Agriculture Reference
In-Depth Information
14 AvinespModel: Predicting Poultry
Growth, Energy and Amino Acid Requirements
L. Hauschild,* N.K. Sakomura and E.P. Silva
Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil
Abstract
In Brazil, modelling is still rarely used as there are no local models that can be applied as tools to
optimize poultry or pig production. Aiming at filling this gap and stimulating interest in modelling in
Brazil, the Nutrition and Modelling research group of Universidade Estadual Paulista (UNESP)-
Jaboticabal developed the AvinespModel. The objective of this chapter is to present the theoretical back-
ground of the AvinespModel, to describe its structure, to demonstrate how it was evaluated, and to dis-
cuss its implications and future perspectives. The model estimates ad libitum feed intake, live weight,
body composition and nutritional requirements of broilers and layer replacement pullets. It also esti-
mates the response of an average chicken to a given feed and environment. Diet composition and chicken
genotype are considered model inputs. Actual protein and lipid body mass are used as body state vari-
ables. The effective energy (EE) system, as proposed by Emmans (1994), is applied. Euler's integration
method was applied to solve equations with one-day integration steps ( dt ). Rates are expressed on a daily
basis, energy in megajoules and mass in grammes. In the model, feed intake and nutritional requirements
of an animal are estimated as a function of its growth rate and body composition. The Gompertz (1825)
equation is used in this model to describe protein deposition in the body and feathers based on biologic-
ally meaningful parameters. In order to estimate the desired lipid deposition, its ratio to protein depos-
ition potential is established in the model. All the parameters required to describe specific genetic strains
were obtained from studies conducted at the Poultry Science Laboratory of the Faculty of Agriculture
and Veterinary Sciences (FCAV) at UNESP-Jaboticabal. The principle used to estimate feed intake in the
model assumes that the bird attempts to eat sufficient to meet its growth potential (desired feed intake),
considering its digestive capacity limitations and the environment. Estimates obtained with Avinesp for
growth and responses to nutrient intake, health challenge and environmental temperature were consist-
ent with the findings in the literature. Avinesp simulates the effects of different nutritional, feeding,
health and environmental scenarios. Therefore, the proposed model, in addition to estimating nutri-
tional requirements, may also be used as a tool to aid decision making by farmers and companies.
Introduction
technologies both to optimize production
and improve sustainability. Nutrition strat-
egies have been applied to enhance the
efficiency of nutrient utilization, aiming at
The competitiveness of the global poultry
industry generates a constant demand for
 
 
Search WWH ::




Custom Search