Banca de DEFESA: GREYCE KELLY SCHMITT REITZ

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : GREYCE KELLY SCHMITT REITZ
DATE: 15/07/2022
TIME: 09:00
LOCAL: Web Conferência - Google Meet - https://meet.google.com/opf-oemm-qiw.
TITLE:

Zootechnical and inflammatory parameters in Jersey dairy cows with subclinical mastitis.

KEY WORDS:

Somatic cell count, lactose, milk, production.

PAGES: 45
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

The aim of the present study is to verify the influence of subclinical mastitis on zootechnical and inflammatory markers in Jersey dairy cows. Zootechnical data, blood and milk samples were collected from 59 Jersey dairy cows kept in a semi-extensive system of a dairy farm located in Braço do Norte - SC. Milk samples were collected using an individual collector cup, sent refrigerated to laboratories of the Brazilian milk quality control network, for analysis of quality characteristics: somatic cell count (SCC), lactose (lact), protein , fat, total and defatted dry extract (ESD), casein, freezing point and urea nitrogen (Nul). Blood collection was performed after milking, by puncturing the coccygeal arteriovenous complex. Samples of the total diet supplied and of pastures were sent for chemical analysis. Samples for analysis of inflammatory biomarkers (Paraoxonase-1, albumin and total plasma proteins) were sent to the Nupeec laboratory at the Federal University of Pelotas - RS. From the zootechnical data, the body condition score, number of lactations, production, days in lactation, interval between calving, number of inseminations until conception, calving interval, conception and days of gestation were analyzed. Cows were categorized by somatic cell count (SCC) into a subclinical mastitis group (Gsub) with SCC results greater than or equal to 200,000 cells/ml and a control group (GC). Data on metabolic variables, milk quality and zootechnical data were submitted to multivariate regression and one-way analysis of variance, using the SAS program. In multivariate regression analysis, several markers influence milk composition, explaining almost 99% of the data, such as lactose, total protein and casein. In the analysis of variance, it was shown that GSub reduced the concentrations of lact (4.37 vs 4.47 %; P= 0.0002), of Nul (20.55 vs 23.85 mg/dL; P = 0.02 ) and ESD (9.24% vs 9.50%; P = 0.02). It was observed that the animals of the Gsub had higher numbers of lactations in relation to the CG (4.30 vs 2.69; P=0.0039). Based on the data obtained in our study, we concluded that Jersey cows with subclinical mastitis have a lower content of lactose, urea and defatted dry extract in their milk, as well as a higher number of lactations. Lactose proved to be a good marker in milk for the diagnosis of subclinical mastitis in Jersey cows.

BANKING MEMBERS:
Interno - 1760760 - CARLOS EDUARDO NOGUEIRA MARTINS
Externa à Instituição - DEISE DALAZEN CASTAGNARA - Unipampa
Presidente - 1046884 - ELIZABETH SCHWEGLER