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Einfluss des Absetzverfahrens und anderer systematischer Effekte auf die Milchleistung und ausgewählte Eutergesundheitsparameter einer Herde Ostfriesischer MilchschafeBauer, Almut 10 June 2013 (has links) (PDF)
In der vorliegenden Arbeit wurde die Bedeutung des Einflusses von Laktationsnummer, Laktationsstadium, Körperkondition und Absetzverfahren auf Merkmale der Milchleistung und Eutergesundheit einer Herde Ostfriesischer Milchschafe untersucht. Die Tiere wurden nach dem Ablammen zufällig einer Früh- bzw. Spätabsetzergruppe zugeordnet (Absetzen der Lämmer 3 bzw. 42 Tage post partum). An insgesamt 40 Terminen wurden über eine vollständige Laktation Vorgemelks-, Hälftenanfangsgemelks- und Einzeltiergemelksproben gewonnen. Das Spektrum der untersuchten Merkmale umfasste die Milchmenge, die Milchinhaltsstoffe (Fett, Eiweiß, Laktose), die klinische Untersuchung des Euters, die somatische Zellzahl, die elektrische Leitfähigkeit und bakteriologische Untersuchungen. Zusätzlich wurden das Körpergewicht und die Körperkondition der Mutterschafe erfasst.
Das durchschnittliche Leistungsniveau der Herde betrug 301±101,3 kg Milch, bei mittleren Milchfett-, Milcheiweiß-, und Laktosegehalten von 5,00, 5,14 bzw. 5,00 % (150-Tageleistung). Die Laktationsnummer hatte keinen signifikanten Effekt auf die Milchleistung. Schafe der Spätabsetzer-Gruppe produzierten im Anschluss an die Säugephase eine um 300 g signifikant höhere Testtagsmilchmenge als Tiere der Frühabsetzer-Gruppe. Das Absetzverfahren hatte keinen nachweisbaren Effekt auf die Milchinhaltsstoffe.
Die Herde wies eine gute Eutergesundheit auf. Der Anteil bakteriologisch positiver Schafmilchproben betrug 28,5 %. Als dominante Erreger wurden in 96,6 % der bakteriologisch positiven Schafmilchproben Koagulasenegative Staphylokokken nachgewiesen. Der Anteil bakteriologisch positiver Euterhälftenbefunde stieg signifikant mit dem Fortschreiten der Laktation und zunehmender Laktationsnummer. Eine Euterinfektion mit Koagulasenegativen Staphylokokken sowie das Verfahren des Spätabsetzens beeinflussten alle drei untersuchten Eutergesundheitsparameter (logarithmierte Zellzahl, elektrische Leitfähigkeit und Laktosegehalt) negativ
(p < 0,001).
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Syřitelnost kravského a kozího mléka / Clotting of cow and goat milkPECOVÁ, Lenka January 2017 (has links)
The thesis deals with two technological properties determining the quality of milk, clotting and fermentation ability by titrable acidity, which are influenced by a large number of factors. The aim of the work was to assess the influence of milk composition, breed, order and stages of lactation on clotting and souring ability of cow and goat milk based on obtained analysis. Detailed analysis focused primarily on cow milk.
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QUALIDADE DO LEITE EM DIFERENTES SISTEMAS DE PRODUÇÃO, ANOS E ESTAÇÕES CLIMÁTICAS NO NOROESTE DO RIO GRANDE DO SUL / MILK QUALITY PRODUCED IN DIFFERENT PRODUCTION SYSTEMS, YEARS AND SEASONS AT REGION NORTHWEST RIO GRANDE DO SUL, BRAZILMilani, Marceli Pazini 25 October 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective was to evaluate the milk quality coming from Region Northwest Rio
Grande Sul, under different technology levels, from October 2007 to September 2010, at
different seasons. The variables were fat, protein, lactose, total solids, somatic cell count
(SCC) and total bacterial count (TBC) of milk. Data were analyzed using mixed model with
repeated measure data, having the effect of fixed production system, years and seasons, and
random effect dairy farm designated in each production system. The results were compared
with the standard required by Normative Instruction 51 (NI 51) of 18 September 2002
(Minisério da Agricultura, Pecuária e Abastecimento). There were significant differences
between the systems of production for fat and total bacterial count milk, with higher values in
non specialized system. All variables were influenced by season, featuring in the autumn, fat,
protein, total solids and higher TBC. The lactose content was influenced by the production
system, presenting the most specialized and smaller in the not specialized, and the season,
being higher in winter and lower in autumn. There was a high percentage of samples in
disagreement with the NI 51 to TBC and SCC, especially those belonging to dairy farm
partially and not specialized. / Foi avaliada a qualidade do leite oriundo da Mesorregião Noroeste do Rio Grande do
Sul, sob distintos níveis tecnológicos, no período de outubro de 2007 a setembro de 2010, nas
diferentes estações do ano. As variáveis analisadas foram gordura, proteína, lactose, sólidos
totais, contagem de células somáticas (CCS) e contagem bacteriana total (CBT) do leite. Os
dados foram analisados por meio de modelo misto com medida repetida no tempo, tendo
como efeito fixo os sistemas de produção, anos e estações do ano, e efeito aleatório a unidade
produtora de leite (UPL) designada em cada sistema de produção. Os resultados foram
comparados com o padrão exigido pela Instrução Normativa 51 (IN 51) de 18 de setembro de
2002 (Ministério da Agricultura, Pecuária e Abastecimento). Observou-se diferenças
significativas entre os sistemas de produção para os teores de gordura e contagem bacteriana
total do leite, com valores superiores no sistema não especializado. Todas as variáveis tiveram
influência da estação do ano, apresentando, no outono, teor de gordura, proteína, sólidos totais
maior e CBT menor. O teor de lactose foi influenciado pelo sistema de produção,
apresentando-se maior no especializado e menor no não especializado, assim como pela
estação do ano, sendo maior no inverno e menor no outono. Observou-se uma porcentagem
alta de amostras em desacordo com a IN 51, para CBT e CCS, principalmente as pertencentes
a UPL`s do sistema semi e não especializado.
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Produção e composição do leite de vacas das raças Holandês e Jersey, em pastagem de azevém anual / Production and milk quality of Holstein and Jersey cows breeds, grazing annual ryegrassDiefenbach, Jairo 29 February 2012 (has links)
This study evaluated the lactation curve shape, the yield and composition of milk from cows
of Holstein and Jersey breeds grazing annual ryegrass (Lolium multiflorum) in northwestern
Rio Grande do Sul, and aimed to analyze its response when subjected to grazing pasture
herd consisting of two genotypes. The experiment was conducted from 08.18.2010 to
10.29.2010 and are used in total, eleven tester cows of each racial group and a variable
number of regulator cows. The animals were managed in rotational grazing with variable
stocking rate and were supplemented at a rate of 1 kg per 3 liters of milk produced above 15
liters / cow / day. Pasture management allowed similar grazing conditions between the two
tested breeds and proved to be not limiting to pasture and animals production. Individual
milking performance was measured once a week throughout experimental period. The visual
body condition score (BCS, 1-5), was also registered weekly, and body weigh was measured
monthly. The experimental design for pasture variables and for individual animal production
was a randomized block design with replications in time, having been used stepwise proc
(SAS, 2009) to test regression models. Only the supplement in the months August,
September and October in analysis, besides individual productions corrected to 4% fat, day
consuption in the months of August, September and October was considered in analysis,
besides individual animal productions corrected to 4% fat, days in lactation period , body
weights, BCS, number of lactations and age. Individual samples were taken by milking in
September and October, and analyzed for the following milk components: fat, protein,
lactose, water, acidity, freezing point, density, and computed total dry extract (TDE) and
defatted dry extract (DDE). The statistical analysis for milk components was randomized
complete blocks with triple factorial arrangement for breeds (2), periods (2), and stages of
lactation (4). ANOVA was performed by GLM (SAS, 2009) and multivariate analysis, through
Software Multiv (Pillar, 1997), using the correlation between variables as a measure of
similarity, and clustering criteria was the least variance of sum of squares Jersey exceeded
Holstein (P <0.005) for fat (%) lactose (%) and protein (%); Holstein was exceeding Jersey (P
<0.0001) for fat (kg), protein (kg) and TDE ( kg). Correlation studies showed a clear
difference in the degree of association between genotypes for dry matter intake of feed, with
lower association for Jersey genotype, Holtstein presented a higher and consistent
dependence of intake throughout the experimental period, coinciding with pasture cycle. This
trend may indicate greater efficiency of Jersey genotype in the use of pastures of high
quality, obtained in the initial pasture phases. The regression studies indicated that
supplement dry matter intake (partial R ²) in September explained 65.69% of milk production
for Holstein breed, and supplement dry matter intake (partial R ²) in October explained
55.73% of milk production of Jersey breed. / Foram avaliados o comportamento da curva de lactação, e a produção e composição do
leite de vacas das raças Holandês e Jersey em pastagens de azevém anual (Lolium
multiflorum) no noroeste do Rio Grande do Sul, com o objetivo de analisar a resposta de
dois genótipos de raças leiteiras, em pastoreio rotativo. O experimento foi conduzido de
18/08/2010 a 29/10/2010, sendo utilizadas, onze vacas testadoras de cada grupo racial e
um número variável de vacas reguladoras. Os animais foram manejados em pastoreio
rotativo com lotação variável e receberam concentrado comercial à razão de 1 kg para cada
3 litros de leite produzidos acima de 15 litros/vaca/dia. O manejo das pastagens permitiu
condições de pastejo semelhantes entre as duas raças testadas e se mostrou não limitante
à produção da pastagem e dos animais. Foi medido o desempenho individual por turno de
produção de leite, uma vez por semana em todo período experimental. Também foram
tomados semanalmente, o escore de condição corporal (ECC, escala de 1 a 5), e
mensalmente o peso vivo (PV), em balança mecânica. O delineamento para variáveis da
pastagem e produção animal foi blocos ao acaso, com medidas repetidas no tempo, tendo
sido utilizado o proc stepwise (SAS, 2009) para testar modelos de regressões. Foi
considerado apenas o consumo do suplemento nos meses de agosto, setembro e outubro
na análise, além de produções individuais corrigidas a 4% de gordura, dias em leite no inicio
e final, pesos, ECC, número de lactações e idade. Foram tomadas amostras individuais de
leite por ordenha, em setembro e outubro, e analisados para os componentes: gordura,
proteína, lactose, além de água, acidez, crioscopia, densidade, e calculados extrato seco
total (EST) e extrato seco desengordurado (ESD). A análise estatística para componentes
do leite considerou o delineamento em blocos ao acaso em arranjo fatorial triplo para raças
(2), períodos (2), e fases de lactação (4). Foi realizada ANOVA por GLM (SAS, 2009) e
análise multivariada, através do Software Multiv (Pillar, 1997), sendo utilizada a correlação
entre variáveis como medida de semelhança, e o critério de agrupamento foi a variância
mínima da soma de quadrados. Jersey foi superior a Holandês (P<0,005) para os teores de
gordura (%) lactose (%) e proteína (%); Holandês foi superior a Jersey (P<0,0001) para as
produções de gordura (kg), proteína (kg) e EST (kg). O estudo de correlações indicou clara
diferença no grau de associação entre genótipos para consumo de matéria seca do
concentrado (CMSR), tendo Jersey menor associação, e Holandês uma mais alta e
consistente dependência desse consumo ao longo do período experimental, coincidente
com o avanço no ciclo da pastagem. Esta tendência pode indicar maior eficiência do
genótipo Jersey no uso de pastos de alta qualidade, obtida nas fases iniciais da pastagem.
O estudo de regressões indicou CMSR (R² parcial) no mês de setembro explicando 65,69%
da produção de leite do genótipo Holandês, e CMSR (R² parcial) no mês de outubro
explicando 55,73% da produção de leite do genótipo Jersey.
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EFEITO DA CONTAGEM DE CÉLULAS SOMÁTICAS E CONTAGEM BACTERIANA TOTAL SOBRE OS CONSTITUINTES DO LEITE / EFFECT OF SOMATIC CELL COUNT AND TOTAL BACTERIAL COUNT ON CONSTITUENTS OF MILKVargas, Diego Prado de 24 July 2012 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The study aims to evaluate the effect of somatic cell count (SCC) and total bacterial count (TBC) on the constituents of milk, checking the influence that the climatic variables have on these hygienic-sanitary indicators. Data were obtained from 1,541 dairy farms located in 15 municipalities in the dairy region of Vale do Taquari, Rio Grande do Sul. It was tabulated the data from somatic cell count (SCC), total bacterial count (TBC) and milk composition, from June 2008 to December 2011, totaling 44,089 samples. The ambient temperature showed positive and significant correlation to score of somatic cell, while rainfall and relative humidity air showed no correlation. Moreover, the climatic variables have no significant correlation to the TBC. The fat, protein, minerals and total solids were directly correlated with the SCC and TBC, while solids-not-fat and lactose showed an opposite behavior. The principal component analysis (PCA) followed by agglomerative hierarchical clustering method, have showed that milk from SCC 401,000 to 750,000 cell mL-1 and TBC from 100,000 to 1,000,000 CFU mL-1, have the same quality, not justifying stratification in these intervals. In addition, it was observed that only limits regulatory standards are not sufficient to improve the quality of milk, suggesting parameters for payment system based on the bonus and penalty relative to the TBC and SCC milk. / Este estudo teve por objetivos avaliar o efeito da contagem de células somáticas (CCS) e da contagem bacteriana total (CBT) sobre os constituintes do leite, verificando a influência que as variáveis climáticas exercem sobre estes indicadores higiênico-sanitários. Os dados utilizados foram de 1.541 unidades produtoras de leite referentes a 15 municípios da bacia leiteira do Vale do Taquari, Rio Grande do Sul. Foram tabulados os dados de contagem de células somáticas (CCS), contagem bacteriana total (CBT) e composição centesimal do leite, referentes ao período de junho de 2008 a dezembro de 2011, totalizando 44.089 amostras analisadas. A temperatura ambiente apresentou correlação positiva e significativa com o escore de células somáticas, enquanto a precipitação pluviométrica e umidade relativa do ar ausência de correlação. Por outro lado, as variáveis climáticas não apresentaram correlação significativa com a CBT. Os teores de gordura, proteína, minerais e sólidos totais foram diretamente correlacionados com a CCS e a CBT, enquanto que os sólidos não gordurosos e a lactose apresentaram comportamento inverso. A análise de componentes principais (ACP) seguida pelo método hierárquico aglomerativo de agrupamento, permitiu constatar que leites com CCS maiores que 400.000 até 750.000 céls mL-1 e CBT superiores a 100.000 até 1.000.000 UFC mL-1, apresentam a mesma qualidade, não justificando a estratificação de intervalos nesta amplitude de variação. Paralelamente, observou-se que somente limites de normas regulatórias não são suficientes para melhoraria da qualidade do leite, sugerindo-se, parâmetros para sistemas de pagamento baseado na bonificação e penalização em relação à CCS e CBT do leite.
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Efeitos da substituição parcial do farelo de soja por uma fonte de proteína microbiana derivada de levedura, em dietas de vacas holandesas em lactação / Effects of the partial substitution of soybean meal by a yeast-derived microbial protein source, in diets of lactating dairy cowsMariana Santos de Miranda 21 August 2015 (has links)
Foi conduzido um estudo com vacas leiteiras no Centro de Análise e Pesquisa Tecnológica do Agronegócio - Bovinos de Leite, do Instituto de Zootecnia, em Nova Odessa, SP, com o objetivo de avaliar os efeitos da substituição parcial do farelo de soja da dieta por uma fonte de proteína microbiana derivada de levedura (PML), e a sua combinação com uma ureia de liberação lenta (ULL), sobre o consumo de MS, produção e composição do leite, bem como alguns parâmetros sanguíneos e o balanço nitrogenado. Foram utilizadas oito vacas primíparas da raça Holandês, distribuídas aleatoriamente em dois quadrados latinos 4x4 em tratamentos arranjados em esquema fatorial 2x2, sendo que cada período experimental foi composto por 28 dias com 21 dias de adaptação e 7 dias de coleta. Foram comparadas quatro dietas, compostas por 49% de volumoso (47% de silagem de milho e 2% de feno de Tifton) e 51% de concentrado, com teor médio de 16,8% de proteína bruta e 2,5Mcal/kg EM. Na dieta controle (CTL = sem PML e sem ULL) o farelo de soja foi a principal fonte proteica e nas outras três dietas o farelo de soja foi parcialmente substituído por 15 g/kg MS de PML (com PML e sem ULL) ou por 7,5 g/kg MS de ULL (sem PML e com ULL) ou ambos, 15 g/kg MS PML+ 7,5 g/kg MS de ULL (com PML e com ULL). Houve interação entre PML e ULL para o consumo de MS (P=0,0003) e produção de leite (P=0,0013). As vacas que receberam o tratamento ULL tiveram menor consumo de MS, sem afetar a produção de leite comparado às vacas que receberam o tratamento PML+ULL (P≤0,05). Não houve interação para os componentes do leite obtido, exceto para o extrato seco desengordurado (P=0,0086), as vacas que receberam o tratamento CTL tiveram os maiores teores de ESD no leite comparada as vacas que receberam o tratamento ULL (P=0,0002) e esses teores mais elevados foram iguais aos das vacas que receberam o tratamento PML (P=0,066). Apesar de não ter havido interação, as vacas que receberam os tratamentos sem ULL tiveram maiores teores de proteína, caseína e sólidos totais no leite comparado às vacas que receberam os tratamentos com ULL (P≤0,05). Não houve interação entre PML e ULL para eficiência na produção de leite (P=0,0694), porém a eficiência na produção de leite corrigida para energia foi maior para as vacas que receberam tratamentos com ULL do que as vacas que receberam os tratamentos sem ULL (P≤0,05). Não houve interação entre PML e ULL para os parâmetros sanguíneos analisados (P>0,05) exceto para o teor de K (P=0,0098). Os teores de hematócrito e hemoglobina foram maiores nas vacas que receberam tratamento com ULL comparado aos valores encontrados nas vacas que receberam tratamento sem ULL (P≤0,05), não afetando a homeostasia. O teor de N retido (balanço de N) foi maior para os animais que receberam o tratamento CTL devido a diferença encontradas no teor de N ingerido e excretado nas fezes (P≤0,05). A eficiência do uso de N aumentou com a substituição do farelo de soja por PML, ULL ou ambos (P≤0,05). A substituição do farelo de soja pela PML, ULL ou por ambos em dietas de vacas leiteiras, teve efeitos sobre o consumo de MS, a produção e composição do leite, bem como na ingestão de N, secreção de N no leite, excreção fecal de N e no balanço nitrogenado. De maneira geral, é possível fazer a substituição do farelo de soja pela PML, ULL ou ambos, sem afetar negativamente os parâmetros de produtividade. Os resultados obtidos foram similares ao tratamento CTL em relação ao consumo, produção de leite e balanço nitrogenado permitindo espaço para a inclusão de alimentos mais baratos e garantindo melhor fornecimento de energia. / This study was conducted to evaluate the effects of partial replacement in the diet of dairy cows of soybean meal by a yeast-derived microbial protein source (YMP) or a combination of YMP with a slow release urea (SRU), on dry matter intake, milk production and composition, blood parameters and nitrogen balance. Eight first lactation cows were distributed randomly into two 4x4 Latin squares, in a 2x2 factorial arrangement of treatments, with four periods with 28 days each one (21 days of adaptation and 7 days of collection). The base diet had 49% roughage (47% corn silage and 2% Tifton hay) and 51% concentrate, with an average of 16.8% crude protein and 2.5 Mcal/kg dry matter (DM). In the control diet (CTL = without YMP and without SRU) soybean meal was the main protein source and in the three other diets the soybean meal was partially replaced by 15 g/kg DM of YMP or 7.5 g/kg DM SRU, or both, 15 g/kg DM YMP plus 7.5 g/kg DM SRU. There was an interaction between YMP and SRU for DM intake (P=0.0003) and milk production (P=0.0013). The cows that received SRU treatment had lower DM intake not affecting milk production compared to cows that received the YMP+SRU treatment and differences among treatments for DM intake and milk production (P≤0,05). There was no interaction of the milk components, except for nonfat dry milk (P=0.0086), the cows that received CTL treatment had the highest nonfat dry milk compared to cows received the SRU treatment (P=0.0002) and these higher levels were equal to those of cows received the YMP treatment (P=0.066). Although there was no interaction, the cows that received the treatments without SRU had higher protein, casein and total solids in milk compared to cows received treatments SRU (P≤0.05). There was no interaction between YMP and SRU for milk production efficiency (P=0.0694), but efficiency in the milk production corrected for energy was greater for cows received SRU treatments than cows received treatments without SRU (P≤0.05). There was no interaction between YMP and SRU for the analyzed blood parameters (P>0.05) except for the K content (P=0.0098). The levels of hematocrit and hemoglobin were higher in cows that received treatment with SRU compared to cows that received treatment without SRU (P≤0.05), not affecting homeostasis. The nitrogen retained (N balance) was higher for animals that received CTL treatment due to differences in N content ingested and excreted in the feces (P≤0.05). The efficiency of use of N increased with the substitution of soybean meal for PML, ULL or both (P≤0.05). The substitution of soybean meal by YMP, SRU or both in dairy cow diets, had effects on DM intake, milk yield and composition, as well as N intake, milk secretion of N, fecal excretion of N and nitrogen balance. In general, it is possible to replace soybean meal for PML, ULL or both, without impacting negatively the production performance parameters. The results obtained in the CTL treatment in the consumption of dry matter, production of milk and nitrogen balance allowing the inclusion of cheaper feeds allowing for better energy supply.
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Analýza kaseinů kravského mléka kapilární elektroforézou / Analysis of cow milk caseins by capillary electrophoresisDvořáková, Irena January 2010 (has links)
The diploma thesis is dealing with the determination of caseins in lyophilised samples of milk using the method of capillary electrophoresis (CE). This method was optimised and verified by Ivana Micikova in her diploma thesis in 2009. The theoretical part of the diploma thesis gives information about the chemical compound of cow's milk. Caseins and their usage in the food and non-food industries are described in a separate unit. Impact of both the nutritional and non-nutritional factors on the composition of the milk is discussed further. The description and the principles of the CE and a list of the methods of CE used in the last several years are stated at the end of this part. The experimental part is focused on the preparation of the solutions, process of casein isolation and its analysis. It summarises the setting of the experiment, sampling and sample processing and the composition of the feeding mixtures. The diploma thesis has arisen on the basis of the cooperation of the Institute of Food Science and Biotechnology, the Faculty of Chemistry, Brno University of Technology and the Research Institute for Cattle Breeding, Ltd., Department of Animal Nutrition Physiology in Pohorelice.
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Einfluss des Absetzverfahrens und anderer systematischer Effekte auf die Milchleistung und ausgewählte Eutergesundheitsparameter einer Herde Ostfriesischer MilchschafeBauer, Almut 04 December 2012 (has links)
In der vorliegenden Arbeit wurde die Bedeutung des Einflusses von Laktationsnummer, Laktationsstadium, Körperkondition und Absetzverfahren auf Merkmale der Milchleistung und Eutergesundheit einer Herde Ostfriesischer Milchschafe untersucht. Die Tiere wurden nach dem Ablammen zufällig einer Früh- bzw. Spätabsetzergruppe zugeordnet (Absetzen der Lämmer 3 bzw. 42 Tage post partum). An insgesamt 40 Terminen wurden über eine vollständige Laktation Vorgemelks-, Hälftenanfangsgemelks- und Einzeltiergemelksproben gewonnen. Das Spektrum der untersuchten Merkmale umfasste die Milchmenge, die Milchinhaltsstoffe (Fett, Eiweiß, Laktose), die klinische Untersuchung des Euters, die somatische Zellzahl, die elektrische Leitfähigkeit und bakteriologische Untersuchungen. Zusätzlich wurden das Körpergewicht und die Körperkondition der Mutterschafe erfasst.
Das durchschnittliche Leistungsniveau der Herde betrug 301±101,3 kg Milch, bei mittleren Milchfett-, Milcheiweiß-, und Laktosegehalten von 5,00, 5,14 bzw. 5,00 % (150-Tageleistung). Die Laktationsnummer hatte keinen signifikanten Effekt auf die Milchleistung. Schafe der Spätabsetzer-Gruppe produzierten im Anschluss an die Säugephase eine um 300 g signifikant höhere Testtagsmilchmenge als Tiere der Frühabsetzer-Gruppe. Das Absetzverfahren hatte keinen nachweisbaren Effekt auf die Milchinhaltsstoffe.
Die Herde wies eine gute Eutergesundheit auf. Der Anteil bakteriologisch positiver Schafmilchproben betrug 28,5 %. Als dominante Erreger wurden in 96,6 % der bakteriologisch positiven Schafmilchproben Koagulasenegative Staphylokokken nachgewiesen. Der Anteil bakteriologisch positiver Euterhälftenbefunde stieg signifikant mit dem Fortschreiten der Laktation und zunehmender Laktationsnummer. Eine Euterinfektion mit Koagulasenegativen Staphylokokken sowie das Verfahren des Spätabsetzens beeinflussten alle drei untersuchten Eutergesundheitsparameter (logarithmierte Zellzahl, elektrische Leitfähigkeit und Laktosegehalt) negativ
(p < 0,001).
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Seasonal Variation of Milk in Central Valley California and the Association of Milk Variation with the Composition and Texture of Low Mositure Part Skim MozzarellaJai, Vaideki 01 December 2014 (has links) (PDF)
The chemical composition of milk (specifically casein, fat, and calcium) is known to affect the quality and functional properties of Mozzarella cheese. Therefore, concentrations of total nitrogen, casein nitrogen, non-casein nitrogen, non-protein nitrogen, true nitrogen, casein nitrogen to total nitrogen ratio, casein nitrogen to true nitrogen ratio, fat, total calcium, total solids, somatic cells, and pH were measured in silo milk samples collected weekly over 18-months from a large dairy plant in Central Valley, California from July 2008 to December 2009 to verify changes and correlate to low moisture part skim Mozzarella (LMPS) characteristics. LMPS mozzarella cheese from the same plant was also collected biweekly during the same period and analyzed five days post manufacture for total nitrogen, water soluble nitrogen, total calcium, water soluble calcium, salt, pH, fat in dry matter and total solids and texture properties (i.e., hardness (g), cohesiveness, springiness, chewiness (g), aggregation index (AGI), and percentage cheese loss during shredding). Significant seasonal variations of total nitrogen, non-protein nitrogen, casein nitrogen, casein nitrogen to total nitrogen ratio, casein nitrogen to true nitrogen ratio, and total calcium in milk were explained using a linear model equivalent to a basic single cosinor model with sine and cosine of week (converted into radians) as predictors. Correlation studies were done between milk composition and cheese composition, milk composition and cheese textural characteristics as well as cheese composition and cheese texture, showing that concentration of total calcium and nitrogen fractions in cheese milk significantly affected the texture and composition of LMPS mozzarella. Also, the cheese total nitrogen, total calcium and water soluble calcium affected the cheese texture. The LMPS Mozzarella that was firmer and more cohesive had less loss during shredding and aggregated to a lesser extent. The milk total nitrogen, non-protein nitrogen, casein nitrogen, casein to total protein ratio, casein to true protein ratio, and total calcium had positive correlation with each other. However, the milk non-casein nitrogen did not significantly correlate with other nitrogen fractions and total calcium of milk. In addition, there was a significant increase of water soluble nitrogen, percent loss in shredding and aggregation index, and a significant decrease of hardness, and chewiness of LMPS Mozzarella ripened at 8.90 C in comparison to the cheese ripened at 3.30 C for 21 days.
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