Banca de QUALIFICAÇÃO: ALINSON DE AQUINO PETRI

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ALINSON DE AQUINO PETRI
DATE: 17/08/2023
TIME: 09:00
LOCAL: Sala Virtual
TITLE:

OCCURRENCE OF NON-ACID UNSTABLE MILK IN DAIRY GIR COWS

KEY WORDS:

LINA; Dairy Cattle; Ethanol Test; Alizarol; Milk Quality.

PAGES: 35
BIG AREA: Ciências Agrárias
AREA: Zootecnia
SUMMARY:

There are few studies on the occurrence of Unstable Non-Acid Milk (UNAM) in Zebu cows, so the objective was to describe the occurrence of UNAM in dairy gir herds. The study was conducted at the Rockefeller Farm, of the Agricultural Research Company of Rio Grande do Norte (EMPARN), in the municipality of São Gonçalo do Amarante-RN. Individual milk samples were obtained from 13 lactating Gir cows (n=60), from morning milking, from July to September 2022, with a collection interval of no less than one week. Mug tests and the California Mastitis Test (CMT) were performed to exclude animals with mastitis, then individual samples from each animal were kept under refrigeration (4°C) and sent for laboratory analysis, verifying the composition of the Milk, Somatic Cell Count (SCC), density, Titratable Acidity (TA), pH and alcohol test in different alcoholic graduations (72°, 74° and 78°). Data were submitted to Pearson's linear correlation test and analysis of variance, means were compared using Tukey's test at 5% significance level. In the ethanol test (72°, 74° and 78°), 48.33% of the samples reacted positively, however, only 20.83% of these were classified as UNAM (8.33% of the total samples). The milk composition parameters, SCC, density, TA and ethanol test at the 72° graduation, complied with the legislation (IN76/MAPA 2018) in 21.67% of the samples and 78.33% were acidic (>18°D). The milk samples were divided into 3 classes (Normal Milk, Acid Milk and UNAM). Only TA differed statistically between classes (P<0.001) - Normal Milk (0.17 ± 0.02) and UNAM (0.17 ± 0.01) in relation to Acid Milk (0.22 ± 0.03). UNAM with coagulation at graduation 74° (37.5%) and 78° (62.5%), with higher means of fat, Total Solids (TS) and TA in the former; and protein, lactose, Non-Fat Solids (NFS), SCC, density and pH in that. In the correlation analysis, there was a significant positive correlation between NFS and protein, NFS and lactose, TS and fat, density and lactose; and negative correlation between density and fat. Therefore, the occurrence of UNAM was low; In the 72° alcohol test, UNAM did not occur; Factors other than TA reduce the stability of milk when using higher alcoholic strengths; The occurrence of UNAM was not related to SCC, Density, TA, pH and milk composition; UNAM presented similar quality to Normal milk, being its unjustified rejection in the industry; Basing the diagnosis solely on the Ethanol test leads to rejection of UNAM by the industry, causing losses to the producer.

 

COMMITTEE MEMBERS:
Presidente - 2313454 - ADRIANO HENRIQUE DO NASCIMENTO RANGEL
Externa à Instituição - EMMANUELLA DE OLIVEIRA MOURA
Externo à Instituição - JOSE GERALDO BEZERRA GALVÃO JUNIOR - IFRN