Banca de QUALIFICAÇÃO: SAMARA DE PAULA LOPES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : SAMARA DE PAULA LOPES
DATA : 04/02/2020
HORA: 14:00
LOCAL: Sala 28 Anexo I do Instituto de Veterinária
TÍTULO:

Economic and productive aspects of beef cattle supplemented with different types of mineral mixtures in relation to phosphorus content

PALAVRAS-CHAVES:

Phosphorus supplementation, beef cattle.

PÁGINAS: 70
GRANDE ÁREA: Ciências Agrárias
ÁREA: Medicina Veterinária
SUBÁREA: Patologia Animal
ESPECIALIDADE: Anatomia Patologia Animal
RESUMO:

Mineral deficiencies cause damage to Brazilian cattle breeding, and are well known and studied and reported throughout the national territory. Among the mineral deficiencies the most important is phosphorus (P), mainly for cattle kept under extensive regime. P deficiency occurs mainly because there are soils throughout the country with some degree of phosphorus limitation; soon there is lower concentration of the mineral in the forage, reflecting directly in the cattle. P deficiency can manifest subclinically, where the damage is slight or in clinical form with sudden decrease in production, frequent fractures, decreased resistance to disease, progressive weight loss, rough hair and osteophagy, which can lead to accidents (choking) or even death from ingestion of Clostridium botulinium toxin. This study was divided into two experimental seasons, covering 2017, 2018 and 2019, in a beef cattle farm in the city of Valença-RJ. The objective was to test two mineral mixtures (40gP/kg or 0gP/kg). Two experiments were performed; the first with nulliparous only and the second with multiparous, of all ages. All animals in both experiments were confirmed pregnancy. During the first experiment the two groups were divided (40gP/kg and 0gP/kg), the periodic nutritional clinical examination, needle test, bone biopsies, weighing, blood collection, feces, simulated grazing and monitoring of supplement consumption. During the second experimental phase, groups were divided and clinical and nutritional monitoring, zootechnical control, consumption and weighing of animals were performed. The cost of mixing with 40gP/kg was R$0.81 and the 0gP/kg was R$0.50, with expenditure on mineral supplementation equivalent to 1.8% (2017), 2.2% (2018) and 1.30% (2019) of the effective operating cost. Consumption of the 40gP/kg group was 38.8g/UA/day (experiment 1) and 32.7g/UA/day (experiment 2); The 0gP/kg group consumed 25.7g/UA/day (experiment 1) and 28.5g/UA/day (experiment 2). The higher consumption of the 40gP/kg mixture was due to the higher P content in the formula, which obviously reduces the NaCl concentration. Through bone samples were estimated bone mineral density, cortical thickness, specific bone density and histological analysis. Blood was also collected for P serum measurement. No matrix showed findings compatible with P deficiency. During the entire experimental period, faeces collection and simulated grazing were performed; The results show that the cattle of group 40gP / kg excreted higher amount P in the environment when compared to cattle that were supplemented with NaCl alone and the results of P concentrations in forage show the similarity of grazing where the breeders were housed, as well as variation of P concentration in forage during the months evaluated. It was concluded that no matrix presented P deficiency, regardless of the group and physiological phase. However, supplementation with NaCl alone was efficient to maintain cows of all categories, presenting lower costs. The farm, after the development of the study, opted to supplement the herd only with NaCl.

MEMBROS DA BANCA:
Presidente - 6387102 - MARILENE DE FARIAS BRITO QUEIROZ
Interno - 2929022 - SAULO ANDRADE CALDAS
Externo à Instituição - MICHEL JOSÉ SALES ABDALLA HELAYEL - UFF