HABRI Central - Resources: Aggression in replacement grower and finisher gilts fed a short-term high-tryptophan diet and the effect of long-term human-animal interaction: About

The Human Animal Bond Research Institute (HABRI) is issuing a call for research proposals from institutions and organizations across the globe to investigate the health outcomes of pet ownership and/or animal-assisted interventions (AAI), both for the people and the animals involved. To learn more, visit https://habri.org/grants/funding-opportunities/ close

You are here: Home / Journal Articles / Aggression in replacement grower and finisher gilts fed a short-term high-tryptophan diet and the effect of long-term human-animal interaction / About

Aggression in replacement grower and finisher gilts fed a short-term high-tryptophan diet and the effect of long-term human-animal interaction

By R. Poletto, R. L. Meisel, B. T. Richert, H. W. Cheng, J. N. Marchant-Forde

View Link (HTM)

Licensed under

Category Journal Articles

Aggression can be a major problem for swine production as it negatively impacts the pigs' health and welfare. Increasing tryptophan (TRP) intake to raise brain serotonin (5-HT) - key for aggression control, and long-term positive social handling can reduce stress in pigs. Objective was to feed a short-term high-TRP diet to grower (3 months) and finisher (6 months) maternal gilts that were either socially handled or not and measure their behavioural activity and aggressiveness. Eight pens of six unrelated gilts were split into two blocks balanced for litter, social handling (non- vs. handled) and dietary treatment (control vs. high-TRP). Social-handling was applied three times per week, from day 45 until 6 months of age. At 3 months, two handled and two non-handled pens were assigned to control while the other four pens were assigned to the high-TRP diet fed ad libitum for 7 days (days 1-7). At 6 months of age, pen assignment to dietary treatments was swapped. Body weights and blood were taken at days 1 (pre-feeding) and 7. Blood samples were analyzed for TRP and 5-HT concentrations using high pressure liquid chromatography. Behaviour was recorded from days 1 to 5 and scan-sampling used to determine time-budget behaviours and postures in a 12-h period each day (06:00-18:00 h). Aggression evaluation in the home pen focused on counts of agonistic interactions, bites and head-knocks per interaction during three, 30-min intervals (08:00, 12:00, and 16:00 h) from days 1 to 5. Resident-intruder (R-I) test was carried out for a maximum of 300 s at days 6 and 7 to measure aggressiveness, predicted by the latency to the first attack and attack outcomes. A 2x2 factorial arrangement of dietary treatment and social handling within age was analyzed by repeated measures of mixed models and Tukey adjustments. The TRP-added diet raised blood TRP concentration of 3- and 6-month-old gilts by 180.7% and 85.2% respectively (P<0.05), reduced behavioural activity and time spent standing, while increasing lying behaviour, mostly in grower gilts (P<0.05). High-TRP diet reduced the number of agonistic interactions, and aggressiveness in 3-month-old gilts, which took longer to attack the intruder pig, and displayed fewer attacks on the first day of testing (P<0.05). Long-term positive social handling improved growth performance and had a slight effect on behaviour (P<0.05). Provision of enhanced TRP diet reduced behavioural activity and aggressiveness of grower gilts, and these results are likely mediated by activation of brain serotonergic system. Short-term high-TRP dietary supplementation may be used to reduce aggression at mixing in young pigs.

Date 2010
Publication Title Applied Animal Behaviour Science
Volume 122
Issue 2/4
Pages 98-110
ISBN/ISSN 0168-1591
DOI 10.1016/j.applanim.2009.11.015
Language English
Author Address USDA-ARS, Livestock Behavior Research Unit, West Lafayette, IN 47907, USA.Jeremy.Marchant-Forde@ars.usda.gov
Additional Language English
Cite this work

Researchers should cite this work as follows:

  1. Aggression
  2. Analysis
  3. Animal behavior
  4. Animal diseases
  5. Animal genetics
  6. Animal nutrition
  7. Animal roles
  8. Bites and stings
  9. Blood
  10. Body weight
  11. Brain
  12. Cleaning
  13. Diets
  14. Evaluation
  15. Farm animals
  16. Feed additives
  17. Feed supplements
  18. Food animals
  19. Gilts
  20. Growth rates
  21. Handling
  22. Health
  23. Interactions
  24. Latency
  25. Mammals
  26. Meat animals
  27. Methodologies
  28. models
  29. open access
  30. pens
  31. performance traits
  32. serotonin
  33. supplementary feeding
  34. Swine
  35. therapeutics
  36. tryptophan
  1. open access