Acta Univ. Agric. Silvic. Mendelianae Brun. 2004, 52, 53-64
Published online 2015-07-03

Homogeneity of the phenotype in the fattening pigs and methodology of its assessments

Ludvík Novák1, Ladislav Zeman2, Pavel Novák3, Petr Mareš2

1Srbská 15a, 612 00 Brno, Česká republika
2Ústav výživy a krmení hospodářských zvířat, Mendelova zemědělská a lesnická univerzita v Brně, Zemědělská 1, 613 00 Brno,Česká republika
3Fakulta veterinární hygieny a ekologie, Veterinární a farmaceutická univerzita v Brně, Palackého 1/3, 612 42 Brno, Česká republika

New method for evaluation of the ideal growth performance in pigs has been proved in the experimental stable room of MZLU in ŠZP Žabčice. This method is based on the biological interpretation of the exponential growth function of Gompertz. This solution defines the dynamic of the animal’s phenotype by the body mass at the begin of the fattening (G0), by the animal's race standard body mass (Gli) which is equal to the value of the growth curve asymptote and by the value of the daily maximum body mass increase (dGmax) given by the genotype of the animal. This phenotype definition yields the possibility to define the exponential growth curve of the animal from birth until to the body mass maturity by the equation in which (t) represents the age of the animal:
Gt = Gli.exp(-ln(Gli/G0).exp(-(e.dGmax/Gli).t)) [kg] (1)
The value of the real daily body mass increase is than estimated by the best approximation of the experimental body mass values by the growth curve defined in the equation (1). The distribution of animals in three groups, according to the calculated daily maximum body mass increase: the thin growing animas, by default growing animals and the most growing animals, demonstrated the dynamic of the relation between the value of the daily maximum body mass increase (dGmax) and the body mass of the animals (Gt). In animals aged 37 days the clear correlation between the daily maximum body mass increase and the body mass reached:
Y = 21.486x – 14.826 (R2 = 0.69); and Y = 28.609x2 – 45.21x + 23.868 (R2 = 0.70).
In animals of the age 150 days the correlation is a little bit looser:
Y = 54.316x +39.146 (R2 = 0.31); and Y = 8.203x2 + 35.192x + 50.241 (R2 = 0.31).
The presented original methodology for evaluation of the animal’s individuality by means of the biological version of Gompertz exponential growth functions has been proved as a tool for direct evaluation of expression of the genotype body mass into its phenotype values, already during the experiment or the fattening process.


12 live references