Amino acid composition of pig meat in relation to live weight and sex

The objective of this study was to find out the amino acid composition of pig meat in relation to live weight and sex. In total 80 (40 barrows/40 gilts) finishing pigs of the final hybrid kept in the Czech Republic ((CL × CLW) × (D × PN)) = ((Czech Landrace × Czech Large White) × (Duroc × Pietrain)) were used in this experiment. The pigs were slaughtered at the average age of 168-171 days after birth, at the average live weight of 112.2 kg. The samples of meat were taken from the musculus longissimus lumborum et thoracis (MLLT) 24 hours post mortem and subsequently subjected to the chemical analysis. As for the essential and semi-essential amino acids (EAA/SEAA), the highest content was found out in lysine, leucine and arginine. Among the nonessential amino acids (NEAA) glutamic and aspartic acid were present. The highest values of threonine (6.81%), isoleucine (6.13%), leucine (9.21%), lysine (10.54%), arginine (7.88%), serine (6.13%), glutamic acid (15.65%), glycine (6.04%) and alanine (6.25%) were found out in gilts, of valine (6.36%) and proline (5.56%) in the group of barrows with the highest live weight, i.e. 115.1 kg and more. The highest value of phenylalanine (1.34%) was measured in the group with the lowest live weight. The indirect dependence between the content of amino acids and live weight was determined only for valine in gilts. The influence of live weight was found in proline and the influence of sex as statistically significant on the probability level P ≤ 0.05 was found in lysine. The highest/lowest values of water content in barrows as well as in gilts were measured in the group of 115.1 kg and more/105.1-115 kg live weight. A decreasing tendency of the content of intramuscular fat (IMF) was recorded with the increasing live weight. The values of water content, IMF and ash content were found to be significant on the probability level P ≤ 0.05 and P ≤ 0.01. In barrows with the growth of live weight the content of crude proteins also increased. In gilts the content of crude proteins reached the point of inflexion already in the group of 105.1-115 kg live weight. In the values of crude protein content the influence of live weight was not significant. With the growth of live weight the content of ash also slightly increased.