UTL Repository >
ISA - Instituto Superior de Agronomia >
BISA - Biblioteca do Instituto Superior de Agronomia / Library >
BISA - Dissertações de Mestrado / Master Thesis >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10400.5/2073

Title: Avaliação da homogeneidade da dieta completa (unifeed) para vacas leiteiras
Authors: Shirley, Marta Isabel Marques O'Connor
Advisor: Cunha, José Júlio Alfaro Cardoso Carreira
Lemos, José Pedro da Costa Cardoso
Keywords: dairy cow
particle size
chemical composition
vaca leiteira
dieta completa
composição quimica
Issue Date: 2009
Abstract: The feed management is very important in animal nutrition, specifically in farm animals. The diet supplements usually associated with high milk yield of cows is often used also by the ease of their management. This work studied the homogeneity of the TMR designed for Holstein dairy cows using an horizontal mixer wagon, by chemical composition (DM, CP, NDF, ADF and ADL) and particle size (sieve with 19, 8, 1 mm and bottom) to ensure that meets their nutritional needs. Also the nutritional parameters (DM, CP, NDF, ADF and ADL) were studied for the feed constituents in the diet: corn silage, alfalfa hay, tomato pomace and compound feed. For this study feed from 3 pens which contain the same diet consisting for 226 cows was analyzed. Samples of the diet were taken in for 4 days (not consecutive) in the beginning and end of each pen, while in the pen 2 and 3 were also sampled in the middle, after distribution of the morning diet. On the chemical composition of the diet, there are only significant variations in levels of DM and ADL, taking into account the day of trial, without these differences result in bad diets formulated or processed. These changes may be due to the quantity of tomato incorporated in the diet (high moisture). Compared to the previously formulated diet, the results indicate that the DM and CP are slightly lower; the values proposed by NRC (2001) for NDF are below the values obtained, while the percentage of ADF is in agreement with the expected. On the study of the ingredients of the diet, there are specific nutritional differences compared with reference values, but in a general rule, feeds in the diet for the parameters under study are within the specified limits. The results of the particle size of the diet showed significant differences in all size classes for the days of testing, including also the particles between 1 to 8 mm in view of the pens of the test. In D1, the percentage of particles between 1 to 8 mm is higher than expected, with other classes within the size limits. The reduction of particles retained in sieve of 8 mm, and an increase in the sieve of 1 mm in D2, can be explain by the mixing time practiced. Overall, the proportion of particles 8-19 mm were under and particles 1-8 mm were above the recommended values. In the last day of testing, the higher processing time of the forage may have led to reduction of particles with size > 19 mm, leading to only the particles < 1 mm were in appropriate proportions. The differences occurred between pens were small and could be a consequence of the distance between pens and the path irregular used by SRMDR.On average the size fractions ranging from 1 to 8 mm to 19 mm and 8 are not inagreement with the expected. The particles retained in sieve of 1 mm are at higher percentage, whereas fractions retained in the sieve with 8 mm are lower.-------------------------------------A dieta completa (MS=53,3%, PB=27,4%) foi formulada de modo a cobrir as exigências nutricionais de vacas Holstein que produzem em média 25,8 kg de leite por dia. Com o objectivo de avaliar a homogeneidade da dieta completa, quer em termos de composição química quer de granulometria, foram recolhidas 8 amostras de alimento ao longo das manjedouras em 4 dias, perfazendo na totalidade 32 amostras. Cada amostra foi sujeita à determinação da composição química (MS, PB, NDF, ADF e ADL) e à avaliação da granulometria usando um ‘Penn State Particle Separator’ (PSPS) composto por 3 crivos (diâmetro com 19, 8 e 1 mm) e um fundo. Foi também analisado cada alimento da dieta individualmente (MS, PB, NDF, ADF e ADL). A composição química verificou-se homogénea ao longo do ensaio, apesar das pequenas alterações no teor de MS e de ADL, para os dias de ensaio, embora irrelevantes. Verificouse um efeito importante do dia de recolha na granulometria da dieta, mas a diferença entre parques foi pequena.
Description: Mestrado em Engenharia Zootécnica - Produção Animal - Instituto Superior de Agronomia / Faculdade de Medicina Veterinária
URI: http://hdl.handle.net/10400.5/2073
Appears in Collections:BISA - Dissertações de Mestrado / Master Thesis

Files in This Item:

File Description SizeFormat
TESE_Marta_Shirley_pdf.pdf1.75 MBAdobe PDFView/Open
Restrict Access. You can request a copy!
FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpaceOrkut
Formato BibTex mendeley Endnote Logotipo do DeGóis 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


Estamos no RCAAP Governo Português separator Ministério da Educação e Ciência   Fundação para a Ciência e a Tecnologia

Financiado por: