Lene Juul Pedersen

Automated body weight (BW) estimation can be a useful tool for continuous monitoring of growth in commercial pigs, whereas deviations could indicate welfare problems. We validated a depth camera for BW estimation in 251 conventional growing pigs on two farms. Scale-based BW of individual pigs was used as gold standard (Farm 1: 107 pigs, BW range: 16–130 kg, recorded on three days; Farm 2: 144 pigs BW range: 20–114 kg, recorded on nine days). The camera was placed above the individual feeding station (Farm 1) or multi-partitioned feeder (Farm 2) and combined with a radio frequency identification system. Whenever a pig visited the feeding site, three-dimensional images were taken, and all individual daily images were used to calculate the median individual estimated BW. The pen estimated BW was calculated by taking the median of all daily picture estimates. A very high agreement (Concordance Correlation Coefficient >0.96) between scale-based BW and estimated BW was found on both farms at individual and pen level. Additionally, the individual-level and pen-level BW estimation errors of the median weight were low on both farms (≤3.6%). Yet, the camera’s BW estimation performance decreased in pigs weighing >110 kg on Farm 1. Whereas, on farm 2, the performance decreased when pigs weighed approximately 60 kg and were subjected to a typical dietary change, which potentially increased the competition for access to the multi-partitioned feeder and, consequently, limited body boundary detection.

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 (n = 26) or a slatted floor (n = 26); built-in floor heating (n = 31) or floor heating as a radiant floor plate on solid floor (FloorPlate; n = 19); radiant heater above a solid floor (RadiantC; n = 22) or a slatted floor (RadiantSlat; n = 18); and provision of straw on a solid floor (Straw; n = 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.