The thesis deals with the assessment of proportion of fatty acids in milk fat on goat farm and watching the selected proportion of major fatty acids in the selected factors. Sampling took place between 2010 and 2011, were made three taking of milk in a different stage of lactation. Evaluation of fatty acids was carried out both within groups and for major acid alone. The thesis was also included evaluation of quality indicators and yield of goat milk.

Made available in DSpace on 2016-12-08T16:24:21Z (GMT). No. of bitstreams: 1 PGCA15MA156.pdf: 357982 bytes, checksum: aec52a8ee239d86a011dbcaa1ec47830 (MD5) Previous issue date: 2015-02-03 / The trans-10, cis-12 conjugated linoleic acid is known to inhibit fat synthesis in the mammary gland of many animal species. The objective of this study was to analyze the effect of PPARγ on mammary lipogenesis and gene expression, through a specific chemical agonist and its response to trans-10, cis-12 CLA. Twenty four 70 ± 3 days in milk (DIM) and body weight (BW) 60 ± 0.45 kg lactating ewes were randomly assigned to one of the four treatments for 7 days: 1) Control (100 mL/day of sterile saline solution, intravenous); 2) Thiazolidinedione (TZD) (4mg/kg of BW/day in 100 mL of sterile saline solution, intravenously); 3) CLA (27g/d orally-dosed rumen-unprotected 29.9% trans-10, cis-12 CLA); 4) TZD+CLA. Compared to Control, milk fat was 22.3% lower in CLA (P=0.05), tended to be 20.7% lower in TZD+CLA (P=0.06) and did not change in the TZD treatment (P=0.39). The lactose content and milk yield and production of components were not affected by treatments. The protein content was lower in the CLA compared to TZD (P=0.01) and tended to be higher with the TZD compared to Control (P=0.08). In the mammary gland, CLA reduced expression of PPARγ, SREBP1 and SCD1, but TZD did not stimulate the expression of these genes. In adipose tissue, PPARγ expression was not affected by treatments, whereas the SREBP1 had more expression in TZD treatment, CLA and TZD + CLA and the SCD1 had more expression with TZD+CLA, compared to the other treatments. In conclusion, the CLA negatively affected the expression of genes involved in lipid synthesis and the TZD was unable to stimulate gene expression and lipogenesis in mammary gland / O ácido linoleico conjugado trans-10, cis-12 é conhecido por inibir a síntese de gordura na glândula mamária de diversas espécies animais. O objetivo deste estudo foi analisar o efeito do PPARγ sobre a lipogênese mamária e expressão gênica, através de um agonista químico específico e sua resposta ao CLA trans-10, cis-12. Vinte e quatro ovelhas em lactação, com 70 ± 3 dias em lactação (DEL) e peso corporal (PC) de 60 ± 0,45 kg, foram distribuídas aleatoriamente em um dos quatro tratamentos, por 7 dias: 1) Controle (100 mL/dia de solução salina estéril, intravenosa); 2) Tiazolidinediona (TZD) (4mg/kg de PC/dia em 100 mL de solução salina estéril, intravenosa); 3) CLA (27g/dia de CLA desprotegido da bio-hidrogenação ruminal, com 29,9% de trans-10, cis-12, dosado oralmente); 4) TZD+CLA. Comparado ao Controle, a gordura do leite foi 22,3% menor no tratamento CLA (P=0,05), tendeu a ser 20,7% menor no tratamento TZD+CLA (P=0,06) e o TZD não afetou o teor de gordura (P=0,39). O teor de lactose e as produções de leite e dos componentes não foram afetados pelos tratamentos. O teor de proteína foi menor no CLA comparado ao TZD (P=0,01) e tendeu a ser maior com o TZD comparado ao Controle (P=0,08). Na glândula mamária, o CLA reduziu a expressão do PPARγ, SREBP1 e SCD1, porém o TZD não estimulou a expressão destes. No tecido adiposo, a expressão do PPARγ não foi afetada pelos tratamentos, enquanto que o SREBP1 teve maior expressão nos tratamentos TZD, CLA E TZD+CLA e a SCD1 teve maior expressão com TZD+CLA, comparada aos demais tratamentos. Concluindo, o CLA afetou negativamente a expressão dos genes envolvidos na síntese de lipídeos e o TZD não estimulou a expressão gênica e lipogênese na glândula mamária

The effect of exogenous unsaturated fatty acids on cellular fatty acid biosynthesis in mammary cells was examined. Under normal situations, even though the diet of a dairy cow contains considerable amounts of unsaturated fatty acids, viz. oleic acid (18:1) and linoleic acid (18:2), the major 18-carbon fatty acid that enters the circulation post-ruminally for delivery to the mammary gland is saturated fatty acid, viz. stearic acid (18:0). This is due to extensive ruminal biohydrogenation of unsaturated fatty acids. Studies have indicated that saturated fatty acids such as 18:0 are enhancers and that certain unsaturated fatty acids are inhibitors of de novo fatty acid synthesis in tissues such as the liver and adipose tissue. The present study investigated the effect of cis and trans isomers of 18:1 and 18:2 on de novo fatty acid synthesis and desaturation in mouse and bovine mammary epithelial cell cultures, and compared it with the effect caused by 18:0. In the first experiment 12.5, 25, 50 or 100 micromoles stearic acid (SA), oleic acid (OA), elaidic acid (EA), trans-vaccenic acid (TVA), linoleic acid (LA) or conjugated linoleic acid (CLA) were supplemented in the media of mouse mammary epithelial (MME) cells that were grown to confluence in Dulbecco's modified Eagle's medium (DMEM). As indicated by cellular palmitic acid (16:0) content and fatty acid synthetase (FAS) activity, when compared with SA all unsaturated fatty acid treatments inhibited de novo fatty acid synthesis in MME cells. In addition, OA at all concentrations and LA and CLA at 50 and 100 micromoles inhibited cellular stearoyl-CoA desaturase (SCD) activity and mRNA abundance. However, EA and TVA, when compared with SA, enhanced SCD activity and mRNA abundance at 12.5 and 25 micromoles. In the second experiment 25, 50 or 100 micromoles SA, OA, TVA, LA or CLA were supplemented in the media of bovine mammary epithelial cells that were grown to confluence in DMEM. As indicated by cellular 16:0 content, acetyl-CoA carboxylase (ACC) activity and FAS activity, treatment with the unsaturated fatty acids inhibited de novo fatty acid synthesis at all concentrations, when compared with SA. Unsaturated fatty acid treatments also reduced the abundance of ACC and FAS mRNA in the cells. When compared with SA at all treatment-concentrations, OA and LA inhibited whereas TVA and CLA enhanced cellular SCD activity and mRNA abundance in the bovine cells. In both cell types, CLA and TVA appeared to be the most potent inhibitors of saturated fatty acid biosynthesis. / Ph. D.

Orientadores: Mirna Lucia Gigante, Rafael Jimenez-Flores / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-09-11T21:12:34Z (GMT). No. of bitstreams: 1 Costa_MarceladeRezende_D.pdf: 1269005 bytes, checksum: be9b972dd7766eba5cc6917dd666c5f0 (MD5) Previous issue date: 2008 / Resumo: O leitelho de soro é um subproduto do processamento de manteiga a partir do creme de soro. Esse subproduto lácteo contém fragmentos da membrana do glóbulo de gordura do leite (MGGL), material rico em componentes com funções nutricionais e efeitos benéficos à saúde, destacando-se os fosfolipídeos. O objetivo desse trabalho foi obter um ingrediente lácteo enriquecido em fosfolipídeos da MGGL a partir do leitelho de soro utilizando a associação de duas tecnologias de fracionamento: ultrafiltração e extração com fluido supercritico (EFS). O leitelho de soro foi submetido à ultrafiltração e a cinco diafiltrações a 25 °C e o retentado obtido foi seco em spray-dryer, obtendo-se o leitelho de soro em pó (LSP), o qual foi submetido a três ciclos de extração a 50 °C com dióxido de carb ono supercrítico. As matériasprimas, produtos finais e uma amostra comercial de leitelho tradicional em pó (LTP) foram analisados quanto a sua composição centesimal, teor de fosfolipídeos, perfis lipídico e protéico. Os leitelhos de soro em pó, submetidos ou não à EFS, e o LTP foram avaliados quanto ao tamanho de partículas e suas propriedades funcionais (solubilidade protéica e capacidade emulsificante) em pH 5 e 7. A filtração em membrana reduziu em 74 e 96% os teores de lactose e cinzas no retentado e aumentou os de proteínas, lipídeos e fosfolipídeos em 91, 190 e 300%, respectivamente. A EFS reduziu em 55,4% o teor de lipídeos, removendo exclusivamente lipídeos apolares, com isso aumentou em 71% o teor de fosfolipídeos no leitelho de soro em pó, resultando em um produto com 73% de proteínas, 21% de lipídeos, 3% de lactose, 3% de cinzas e 12% de fosfolipídeos, em base seca. As propriedades funcionais dos leitelhos de soro em pó, submetidos à extração supercrítica (LSP-EFS) ou não (LSP), foram pouco ou não afetadas pelo pH, enquanto o abaixamento de pH prejudicou as características do LTP, devido ao alto teor de caseínas nesse tipo de pó em relação aos de leitelhos de soro. Os pós em soluções (5% de proteína) apresentaram de 69 a 84% de suas partículas, em % volumétrica, entre 10 e 100 µm. A solução de LTP em pH 5 foi a que apresentou a maior quantidade de partículas acima de 100 µm. LSP e LSP-EFS apresentaram solubilidades protéicas em torno de 86 e 84%, respectivamente, independente do pH. O LTP teve a solubilidade reduzida de 86 para 73% quando o pH foi reduzido de 7 para 5. Em pH 7, as emulsões (20% óleo de canola, 1% proteína) de LSP e de LSPEFS apresentaram melhor estabilidade (IC de 0,2 e 0,4%, respectivamente) do a emulsão de LTP (IC de 3,0%). Em pH 5, a emulsão de LSP-EFS foi a que mostrou melhor estabilidade, apresentando um IC de 7%, valor cerca de 82% menor do que os das emulsões de LSP e LTP. Os leitelhos de soro em pó obtidos podem ser considerados ingredientes com características promissoras, associando propriedades tecnológicas, especialmente para uso em alimentos de baixo pH, e conteúdo de compostos potencialmente benéficos à saúde, principalmente após o tratamento com extração supercrítica / Abstract: OBTENTION OF DAIRY INGREDIENT ENRICHED IN POLAR LIPIDS FROM WHEY BUTTERMILK. Whey buttermilk is a by-product from the whey cream processing into butter. This dairy by-product contains milk fat globule membrane (MFGM) fragments, a material rich in components with nutritional functions and beneficial health effects, especially phospholipids. The objective of this research was obtaining a dairy ingredient enriched in MFGM phospholipids from whey buttermilk using the association of two fractionation technologies: ultrafiltration and supercritical fluid extraction (SFE). Whey buttermilk was submitted to ultrafiltration and five diafiltrations at 25 °C. The retentate was spray-dried and later s ubmitted to three cycles of extraction at 50 °C with supercritical carbon dioxi de. Raw materials, final products and a commercial traditional buttermilk powder sample (BMP) were analyzed for gross composition, lipid and protein profiles, and phospholipids content. Whey buttermilk powders, before and after the SFE, and the BMP had particle size and some functional properties (protein solubility and emulsifying capacity) evaluated in pH 5 and 7. Membrane filtration reduced in 74 and 96% lactose and ash contents in the retentate and increased proteins, lipids and phospholipids in 91, 190 and 300%, respectively. SFE reduced in 55.4% the lipids content, removing exclusively non-polar lipids, while increased in 71% the phospholipids content in whey buttermilk powder, resulting in a product with 73% of proteins, 21% of lipids, 3% of lactose, 3% of ash and 12% of phospholipids, in dry matter basis. Functional properties of the whey buttermilk powders, treated (WBP-SFE) or not through SFE (WBP), were little or not affected by pH, while dropping the pH impaired the BMP features, due the high casein content in this type of powder in relation to the ones from whey buttermilk. The powders in solutions (5% protein) presented from 69 to 84% of the particles, in volume%, between 10 and 100 µm. The BMP solution in pH 5 was the one with the biggest amount of particles above 100 µm. WBP and WBP-SFE showed protein solubilities around 86 and 84%, respectively, independent of pH. BMP had the solubility reduced from 86 to 73% when pH was reduced from 7 to 5. In pH 7, the emulsions (20% canola oil, 1% protein) of the WBP and the WBP showed better stability (CI of 0.2 and 0.4%, respectively) than the BMP emulsion (CI of 3.0%). When in pH 5, WBP-SFE emulsion had the best stability, presenting CI of 7%, value about 82% smaller than the ones of WBP and BMP emulsions. Whey buttermilk powders obtained in this work can be considered ingredients with promising features, combining technological properties, especially for use in low pH foods, and content of components with potential health benefits, mainly after the supercritical extraction treatment / Doutorado / Doutor em Tecnologia de Alimentos

O objetivo do presente trabalho foi avaliar o efeito da suplementação com óleo de girassol, selênio e vitamina E em vacas lactantes, com base no perfil de ácidos graxos e estabilidade oxidativa da gordura do leite, além da aceitabilidade do produto pelos consumidores. Para tal, 32 vacas da raça Jersey em início de lactação foram distribuídas aleatoriamente entre os seguintes tratamentos dietéticos: C) controle; O) inclusão de 4% de óleo de girassol (% na MS); SE) inclusão de 3.000 UI de vitamina E/d + 3,5 mg de selênio/kg de MS; OSE) inclusão de 4% de óleo de girassol + 3.000 UI de vitamina E/d + 3,5 mg de selênio/kg de MS. Foram realizadas análises do perfil de ácidos graxos, TBARS e índice de peróxidos. Para caracterização sensorial do produto final, foram empregados os testes de aceitabilidade e diferença do controle. Os tratamentos dietéticos não influenciaram o desempenho produtivo e a composição do leite (P>0,05). Os animais suplementados com óleo de girassol produziram leite com elevado teor de ácido vacênico (P<0,0001) e ácido esteárico (P<0,05). O leite dos animais que receberam óleo de girassol apresentou menor concentração de C10:0, C12:0 e C14:0 (P<0,05). A inclusão dos antioxidantes na dieta não conseguiu retardar a oxidação do leite (P>0,05). Os resultados da análise sensorial mostraram que os avaliadores conseguiram identificar diferenças na cor das amostras de leite dos grupos tratados e do controle, em relação a um padrão conhecido (P<0,01), obtendo este a maior nota. Concluiu-se que a inclusão de óleo de girassol na dieta de vacas leiteiras resulta em mudanças no perfil de ácidos graxos do leite, com aumento de CLA, sem alterar a susceptibilidade da gordura à oxidação. A suplementação dietética com vitamina E e selênio não representou nenhum benefício à estabilidade oxidativa do leite. Além disso, as mínimas diferenças observadas pelos consumidores, referente às características organolépticas do leite frente a uma amostra padrão indicam que o produto final teria boa aceitação no mercado. / The objective of this study was to evaluate the effect of supplementation with sunflower oil, vitamin E and selenium in lactating cows based on fatty acid profile and oxidative stability of milk fat in addition to the acceptability of the final product by consumers. For this, 32 Jersey cows in early lactation were randomly distributed among the following dietary treatments: C) control; O) inclusion of 4% sunflower oil (% DM); SE) inclusion of 3,000 IU vitamin E/d + 3.5 mg selenium/kg DM; OSE) inclusion of 4% sunflower oil + 3,000 IU vitamin E/d + 3.5 mg selenium/kg DM. Analysis of the milk fatty acid profile, TBARS and peroxide value were performed. For sensory characteristics of the final product, acceptability testing and difference from the control test were conducted. Dietary treatment did not affect cow\'s performance and milk composition (P>0.05). The animals supplemented with sunflower oil produced milk with higher vaccenic acid (P<0.0001) and stearic acid (P<0.05) content. The milk of animals receiving sunflower oil showed the lowest concentrations of C10:0, C12:0 and C14:0 (P<0.05). The inclusion of antioxidants in the diet failed to retard the oxidation of the milk (P>0.05). The results of sensory analysis showed that the evaluators were able to identify differences in the color of the milk samples from control and treated groups, compared to a known standard (P<0.01), to which it was given the highest score. It was concluded that the sunflower oil inclusion in the diet of dairy cows results in changes in milk fatty acids profile, increasing CLA content, without altering the fat susceptibility to oxidation. Dietary supplementation with vitamin E and selenium did not represent any benefit to oxidative stability of milk. Furthermore, the minimum differences observed by consumers, regarding the organoleptic characteristics of milk compared to a known standard indicates that the final product would have good market acceptance.

A formulação de dietas para ruminantes pode alterar o perfil de ácidos do leite, potencializando o valor nutritivo e nutracêutico do mesmo. Estas alterações podem, no entanto, aumentar a susceptibilidade do leite à oxidação, perdendo qualidade em sabor e tempo de prateleira. O objetivo deste trabalho consistiu em avaliar o efeito do fornecimento de dieta com alto teor de soja integral extrusada, associada ou não à suplementação com selênio orgânico, sobre a produção, a composição, a concentração de CLA, o perfil de ácidos graxos e a estabilidade oxidativa do leite. Vinte e quatro vacas holandesas foram agrupadas em três blocos, de acordo com o número de lactações e alimentadas com dieta total contendo 56% de volumoso e 44% de concentrado. Os animais foram distribuídos aleatoriamente nos seguintes tratamentos: A) dieta controle, B) dieta contendo 21% de soja extrusada e C) dieta contendo 21% de soja extrusada + 5 mg de selênio orgânico. As dietas foram balanceadas para obtenção dos mesmos níveis de energia e proteína. O fornecimento de soja extrusada não afetou o consumo de matéria seca, o peso vivo dos animais e a produção de leite. As vacas alimentadas com soja extrusada produziram leite com menor (P<0,01) porcentagem de gordura, menor (P<0,01) concentração de ácidos graxos de cadeias curta e média e maior (P<0,01) concentração de ácidos graxos de cadeia longa, quando comparadas às vacas alimentadas com a dieta controle. Com relação ao teor de saturação, produziram leite com menor (P<0,01) concentração de ácidos graxos saturados e maior (P<0,01) concentração de ácidos graxos poliinsaturados e de ácido linoléico conjugado (CLA). A concentração de colesterol total foi maior (P<0,01) no soro sanguíneo das vacas alimentadas com soja extrusada, quando comparado ao controle. A suplementação com selênio aumentou (P<0,05) significativamente a concentração do mineral no leite e retardou a oxidação do mesmo, avaliada pelo índice de peróxido (P<0,01). O fornecimento da dieta contendo 21% de soja alterou o perfil de ácidos graxos do leite, diminuindo a concentração de ácidos graxos saturados e aumentando a concentração de ácidos graxos poliinsaturados e ácido linoléico conjugado, no entanto, produziu um leite mais susceptível à oxidação. O enriquecimento do leite com selênio conseguiu minimizar este efeito influenciando positivamente a estabilidade do leite. / The manipulation of ruminant diet can modify the fatty acid profiles increasing its nutritive and therapeutic value. However, this change in fatty acid composition can increase milk oxidation and can affect its flavor and shelf life. The objective of this study was to evaluate the effect of extruded soybean diet and organic selenium supplementation on milk composition, CLA content, fatty acid profiles and oxidative stability of milk. Twenty four Holstein cows were grouped into three blocks according to number of parturition and were fed diets containing 56% forage and 44% concentrate. The animals were allocated to three treatments: A) control diet, B) 21% extruded soybean diet and C) 21% extruded soybean diet + 5 mg of organic selenium. The diets were formulated to provide the same energy and protein levels. The extruded soybean did not affect the dry matter intake, body weight and milk production. The cows fed extruded soybean diet produced milk with lower (P<0,01) concentration of fat, lower (P<0,01) concentration of short and medium chain fatty acids and higher (P<0,01) concentration of long chain fatty acids when compared to control group. Regarding to saturation level, those animals produced milk with lower (P<0,01) concentration of saturated fatty acids and higher (P<0,01) concentration of polyunsaturated fatty acids and CLA content. The serum concentration of cholesterol was higher (P<0,01) for treatments containing extruded soybean when compared to control. The organic selenium supplementation increased (P<0,05) milk selenium concentration and delayed milk oxidation measured by peroxide value (P<0,01). The inclusion of 21% of extruded soybean in dairy cattle diet resulted in production of milk fat with modified fatty acid profile with lower concentration of saturated fatty acids and higher concentration of polyunsaturated fatty acids and CLA content. However the milk fat was more susceptible to oxidation. The organic selenium supplementation was efficient to overcome this problem and therefore could maintain the stability of milk.

A formulação de dietas para ruminantes pode alterar o perfil de ácidos do leite, potencializando o valor nutritivo e nutracêutico do mesmo. Estas alterações podem, no entanto, aumentar a susceptibilidade do leite à oxidação, perdendo qualidade em sabor e tempo de prateleira. O objetivo deste trabalho consistiu em avaliar o efeito do fornecimento de dieta com alto teor de soja integral extrusada, associada ou não à suplementação com selênio orgânico, sobre a produção, a composição, a concentração de CLA, o perfil de ácidos graxos e a estabilidade oxidativa do leite. Vinte e quatro vacas holandesas foram agrupadas em três blocos, de acordo com o número de lactações e alimentadas com dieta total contendo 56% de volumoso e 44% de concentrado. Os animais foram distribuídos aleatoriamente nos seguintes tratamentos: A) dieta controle, B) dieta contendo 21% de soja extrusada e C) dieta contendo 21% de soja extrusada + 5 mg de selênio orgânico. As dietas foram balanceadas para obtenção dos mesmos níveis de energia e proteína. O fornecimento de soja extrusada não afetou o consumo de matéria seca, o peso vivo dos animais e a produção de leite. As vacas alimentadas com soja extrusada produziram leite com menor (P<0,01) porcentagem de gordura, menor (P<0,01) concentração de ácidos graxos de cadeias curta e média e maior (P<0,01) concentração de ácidos graxos de cadeia longa, quando comparadas às vacas alimentadas com a dieta controle. Com relação ao teor de saturação, produziram leite com menor (P<0,01) concentração de ácidos graxos saturados e maior (P<0,01) concentração de ácidos graxos poliinsaturados e de ácido linoléico conjugado (CLA). A concentração de colesterol total foi maior (P<0,01) no soro sanguíneo das vacas alimentadas com soja extrusada, quando comparado ao controle. A suplementação com selênio aumentou (P<0,05) significativamente a concentração do mineral no leite e retardou a oxidação do mesmo, avaliada pelo índice de peróxido (P<0,01). O fornecimento da dieta contendo 21% de soja alterou o perfil de ácidos graxos do leite, diminuindo a concentração de ácidos graxos saturados e aumentando a concentração de ácidos graxos poliinsaturados e ácido linoléico conjugado, no entanto, produziu um leite mais susceptível à oxidação. O enriquecimento do leite com selênio conseguiu minimizar este efeito influenciando positivamente a estabilidade do leite. / The manipulation of ruminant diet can modify the fatty acid profiles increasing its nutritive and therapeutic value. However, this change in fatty acid composition can increase milk oxidation and can affect its flavor and shelf life. The objective of this study was to evaluate the effect of extruded soybean diet and organic selenium supplementation on milk composition, CLA content, fatty acid profiles and oxidative stability of milk. Twenty four Holstein cows were grouped into three blocks according to number of parturition and were fed diets containing 56% forage and 44% concentrate. The animals were allocated to three treatments: A) control diet, B) 21% extruded soybean diet and C) 21% extruded soybean diet + 5 mg of organic selenium. The diets were formulated to provide the same energy and protein levels. The extruded soybean did not affect the dry matter intake, body weight and milk production. The cows fed extruded soybean diet produced milk with lower (P<0,01) concentration of fat, lower (P<0,01) concentration of short and medium chain fatty acids and higher (P<0,01) concentration of long chain fatty acids when compared to control group. Regarding to saturation level, those animals produced milk with lower (P<0,01) concentration of saturated fatty acids and higher (P<0,01) concentration of polyunsaturated fatty acids and CLA content. The serum concentration of cholesterol was higher (P<0,01) for treatments containing extruded soybean when compared to control. The organic selenium supplementation increased (P<0,05) milk selenium concentration and delayed milk oxidation measured by peroxide value (P<0,01). The inclusion of 21% of extruded soybean in dairy cattle diet resulted in production of milk fat with modified fatty acid profile with lower concentration of saturated fatty acids and higher concentration of polyunsaturated fatty acids and CLA content. However the milk fat was more susceptible to oxidation. The organic selenium supplementation was efficient to overcome this problem and therefore could maintain the stability of milk.

The study was carried out at the Laboratory of Animal Breeding Value Establishment and Selection of Lithuanian Veterinary Academy in the time of postgraduate studies from 2003 to 2005. During the last seven years Lithuanian red and red-and-white controlled dairy cattle breeds average yield increased 41.7%, milk fat production - 50.9%, milk proteins production – 46.1%. Between milk fat and milk proteins was found medium positive correlation coefficient (rp =0.36-0.56; p<0.01), which show milk fat increasing has positive effect to milk proteins increasing. Correlation coefficient between milk production and milk fat, milk proteins is very high (rp =0.87-0.96; p<0.01). The analysis of Variance showed the breed influence on reproductive traits of cow to be statistically reliable (p<0.001). The breed had the greatest influence on cows age during calving. The influence of bulls line on many traits of cows exterior is statistically reliable (p<0,001).

Tiriamasis darbas atliktas Lietuvos sveikatos ir mokslų universitete ir Lietuvos pieninių galvijų fermose 2011 – 2014 metais. Darbą sudaro 49 puslapių, 12 lentelių, 8 paveikslai. Baigiamojo darbo tikslas: įvertinti somatinių ląstelių skaičių karvių piene, išnalizuoti jų kitimo priežastis, nustatyti jų ryšį su produktyvumu. Baigiamojo darbo uždaviniai: Įvertinti somatinių ląstelių skaičių karvių piene, karvių pieno kiekio ir sudėties (riebumo, baltymingumo, laktozės) rodiklius, negenetinių veiksnių įtaką karvių produktyvumui ir SLS piene, genetinių veiksnių įtaką karvių produktyvumui ir SLS piene. Ištirtos 9 veislių karvės, trijuose skirtinguose ūkiuose. Iš viso buvo ištirtos 726 karvės Tyrimo metu buvo nagrinėta genetinių ir negenetinių veiksnių įtaka karvių pieno somatinių ląstelių skaičiui (tūkst./cm3), pieningumui (kg), riebumui (proc.), baltymingumui (proc.) bei laktozės kiekiui (proc.). Įvertinus tirtų karvių SLS piene nustatyta, kad vidutinis SLS kiekis piene buvo 220,65±10,477 tūkst./cm3. 43,09 proc. karvių piene SLS buvo mažesnis nei 100 tūkst./cm3, 68,92 proc. – svyravo nuo 100 iki 200 tūkst./cm3, 31,08 proc. - viršijo 200 tūkst./cm3, rodo, kad trečdalis tirtų karvių sirgo tešmens uždegimu. Įvertinus tirtų karvių pieno kiekio ir sudėties rodiklius nustatyta, kad vidutinis tirtų karvių pieningumas 19,78±0,192 kg, pieno riebumas buvo 4,61±0,022 proc., baltymingumas – 3,62±0,011 proc., laktozės kiekis piene - 4,50±0,005 proc. Didėjant karvių produktyvumui SLS piene... [toliau žr. visą tekstą] / Place of research: Lithuanian University of Health Sciences and Lithuanian farms of dairy cattle. The research work was accomplished in 2011 – 2014 years of studies. Volume of the research work – 49, 12 tables, 8 pictures. Goal of work: to evaluate somatic cells count in cows’ milk, to analyse their causes of changes and to determine their relationship with productivity. Goal of thesis: to evaluate the somatic cells count in cows’ milk, to determine milk yield and composition (fat, protein, lactose). The analysis is based on 726 dairy cows from different breeds (9 breeds) in three farms. During the study some data have been analysed influence of the genetic and non–genetic factors such as somatic cell count (SCC) in milk (thousand./cm3), milk yield (kg), milk fat (%) and protein (%) milk lactose content (%) and cow origin data. The estimation of somatic cells count in cows’ milk shows that average of SCC was 220.65±10.477 thousand/cm3. The 43.09 percent of cows’ SCC in milk was less than 100 thousand/cm3, 68.92 percent – ranged from 100 to 200 thousand/cm3 and 31.08 percent had more than 200 thousand/cm3. The evaluation of cows’ milk yield and composition traits showed that the average of cows’ milk yield was 19.78 ±0.192 kg, milk fat – 4.61 ±0.022 percent, the amount of protein – 3.62 ±0.011 percent, lactose content of milk – 4.50 ±0.005 percent. Increase of cows’ milk production, increased and SCC in milk. The statistical analysis of the data showed that non–genetic factors... [to full text]

The objectives of the present study were to: 1) describe the gross chemical milk composition of the New Zealand sea lion (NZSLs), Phocarctos hookeri, in early lactation; 2) validate an analytical method for sea lion milk composition; 3) investigate a series of temporal, individual and dietary factors that influence the milk composition of the NZSL and; 4) investigate the temporal and spatial differences in the fatty acids signatures of sea lion milk. A comprehensive literature review revealed that data on milk composition in otariid species is either missing or limited, that to be able to fully describe their milk composition extensive sampling was required and that the temporal, maternal and offspring factors that influence milk composition in pinnipeds are poorly understood. The review identified that considerable work has been conducted to infer diet via the application of fatty acids signature analysis of milk and blubber. There are many factors (i.e. metabolism, de novo synthesis and endogenous sources) that contribute to the differences in fatty acid composition between the diet and milk or blubber. Milk samples from NZSL were used to test whether a new method would give similar results as the standard methods of milk analysis. Agreement between analytical methods for milk components was assessed using different measures of statistical fitness and the results indicated that the new method was comparable to the standard methods and applicable to the milk of sea lions, pinnipeds and to ecological studies of lactation. Milk from NZSLs was collected over a period of seven years (1997, 1999 to 2003, and 2005) in early lactation to describe the composition of milk of NZSL and to test for differences between years. The results indicated that: i) the milk protein concentration was comparable to other species of pinnipeds; ii) the milk fat concentration and the milk energy content of NZSL is the lowest reported for otariids in early lactation; however iii) the milk fat concentration was significantly different between years. These results suggested that the milk composition of NZSLs was influenced by annual changes in the environment; however, there may be other unidentified factors. Month, maternal body condition, age, body weight and length, offspring sex and age, and attendance pattern were compared with milk components. The results identified that month, maternal body condition and age significantly affected milk fat concentration. These results and the fact that maternal body condition varied significantly between years and mothers nursing male pups had lower body condition and produced milk lower in energy content suggested that local food resources along with other unidentified factors have an effect on the reproductive success of NZSLs. To test whether the fatty acid signature analysis (FASA) of lipid rich tissues (milk, blubber and serum) of otariids could be used to infer diet a mixture of vegetable oil (with distinctive fatty acid signature) was fed to 24 lactating NZSL and tissue samples were collected at different time intervals. Significant increases in the concentration of specific fatty acids in serum and milk were observed with peaks within 12hrs and 24hrs respectively of ingestion. Concentrations in milk remained elevated for up to 72hrs and there were differential rates of incorporation into milk. These findings confirm the potential of FASA to infer the composition of the diet. The variation in milk fatty acid signatures from lactating NZSL from four years (1997, 2003, 2004 and 2005) of sampling were measured in order to test whether differences occurred between years. Fatty acids signatures from five potential prey species including the commercially important arrow squid were incorporated into the analysis to associate the changes in milk fatty acids with a shift in prey choice. The results indicated that milk fatty acid signatures were different in 1997 and 2003; however, it was not possible to relate these differences to the five prey species. The variability in the annual arrow squid catch data suggested that local food resources around the Auckland Islands may also be variable. In conclusion, the milk produced by the NZSL has the lowest concentration of fat and energy in early lactation reported for any otariid species. The main factors that contributed to changes in milk quality were stage of lactation, year and maternal body condition. The yearly variation in the quality of milk appears to be a result of their lactation strategy or to variable local food conditions that also affect maternal body condition. Therefore monitoring the annual milk quality may be a means to monitor the health of a pinniped population and potential management tool for pinniped species. This thesis has shown that annual changes in the diet of NZSL can be assessed with milk fatty acid signatures.