No abstract

Perinatal mortality is a widespread problem in laboratory mouse breeding and is often manifested by the loss of the entire litter within the first days of life. High mortality is an animal health and welfare concern that violates the 3R principles of reduction and refinement. High pup mortality is often considered "normal" in mouse breeding and the underlying causes are poorly understood. This study investigated the role of the social environment on pup survival and parental behaviour in C57BL/6 mice. Before parturition, multiparous females were allocated to three treatments: single-housing (SH, n=54) or group-housing in trios of two females and a male, with group-housing further divided into trios with (GH1, n=20) or without (GH0, n=35) the presence of another litter. Mouse behaviour was recorded from 24h before to 24h after parturition. Mouse breeding performance (offspring survival and weight) was analysed using logistic and generalized linear models, and behaviours using logistic and multivariable linear models. We confirmed previous findings of high mortality rates for all treatments, but the highest rates were found in GH1 where half of the litters were lost entirely. Social environment had an impact on breeding performance. On the one hand, the presence of adult cagemates in GH0 did not affect litter survival nor pup body weight at 20 days. Adult cagemates shared the work of breeding by performing nest building before and after litter birth, and parental care after birth. GH0 and GH1 dams were less frequently seen performing nest building before and after parturition than SH dams. GH0 and GH1 dams were also less frequently seen inside the nest and performing parental behaviour after parturition than were SH dams. On the other hand, the risks for litter and pup loss were dramatically increased by 2.3 and 1.8 times, respectively, in GH1 compared to GH0. Parturition lasted longer in GH1 than in GH0 treatment. While dam behaviour did not differ between GH1 and GH0, GH1 adult cagemates spent less time performing parental care than did GH0 cagemates. Plausible reasons for the higher mortality in the presence of another litter are insufficient parental care, competition for milk access, poor nest quality, and crushing of newborns by older pups in the nest. This study indicates that being born in a cage where there is already an older litter, so-called reproductive asynchrony, is a major risk factor for litter loss.

This experiment was carried out in a 104 m² poultry house located between the geographical coordinates 25°45'00" south latitude and 53°03'25" west longitude and an average altitude of 550 m, from September to November, 2008. The chickens were placed in 12 pens measuring 2 m² each at a stocking density of 12 chickens m-2. This study aimed at evaluating the effect of two different initial weights (chick weight on first day of experiment) and two types of litter material on broiler production parameters, litter humidity, as well as on breast and footpad lesions. A total of 240 female Cobb® chickens, derived from the same flock of breeders, was distributed in a completely randomized experimental design with a 2 (initial weight) by 2 (litter material) factorial arrangement with three replicates per treatment. Initial weights were classified as light (34.40 - 35.22 g) or heavy (39.29 - 41.30 g), whereas wood shavings and sawdust were used as litter material. Data were analyzed by ANOVA and means were compared by Tukey's test at 95% confidence level. Initial weight significantly influenced bird performance, as chickens with heavy initial weight presented higher feed intake and body weight. Type of litter did not have any effect on breast injuries and litter humidity. However, the wood shavings litter significantly influenced footpad lesions

This study aimed at identifying the factors that affect the financial performance of broiler chicken production in Southwest of Paraná state in Brazil, as well as to study the relationship of these factors with the social-economic situation of poultry farmers. Data were obtained from a questionnaire applied to broiler chicken farmers between February and March, 2011. The questionnaire included 39 questions relative to farmer's age, family size, land possession, capital invested in broiler farming, gross income per flock, training and broiler farming experience, production size, credit needs, technical service, labor, production problems, and bird weight at slaughter. Data were submitted to descriptive statistical analysis. The relationship between production data and financial performance was determined using Pearson correlation coefficient, at 95% confidence level. Approximately 64.84% of the interviewed broiler farmers in Paraná state presented medium to low financial performance. Factors such as education level, facility size, labor, gross income per flock, and average bird weight at slaughter had a positive impact on financial performance. The production problems that most affected the broiler production were environmental challenges, poor feed conversion, as well as management problems and low-quality chicks.

Dog training methods range broadly from those using mostly positive punishment and negative reinforcement (aversive-based) to those using primarily positive reinforcement (reward-based). Although aversive-based training has been strongly criticized for negatively affecting dog welfare, there is no comprehensive research focusing on companion dogs and mainstream techniques, and most studies rely on owner-reported assessment of training methods and dog behavior. The aim of the present study was to evaluate the effects of aversive- and reward-based training methods on companion dog welfare within and outside the training context. Ninety-two companion dogs were recruited from three reward-based schools (Group Reward, n = 42), and from four aversive-based schools, two using low proportions of aversive-based methods (Group Mixed, n = 22) and two using high proportions of aversive-based methods (Group Aversive, n = 28). For evaluating welfare during training, dogs were video recorded for three sessions and six saliva samples were collected, three at home (baseline levels) and three after training (post-training levels). Video recordings were used to examine the frequency of stress-related behaviors (e.g., lip lick, yawn) and the overall behavioral state of the dog (e.g., tense, relaxed), and saliva samples were analyzed for cortisol concentration. For evaluating welfare outside the training context, dogs participated in a cognitive bias task. Results showed that dogs from Group Aversive displayed more stress-related behaviors, were more frequently in tense and low behavioral states and panted more during training, and exhibited higher post-training increases in cortisol levels than dogs from Group Reward. Additionally, dogs from Group Aversive were more ‘pessimistic’ in the cognitive bias task than dogs from Group Reward. Dogs from Group Mixed displayed more stress-related behaviors, were more frequently in tense states and panted more during training than dogs from Group Reward. Finally, although Groups Mixed and Aversive did not differ in their performance in the cognitive bias task nor in cortisol levels, the former displayed more stress-related behaviors and was more frequently in tense and low behavioral states. These findings indicate that aversive-based training methods, especially if used in high proportions, compromise the welfare of companion dogs both within and outside the training context.

The ability to determine total heat production (THP) in individual sows and litters can be logistically difficult and often requires the use of multiple animals to generate data on a per room basis. Furthermore, these systems may be costly to construct, precluding their use by many researchers. Therefore, the objective was to develop a low-cost indirect calorimetry system to determine THP in individual lactating sows and litters. Six indirect calorimeters were constructed to house 1 sow and litter in a crate throughout farrowing and a 21-d lactation period. Farrowing crates were placed within a high-density polyethylene pan filled with water and then a polyvinyl chloride frame was constructed around the crate. The frame provided a structure to hold the inlet and outlet air pipes, feed and water inlets, air circulation fans, and a polyethylene plastic sheet that was secured at the bottom of the frame and submerged under water to maintain an air tight seal. Chamber accuracies for O 2 and CO 2 were evaluated by ethanol combustion. One week pre-farrowing, 6 pregnant multiparous sows (parity 2.9 ± 0.9; 218.3 ± 38.6 kg BW) were housed individually in each farrowing crate and the calorimeters were maintained at thermoneutral conditions (20.9 ± 2.6°C and 43.7 ± 18.6% relative humidity) throughout lactation. On lactation day 4, 8, 14, and 18, indirect calorimetry was performed on all sows and their litters, as well as 2 piglets from a sentinel litter to determine THP and the respiratory quotient (RQ). Sentinel piglet data were used to estimate THP and RQ for the sows independent of the litter. Sow + litter THP (kcal/h) increased (P = 0.01; 16.6%) on day 8 compared to day 4 and was greater (27.3%) on day 14 and day 18 compared to day 4 and day 8. Sow THP was greater (P = 0.01) on day 8 (401.19 ± 17.15 kcal/h) and day 14 (430.79 ± 12.42 kcal/h) compared to day 4 (346.16 ± 16.62 kcal/h), and was greater on day 14 compared to day 8, and on day 18 (386.16 ± 20.02 kcal/h) compared to day 14. No sow + litter RQ differences (P = 0.21; 1.02 ± 0.04) were detected by day of lactation. However, sow RQ was reduced (P = 0.01) on day 14 (0.98 ± 0.02) compared to day 4 (1.03 ± 0.03), day 8 (1.02 ± 0.02), and day 18 (1.04 ± 0.03). In summary, this cost-effective system (total cost: $1,892 USD) can allow researchers to accurately evaluate THP in individual lactating sows and their litters.

High and variable pre-weaning mortality is a persistent problem in laboratory mouse breeding. Assuming a modest 15% mortality rate across mouse strains, means that approximately 1 million more pups are produced yearly in the EU to compensate for those which die. This paper presents the first large study under practical husbandry conditions to determine the risk factors associated with mouse pre-weaning mortality. We analysed historical records from 219,975 pups from two breeding facilities, collected as part of their management routine and including information on number of pups born and weaned per litter, parents' age and identification, and dates of birth and death of all animals. Pups were counted once in their first week of life and at weaning, and once every one or two weeks, depending on the need for cage cleaning. Dead pups were recorded as soon as these were found during the daily cage screening (without opening the cage). It was hypothesized that litter overlap (i.e. the presence of older siblings in the cage when new pups are born), a recurrent social configuration in trio-housed mice, is associated with increased newborn mortality, along with advanced dam age, large litter size, and a high number and age of older siblings in the cage. The estimated probability of pup death was two to seven percentage points higher in cages with litter overlap compared to those without. Litter overlap was associated with an increase in death of the entire litter of five and six percentage points, which represent an increase of 19% and 103% compared to non-overlapped litters in the two breeding facilities, respectively. Increased number and age of older siblings, advanced dam age, small litter size (less than four pups born) and large litter size (over 11 pups born) were associated with increased probability of pup death.

The study objective was to characterize effects of early gestation in utero heat stress (IUHS) on postnatal fasting heat production (FHP) and blood biomarkers associated with metabolism in growing pigs. Based on previous observation of increased postnatal core body temperature set point in IUHS pigs, we hypothesized that FHP would be altered during postnatal life because of IUHS. Pregnant first-parity gilts were exposed to thermoneutral (TN; = 4; 17.8 ± 0.1°C) or heat stress (HS; = 4; cyclical 28 to 38°C) conditions from d 30 to 60 of gestation. At weaning (21 d of age), 2 median-weight male pigs (1 barrow and 1 boar) were selected from each litter ( = 8 in utero TN [IUTN] and 8 IUHS pigs) and then housed in TN conditions based on age. Blood samples were collected at 8, 9, and 10 wk of age when pigs were in a fed state to analyze thyroxine (T4) and triiodothyronine (T3) concentrations. Pigs were trained to enter an indirect calorimeter from wk 8 through 10 of life and then acclimated over a 24-h period 1 wk prior to testing. At 12 wk of age, pigs were fasted for 24 h, and then indirect calorimetry was performed on individual pigs over a 23-h testing period to determine FHP and the respiratory quotient in 3 intervals (0900 to 1700 h, 1700 to 0000 h, and 0000 to 0800 h). Body weight was determined before and after testing and was similar for all pigs ( = 0.77; 37.0 ± 0.5 kg BW). Data were analyzed using PROC MIXED in SAS 9.4. No boar vs. barrow differences were observed with any analysis. Overall, FHP per kilogram BW was greater ( = 0.03; 12.1%) in IUHS pigs compared with IUTN pigs. Fasting heat production per kilogram BW was greater ( < 0.01; 19.8%) from 0900 to 1700 h compared with 1700 to 0000 h and 0000 to 0800 h and was greater (10.9%) from 1700 to 0000 h compared with 0000 to 0800 h. The RQ did not differ by in utero treatment ( = 0.51; 0.72 ± 0.01); however, the RQ was increased ( < 0.01; 13.0%) from 1700 to 0000 h compared with 0900 to 1700 h and 0000 to 0800 h. No other FHP and RQ differences were detected. Although no in utero treatment differences were observed for T4 ( = 0.11; 52.2 ± 6.2 ng/mL), T3 was greater overall ( = 0.04; 19.5%) in IUHS pigs than in IUTN pigs. In summary, FHP and circulating T3 were increased in IUHS pigs, and this may have implications for postnatal production efficiency in pigs gestated during hot summer months.