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Previous issue date: 2013-02-27 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The direct relationship with the processing, industrial yield and price of
milk, the importance of the centesimal composition of milk and their protein fractions has
increased for both the dairy industry and for the producers, so it is important to identify the
possible causes on variation of these components. The aim of this study was to evaluate the
effect of the seasons, order of calving and lactation phase on milk composition and protein
fractions in dairy farms in the Agreste and Leste meso-regions, of Rio Grande do Norte
State (RN). Milk samples were taken in seven milk farms directly from the bulk tanks
except for one farm where samples were taken from higher milking cows producers and
heifers. The experiment was done in seven properties with milk samples taken directly
from the bulk tanks and in one property were collected from higher production cows and
heifers. Composition analyses were carried out for both experiments and sensorial trial was
performed for the second experiment only. The data results were submitted to analysis of
variance (ANOVA) and Tukey test performed for 5% significance level. In the first
experiment was observed response of the seasons, dry and rainy season; while in the
second, the effect of the order of calving and lactation phase had influence on milk
composition and protein fractions. There was significant response (p < 0.05) for season
effects but due to farms. The rainy season had higher averages in the protein, lactose, total
solids and nonfat dry extract. Multiparous cows had higher CCS, NUL and PCAS milk
contents; while, first calving heifers showed higher average for the sensory attribute, color
of milk. The final third of lactation was responsible for the elevation of the levels of almost
all milk components and their protein fractions / Mediante a crescente import?ncia da composi??o centesimal do leite e suas
fra??es proteicas, para a ind?stria de latic?nios e para os produtores, em fun??o da rela??o
direta com o processamento, rendimento industrial e pre?o do leite, torna-se relevante
verificar poss?veis causas de varia??o desses componentes. Dessa forma, objetivou-se com
este estudo avaliar o efeito das esta??es do ano (seca e chuvosa), da ordem de parto e da
fase de lacta??o sobre a composi??o do leite e suas fra??es proteicas em propriedades nas
mesorregi?es agreste e leste do Rio Grande do Norte - RN. O experimento foi realizado em
sete propriedades, com coleta de leite em tanques de expans?o e em uma destas por
amostragem do lote de vacas de maior produ??o e de novilhas. Foram realizadas an?lises
de composi??o do leite e sensorial. Os respectivos resultados foram analisados por meio da
an?lise de vari?ncia (ANOVA) com as poss?veis diferen?as entre as m?dias (p<0,05) pelo
teste de Tukey. N?o houve efeito da esta??o do ano nos componentes do leite. No entanto,
houve efeito de intera??o da esta??o do ano com a fazenda na prote?na, lactose, s?lidos
totais e no extrato seco desengordurado. Na composi??o do leite a ordem de parto
influenciou os teores de CCS, NUL e PCAS e na sensorial o atributo cor. Os est?dios de
lacta??o influenciaram os teores todos os componentes do leite, com exce??o do ESD
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17181 |
| Date | 27 February 2013 |
| Creators | Barreto, Mayara Leilane de Jesus |
| Contributors | CPF:29183375449, http://lattes.cnpq.br/9757343999118047, Lima J?nior, Dorgival Morais de, CPF:01358734445, http://lattes.cnpq.br/9054517540280709, Guilhermino, Magda Maria, CPF:05195601836, http://lattes.cnpq.br/2481533325379100, Spyrides, Maria Helena Constantino, CPF:79203183434, http://lattes.cnpq.br/5023632543506327, Rangel, Adriano Henrique do Nascimento |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Produ??o Animal, UFRN, BR, Sistemas de Produ??o Sustent?veis no Semi-?rido; Caracteriza??o, conserva??o e melhoramento gen?tico |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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