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Four studies were conducted to investigate some factors affecting milk fatty acid composition of dairy ewes. The first study was performed to determine the influence of freezing temperatures and storage time on ovine milk composition and cheese making. The other three experiments were conducted to examine the effects of dietary added fats with different profiles of fatty acids from canola, sunflower and flaxseeds on animal performance, nutrient utilization, milk yield and cheese making. The main emphasis was on fatty acid composition, particularly CLA and Omega-3 fatty acids, in milk and cheese. Results showed that: (1) feeding up to 8% of canola, sunflower and flaxseed had no adverse effects on dry matter intake and total tract digestibilities of dry matter, neutral detergent fiber, acid detergent fiber and crude protein, while the digestibilities of fatty acids and gross energy were increased with oilseed supplementation; (2) feeding flaxseed to lactating ewes up to 260g/ewe/d increased milk yield by up to 8.4%, and fat content by up to 14.3% without adversely affecting other milk components or cheese yield and composition; (3) Oilseed supplementation increased milk concentrations of long-chain and unsaturated fatty acids in the expenses of short-chain, medium-chain and saturated fatty acids. The concentrations of CLA and Omega-3 fatty acids were also increased by oilseed supplementation; (4) the manipulated fatty acids profiles can be reflected in cheese; (5) good quality cheese can be produced from ovine milk frozen at -15°C and -25°C for up to 6 months without influencing cheese content of fat and protein and fatty acid composition. / In conclusion, ovine milk with nutritionally healthy characteristics can be produced by feeding ewes diets with oilseeds, and freezing storage of milk for up to 6 months at -15°C or -25°C does not significantly affects milk composition including fatty acid composition. The characteristics of milk can be reflected in cheese.

Graduation date: 1995

In Mediterranean countries, sheep and goat’s milk production has traditionally been destined for the manufacture of cheese, often as raw milk. Cheese quality is closely related to milk composition but also to hygienic aspects such as somatic cell count, bacteriology or presence of antibiotic residues, currently regulated by European legislation. The implications of the presence of antibiotic residues in milk as a result of veterinary treatments include negative effects on consumer’s health such as allergies or antibiotic resistance and problems on the manufacturing processes of fermented products. For the screening of milk samples for antimicrobial residues, there are various methods available, microbial inhibitor tests and assays based on specific receptors, both widely used, especially in farms, the dairy industry and control laboratories. Screening methods have been validated for the use in raw milk from cows, but information on the performance of these tests in sheep and goat’s milk is rather limited. The aim of this study was to evaluate the performance of some microbial and receptor-binding screening tests to detect antibiotics in sheep and goat’s milk according to Commission Decision 2002/657/EC to determine their suitability to monitor the presence of antibiotic residues in milk and establish the most convenient analytical strategy in Spain. The Detection capability (CCβ) of microbial screening tests, the BRT MRL, the Delvotest MCS SP-NT, the Delvotest MCS Accelerator and the Eclipse 100, was at or below the maximum residue limits (MRLs) for most beta-lactam antibiotics assessed and other non-beta-lactam drugs such as neomycin, tylosin, sulfadiazine and sulfadimethoxine. However, they were less sensitive in the detection of quinolones and tetracyclines at safety levels. When individual milk samples were analysed, microbiological tests showed a higher occurrence of non-compliant results in sheep milk than in goat’s milk, being related in all cases to an elevated somatic cell count (SCC). The microbiological system consisting of two complemetary microtiter plates containing Geobacillus stereathermophilus var. calidolactis and Bacillus subtilis, respectively, allows improving the detection level in sheep milk with respect to the use of a single commercial test using G. stearothermophilus, detecting some quinolone and macrolide substances more closely related to their respective MRLs. The rapid receptor-binding assays (the Betastar Combo, the Charm MRL BLTET, the SNAP Betalactam, the SNAP Tetracycline and the TwinsensorBT) were able to detect most beta-lactams and tetracyclines at or below MRLs (CCβ ≤ MRL). A higher specificity of the rapid receptor tests was obtained in all cases even when individual milk samples were analysed. Only the TwinsensorBT test presented non-compliant results when antibiotic-free milk samples from individual animals were analysed, especially in the last weeks of lactation. No cross-reactions were found when drugs belonging to antimicrobial groups other than beta-lactams or tetracyclines were present in milk. Azidiol, used as a preservative, had no effect on the performance of the rapid receptor tests. Moreover, differences between the visual and instrumental classification of the test results were not found. Taking into account the frequency of use of antibiotics commonly employed in Spain and the screening test sensitivity at MRLs equivalent to antibiotic concentrations, total detection rates have been calculated. In general, the use of a single test allows detecting 62.8-82.4 % of the antibiotics employed. For sheep milk, the total detection range achieved with microbial tests was significantly higher than that reached with rapid receptor tests. However, no significant differences between the two types of tests were found when goat's milk was analysed. In both types of milk, the simultaneous use of two screening tests with a different analytical basis increases the total detection range significantly, reaching values ≥ 90 % in some cases. However, antibiotics such as enrofloxacin, marbofloxacin, spiramycin, and streptomycin also used to treat mastitis and other infectious diseases could not be detected by the screening tests assessed. Therefore, the improvement of the analytical strategy through the periodical implementation of screening tests able to detect these substances at safety levels would be recommended. / Beltrán Martínez, MC. (2014). Analytical strategy for the detection of antibiotic residues in milk from small ruminants [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48164 / TESIS

Cyclosporine (CsA), a fungal peptide with remarkable anti-lymphocytic properties, has been shown to be an effective immunosuppressive agent. In three separate experiments, mice receiving CsA at various doses (8 mg/kg/day in the first two experiments and 70-100 mg/kg/day in the third), were implanted with ovine mammary tissue expants at various sites (subcutaneous dorsum, ovarian fat-pad, and cleared mammary gland fat-pad). After different periods of time, (day 3, 7, 14, 21, and 35) implants were removed, fixed, stained, and embedded. Epithelial morphology of the implants was evaluated via a grading system that classified epithelium from 1 (poor) to 5 (excellent). Leukocyte type and number was determined in subepithelial stroma of implants in the third experiment. In the first two experiments, histological evaluation revealed that the transplanted tissue did not survive, regardless of site of implantation or developmental stage of donor tissue. In experiment three higher, dosages of CsA and different donor tissue were used, this resulted in significantly higher (P < .05) mean epithelial scores (indicative of healthier epithelium) for two CsA treated groups vs two control groups (3.75 and 2.33 vs 2.0 and 1.25, respectively). Within each treatment group (CsA and control), one group of mice received exogenous estrogen and progesterone (EjP) implants. CsA treated mice receiving E/P had significantly higher (P < .05) epithelial scores than those not receiving hormones (3.68 vs 2.83). The reverse was true for lymphocyte number (18.9 vs 40.5 cells per 117,600 um² of subepithelial stroma) which were significantly less in CsA + E/P treated mice. The overall correlation between lymphocyte number and epithelial score was -.55 (P < .0001). These results indicate that ovine mammary tissue xenografted into mice treated with high doses of CsA, are capable of surviving for extended periods of time (at least 35 days). / Master of Science

[Truncated abstract] It is well known that cows produce more milk if they are comfortable at milking, because stress from milking may cause them milk ejection problems. Temperament is an intrinsic characteristic of the animals so may affect the level of comfort at milking, and stress from the milking process itself may have a greater impact on animals with nervous temperament than on those of nervous temperament. When the milking becomes a stressor, it may affect secretion of milk ejection hormones that, in turn, may affect milk yield and composition. There is little evidence for how animal temperament affects milk quality in different farm animals. In this thesis, I have examined the effects of temperament on quantity and quality of the milk from Merino ewes and Holstein cows. I also tested whether temperament affected the processing performance (clotting properties) of the milk from Merino ewes. The general hypotheses tested were: 1. Calm ewes would produce more milk of better quality than nervous ewes, and, consequently, the clotting properties would be better in the milk from calm ewes than from nervous ewes. 2. Calm cows would produce more milk of better quality than nervous cows.

No / This research work was carried out to compare the physicochemical parameters of milk samples from four different animal species namely cow, goat, camel and sheep. Milk samples were collected from different areas of Misurata, Libya and analyzed for the key physiochemical parameters, pH, titratable acidity, total solids, ash, fat, protein and lactose. Furthermore in this study the concentrations of Zinc (Zn), Cadmium (Cd), Chromium (Cr), Magnesium (Mg), Manganese (Mn), Potassium (K), Calcium (Ca) Copper (Cu), Iron (Fe) and Lead (Pb) in similar commercial milk specimens from the same area were determined using microwave plasma- atomic emission spectrometry In fresh cow’s milk, the mean concentrations of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K were 0.13± 0.19 (mg/l), 0.004± 0.001 (mg/l), 0.04± 0.01 (mg/l), 0.17± 0.11 (mg/l), 0.72± 0.02 (mg/l), 1.98± 0.04 (mg/l), 214.00± 0.20 (mg/l), 0.080± 0.05 (mg/l), 423.0± 3.5 (mg/l) and 427.0± 2.5 (mg/l), respectively. While the mean concentration of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K, in the goat’s milk were 0.761 ± 0.78 (mg/l), 0.085 ± 0.02 (mg/l), 1.253 ± 0.18 (mg/l), 0.400± 0.08 (mg/l), 1.23± 0.21 (mg/l), 3.110± 0.15 (mg/l), 140.0± 0.31 (mg/l), 0.097± 0.07 (mg/l), 473± 5.12 (mg/l) and 510± 6.05 (mg/l), respectively. The concentration of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K, in the camel’s milk were 0.025 ± 0.019 (mg/l), 0.091± 0.05 (mg/l), 0.069± 0.07 (mg/l), 0.080 ± 0.05 (mg/l), 1.680 ± 0.43 (mg/l), 5.380 ± 1.17 (mg/l), 120.0 ± 0.11 (mg/l), 0.094 ± 0.04 (mg/l), 520.0 ± 0.32 (mg/l) and 571.0± 0.81 (mg/l), respectively. The concentration of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K, in the sheep’s milk were 0.062± 0.03, 0.106± 0.11, 0.040± 0.01, 0.201± 0.10, 0.880± 0.31, 5.350± 0.50, 180± 1.20, 0.072± 0.01, 478± 3.10, and 593.96± 1.87, respectively.

Made available in DSpace on 2016-12-08T16:24:13Z (GMT). No. of bitstreams: 1 PGCA12MA098.pdf: 24862835 bytes, checksum: d3d764a2dbe78f9292aa2653b2120a07 (MD5) Previous issue date: 2012-08-20 / Most of ovine milk ´roduced worldwide is processed in dairy products, for this reason their quality is measured by rechnological properties, which are markedly affected by the composition, as well as the microbiological count. The objective of this study was to characterize rural properties that explore commercially milk sheep in the wester of the state of Santa Catarina by recording the production, composition an microbiological quality of the milk and the water used for the milking parlor. The experiment was conducted during august 2009 to june 2012 on tive farms. The animals used the experiment belonged to Milchschaf and Laucane breeds as wel their crosses, and crosses with beff breeds. Evaluations consisted in registration of production (ml/ewe/day), composition (fat, protein, lactose and minerais) an Somatic Cell Count (SCC) of milk, as well as the microbiological quality (total coliforms, Escherichia coli, mesophiles, salmonella sp., Listaria monocytogenes and Staphylococcus aureus) and microbiological quality of water (total coliforms, fecal coliforms and mesophiles) used for cleaning of milking equipment and utensils. For the assessment of milking, and then samples were separated and sent to and accredited laboratory. For the microbiological evaluation of milk the samples were collected directky from the cooling tank and the water obtained directly from the source to be evaluated in the Centro de diagnostic Microbiológico Animal (CEDIMA) of Centro de Ciências Agroveterinárais (CAV) at the Universidade do Estado de Santa Catarina (UDESC) for bacterial isolation. The results of the average daily milk production during the 150 days of lactation was 926.88 ml/ewe, while for the composition was 7.11% offat, 4.91% of protein, 4.52% of lactose, 17.81% of total solids and 490x10³/mlof SCC. The average results obtained by microbiological analysis of milk from ali sampling were 3535.29 x10³ CFU/ml for Standard Plate Count (SPC), 30x10³ CFU/ml for total coliforms, 12.12 CFU E. coli and 0.47x10³ CFU/ml for S. aureus, three isolates of Salmonella sp. And no isolates of Listeria monocytogenes. For water the average of ali properties was 76.31 x10³ CFU/ml for SPC, 37.82 NMP/100 ml for total coliforms and no isolates of fecal coliforms. Data of production, composition and microbiological were statistically analyzed using the GLM procedure (General Linear Model) of the SAS statistically analyzed using the GLM procedure (General Linear Model) of the SAS statistically package (SAS Institute, 2005). SCC data were previously transformed into a logarithm base 10. The study allowed to characterize the ovine milk as well the microbiological water quality of these properties. The results for microbiological contamination of milk and water did not correspond with the limits established by Brazilian legislation compared with cow s milk and water consumption, however, as for the evaluation of milk production and compositional, these data can guidance for those involved in the activity and useful for industry that absorb the production of ovine milk in the region ultin further research is done / A maior parte do leite ovino produzido no mundo é transformado em produto lácteos, por esta raz!lo a qualidade deste é medida principalmente pelas sua propriedades tecnológicas, que são marcadamente afetados pela composição assim como pela sua qualidade microbiológica. O objetivo deste trabalho fo caracterizar as propriedades rurais que exploravam comercialmente o leite ovino n região oeste do estado de Santa Catarina quanto a sua produção, composição qualidade microbiológica do leite e da água utilizada para a higienizaçao d equipamentos. O experimento foi conduzido entre os meses de agosto de 2009 junho de 2012 em cinco propriedades rurais. Os animais utilizados no experimento pertenciam às raças Milchschaf, Lacaune e suas cruzas, além de cruzamentos co raças de corte. As avaliações consistiram no registro da produçao (mUovelha/dia) composição (gordura, proteína, lactose e minerais) e Contagem de Célula Somáticas (CCS) do leite, assim como a qualidade microbiológica (Coliformes totais Escherichia co/i, Mesófilos, Sa/mone//a sp., Usteria monocytogenes Staphylococcus aureus) deste e a qualidade microbiológica da água (Coliforme totais, Coliformes termotolerantes e Mesófilos) utilizada para a higienização do equipamentos e utensílios de ordenha. Para a avaliação da produção e composiçã o leite foi coletado no momento da ordenha, em seguida uma amostra era separad e enviada para laboratório credenciado. Para a avaliação microbiológica as amostra de leite foram coletadas diretamente do tanque de resfriamento e a água obtid diretamente da fonte, para serem avaliadas no Centro de Diagnóstico Microbiológic Animal (CEDIMA) do Centro de Ciências Agroveterinárias (CAV) da Universidade d Estado de Santa Catarina (UDESC) para isolamento bacteriano. Os resultados d produção média diária de leite durante os 150 dias de lactação foi de 926,8 mL/ovelha, enquanto que para a composição foi de 7,11% de gordura, 4,91% d proteína, 4,52% de lactose, 17,81% de sólidos totais e 490x103 CCS/mL. As média dos resultados obtidos através das análises microbiológicas do leite de todas a coletas foram de 3.535,29x103 UFC/mL para CPP totais, 12,12 UFC/mL para E. co/i e 0,47x103 30x103 UFC/mL para Coliforme UFC/mL para S. aureus, trê isolamentos de Sa/mone//a sp. e ausência de Usteria monocytogenes. Para a águ utilizada nas propriedades as médias entre todas as propriedades foi de 76,31x10 UFC/mL para CPP, 37,82 NMP/100mL para Coliformes totais e ausência d Coliformes termotolerantes. Os dados de produção, composição e microbiológico foram submetidos a análise estatística utilizando-se o procedimento GLM (Genera Linear Model) do pacote estatístico SAS (SAS INSTITUTE, 2005). Os dados de CCS foram previamente transformadas para logaritmo de base 10. O estudo permiti caracterizar o leite ovino assim como a qualidade microbiológica da água desta propriedades. Os resultados para a contaminaçao microbiológica do leite e da água não corresponderam com os limites estabelecidos pela legislação brasileira quand comparados com o leite bovino e para a água de consumo, entretanto, assim com para a avaliação produtiva e composicional do leite, estes dados podem servir d subsídio para os envolvidos na atividade e úteis para a indústria que absorve produção de leite ovino da região até que novas pesquisas sejam realizadas

O leite ovino se diferencia do das demais espécies devido à sua riqueza em sólidos. Contudo, mesmo no caso de raças especializadas, a produção de leite é representativamente menor, em termos de volume, quando comparado ao leite de vaca. Em função disso, o resfriamento prolongado ou o congelamento do leite podem ser uma alternativa ao produtor e à indústria. Sendo assim, os objetivos do presente estudo foram avaliar o efeito do resfriamento e do congelamento, por sete dias, sobre as características físico-químicas do leite de ovelhas da raça Lacaune, considerando a influência dos meses do ano, sobre o rendimento da coalhada produzida e as características físicas do soro obtido. Também foi verificada a influência do resfriamento e do congelamento no comportamento reológico, viscosidade e distribuição do tamanho de partículas do leite. Foram realizadas coletas mensais de leite, no período de janeiro a dezembro de 2011, em quatro propriedades produtoras de leite de ovelha, localizadas no Rio Grande do Sul, sendo as amostras encaminhadas ao Laboratório LEITECIA, da UFRGS. Cada amostra foi dividida em três alíquotas: a primeira era analisada no mesmo dia e as restantes armazenadas até sete dias, uma em refrigeração (5ºC) e outra em congelamento doméstico (- 18ºC). As análises realizadas foram: determinação da densidade, pH, acidez titulável, estabilidade ao etanol e estabilidade térmica. Uma alíquota de cada amostra era encaminhada ao Laboratório de Qualidade do Leite, da Embrapa Clima Temperado, para determinação da composição química do leite. Avaliou-se o rendimento da coalhada obtida com cada uma das amostras compostas de leite fresco, resfriado e congelado. O volume de soro foi medido e realizou-se análise de determinação da densidade, pH e acidez titulável. A viscosidade das amostras de leite foi determinada utilizando-se viscosímetro rotacional (Brookfield DV-II + Pro Viscometer, modo LVF, spindle CS4-25). A descrição do comportamento reológico foi feita através da relação entre a taxa de deformação e a tensão de cisalhamento e da aplicação do modelo da Lei da Potência. A comparação dos valores de viscosidade quando os fluidos apresentaram comportamento newtoniano foi realizada a 60 rpm. A distribuição do tamanho de partículas do leite foi determinada através da técnica de difração de laser. Os parâmetros utilizados foram diâmetro médio das partículas, uniformidade da distribuição (Span) e a área de superfície específica. A composição do leite não apresentou variação significativa quando comparados os diferentes tratamentos (P>0,05). Contudo, os teores de proteína e lactose apresentaram variação sazonal. O resfriamento do leite afetou as características físicas das amostras, apresentando menor pH e maior acidez titulável, com a consequente diminuição da estabilidade térmica. Na produção da coalhada, o resfriamento e o congelamento do leite ovino não afetaram o rendimento. A densidade dos soros obtidos não apresentou variação. Porém, o soro da coalhada de leite resfriado apresentou-se mais ácido. As amostras de leite de ovelha analisadas demonstraram comportamento newtoniano. A viscosidade das amostras não foi afetada pelo congelamento do leite, porém o resfriamento provocou aumento deste parâmetro analisado. O diâmetro médio das partículas não apresentou variações. Conclui-se que o congelamento do leite, por até sete dias, não interfere na sua caracterização físico-química. / Ewe milk differs from other species due to its richness in solids. However, even in the case of specialized breeds, milk production is representatively smaller in volume compared to cow milk. As a result, prolonged chilling or freezing of the milk can be an alternative to the dairy producer and the industry. The objectives of this study were to evaluate the effect of cooling and freezing for seven days, on the physicochemical characteristics of milk from Lacaune ewes, considering the influence of the months of the year on the income produced curd and physical characteristics of the whey obtained. The effect of chilling and freezing on rheological properties, viscosity and particle size distribution of the milk were also observed. Milk samples were collected monthly from January to December 2011 in four dairy of Lacaune sheep located in Rio Grande do Sul. Samples were sent to the laboratory LEITECIA, UFRGS. Each sample was divided into three aliquots: the first was analyzed on the same day and the remaining stored up to seven days, one under refrigeration (5ºC) and other under freezing (- 18ºC). Density, pH, titratable acidity, ethanol stability and thermal stability were performed in three aliquots. One aliquot of each sample was sent to the Milk Quality Laboratory of Embrapa Clima Temperado for determination of chemical composition. The three aliquots were used to produce cheese. The yield of the obtained curd in each of the samples comprised from fresh, chilled and frozen milk was determined, as well as volume, density, pH and titratable acidity from whey. Viscosity of milk samples was determined using a rotational viscometer. The description of rheological behavior was made using the relationship between shear rate and shear stress by application of Potency Law model. Comparison of viscosity values, as the fluid showed Newtonian behavior, was performed at 60 rpm. Particle size distribution was determined by laser diffraction technique. Parameters used were average particle diameter, uniformity of distribution (Span) and specific surface area. Milk composition did not change significantly when comparing the different treatments (P> 0.05). However, protein and lactose showed seasonal variation. Milk chilling affected the physical characteristics of the samples, with lower pH and higher acidity, with a consequent decrease in thermal stability. In the production of curd, chilling and freezing of ewe milk did not affect yield. Whey density did not change, although chilled milk produced more acidic whey. Viscosity of the samples was not affected by freezing, but chilling caused an increased viscosity. Average particle diameter showed no variations. In conclusion, freezing of ewe milk for seven days does not interfere with its physic-chemical characterization.