Use of drinkers by finisher pigs depend on drinker location, pig age, time of day, stocking density and tail damage

Water is a vital nutrient for mammals, including the pig. Despite this, the use of drinkers and water have not yet been explicitly quantified across the finisher period. The current study aimed at gaining greater insight into finisher pigs' drinker use and its relation to drinker location, age, time of day, stocking density, enrichment provision and tail damage. The experiment included 110 pens of finisher pigs over a 9-week period, with two drinker cups per pen. Pens had a stocking density of either 0.73 m²/pig (n = 54 pens, 18 pigs per pen) or 1.21 m²/pig (n = 56 pens, 11 pigs per pen), were either provided with straw (n = 54, 150 g per pig and day) or not (n = 56), and had pigs with either undocked (n = 50) or docked tails (n = 60). Drinker use was recorded automatically by water-flow meters and summed to L and number of activations per hour and pig. Pens never experiencing a tail damage event (at least one pig in the pen with a bleeding tail) were used to investigate the normal drinker use of finisher pigs (n = 56). The water use of pigs increased from 3.7 to 8.2 L per pig and day during the 9 weeks, and this increase was mainly seen during the two large peaks of the diurnal pattern within the pigs' active period (06:00-18:00 h). No such increase was seen in the activation frequency at average 50 activations per pig and day. A decrease in stocking density increased both water use and activation frequency during the active period, suggesting that pigs at the standard space allowance and pig:drinker ratio could be restricted in their access to the drinking cups. The pigs also seemed to prefer to use the drinking cup closest to the feeder. Water use and activation frequency did not change the last 3 days prior to an event of tail damage, but general differences were seen between pens with and without a tail damage event. The current results may explain the success of previous studies in classifying tail damage pens from pens without tail damage using sensor data on drinker use.

Influence of temperature during incubation on the mRNA levels of temperature sensitive ion channels in the brain of broiler chicken embryos

Thermosensation is crucial for the survival of any organism. In animals, changes in brain temperature are detected via sensory neurons, their cell bodies are located in the trigeminal ganglia. Transient receptor potential (TRP) ion channels are the largest temperature sensing family. In mammals, 11 thermoTRPs are known, as in poultry, there are only three. This research further elucidates TRP mRNA expression in the brain of broiler embryo's. Three incubation treatments were conducted on 400 eggs each: the control (C) at 37.6 °C; T1 deviating from C by providing a + 1 °C heat stimuli during embryonic day (ED) 15-20 for 8 h a day; and T2, imposing a + 2 °C heat stimuli. After each heat stimuli, 12 eggs per treatment were taken for blood sampling from the chorioallantoic membrane and brain harvesting. Incubation parameters such has residual yolk (free embryonic) weight, chick quality and hatch percentage were collected. After primer optimization, 22 target genes (13 TRPs and 9 non-TRPs) were measured on mRNA of the brain using a nanofluidic biochip (Fluidigm Corporation). Four target genes (ANO2, TRPV1, SCN5A, TRAAK) have a significant treatment effect - independent of ED. Another four (TRPM8, TRPA1, TRPM2, TRPC3) have a significant treatment effect visible on one or more ED. Heat sensitive channels were increased in T2 and to a lesser degree in T1, which could be part of an acclimatisation process resulting in later life heat tolerance by increased heat sensitivity. T2, however, resulted in a lower hatch weight, quality and hatchability. No hormonal differences were detected.

Prediction of Tail Biting Events in Finisher Pigs from Automatically Recorded Sensor Data

Simple Summary

Tail biting is a major animal welfare issue within modern pig production, and tail biting should be prevented whenever possible. If the farmer could get an alarm when a pen of pigs is at high risk of developing tail damage, the farmer would be able to take timely action to prevent tail damage in specific pens. In the current investigation, a method for prediction of tail biting events was developed and tested in a real-life setting. The method used changes in pigs’ drinking behaviour and in the temperature of the pen. The method was able to alarm the farmer about 12 of the 14 tail biting events prior to serious tail damage. However, the farmer did also get false alarms on 30% of the days without tail biting events, which is not optimal. Thus, the farmer could use the alarms as indications of which pens to pay greater attention to. The next step could be to expand the method to include behavioural changes that are more specific to tail biting such as changes in the pigs’ tail posture.

Abstract

Tail biting in pigs is an animal welfare problem, and tail biting should be prevented from developing into tail damage. One strategy could be to predict events of tail biting so that the farmer can make timely interventions in specific pens. In the current investigation, sensor data on water usage (water flow and activation frequency) and pen temperature (above solid and slatted floor) were included in the development of a prediction algorithm for tail biting. Steps in the development included modelling of data sources with dynamic linear models, optimisation and training of artificial neural networks and combining predictions of the single data sources with a Bayesian ensemble strategy. Lastly, the Bayesian ensemble combination was tested on a separate batch of finisher pigs in a real-life setting. The final prediction algorithm had an AUC > 0.80, and thus it does seem possible to predict events of tail biting from already available sensor data. However, around 30% of the no-event days were false alarms, and more event-specific predictors are needed. Thus, it was suggested that farmers could use the alarms to point out pens that need greater attention.

Pen Fouling in Finisher Pigs: Changes in the Lying Pattern and Pen Temperature Prior to Fouling

Pen fouling, where the pigs choose to rest in their designated excretion area (the slatted floors) and excrete in their designated resting area (the solid floors), is an undesired behaviour and should be prevented when possible. One strategy to prevent fouling is early detection by means of either animal or environmental measures changing prior to fouling. The aim of the present study was to investigate whether the lying pattern of pigs and the temperature in the pen changed the last 5 days prior to an event of fouling and whether this differed from pens without an event of fouling (controls). Fouling events was recorded at pen level when at least half of the solid floor was wet with excreta and/or urine (day0). Each fouling pen was paired with a control pen that had not been scored as a fouling pen prior to or at least 1 week after the fouling event. Fouling and control pens were either not provided with straw or provided daily with 150 g of straw per pig. Percentage of pigs lying on the solid floor and the slatted floor (36 events) as well as pen temperature above the solid and slatted floor (24 events) was analysed using four linear mixed effects models. The percentage of pigs lying on the solid floor decreased (40–24%; P < 0.05) while the number of pigs lying on the slatted floor increased (14–24%; P < 0.05) from day-2 to day0 only in the fouling pens, with differences seen between fouling and control pens on the same days (P < 0.01). However, these changes and differences was only seen in pens without straw. Also only in pens without straw did pen temperature above the solid floor decrease from day-2 to day0 (18.6–17.6°C; P < 0.001), with differences seen between fouling and control pens only on day0 (P < 0.05). In contrast, pen temperature measured above the slatted floor did not change, independent of whether the pen was provided with straw or not. Thus, in pens not provided with straw, both the lying pattern of pigs and pen temperature above the solid floor have potential as early detectors of pen fouling.

The ability of different thermal aids to reduce hypothermia in neonatal piglets

We investigated whether hypothermia in newborn piglets could be reduced by applying different thermal aids. The experiment was performed on 150 newborn piglets from 24 sows. Right after birth, the piglets were moved to a wire mesh cage for the first 2 h of life where they experienced 1 of 7 different combinations of flooring (solid vs. slatted) and treatments: control, with no additional thermal aids on a solid floor ( = 26) or a slatted floor ( = 26); built-in floor heating ( = 31) or floor heating as a radiant floor plate on solid floor (FloorPlate; = 19); radiant heater above a solid floor (RadiantC; = 22) or a slatted floor (RadiantSlat; = 18); and provision of straw on a solid floor (Straw; = 8). Piglets' rectal temperature was measured both continuously and manually every 10 min for the first 2 h after birth using a thermal sensor inserted in the rectum of the piglets. The rectal temperature curve was analyzed for differences in the slope of the drop in rectal temperature and the deflection tangent of the curve. Furthermore, differences in average rectal temperature, minimum rectal temperature, rectal temperature 2 h after birth, and time with rectal temperature below 35°C were analyzed. All statistical analyses were performed using a mixed model. All thermal aids/heat solutions resulted in a less steep drop in rectal temperature, a faster recovery, and, for the smaller piglets, also a greater average rectal temperature (except for built-in floor heating) and less time with rectal temperature below 35°C. The most efficient thermal aids to reduce hypothermia in newborn piglets were Straw and RadiantC. Furthermore, Straw, RadiantC, and FloorPlate also eliminated the effect of birth weight on some of these indicators of thermoregulatory success. Otherwise, FloorPlate and RadiantSlat showed an intermediate outcome for most measures. With no heating, piglets on a solid floor experienced more severe hypothermia than piglets on a slatted floor. In conclusion, several types of thermal aids can reduce hypothermia in newborn piglets, but some are more efficient and can partly eliminate the effect of birth weight on hypothermia. These results are especially important in countries where breeding for large litter sizes has resulted in a reduction in average birth weight of the piglets and, thus, creates a greater demand for an early, adequate thermal environment to secure piglet viability.

High environmental temperature around farrowing induced heat stress in crated sows

The aim of the experiment was to study the impact of high ambient temperature (25°C) around farrowing on crated sows unable to perform thermoregulatory behavior. Twenty sows were housed in 2 farrowing rooms in conventional farrowing crates. In 1 room (CONTROL) temperature was kept at 20°C. In the other room (HEAT) temperature was initially kept at 20°C and gradually raised until it reached 25°C from d 112 to 115 of gestation. Then the temperature was gradually lowered to 20°C. Sows were continuously video recorded for behavior recording. Sows' respiration rates were recorded from d 3 before farrowing to d 5 after farrowing. Sows' rectal temperatures were recorded from d 1 before farrowing to d 8 after farrowing, and sows' udder surface temperatures were recorded from the day of farrowing to d 3 after farrowing. All measures were recorded daily. Sows' BW were recorded at d 108 of gestation and at weaning. Sows' back fat was recorded on farrowing day, when room temperature was set again at 20°C, and at weaning. Piglets were weighed at d 1, 14, and 21. The HEAT sows spent a higher proportion of time lying in the lateral position than CONTROL sows, both during the 16 h before farrowing and the 24 h after the start of farrowing ( < 0.05), but with no difference in the amount of time spent lying down between groups ( > 0.10). The HEAT sows had higher rectal temperature on d 1 after farrowing ( < 0.05) and had udder surface temperature 0.9°C higher than that of CONTROL sows during the recording period ( < 0.05). The HEAT sows also tended to have longer farrowing duration ( < 0.10). Respiration rate was higher in HEAT sows on d 1 before farrowing and on the day of farrowing. On d 7, 8, and 9, CONTROL sows had higher feed intake ( < 0.05), and piglets from CONTROL sows were heavier at d 21 after farrowing ( < 0.05). High ambient temperature around farrowing altered sows' postural behavior. Sows reacted to the thermal challenge with higher respiration rate around farrowing, but both their rectal and udder temperatures were elevated, indicating that they were not able to compensate for the higher ambient temperature. High ambient temperature negatively influenced sows' feed intake, with negative impact on piglets' weaning weight. High temperatures around farrowing (25°C) compromise crated sows' welfare, with a potential negative impact on offspring performance.

Can tail damage outbreaks in the pig be predicted by behavioural change?

Tail biting, resulting in outbreaks of tail damage in pigs, is a multifactorial welfare and economic problem which is usually partly prevented through tail docking. According to European Union legislation, tail docking is not allowed on a routine basis; thus there is a need for alternative preventive methods. One strategy is the surveillance of the pigs' behaviour for known preceding indicators of tail damage, which makes it possible to predict a tail damage outbreak and prevent it in proper time. This review discusses the existing literature on behavioural changes observed prior to a tail damage outbreak. Behaviours found to change prior to an outbreak include increased activity level, increased performance of enrichment object manipulation, and a changed proportion of tail posture with more tails between the legs. Monitoring these types of behaviours is also discussed for the purpose of developing an automatic warning system for tail damage outbreaks, with activity level showing promising results for being monitored automatically. Encouraging results have been found so far for the development of an automatic warning system; however, there is a need for further investigation and development, starting with the description of the temporal development of the predictive behaviour in relation to tail damage outbreaks.