Med. Weter. 68 (7), 430-435, 2012

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Wrotkowski K..
Computational method for determining the thermal requirements of growing pigs for ventilation purposes
The study presents a method of determining the thermal requirements of swine, that is, a range constrained by lower and upper critical temperatures,. The method is based on energy relationships between the nutrition system, the process of energy accumulation in an animal’s organism, the amount of heat produced, and the possibilities of returning this heat to the environment depending on conditions in the immediate surroundings of swine. The method consists of a uniform calculation system formed by commonly known and practically applied formal descriptions of the above energy interactions. The model of the animal’s growth is implemented with and based on qualitative changes in the chemical composition of daily gains as a function of the animal’s body weight. This makes it possible to link these energy interactions with the animal’s genotype, as well as its production and breeding parameters, such as the daily gain and its chemical composition, feed consumption, the efficiency of the utilization of energy provided with feeds, efficiency measured with the daily gain, etc. Moreover, the method makes it possible to determine the ambient temperature needed to maintain a constant thermal interaction with the surroundings regardless of changes in technological factors such as feeding intensity or animal husbandry conditions. This may be useful in comparative research, in which disturbing influences of the environment on the rate and composition of the animal’s daily gains need to be eliminated..
Key words: method, thermal requirements, integrated theoretical model of animal