Effects of simplified group housing on behavior, welfare, growth performance, and health of preweaned dairy calves on a California dairy.

Most US dairy calves are raised in individual hutches for biocontainment purposes and to facilitate monitoring and handling of calves. However, individual hutches typically restrict calves' activity and social interactions. Previous studies showed that group housing (GH) is beneficial to calf welfare and is associated with social benefits. The adoption of GH on dairies is hindered by several concerns, with the primary concern being the potential for increased transmission of diseases due to heightened calf-to-calf contact. In light of this, our study aimed to compare the behavior, health, and growth outcomes of calves housed in groups of 3 to individually housed (IH) calves during the preweaning period. A total of 42 Holstein heifer calves on a commercial dairy in Northern California were enrolled in groups of 3 to different housing treatments; IH (n = 21) or GH (n = 21) between July and October 2020. Each treatment was composed of 7 groups of 3 calves each. Calves in the GH treatment were housed in groups of 3 from 6 to 10 d until 70 d of age. Individual pens consisted of one polyethylene hutch with a 1.5 m × 1.2 m outside exercise area. Group pens were constructed by assembling 3 polyethylene hutches with a 1.5 m × 3.6 m outside exercise area of wire panel fencing. Calves were weighed and measured for height at birth and weaning. Diarrhea and bovine respiratory disease (BRD) scores were recorded daily throughout the preweaning period. Cumulative incidence and hazard ratios were estimated for BRD and diarrhea for GH and IH. A mixed model with pen as a random effect was specified to evaluate the effect of treatment. Group-housed calves gained 0.64 ± 0.02 kg/d while IH calves gained 0.65 ± 0.02 kg/d. Similarly, there was no evidence for treatment differences in withers height gain in GH calves (0.22 ± 0.01 cm/d) compared with IH calves (0.21 ± 0.01 cm/d). The cumulative incidence of BRD based on the California scoring system in GH calves was 75 ± 9.68% compared with 66.66 ± 10.28% in IH calves. Group-housed calves had a BRD hazard of 1.14 times that of IH calves (95% CI: 1.21-2.40). The cumulative incidence of diarrhea (fecal score 3) in GH calves was 100% in comparison to 95.20% ± 4.66% in IH calves. The mean proportion of scan observations of calves feeding on concentrates was significantly higher in GH (0.145 ± 0.004/h) compared with IH calves (0.076 ± 0.003/h) during the preweaning period. The study results provide evidence that this simplified GH system provides benefits of GH without detrimental short-term effects on calf growth and health during the preweaning period.

An assessment of thermoneutral housing conditions on murine cardiometabolic function.

Mouse models are used to model human diseases and perform pharmacological efficacy testing to advance therapies to humans; most of these studies are conducted in room temperature conditions. At room temperature (22°C), mice are cold-stressed and must use brown adipose tissue (BAT) to maintain body temperature. This cold stress increases catecholamine tone to maintain adipocyte lipid release via lipolysis, which will fuel adaptive thermogenesis. Maintaining rodents at thermoneutral temperatures (28°C) ameliorates the need for adaptive thermogenesis, thus reducing catecholamine tone and BAT activity. Cardiovascular tone is also determined by catecholamine levels in rodents, as ß-adrenergic stimuli are primary drivers of not only lipolytic but also ionotropic and chronotropic responses. As mice have increased catecholamine tone at room temperature, we investigated how thermoneutral housing conditions would impact cardiometabolic function. Here, we show a rapid and reversible effect of thermoneutrality on both heart rate and blood pressure in chow-fed animals, which was blunted in animals fed a high-fat diet. Animals subjected to transverse aortic constriction displayed compensated hypertrophy at room temperature, whereas animals displayed less hypertrophy and a trend toward worse systolic function at thermoneutrality. Despite these dramatic changes in blood pressure and heart rate at thermoneutral housing conditions, enalapril effectively improved cardiac hypertrophy and gene expression alterations. There were surprisingly few differences in cardiac parameters in high-fat-fed animals at thermoneutrality. Overall, these data suggest that thermoneutral housing may alter some aspects of cardiac remodeling in preclinical mouse models of heart failure.NEW & NOTEWORTHY Thermoneutral housing conditions cause rapid and reversible changes in mouse heart rate and blood pressure. Despite dramatic reductions in heart rate and blood pressure, thermoneutrality reduced the compensatory hypertrophic response in a pressure overload heart failure model compared with room temperature housing, and ACE inhibitors were still efficacious to prevent pressure overload-induced cardiac remodeling. The effects of thermoneutrality on heart rate and blood pressure are abrogated in the context of diet-induced obesity.

Identification of blood immune and metabolic indicators explaining the variability of growth of pigs under contrasted sanitary conditions.

BACKGROUND: Health and growth of pigs are affected by the hygiene of housing. Lower growth performance observed in poor hygiene of housing conditions is explained by reduced feed intake and metabolic changes caused by the activation of body defences. In a previous experiment, we reported contrasted average values of body weight gain, concentrations of circulating metabolites, redox and immune indicators in blood of pigs housed in good or poor hygiene conditions during the growing period. This study addressed inter-individual variability in these responses to determine whether a particular blood profile explains average daily gain (ADG) of the pig. RESULTS: The data originated from 160 growing pigs, half of which subjected to a hygiene challenge for 6 weeks (W0 to W6) and the others housed in good hygiene conditions. Pigs originated from two lines divergently selected for residual feed intake (RFI). Individual body weights were recorded during this period, and relative ADG (rADGW0-W6) was calculated as the ADG corrected by the initial body weight measured at W0. Blood samples were taken before (W0) and 3 weeks (W3) after the beginning of the challenge. The analysed dataset consisted of 51 metabolites and indicators of immune and inflammatory responses measured on 136 pigs having no missing value for any variables, when calculated as the differences W3 minus W0 in circulating concentrations. An algorithm tested all possible linear regression models and then selected the best ones to explain rADGW0-W6. Six variables were identified across the best models and correlated with rADGW0-W6 with a goodness of fit (adjusted R2) of about 67%. They were changes in haptoglobin, global antioxidant capacity of plasma (Biological Antioxidant Power or BAP), free fatty acids, and 3 amino acids: leucine, tryptophan, and 1-methylhistidine. The effects of housing conditions and RFI lines were comprised in the variables of the selected models and none of these conditions improved accuracy of the predictive models, leading to genericity of the pinpointed metabolic changes in relation to variability of ADG. CONCLUSIONS: This approach allows us to identify blood variables, whose changes in blood concentrations correlated to ADG under contrasted sanitary conditions.

Refinement of international recommendations for cubicles, based on the identification of associations between cubicle characteristics and dairy cow welfare measures.

Maladjusted cubicles for dairy cattle may cause increased skin alterations, lameness, and dirtiness. The International Commission of Agricultural and Biosystems Engineering has produced several recommendations for cubicle design, but a previous study showed that not all of them seem efficient. Here, we aim to refine and complete these recommendations. We collected data on 76 dairy farms (2,404 cows). We modeled the association between combinations of cubicle properties (e.g., type of bedding litter) and dimensions (e.g., cubicle width) relative to cow size, and prevalence of cow skin alterations, lameness, and dirtiness. We used weighted multivariable logistic regression models to predict the presence of skin alteration on the carpus; the neck, shoulder, and back; the flank, side, and udder; and the tarsus or hindquarters. We also evaluated the presence of lameness as well as the dirtiness of the lower hind legs including hocks; the hindquarters, upper hind legs, and flank; the cow rear including tail; and the udder. The risk factors highlighted led us to recommend (1) position cubicles in a way that leaves more than 1 m of clearance from any obstacle in front of the cubicle; (2) if there is an obstacle on the lateral plane (i.e., where the cubicle partition is) in front ahead of the cow, put the obstacle in front of the fore knees; (3) if there is an obstacle in front of the cow on the median plane (e.g., neck or front rail), the position the obstacle between 1.25 and 1.5 of the cow length from the curb and between 1.0 and 1.25 of its height; (4) use curb height between 0.11 and 0.15 of cow height with no sharp edges on the curb; (5) use round or at least has no sharp edges brisket board; (6) use a stone-free soil instead of concrete or use a mattress thicker than 1 cm, with microrelief, and a soft fixing area at the curb, (7) litter with straw (rather than nothing or sawdust) and keep it dry. This risk factor analysis should be followed by experiments in controlled environments to further validate these conclusions and used to update the International Commission of Agricultural and Biosystems Engineering recommendations.

Genomic, microbial and environmental standardization in animal experimentation limiting immunological discovery.

BACKGROUND: The use of inbred mice housed under standardized environmental conditions has been critical in identifying immuno-pathological mechanisms in different infectious and inflammatory diseases as well as revealing new therapeutic targets for clinical trials. Unfortunately, only a small percentage of preclinical intervention studies using well-defined mouse models of disease have progressed to clinically-effective treatments in patients. The reasons for this lack of bench-to-bedside transition are not completely understood; however, emerging data suggest that genetic diversity and housing environment may greatly influence muring immunity and inflammation. RESULTS: Accumulating evidence suggests that certain immune responses and/or disease phenotypes observed in inbred mice may be quite different than those observed in their outbred counterparts. These differences have been thought to contribute to differing immune responses to foreign and/or auto-antigens in mice vs. humans. There is also a growing literature demonstrating that mice housed under specific pathogen free conditions possess an immature immune system that remarkably affects their ability to respond to pathogens and/or inflammation when compared with mice exposed to a more diverse spectrum of microorganisms. Furthermore, recent studies demonstrate that mice develop chronic cold stress when housed at standard animal care facility temperatures (i.e. 22-24 °C). These temperatures have been shown alter immune responses to foreign and auto-antigens when compared with mice housed at their thermo-neutral body temperature of 30-32 °C. CONCLUSIONS: Exposure of genetically diverse mice to a spectrum of environmentally-relevant microorganisms at housing temperatures that approximate their thermo-neutral zone may improve the chances of identifying new and more potent therapeutics to treat infectious and inflammatory diseases.

Recommended housing densities for research mice: filling the gap in data-driven alternatives.

Space recommendations for mice made in the Guide for Care and Use of Laboratory Animals have not changed since 1972, despite important improvements in husbandry and caging practices. The 1996 version of the Guide put forth a challenge to investigators to produce new data evaluating the effects of space allocation on the well-being of mice. In this review, we summarize many studies published in response to this challenge. We distinguish between studies using ventilated or nonventilated caging systems and those evaluating reproductive performance or general well-being of adult mice. We discuss how these studies might affect current housing density considerations in both production and research settings and consider gaps in mouse housing density research. Additionally, we discuss reliable methods used to monitor and quantify general well-being of research mice. Collectively, this large body of new data suggests that husbandry practices dictating optimal breeding schemes and space allocation per mouse can be reconsidered. Specifically, these data demonstrate that prewean culling of litters has no benefit, trio breeding is an effective production strategy without adversely affecting pup survival and well-being, and housing of adult mice at densities of up to twice current Guide recommendations does not compromise well-being for most strains.-Svenson, K. L., Paigen, B. Recommended housing densities for research mice: filling the gap in data-driven alternatives.

Symposium review: Animal welfare in free-walk systems in Europe.

Providing more space per animal, soft bedding, and free roaming in animal housing systems is widely presumed to be beneficial for the welfare of the animals. This observational study aimed to investigate the basis of this assumption in free-walk housing systems (FWS) for dairy cows in Europe. The dairy cattle Welfare Quality assessment protocol was adapted for application to FWS, and the focus was on animal-based measures, from individual cow scoring to comfort around resting. The study was conducted on 41 farms [21 FWS and 20 cubicle housing (CH)] from 6 European countries (Germany, the Netherlands, Italy, Austria, Slovenia, and Sweden) displaying a variety of management systems. A total of 4,036 animals were scored. We found differences in animal welfare under different management conditions. The hindquarters and lower hind legs of cows from FWS were dirtier than those of cows in CH, but we found no difference in the dirtiness of udders or teats. Cows from FWS showed fewer hairless patches in all body areas except the neck; fewer lesions in the lower hind legs and hindquarters; and less swelling in the lower hind legs, flanks, and carpus than cows from CH. The prevalence of sound cows appeared to be higher in FWS, and moderate lameness prevalence was lower compared with CH. We found no difference in the prevalence of severe lameness between systems. We conducted a total of 684 observation sessions of comfort around resting, consisting of 830 lying down and 849 rising up movements. Cows in FWS took less time to lie down, had less difficulty rising up, and had fewer collisions with the environment during both behaviors than cows in CH. Cows lay partly or completely outside the supposed lying area less frequently in FWS than in CH. Cows in FWS adopted comfortable lying positions more often compared with CH, showing a higher occurrence of long and wide positions than cows in CH. Short positions were more common in FWS, and narrow positions were slightly more common in CH. We found large variations in animal-based measures between study herds and within housing systems. However, the observed patterns associated with each system demonstrated differences in cow scoring and comfort around resting. This study shows that a wide range of good and bad management practices exist in FWS, especially related to cow hygiene.

Symposium review: The impact of management and facilities on cow culling rates.

This symposium review examines the association between comfort and cow longevity, with a particular emphasis on optimizing resting behavior in confinement-housed systems. Housed dairy cattle demonstrate a variety of negative behavioral and physiological effects when lying time is restricted, with cows prioritizing the recovery of rest over feeding when both are deprived. There is, however, wide individual-cow variation in daily lying times, influenced by an array of cow-, housing-, and management-related factors. Cow-related factors include individual preference, parity, stage of lactation cycle, milk yield, ill health, and lameness. Lying time tends to increase with age and days in milk and during periods of ill health, whereas milk yield is negatively correlated with lying time. The effect of lameness is complicated by severity and by interactions with bedding type, which modifies the cows' ability to rise and lie down. Generally, lame cows suffer prolonged lying bouts of greater variability in length and take fewer bouts per day. Often this results in an overall increase in lying time. Thus, higher standards of cow comfort and improved cow health are not always reflected by longer lying times. Housing and management factors that influence resting behavior include the design of the resting area, access to the resting space, and the thermal microenvironment of the lying area. Provision of dry, deep loose bedding, stocking cows to allow each animal access to a resting space, allowing sufficient time to access the resting area, and providing heat abatement to reduce heat load optimize resting behavior. Because lameness and poor body condition are commonly found in culled dairy cattle, the link between cow comfort and culling is likely mediated through lameness onset and management. Optimal comfort helps prevent the onset of lameness and facilitates recovery once cows become lame, which limits the effect of lameness on feeding behavior and reduces the risk for other health-related disorders, poor reproductive performance, and early herd removal. Cow comfort cannot be assessed by measuring the duration of lying time alone. Rather, comfort is reflected by the optimization of resting behavior, providing facilities and management to allow cows to lie down when they choose to do so for as long as they need to.

Thermoneutral zone for laying hens based on environmental conditions, enthalpy and thermal comfort indexes.

Controlling environmental conditions inside laying hens facilities systems and their effects on physiology and performance is essential in defining management strategies to alleviate the adverse effects of thermal stress in laying hens. Thus, we estimated thermoneutral zones for laying hens exposed to different heat-challenging conditions based on environmental conditions, enthalpy, and thermal comfort indexes being evaluated out in four thermal environment-controlled wind tunnels equipped with heating and air moistening function, housed in an experimental room with an area of 31.92 m2. Clustering analysis and empirical models were used to estimate thermoneutral zones for laying hens based on environmental conditions, enthalpy and thermal comfort indexes, and compare them with data available in the literature through graphics. The thermoneutral zones characterizing homeostasis for laying hens based on respiration rate (RR) are as follows: from 25.9 to 29.9 °C for air dry-bulb temperature (tdb), from 67 to 75 for temperature-humidity index (THI), from 68 to 73 for black globe-humidity index (BGHI), from 45 to 56 kJ kg dry air-1 for enthalpy (H) and 441.7-465.6 W for radiant heat load (RHL). Comfort limits for physiological responses cloacal temperature (tclo), surface temperature (tsur) and RR found in this study are 39.4-39.9 °C, 26.5 to 29.9 °C and 30 to 67 mov. min-1, respectively. The number of repetitions and the use of mathematical modeling to be worked on, may directly impact the amplitude of each limit to be established for each variable of interest.

Microclimate modeling in naturally ventilated dairy barns during the hot season: Checking the accuracy of forecasts.

Monitoring and predicting the microclimate in naturally ventilated barns (NVB) is important given the adverse effects of high summer temperatures on dairy cows in the context of global climate change. The aim of the work was to verify the accuracy of the microclimate forecast in a NVB using linear regression (LR). Our working hypothesis suggested that multiple periodic measurements of air temperature and relative humidity outside and inside the barns at the same time will allow us to build LR models for predicting the temperature-humidity index (THI). This was done not only for a specific dairy barn based on this indicator outside, but also in other dairy barns with a similar design, located in similar weather conditions. The results of the research indicate that the use of LR had a high accuracy of forecasting (93-96%) the THI in NVB of various designs during the summer heat. At the same time, differences were found between traits (air temperature, relative humidity as well as resulting THI) provided by meteorological weather stations and these data measured simultaneously next to the dairy barns. The proposed LR models can be used to predict THI in NVBs of different designs.

Neither altered incubation temperature during fetal development nor preferred rearing temperature improves leg bone characteristics of broilers.

The present study evaluated whether broiler femoral and tibiotarsal characteristics (as assessed at slaughter age) could be improved if birds were reared under their preferred temperature and whether continuous high or low incubation temperature during the fetal period improves bone characteristics of broilers reared under heat stress or thermal preference. Broiler breeder eggs were incubated from day 13 until hatching under cold (36 °C), control (37.5 °C), or hot (39 °C) temperatures. Under these conditions, the eggshell temperatures were 37.4 ± 0.1°C, 37.8 ± 0.15°C, and 38.8 ± 0.3°C, respectively. Then, broiler chicks were reared under control, preferred (determined previously in thermal preference test), or high temperatures. At day 42 of age, the broilers were weighed and euthanized, and femora and tibiotarsi collected to measure weight, length, diaphysis perimeter, breaking strength, maximum flexion, rigidity, ash, phosphorus, and calcium. Rearing under the preferred temperature did not affect broiler body weight or femoral and tibiotarsal characteristics (P > 0.05). In contrast, high rearing temperature, decreased the body weight, mineral contents of both bones, femoral breaking strength, and tibiotarsal rigidity (P < 0.05). Regarding incubation temperature effects, egg exposure to cold and hot temperatures during the fetal period minimized or avoided a few effects of high rearing temperature, such as those on femoral and tibiotarsal morphological characteristics, mineral composition, and mechanical properties at slaughter age (P < 0.05), but not all. In conclusion, rearing under the preferred broiler temperature did not improve the bone characteristics, and the negative effects of high rearing temperature on bone development were minimized but not completely prevented by high or low temperature incubation during the fetal period.

Long-Term Study on the Effects of Housing C57BL/6NCrl Mice in Cages Equipped With Wireless Technology Generating Extremely Low-Intensity Electromagnetic Fields.

The recent development of mouse cages equipped with monitoring wireless technology raised questions on the potential effects on animals induced by electromagnetic fields (EMFs) generated by electronic boards positioned underneath the cages. The aims of this study were to characterize the EMF produced by digitally ventilated cages (DVC) and perform a clinicopathological study on mice maintained in DVC for up to 1 year. The EMFs were measured in empty individually ventilated cages (IVC) and DVC. Male (n = 160) and female (n = 160) C57BL/6NCrl mice were randomly housed in IVC and DVC in a single rack, 4 mice per cage. Body weight and food and water consumption were recorded at 14-day intervals. At sacrifice (days 60, 120, 180, and 365), body and testes weight was measured, and necropsy, hematology, bone marrow cytology, histology, and immunohistochemistry for cleaved-caspase 3 on the testes were performed. Digitally ventilated cages produced extremely low-intensity electric fields ranging from 5 Hz to 3 GHz. No exposure-related clinical signs and mortality occurred. Occasional statistical differences in body weight, food and water consumption, hematology, bone marrow, and histopathology were recorded, but considered without biological or clinical relevance. In conclusion, long-term maintenance in DVC had no definite effects on C57BL/6NCrl mice.

A study of the relationship between human infection with avian influenza a (H5N6) and environmental avian influenza viruses in Fujian, China.

BACKGROUND: Avian influenza A (H5N6) virus poses a great threat to the human health since it is capable to cross the species barrier and infect humans. Although human infections are believed to largely originate from poultry contaminations, the transmissibility is unclear and only limited information was available on poultry environment contaminations, especially in Fujian Province. METHODS: A total of 4901 environmental samples were collected and tested for Avian Influenza Virus (AIV) from six cities in Fujian Province through the Fujian Influenza Surveillance System from 2013 to 2017. Two patient-related samples were taken from Fujian's first confirmed H5N6 human case and his backyard chicken feces in 2017. Chi-square test or Fisher's exact probability test was used to compare the AIV and the viral subtype positive rates among samples from different Surveillance cities, surveillance sites, sample types, and seasons. Phylogenetic tree analysis and molecular analysis were conducted to track the viral transmission route of the human infection and to map out the evolutions of H5N6 in Fujian. RESULTS: The overall positive rate of the H5 subtype AIVs was 4.24% (208/4903). There were distinctive differences (p < 0.05) in the positive rates in samples from different cities, sample sites, sample types and seasons. The viruses from the patient and his backyard chicken feces shared high homologies (99.9-100%) in all the eight gene segments. Phylogenetic trees also showed that these two H5N6 viruses were closely related to each other, and were classified into the same genetic clade 2.3.4.4 with another six H5N6 isolates from the environmental samples. The patient's H5N6 virus carried genes from H6N6, H5N8 and H5N6 viruses originated from different areas. The R294K or N294S substitution was not detected in the neuraminidase (NA). The S31 N substitution in the matrix2 (M2) gene was detected but only in one strain from the environmental samples. CONCLUSIONS: The H5 subtype of AIVs has started circulating in the poultry environments in Fujian Province. The patient's viral strain originated from the chicken feces in his backyard. Genetic reassortment in H5N6 viruses in Fujian Province was indicated. The H5N6 viruses currently circulating in Fujian Province were still commonly sensitive to Oseltamivir and Zanamivir, but the resistance against Amantadine has emerged.

Do International Commission of Agricultural and Biosystems Engineering (CIGR) dimension recommendations for loose housing of cows improve animal welfare?

Design of cubicles and self-locking barriers can affect cow skin alterations, lameness, and dirtiness. We investigated whether the International Commission of Agricultural and Biosystems Engineering (CIGR, Gainesville, FL)-recommended cattle housing design and dimensions actually improve cow welfare. We recorded individual cow body dimensions and assessed skin alterations, dirtiness, and lameness on 3,841 cows from 131 loose housing dairy farms (76 farms with cubicles and 55 straw-yard systems). We recorded the dimensions of cubicles (e.g., width, length, and so on) and of the self-locking barrier (e.g., top rail height and so on) for each farm. We then compared whether these dimensions would match with the individual cow body dimensions and whether compliance was associated with the occurrence of skin alterations, lameness, and dirtiness. Most cows (69.2%) had at least one skin alteration, on the tarsus (41.2%); neck, shoulder, or back (28.2%); hindquarters (22.0%); carpus (21.2%); and flank, side, or udder (11.6%). Lameness prevalence reached 17.9%. Most cows (83.1%) were scored dirty in at least one body region, mainly on the lower hind legs including hocks (81.4%), hindquarters (41.8%), and udder (21.0%). Cubicle recommendations were mostly met for cubicle resting length (75.9% of cubicles) and neck rail distance (NRD, 60.7%) but less so for overall cubicle length (CL, 38.8%), cubicle width (CW, 30.9%), neck rail height (NRH, 22.5%), head space (HS, 15.8%), partition zone for controlling lying position (ii zone, 15.7%), head and lunging space (HLS, 10.6%), partition head zone (i zone, 9.4%), and partition zone for pelvis freedom (iii zone, 6.0%). Compliance with design recommendations was associated with fewer skin alterations on neck (recommendation met for CW, CL, HS, and NRD and i zone), hindquarters (CW, CL, NRD), tarsus (CW, i and ii zones), and carpus (CW, HS, i and ii zones); less lameness (CW, NRH, i zone); and less dirtiness on the hindquarters (CW, HLS, NRD), lower hind legs (iii zone), and udder (CW, CL, HLS, NRD). Compliance with recommended i zone and ii zone design was associated with less injury and lameness but more dirtiness, whereas the opposite was true for the iii zone. Self-locking barrier recommendations were mostly met for bottom rail height (68.2%), separation wall width (SWW, 68.3%), and top rail height (TRH, 56.9%) and less often met for separation wall height (36.3%) and height difference between feeding floor and walking alley (26.5%). Risk for skin alterations on carpus and neck only decreased when SWW and TRH met recommendations. In conclusion, compliance with CIGR recommendations for some cubicle dimensions and neck rail position was associated with lower risk for cow welfare. However, the CIGR recommendations on cubicle partitions and self-locking barriers still leave welfare at risk and so need to be refined through further research with close observation of cow lying and feeding behavior.

Bacterial spore levels in bulk tank raw milk are influenced by environmental and cow hygiene factors.

Sporeforming bacteria are responsible for the spoilage of several dairy products including fluid milk, cheese, and products manufactured using dried dairy powders as ingredients. Sporeforming bacteria represent a considerable challenge for the dairy industry because they primarily enter the dairy product continuum at the farm, survive processing hurdles, and subsequently grow in finished products. As such, strategies to reduce spoilage due to this group of bacterial contaminants have focused on understanding the effect of farm level factors on the presence of spores in bulk tank raw milk with the goal of reducing spore levels in raw milk, as well as understanding processing contributions to spore levels and outgrowth in finished products. The goal of the current study was to investigate sources of spores in the farm environment and survey farm management practices to identify variables using multimodel inference, a model averaging approach that eliminates the uncertainty of traditional model selection approaches, that affect the presence and levels of spores in bulk tank raw milk. To this end, environmental samples including feed, bedding, manure, soil, water, and so on, and bulk tank raw milk were collected twice from 17 upstate New York dairy farms over a 19-mo period and the presence and levels of various spore types (e.g., psychrotolerant, mesophilic, thermophilic, highly heat resistant thermophilic, specially thermoresistant thermophilic, and anaerobic butyric acid bacteria) were assessed. Manure had the highest level of spores for 4 out of 5 aerobic spore types with mean counts of 5.87, 5.22, 4.35, and 3.68 log cfu/g of mesophilic, thermophilic, highly heat resistant thermophilic, and specially thermoresistant thermophilic spores, respectively. In contrast, bulk tank raw milk had mean spore levels below 1 log cfu/mL across spore types. Multimodel inference was used to determine variables (i.e., management factors, environmental spore levels, and meteorological data from each sampling) that were important for presence or levels of each spore type in bulk tank raw milk. Analyses indicated that variables of importance for more than one spore type included the residual level of spores in milk from individual cows after thorough teat cleaning and forestripping, udder hygiene, clipping or flaming of udders, spore level in feed commodities, spore level in parlor air, how often bedding was topped up or changed, the use of recycled manure bedding, and the use of sawdust bedding. These results improve our understanding of how spores transfer from environmental sources into bulk tank raw milk and provide information that can be used to design intervention trials aimed at reducing spore levels in raw milk.

The heat is on: A device that reduces cold stress-induced tachycardia in laboratory mice.

Mouse vivaria are typically maintained at an ambient temperature (Ta) of 20-26 °C which is comfortable for human researchers. However, as this Ta is well below the mouse thermoneutral zone (TNZ) of 30-32 °C, typical vivarium temperatures result in cold stress for mice. Recently, a cage has been developed that provides variable cage floor heating, allowing mice to behaviorally regulate body temperature through thermotaxis. A hand warmer provides supplemental heat, elevating cage floor surface temperature for 13 + hours up to 30 °C. This provides a heated surface for the entirety of the light phase. Here, we test the ability of these local heat sources to remove physiological signs of cold stress in mice housed at room temperature by analyzing heart rate (HR), activity, and body temperature in three experimental conditions: 23 °C, 23 °C + heated surface, or 30 °C. The location of C57Bl/6 J mice within the cage was recorded using an infrared camera. In the presence of supplemental heat at a Ta of 23 °C, mice resided atop of the area of the heated surface 85 ±â€¯3% of the 12-h light phase, as compared to 7 ±â€¯2% in the absence of supplemental heat. Further, addition of supplemental heat lowered light phase HR and activity to that seen at a Ta of 30 °C. These results indicate that provision of a local heat source is successful in reducing cold-induced tachycardia in mice housed at typical vivarium temperatures without increasing the ambient temperature of the entire laboratory and subjecting researchers to heat stress.

Survivability, immunity, growth and production traits in indigenous and White Leghorn breeds of chicken.

1. The survivability, innate and adaptive immunity, growth and production traits up to 72 weeks of age were determined in Ghagus, Nicobari (unimproved indigenous) and White Leghorn (WLH) breeds and the study investigated links between innate and adaptive immunity and survivability and production traits.2. At 20 and 40 weeks of age, there was a significant effect of breed on innate immunity assessed by measuring titres of natural antibody (NAb) binding to rabbit red blood cells (RRBC) and adaptive immunity assessed by measuring specific antibody titre (SpAb) to Newcastle disease virus.3. Highest survivability was in WLH (91.6%) followed by Nicobari (87.1%) and Ghagus (82.9%) breeds. Growth traits at different ages were higher (P< 0.001) in Ghagus followed by WLH and Nicobari breeds. Egg production up to 72 weeks was higher (P < 0.001) in WLH followed by Nicobari and Ghagus breeds, whereas egg weight at different ages was higher (P < 0.001) in WLH than Ghagus and Nicobari breeds.4. NAb titres measured at 20 weeks were significantly (P = 0.002) associated with the survivability of hens during 20 to 72 weeks of age. Breed-wise analysis showed a significant (P = 0.019) association between NAb titres at 20 weeks and survivability in the Ghagus breed. Furthermore, NAb titres at 20 weeks were higher in hens which survived to 72 weeks compared with those that died (P = 0.002).5. Measuring NAb titres to RRBC is quick, economical and simple. This method has potential to be used in a breeding programme to increase survivability of laying hens.

A qualitative risk assessment of cleansing and disinfection requirements after an avian influenza outbreak in commercial poultry.

1. During an avian influenza (AI) outbreak in the United Kingdom, the joint aim of the poultry industry and the Government is to eliminate and prevent the spread of infection, through control measures based on the current European Union (EU) Council Directive (2005/94/EC). An essential part of these measures is the cleansing and disinfection (C&D) of infected premises.2. This risk assessment assessed the differences in re-infection in a repopulated flock if the EU Directive is interpreted to permit secondary C&D to be undertaken either with or without dismantling complex equipment. The assessment estimated the probability of virus survival on different types of equipment in a depopulated contaminated poultry house before and after preliminary and secondary C&D procedures. A risk matrix spreadsheet tool was used to carry out the assessment and concluded that, provided secondary C&D is carried out with due diligence (i.e. carried out to a defined code of practice as agreed by both industry and policymakers), the risk of re-infection from equipment is negligible, both with and without dismantling complex equipment in all farm types considered.3. By considering the equipment types individually, the assessment identified those areas of the house which may still contain viable virus post-preliminary C&D and on which attention should be focussed during secondary C&D. The generic risk pathway and matrix spreadsheet tool have the potential to be used for other pathogens and species, given appropriate data.

Feather pecking in laying hens housed in free-range or furnished-cage systems on French farms.

1. Beak trimming is currently used in France to avoid the negative consequences of severe feather pecking (SFP). However, this practice is controversial in terms of animal welfare, and forbidden in some European countries.2. This study aimed to assess the prevalence of SFP in French laying hen farms, to describe how farmers manage this behavioural disorder and to better understand the risk factors involved.3. A study was carried out from April 2015 to June 2016. Visits were paid to 79 flocks kept in furnished cages (FC) and 80 flocks in a free-range (FR) system. All the hens had trimmed beaks and were genotypically brown. The information collected included feather cover, skin damage, beak condition, farm and poultry house characteristics, livestock performance and management.4. The prevalence of SFP in FC flocks was estimated at 32.9% (IC = 95%, [22.5; 43.3]) and the prevalence of cannibalism as 2.5% (IC = 95%, [0.7; 8.8]) at 70 weeks of age. The prevalence of SFP in FR flocks was estimated to be 23.8% (IC = 95%, [14.5; 31.1]) and the prevalence of cannibalism was 8.8% (IC = 95%, [4.3; 17.0]) at 61 weeks of age.5. In FC flocks, SFP was associated with the combination of genotype, type and length of perches, cage area per hen, type of lighting, number of hens per cage and farm location. In FR flocks, feather cover was associated with use of the outdoor run, lighting programme, genotype, farm location and date of house construction.

Flight patterns in zoo-housed fruit bats (Pteropus spp.).

Maintaining the capacity for sustained flight in captivity is a key goal for the management of threatened fruit bats. We developed quantifiable descriptions of flight complexity and used them to assess the suitability of an enclosure for two species of fruit bat of differing size, the large Livingstone's fruit bat, Pteropus livingstonii, and the smaller Rodrigues fruit bat, Pteropus rodricensis, in a two-part study. In Phase 1, Rodrigues fruit bats flew more often than Livingstone's fruit bats and although the majority of flights in both species were linear, Rodrigues fruit bats were more likely to display complex flight paths involving turns, while flights by Livingstone's fruit bats were more likely to end in a crash-landing than Rodrigues fruit bat flights. The enclosure may therefore not have been large enough for Livingstone's fruit bats to display a full range of flight behavior over longer distances. In Phase 2, juvenile Livingstone's fruit bats ( < 3 years old) flew more than twice as often as younger adults (3-10 years old) did. Older adult Livingstone's fruit bats over the age of 10 years were not observed to fly. We could not separate out the effects of age, weight and environment during development as these factors were strongly correlated in our study; future work in this area will be very important in understanding the factors that affect flight in captive bats, and how it can be encouraged by appropriate enclosure design.