Effects of low protein diets on pigs with a lean genotype. 1. Carcass composition measured by dissection and muscle fatty acid composition

• Published in: Meat science Vol. 95; no. 1; pp. 123 - 128
• Main Authors: Wood, J.D., Lambe, N.R., Walling, G.A., Whitney, H., Jagger, S., Fullarton, P.J., Bayntun, J., Hallett, K., Bünger, L.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2013
• Subjects: Adipose Tissue - chemistry; Amino acids; Amino Acids - chemistry; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Body Weight; Carcass composition; Diet, Protein-Restricted; Fatty Acids - chemistry; Female; Genotype; Humans; Hydrogen-Ion Concentration; Intramuscular fat; Male; Meat - analysis; Muscle, Skeletal - chemistry; Nitrogen - administration & dosage; Pigs; Protein; Swine; Taste; Pigs; Amino acids; Carcass composition; Protein; Intramuscular fat
• ISSN: 0309-1740; 1873-4138
• DOI: 10.1016/j.meatsci.2013.03.001

Pigs with a lean genotype were fed diets differing in protein and amino acid contents between 40 and 115kg live weight. A high protein control regime (C) was compared with one supplying 11% less total protein but the same essential amino acid levels (LP1) and one supplying 16% less protein but lower amino acid levels (LP2). Regime LP2 produced fatter pigs in terms of subcutaneous, intermuscular and intramuscular fat (IMF), the latter measured in longissimus and semimembranosus muscles. The percentage of linoleic acid was lowest and that of oleic acid highest in IMF from LP2 pigs (11.57 and 34.59% respectively in longissimus). Pigs in regime LP1 had more longissimus IMF than C but similar semimembranosus IMF although both muscles had lower percentages of linoleic acid in LP1 than C, suggesting a tendency towards greater fat deposition in LP1. The high IMF content in LP2 produced the most tender, juicy steaks. •Pig feeds with low levels of protein and essential amino acids (EAA) produce fat pigs.•If protein is reduced but EAA are maintained, carcasses have similar fat content.•IMF in loin muscle is increased when low protein diets are fed.•High IMF concentrations result in more tender, juicy loin steaks.