Physical meat quality and chemical composition of the Longissimus thoracis of entire and immunocastrated pigs fed varying dietary protein levels with and without ractopamine hydrochloride

• Published in: Meat science Vol. 110; pp. 101 - 108
• Main Authors: Needham, T., Hoffman, L.C.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.12.2015
• Subjects: Adrenergic beta-Agonists - pharmacology; Animal Nutritional Physiological Phenomena; Animals; Boar taint; Body Composition; Castration - methods; Color; Colour; Cooking; Diet; Dietary Proteins - administration & dosage; Dietary Proteins - metabolism; Dietary Proteins - pharmacology; Female; GnRH; Humans; Improvac; Male; Meat - analysis; Odorants; Paraspinal Muscles - metabolism; Phenethylamines - pharmacology; Pork; Stress, Mechanical; Swine; Tenderness; Vaccination; Water - analysis; Improvac; GnRH; Pork; Tenderness; Boar taint; Colour
• ISSN: 0309-1740; 1873-4138
• DOI: 10.1016/j.meatsci.2015.06.017

Physical and chemical attributes of the Longissimus thoracis (LT) of 96 PIC© entire (E) and immunocastrated (C) pigs were evaluated. The study followed a 2×2×3 factorial design where three diets of low, medium and high proteins (7.50, 9.79 and 12.07g digestible lysine/kg) were fed either with (10mg/kg) or without ractopamine (RAC) for the last 28days of growth. Vaccination of C occurred at 16 and 20weeks and slaughtering at 24weeks of age. The LTs were analysed for moisture, protein, fat and ash contents as well as CIE L*, a*, b* colour, drip loss, cooking loss and Warner–Bratzler shear force (WBSF). Various sex and protein interactions were observed for LT protein content, L* values and WBSF. Cooking loss was decreased in C and by the medium protein diet. Feeding RAC increased WBSF values, whilst decreasing a* and b* values. However, the differences observed are minor and might be considered negligible when evaluated by a consumer. •Immunocastrates and entire male pigs were fed RAC with varying dietary proteins.•Immunocastration and feeding a medium protein diet decreased cooking loss.•RAC increased WBSF and decreased a* and b* values.•Sex–protein interactions were observed for muscle protein content, L* values and WBSF.•Differences observed were minor thus effects on meat quality are possibly negligible.