The effect of fattening periods on blood metabolites of Landrace pigs and their two-breed hybrids

A comparative intergroup analysis of fattening pigs of different breed and age groups according to biochemical and amino acid parameters of blood serum was carried out. When forming groups based on the principle of analogues, n = 10 heads of animals were selected in each group: 1 – Landrace 60-65 days of fattening; 2 – Landrace x Large White 60-65 days of fattening; 3 – Landrace 100-110 days of fattening; 4 – Landrace x Large White 100–110 days of fattening. Pairwise intergroup comparisons were performed after checking the distribution of data according to the Shapiro-Wilk criterion and evaluating the uniformity of variance using the Levene’s test. Univariate variance analysis and the Tukey-Kramer test were used for data where the distribution corresponded to normal, and the condition of uniformity of variance in groups was confirmed. If one of the two conditions is not met, the comparative analysis is performed using the Kruskal-Wallis test with the Bonferroni correction, in combination with the Mann-Whitney test. No statistically significant differences were found in groups 1 and 2. With age, for groups 3 and 4, significant differences were found only for amino acids – methionine and valine. in Landrace breed (group 3) on the 100-110 th day of fattering the content of the following amino acids in the blood was significantly higher: aspartic acid (p = 0.014), glutamic acid (p = 0.042), isoleucine (p = 0.035), cysteine (p = 0.003), alanine (p = 0.035), serine (p = 0.013), valine (p = 0.006), arginine (p = 0.001) in comparison with the animals of the 1 group; whereas the average values for the methionine index were lower (p = 0.008). In Landrace x Large White hybrids (group 4) on the 100-110th day of fattering the content of total protein (p = 0.015), albumins (p<0.001), urea (p = 0.008), aspartic acid (p><0.001), alanine (p><0.001), isoleucine (p = 0.003), lysine (p = 0.001), cysteine (p = 0.002), valine (p><0.001), arginine (p><0.001) was higher while the content of proline (p = 0.028) and methionine (p><0.001), serine (p><0.001), glycine (p = 0.003) was lower in comparison with the animals of the 2 group. Thus, the change in biochemical parameters and amino acid composition of pig blood is mostly influenced by age dynamics that is more vividly manifested in hybrids compared with the pure breed. Keywords: pig breeding, age dynamics, metabolic changes caused by breeding> < 0.001), urea (p = 0.008), aspartic acid (p < 0.001), alanine (p < 0.001), isoleucine (p = 0.003), lysine (p = 0.001), cysteine (p = 0.002), valine (p < 0.001), arginine (p < 0.001) was higher while the content of proline (p = 0.028) and methionine (p < 0.001), serine (p < 0.001), glycine (p = 0.003) was lower in comparison with the animals of the 2 group. Thus, the change in biochemical parameters and amino acid composition of pig blood is mostly influenced by age dynamics that is more vividly manifested in hybrids compared with the pure breed.