Providing Meaningful Environmental Enrichment and Measuring Saliva Cortisol in Pigs Housed on Slatted Flooring

Summary

This protocol demonstrates how to provide practical meaningful environmental enrichment for pigs which are housed on slatted flooring during the different stages of their lives, and how to collect saliva samples in a non-invasive manner for the measurement of cortisol concentrations, as a biomarker for acute stress.

Abstract

As pork is the most consumed meat worldwide, the welfare of animals in the swine industry has increasingly become a major public concern, which imposes a substantial pressure coming from customers, legislators and other stakeholders, to make management changes to improve the well-being of these animals. Several studies have demonstrated that providing environmental enrichment to pigs allows them to express their natural behavior, such as rooting and exploring, as well as nesting prior to farrowing, and is associated with reduced stress and improved production and welfare. However, many considerations should be taken into account when providing environmental enrichment, such as the type of floor, drainage and sewage systems, the pigs' stage in life, the material, as well as its hanging method, height and location within the pen. The objectives of this paper are (1) to give methodologic information on how to provide a relatively simple and practical meaningful environmental enrichment for pigs which are housed on slatted floors during the different stages of their life, and (2) to demonstrate how to collect saliva samples for the measurement of cortisol concentrations, as a biomarker for acute stress. Protocols include information regarding the use of jute, cotton ropes, straw in racks, as well as chewable silicone sticks devices as environmental enrichment in pens of farrowing and lactation, weaners and finishers. In addition, the use of cotton rope for a non-invasive saliva samples collection for cortisol concentrations analysis is detailed. The protocols provided are relevant for professionals aiming to improve and monitor animal welfare, in both research and industrial swine farming.

Introduction

Pork is the most consumed meat worldwide, with over 1.3 billion pigs being raised and slaughtered annually^1,2. In recent years, the welfare of animals in the swine industry has increasingly become a major public concern, which imposes substantial pressure, coming from customers, legislators and other stakeholders, to make management changes to improve the well-being of these animals. Several studies demonstrated that providing environmental enrichment to pigs is associated with reduced stress and improved production and welfare, as it allows the pigs to express their natural behavior, such as rooting and explo....

Protocol

The study protocol was ethically approved by the Hebrew University's Institutional Animal Care and Use Committee (MD-16-14754-2). The study was conducted during 2017, at Lahav Animal Research Institute and the Hebrew University of Jerusalem, Israel.

1. Environmental enrichment protocol during farrowing and lactation period

NOTE: In this study, sows were housed in farrowing/lactation pens, under restraint for a limited time, from 3-5 days prior to the expected farrowing date and up to 10 days post-farrowing; thereafter, confinement bars were removed, to allow free movement and interaction between the sow and its....

Results

In the current study, 16 litters (170 piglets) were allocated randomly into two treatment groups; in one group, environmental enrichment was provided to eight litters ("Enriched Group", as described in protocol sections 1-3), while it was not provided to the other eight litters ("Non-enriched Group"). After weaning, each two litters were grouped into one group of about 20 pigs. Saliva samples were collected and analyzed for cortisol concentrations every two weeks in each pen, as described.......

Discussion

Herein, we describe protocols detailing how to provide simple and practical environmental enrichment for pigs which are housed on slatted floor during different stages of their life, and how to non-invasively collect saliva samples for the measurement of cortisol concentrations, as a biomarker for acute stress. Straw as a bedding is considered as one of the most suitable environmental enrichment for pigs, but may be impractical on slatted floors. However, relatively inexpensive alternatives such as jute, cotton rope.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Bite-Rite	Ikadan System USA Inc.		Consider ordering additional replaceable silicone sticks
ELISA; Saliva Cortisol Kit	DRG International Inc. NJ, USA	Slv2930
HALM 60/80 CM	W. Domino A/S, DK	49084/ 85
TEGO Swine Oral Fluids Kit	ITL BioMedical, USA	A100930	Including everything needed for the saliva sampling protcol