Effect of Artificial Piglet Suckling Sounds on Behavior and Performance of Piglets and Adrenal Responses of Sows

Season effects on the suckling behavior of piglets

The suckling behavior of piglets was evaluated in summer and winter, using 21 sows of the same genetic line. Data were collected in July (winter) and in January (summer). The experimental design was a randomized complete block (age of piglets) in a 2x2 factorial scheme, with season of the year (winter and summer) and shift (day, from 06 h to 1h:59min and night from 18h to 05h:59min) as factors. The behavioral variables analyzed were number, interval, and frequency of suckling. The behaviors were monitored on day 7 and 15 of lactation, for 24 hours. In winter, the farrowing room had a mean temperature of 20.32 ±2.17°C and a relative humidity (RH) of 58.63 ±2.99%. In the summer, the mean temperature was 26.65 ±4.02°C, with an RH of 62.22 ±12.06%. During winter, the piglets presented longer sucklings during the night, dedicating 1.84 minutes more to suckling compared to the daytime. Nighttime sucklings were 3.13 minutes longer in winter than in summer. However, in summer, piglets suckled more often during the night, with greater interval between feeds during the day. Based on our results, the season influences the suckling behavior of piglets, with shorter feedings and greater frequencies in summer.

Non-invasive monitoring of adrenocortical function in female domestic pigs using saliva and faeces as sample matrices

Intensive pig management involves in a commercial setting the housing and implementation of certain procedures, such as castration and tail docking, which may be stressful for the animal. Good farming practices include the reduction of stress due to management processes, but assessing the level of stress perceived entirely through behavioural observations can be challenging. The monitoring stress-related physiological markers, like glucocorticoids (GC), can be an accurate alternative that would presumably be more objective. In order to avoid an additional stressor by taking blood, a non-invasive approach is advisable. We used an adrenocorticotropic hormone (ACTH) stimulation test and the effect of transport to examine the suitability of different enzyme immunoassays (EIAs) for monitoring adrenocortical function in domestic pigs using saliva and faeces as sample matrices. An assay measuring faecal glucocorticoid metabolites (fGCMs) with a 3ß,11ß-diol group has proven suited to determine adrenocortical activity, showing an overall increase of 180% in fGCM concentrations related to ACTH administration and of 70% related to transport, respectively. A cortisol EIA was used to detect salivary glucocorticoid (sGC) concentrations, revealing a 1100% increase in sGC concentrations after ACTH administration. The stability of fGCM concentrations post-defecation was determined to assess possible changes in measured fGCM concentrations in unpreserved faecal material over time, with fGCM concentrations being relatively stable (maximal 12% change) under natural conditions for approximately two days after defecation. This implicates that untreated faecal material from pigs can be analysed for up to two days after collection without appreciable level of depreciation in fGCM concentrations. Being able to assess the physiological stress response of domestic pigs non-invasively can help to improve the well-being of commercially reared pigs.