Banca de DEFESA: RODRIGO FERREIRA DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RODRIGO FERREIRA DA SILVA
DATE: 28/02/2023
TIME: 14:00
LOCAL: Videoconferência
TITLE:

WEIGHT DEVELOPMENT OF SANTA INESE SHEEP IN THE BREEDING PHASE, MANAGED IN PASTURE AND SUPPLEMENTED

KEY WORDS:

sheep meat, growth efficiency, regression equation, growth curve, sheep farming, semiarid

PAGES: 39
BIG AREA: Ciências Agrárias
AREA: Zootecnia
SUBÁREA: Produção Animal
SUMMARY:

The objective was to characterize the weight development of male and female Santa Inês lambs, from birth to weaning, managed on pasture, and receiving concentrated supplementation via creep-feeding. Data from 212 sheep of the Santa Inês breed were used. During the data collection period, the animals were kept on massai grass pasture, all paddocks were equipped with drinkers and troughs for mineral supplementation. The lambs received concentrated supplementation, ad libitum from the first day of life. To evaluate the total weight gain (GPT) and average daily gain (ADG) the lambs were weighed every seven days. With the aid of a hypometer, the biometric measurements of the animals were taken every 28 days. Multiple regression models were tested to estimate body weight using biometric measurements as independent variables and a non-linear Gompertz model to describe weight development through repeated measurements over time. There was an effect (<0.05) of the type of delivery on birth weight, average daily gain, total weight gain and weaning weight, there was also an effect (<0.05) of sex on the variables of weight at birth. birth and weaning weight. The growth curves according to the model proposed by Gompertz, described the development of the animals similar to that observed, as it is possible to predict the weight at maturity of the animals. Pearson's correlation coefficients between biometric measurements and weight were positive and significant (P<0.05). In the simple linear regression and multiple linear regression models, all equations were able to predict the weight of animals at weaning, however from a practical point of view and with a high coefficient of determination (adjusted R² = 0.824) body length and perimeter of barrel, proved to be efficient, finally it is emphasized that the more measurements used, the greater the predictive power of the model. Lambs with twin births develop more slowly than animals with single births, but when weaned at 84 days, they present compensatory gains in relation to traditional systems of early weaning when supplementation is performed. The Gompertz model can be used to predict the development of animals still in the breeding phase and help in decision making and selection of precocious animals for the production system. Simple and multiple linear equation models are efficient to predict the weight of animals at weaning through biometric measurements.

COMMITTEE MEMBERS:
Presidente - 2339534 - STELA ANTAS URBANO
Interno - 1233988 - JOAO VIRGINIO EMERENCIANO NETO
Externa à Instituição - JULIANA PAULA FELIPE DE OLIVEIRA FREITAS - UFS