The effect of environmental enrichment on behaviour, production parameters and meat quality of finishing lambs in a feedlot
Year: 2017
Type: dissertation
Abstract: The effect of environmental enrichment in the form of a wooden platform on the production parameters, social, maintenance and feeding behaviour, frequency of stereotypical behaviours and meat quality of Merino lambs in an indoor feedlot was assessed.In the first study, the effect of the wooden platform on weight gain, maintenance behaviour, social interactions and stereotypical behaviours was assessed.Two lambs were infected with footrot (infectious pododermatitis) prior to arrival at the feedlot and the effect of this disease on production parameters and behaviour was also included in the analyses.Lambs infected with footrot had the same final weight as healthy lambs, although they gained weight at a slower rate (y=1.27x+34.33 of infected lambs (n=13) versus y=2.06x+34.24 of healthy lambs (n=34)).This study found no differences in maintenance or stereotypical behaviours between lambs in treatment pens and lambs in control pens.Lambs in treatment pens did, however display a higher frequency of affiliative interactions of which the frequency increased over the fattening period.When correlations within the treatment pens were assessed, there was a significant positive correlation between affiliative interactions and the use of the platform and a significant negative correlation between the use of the platform and aggressive interactions.During the second study, the effect of the wooden platform on production parameters (ADG and FCR), social interactions, stereotypical and feeding behaviours as well as physical meat quality indicators was assessed.In this study the lambs were housed in an indoor feedlot of which one side had large open windows.It became clear that these windows also had an impact on the welfare of animals and was thus included in the analyses.Lambs in treatment that were in treatment groups on the open side of the shed showed the highest ADG and the most desirable FCR, while lambs in control pens on the open side performed intermediately and lambs on the closed side (both control and treatment pens) had the least desirable FCR and lowest ADG.The wooden platform had no effect on the meat quality, however, lambs on the open side of the pen side had heavier carcasses, lower initial pH, more back fat and a higher drip loss percentage.Lambs in control pens showed higher frequencies of stereotypical behaviours and less affiliative interactions.These lambs also had a lower frequency of feeding bouts than lambs in treatment groups, however, there were no differences in dry matter intake between the groups.All lambs fed more during the morning than in the afternoons and the feeding bouts as well as time spent feeding declined over the fattening period.However, once again there were no differences in feed intake over the fattening period and lambs most likely fed more during the night when temperatures were lower.Stellenbosch University https://scholar.sun.ac.za vi Differences in temperaments and individual personalities of lambs most likely have a very large effect on whether or not the wooden platform will serve to improve animal welfare.Although the indicators measured did not prove the wooden platform to be overwhelmingly successful as a method of improving animal welfare, it had no detrimental effects on the lambs and it could be optimised to serve as an economical form of environmental enrichment in lamb feedlots.
Author: Mariska Liebenberg
Language: English
Subfield: Animal Science and Zoology
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2610293206