Development and evaluation of empirical and dynamic models for predicting passage ...
| Grant number: | 15/22600-5 |
| Support type: | Scholarships abroad - Research Internship - Post-doctor |
| Effective date (Start): | February 01, 2016 |
| Effective date (End): | January 31, 2017 |
| Field of knowledge: | Agronomical Sciences - Animal Husbandry |
| Principal Investigator: | Izabelle Auxiliadora Molina de Almeida Teixeira |
| Grantee: | Amélia Katiane de Almeida |
| Supervisor abroad: | Luis Orlindo Tedeschi |
| Home Institution: | Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil |
| Local de pesquisa : | Texas A&M University, United States |
| Associated to the scholarship: | 14/14939-0 - Development of models for predicting the energy and protein requirements for growing goats, BP.PD |
Abstract Models are important tool to understand the nutrition and growth of goats enabling the manager in the decision-making. In this context, the use of system dynamic approach would help researchers to stare complex issue, such as intake regulation, with a holistic view. The voluntary dry matter intake (DMI) intake is under control of long-term signals (e.g., lypostatic theory) integrated with the various short-term signals (gut fill and energy status). Because of the complexity of this scenario, DMI prediction equations, developed by current feeding systems, frequently fails in predicting DMI in goats. Thus, intake prediction equations can be improved using the system thinking. This may lead to an increase in the adequacy of nutritional requirements recommendations, because prediction of DMI is an important step to formulate diets properly. The objective of this internship abroad is to develop a dynamic model to predict DMI associated with body composition changes throughout growth in male (intact and castrated) and female Saanen goats. Statistical analysis will be performed sequentially. Firstly, differential equations (i.e., fluxes in the system are computed as differential equations) will be converted into algebraic equations using Mathematica v.8.0 (Wolfman Research, Champaign, IL). The algebraic equations will be solved using the PROC NLMIXED (SAS Institute Inc. Cary, NC). Fixed effects of sex and feed restriction and random effect of experiment on model parameters and output variables will be depicted using PROC MIXED of SAS. After, the Model Evaluation System (MES, College Station; TX) will be used to verify model adequacy. In this step, 564 individual records of growing goats from experiments conducted between 1989 and 2014, will be used as evaluation database. At last, the analysis of sensitivity will be performed by identifing the most influential variables by the Standardized Regression Coefficient (SRC) generated in a previous Monte Carlo simulation. | |