfare level of 'excellence'.

Effect of age of introduction to an automated milk feeder on calf learning and performance and labor requirements.

Group housing of dairy calves with automated milk feeders (AMF) is increasingly being used, but the effect of introducing calves to the AMF at a very young age (<24 h) on calf performance, health, and welfare, as well as farm personnel labor requirements are unknown. The objective of this controlled trial was to investigate whether early (<24 h after birth) introduction of calves affects the time to learn how to drink from the AMF, labor requirements for feeding milk during the learning phase, and average daily gain during the milk-feeding period compared with calves conventionally introduced at 5 d of age. Sixty Holstein calves (heifers and bulls) were assigned at birth to either early introduction (<24 h after birth) or conventional introduction (at 5 d of age) to the group pen with AMF. After birth, calves were housed in individual pens and then introduced, based on assigned treatment, to the group pen with an AMF and a continuous flow stocking approach. Calves were fed milk replacer and gradually weaned from d 47 to 60 of age. Calves had access to starter from 5 d of age, and to water and straw right after colostrum feeding. We measured the time between first training to use the AMF and first unassisted visit to the AMF with milk intake, the number of assisted visits until the calf was independent in its use of the AMF (successful learning), and the total time required for milk feeding (labor) until successful learning. Calves were weighed at birth, 30, 46, and 61 d of age, and were monitored daily for signs of disease. Daily milk and starter intake per calf were automatically recorded. Early-introduced calves took longer to successfully learn to use the AMF {64.9 h [95% confidence interval (CI) = 59.1 to 77.9] vs. 31.4 h (95% CI = 22.8 to 47.9)} and tended to require more assisted visits [7.8 visits (95% CI = 6.2 to 9.7) vs. 5.9 visits (95% CI = 4.8 to 7.5)] compared with conventionally introduced calves. Labor for milk feeding was greater for conventionally introduced calves relative to early-introduced calves [145.6 min (95% CI = 125.1 to 169.4) vs. 39.9 min (95% CI= 33.5 to 47.6)]. Disease risk was similar between treatments but the risk of severe versus mild diarrhea was greater for early- compared with conventionally introduced calves (odds ratio = 4.7; 95% CI 1.01 to 31.1). Early-introduced calves consumed less milk during the first days of life compared with conventionally introduced calves (d 2 = 5.5 vs. 6.4 L; d 3 = 7.0 vs. 8.2 L; d 4 = 7.0 vs. 8.4 L; d 6 = 6.4 vs. 7.9 L; d 7 = 6.0 vs. 7.0 L, respectively), with no differences after 8 d. We found no effect of treatment on average daily gain. Although introducing calves <24 h after birth required more assistance to use the AMF, farm labor for milk feeding tasks was less for early-introduced calves. Thus, with early introduction to AMF, a trade-off may exist between reduced labor per calf, with no effect on weight gain, but potentially a higher risk of severe diarrhea (vs. mild).

Associations between management practices and within-pen prevalence of calf diarrhea and respiratory disease on dairy farms using automated milk feeders.

Data on management practices used with automated milk feeders (AMF) are needed to identify factors associated with calf health in these systems. The objectives of this observational, longitudinal, cross-sectional study were to estimate the prevalence of calf diarrhea (CD) and bovine respiratory disease (BRD), and to identify factors associated with prevalence of these diseases at the pen level on dairy farms feeding milk to group-housed calves with AMF. Seventeen dairy farms with AMF in Ontario, Canada, were visited 4 times, seasonally, over 1 yr. The clinical health of all calves (n = 1,488) in pens (n = 35) with AMF was scored to identify the number of calves with CD and BRD. Data on calf, feeder, and pen management practices were analyzed using generalized linear mixed regression models for each disease. Overall calf-level prevalence of CD and BRD were 23 and 17%, respectively. Median (interquartile range, IQR) within-pen prevalence of CD and BRD were 17% (7 to 37%) and 11% (0 to 28%), respectively. Median age (IQR) for diarrheic calves was 25 d (16 to 42 d), and for calves with BRD was 43 d (29 to 60 d). Factors associated with lower within-pen prevalence of CD were the administration of vitamin E and selenium at birth [odds ratio (OR) = 0.56; 95% confidence interval (CI): 0.32 to 0.99], feeding of probiotics (OR = 0.44, 95% CI: 0.22 to 0.93), and adding fresh bedding every 2 to 3 d (OR = 0.43; 95% CI: 0.24 to 0.76) compared with every 7 or more days. In contrast, sharing air with older cattle (>9 mo old) was associated with increased within-pen prevalence of CD (OR = 4.54, 95% CI: 1.88 to 10.52). Additionally, total bacteria counts ≥100,000 cfu/mL in milk samples taken from the AMF mixing jar were associated with increased within-pen prevalence of CD during the summer visit (OR = 3.34; 95% CI: 1.31 to 8.54). Increased total solids in milk or milk replacer (OR = 0.48, 95% CI: 0.27 to 0.85) and feeding whole milk versus milk replacer (OR = 0.29, 95% CI: 0.11 to 0.75) were associated with lower within-pen prevalence of BRD. Factors associated with greater within-pen prevalence of BRD were sharing air with weaned cattle up to 8 mo old (OR = 3.21, 95% CI: 1.26 to 8.16), and greater depth of the wet bedding pack. The use of maternity pens for reasons other than just calving was associated with increased prevalence of both CD and BRD (OR = 1.85, 95% CI: 1.03 to 3.33; OR = 2.61, 95% CI: 1.21 to 5.58, respectively). These results suggest that isolation from older animals and frequent cleaning of the feeder and pen may help to reduce disease prevalence in group-housed calves fed with an AMF.

A survey of dairy calf management practices among farms using manual and automated milk feeding systems in Canada.

Dairy calves in North America traditionally are housed individually and fed by manual milk feeding (MMF) systems with buckets or bottles. Automated milk feeders (AMF) allow for more natural milk feeding frequencies and volumes, and calves are usually housed in groups. The objectives of this study were to (1) determine the prevalence of various milk-fed calf management and feeding practices and (2) compare these practices between dairy farms using MMF and AMF systems. A national online survey was performed from January to May 2015 to quantify management practices for the care of milk-fed dairy calves in Canada. A total of 670 responses were received (6% of all dairy farms in Canada). Among respondents, 16% used AMF and 84% used MMF. Seventy percent of the farms using AMF had freestall barns compared with only 48% of those using MMF. A greater proportion of AMF farms (30%) also had automatic milking systems (AMS) compared with MMF farms (8%). Among tiestall farms, a herd size of >80 milking cows was associated with having an AMF [odds ratio (OR) = 3.8; 95% confidence interval (CI): 1.6-11.4]. For freestall or bedded-pack farms, a herd size of >80 milking cows (OR = 3.5; CI: 1.8-6.6), having an AMS (OR = 3.1; CI: 1.6-5.7), and use of cow brushes (OR = 3.1; CI: 1.3-6.9) were associated with having an AMF. Calves fed with AMS typically were housed in groups of 10 to 15, whereas almost 76% of the farms with MMF housed calves individually. Although both AMF and MMF farms fed similar amounts of milk in the first week of life (median = 6 L/d), the cumulative volume fed in the first 4 wk differed significantly, with a median of 231 versus 182 L for AMF and MMF, respectively. Median peak milk allowance was higher for AMF than for MMF (10 vs. 8 L/d, respectively). In summary, farms using AMF were larger, provided more milk to calves, and used more automation in general (i.e., in other areas of their operation). These data provide insights into calf-rearing practices across Canada and into how the use of AMF is affecting calf feeding and management on dairy farms.

Diagnóstico de leptospirosis canina por medio de las técnicas Dot-ELISA y MAT en perros con enfermedad renal en Bogotá / Diagnostic of canine leptospirosis by Dot – ELISA and MAT tests in dogs with renal disease in Bogota

La leptospirosis es una enfermedad zoonótica, causada por especies del género Leptospira(orden Spirochaetales, familia Leptospiraceae), de gran importancia mundial, debido a su amplia distribución y diversidad de serogrupos y serovares que afectan a varias especies. Una de las especies más afectada por esta bacteria es la canina, en la cual esta bacteria desencadena una infección renal o hepática aguda. La falla renal crónica es una consecuencia común de la infección y los abortos pueden ocurrir en hembras preñadas. En los últimos años, la leptospirosis se ha catalogado como uno de los posibles diagnósticos diferenciales más comunes para perros que presentan signos de enfermedad renal aguda o hepática. En el presente trabajo se estudiaron treinta caninos con enfermedad renal, a los cuales se les realizó una prueba de diagnóstico serológico para leptospirosis: la técnica de aglutinación microscópica (MAT) para seis serovares de Leptospira interrogans, y una prueba de diagnóstico en orina por medio de la prueba Dot-Elisa para los serovares canicola, icterohaemorrhagiae, pomona y grippotyphosa. Se diagnosticaron como positivos a Leptospira, como causa de la enfermedad renal, utilizando los resultados de las dos pruebas, diez caninos (33,3%), los cuales presentaron títulos a MAT para los serovares icterohaemorrhagiae, canicola y grippotyphosa principalmente. Nueve de los diez perros fueron positivos a Dot-Elisa con una distribución homogénea en los cuatro serovares que se manejaron. Los veinte perros restantes (66,7%) fueron negativos. La asociación entre la prueba Dot-Elisa y la prueba MAT fue altamente significativa (P < 0,01).

Leptospirosis is a zoonotic disease that is caused by species of genus Leptospira (Order Spirochaetales, Family Leptospiraceae). This is very important on a global level, due to its widespread distribution and diversity of serogroups and serovars that affect an extensive group of animal species. Canines are one of the most affected species, where this bacterium generates an acute renal or hepatic infection. Chronic kidney disease is a common consequence of the infection and miscarriage can also happen in pregnant females. During the past few years, Leptospirosis has been catalogued as one of the most common differential diagnostics for dogs with acute renal and hepatic disease symptoms. Thirty (30) dogs with renal disease were evaluated during this project, undergoing serological testing for Leptospirosis: the Microscopy Agglutination Test (MAT) for six Leptospira interrogans serovars and a diagnostic urine test through Dot–ELISA for serovars canicola, icterohaemorrhagiae, pomona and grippotyphosa. The results of both tests came out positive for Leptospira as the cause of the renal disease in ten (10) dogs (33.3%), which showed titles on MAT mainly in serovars icterohaemorrhagiae, canicola and grippotyphosa. Dot–ELISA was positive in 9 of the 10 dogs, with a homogeneous distribution in the 4 serovars. The remaining 20 dogs (66.7%) came out negative. The association between the Dot–ELISA test and the MAT test was highly significant (P < 0.01).