No description available.

Graduation date: 1995

This dissertation provides a comprehensive and systematic examination of anthropoid primate milk composition and its relationship to a species' evolutionary history, ecological context, and life history strategy. Milk samples from 14 species of anthropoid primate (Alouatta paliatta, Callithrix jacchus, Cebus apella, Gorilla beringei beringei, Gorilla gorilla gorilla, Hylobates lar, Leontopithecus rosalia, Macaca mulatta, Macaca sinica, Pan paniscus, Pan troglodytes, Pongo pygmaeus, Saimiri boliviensis boliviensis, and Symphalangus syndactylus) were analyzed for proximate composition (fat, protein, lactose, dry matter, and minerals) and milk fatty acid composition. The objectives of this study were identification of primitive features in anthropoid milks, shared-derived features of anthropoid families or superfamilies, and unique-derived features of species, including Homo sapiens.Results did not support the null hypothesis of a generalized anthropoid milk composition. Variation among anthropoids in milk fatty acid profiles and proximate milk composition was influenced by phylogeny and the life history strategy of the species, as well as the diet and environment (captive or wild living) of the mother.Maternal diet had a direct influence on fatty acid profiles and created distinct groupings of wild and captive living individuals. Phylogenetic patterns were identified within captive and wild groups, particularly a distinction between milk fatty acid profiles of hominoids (including humans) and monkeys.Significant variation in proximate milk composition was identified at the level of the superfamily. Cercopithecoid milk was highest in mean fat, dry matter, the proportion of energy from fat, and total gross energy. Ceboid milk was highest in mean protein and the proportion of energy from protein. Hominoid milks were lowest in mean fat, protein, dry matter, the proportion of energy from fat, and total gross energy.Hominoid milk also was lowest in the degree of plasticity in milk composition. Milk of captive living monkeys was higher than milk of wild living monkeys in mean fat, percent energy from fat, and total gross energy. Milk fat and energy also were highly variable within captive living monkeys. In contrast, fat and total gross energy were not significantly different between captive and wild living hominoids and were less variabile among captive living hominoids as compared to monkeys. The lack of variability and the relatively low energy values in hominoid milk suggest that it may be buffered against environmental fluctations. Larger body size and a longer duration of lactation may permit hominoids, including humans, to decouple maternal condition from milk energy and instead relying on energy storage.

The objective of the first part of this study was to observe and describe the profile of test-day somatic cell counts throughout a lactation in individual cows, and to examine the correspondence between such profiles and various lactation measures of cell count presently available. The objective of the second part of the study was to obtain estimates of the genetic and phenotypic parameters of lactation measures of cell count in different lactations, possibly for use in a breeding program. / In the first part of the study, the lactation cell count profiles of eighteen Holstein heifers of the Macdonald College Herd were individually examined. Weekly cell counts were expressed as deviations from the herd test-day average and plotted against week of test. A labile cell activity was found for most of the plotted lactations. The cellular responsiveness of cows facing external challenges seemed a trait peculiar to each individual. Lactation measures of cell count were unable to give good descriptions of cell count profiles of individual cows. However, they were better expressions of the lactation cell count performance than single test-day observations. / In the second part of the study, monthly cell count observations were obtained between February, 1977, and February, 1982, for the Holstein cows in herds enrolled on the official option of the Quebec Dairy Herd Analysis Service. Maximum likelihood, I-MINQUE (iterative Minimum Norm Quadratic Unbiased Estimation), and multivariate REML (Restricted Maximum Likelihood) procedures were used for the estimation of genetic and phenotypic parameters. / Repeatabilities of log test-day cell counts and log of test-day cell counts corrected for milk yield varied between 0.36 and 0.42 in first, second, third, fourth, and fifth and later lactations. Repeatabilities of test-day cell counts (cells/ml) in the five lactation groups varied between 0.17 and 0.25. Repeatabilities of lactation expressions for cell count between lactations ranged from 0.13 to 0.44. / Heritabilities of lactation expressions of cell count were low and varied from 0.06 to 0.14 in the five lactation groups examined; however, the genetic correlations between lactations were very close to unity, 0.90 to 0.97.

Four lactating Holstein cows fitted with ruminal and duodenal cannulae were used in a 4 x 4 Latin square design to determine the effects of feeding raw and heat-treated flaxseed on ruminal fermentation parameters, ruminal fatty acid biohydrogenation (BH), nutrient utilization in various segments of the gastrointestinal tract, and plasma and milk composition of lactating dairy cows. Four diets were formulated: a control diet with no flaxseed (C); a raw flaxseed (RF); a micronized flaxseed (MF); and an extruded flaxseed (EF) diet. Ruminal pH, NH3N and total volatile fatty acids were not affected by dietary treatments. However, feeding flaxseed decreased ( P < 0.01) molar proportion of acetate and increased ( P < 0.01) that of propionate. Ruminal fiber digestion was lower (P < 0.04) for cows fed the flaxseed diets relative to those fed C. Feeding flaxseed had no effect on milk yield, milk fat and protein content, and milk fat yield, but decreased (P = 0.02) milk protein yield. (Abstract shortened by UMI.)

"Ititu" is a concentrated fermented milk utilized by Borana pastoralists in Southern Ethiopia. The effect of types of container used (glass, fibrous), smoking (smoked, non-smoked) and whey withdrawal (whey, non-whey withdrawn) treatments on the microbiological and chemical compositions of the fermented milks were investigated over a storage period of 28 days. Microbiological results indicated that the type of container used had significant effect (p $>$ 0.05) on total bacterial count (TBC) and lactic acid bacterial counts (LAB) for Weeks 1, 2, 3 and 4 and on coliform count (COLI) for Weeks 3 and 4. These counts determined for the fermented milks in the glass containers were found to be significantly lower compared to those in the fibrous vessels. There was significant difference (p $>$ 0.05) in the overall proximate composition for container and whey withdrawal treatments compared to smoking treatment. / An increased breakdown of the major caseins ($ alpha sb{ rm s1}$ and $ beta$) over the storage period was indicated. / A significant increase was noted on the content of the free amino acids compared to the total amino acids over the storage period.

The objective of this study was to evaluate the effect of two different feeding systems and of four different energy sources (Grain diet) on lactation characteristics and milk composition of dairy cattle. A total of 8,808,798 test-day records from 566,736 Holstein cows in 5,183 different herds, and 416,883 test-day records from 26,973 Ayrshire cows in 652 different herds covering a period of five years were obtained from the Quebec dairy herd improvement agency (Valacta). In addition to test-day records, information on lactation, animal status, feed composition and feeding systems was also available. For both Ayrshire and Holstein cows the fixed effect of Feeding System*DIMB (Blocks of 15 days in milk) was a significant effect in predictive models of daily milk, milk-fat, protein, and lactose yields and on milk urea nitrogen (MUN) concentration. Cows served a diet prepared with a Total Mixed Ration (TMR) compared to cows served a diet in a Traditional way tended to have higher peak milk yields and appeared to have a stronger persistency after peak milk yield. TMR-fed cows also showed a tendency for higher milk-fat, protein, and lactose yields and lower MUN concentrations than Traditionally-fed ones. Significantly higher milk yields (peak to 135 days in milk) and higher milk-fat and protein yields (peak to mid-lactation) were found in TMR-fed cows compared to Traditionally-fed ones in 3rd parity Holsteins. Both milk-fat and protein-yield lactation curves of TMR-fed cows displayed a different pattern than Traditionally-fed cows. The fixed effect of the Grain diet*DIMB was found to be a significant effect in predictive models of milk and milk-protein yields of both Ayrshire and Holstein. It was also found to be a significant effect in predictive model of MUN concentration but only in 2nd parity Ayrshire. The effect was non-significant in predictive models of both milk-fat or lactose yields. A tendency for higher milk and milk-protein yields, and lower MUN values was seen when cows received Corn Grain or High Moisture Corn compared to Barley or Commercial Concentrate but no significant differences were observed. It was concluded that a tendency for higher milk and components yields can be observed when cows are fed with a TMR compared to a Traditional system.

No description available.

This trial was carried out in order to elucidate factors affecting milk urea nitrogen (MUN). Twenty-five herds were selected for MUN testing. Three sampling periods were chosen. The first occurred during the months of March and April, the second during July and August, and the third during November and December 1997. A total of 2,686 samples were collected and analyzed. Two different methods were employed for MUN analysis and were referred to as the Macdonald Campus method (MUN-MAC) and the Programme d'Analyse des Troupeaux Laitiers du Quebec method (MUN-P.A.T.L.Q.). The MUN-MAC consists of an enzymatic method while the P.A.T.L.Q. method is an infra-red method. Prior to initiation of the trial, the MUN-MAC method was validated and found suitable for use in this experiment. The results demonstrated that the factors which significantly contributed to the models were the ration's net energy of lactation, season, region, somatic cell count, total dry matter, neutral detergent fiber, non-structural carbohydrates, total fat, crude protein, protein to energy ratio, starch to protein ratio, parity and days in milk. (Abstract shortened by UMI.)

Darbo tikslas – nustatyti piene ir jo produktuose esantį riebaluose tirpų vitaminą E ir įvertinti jo dinamiką įtakojančius veiksnius bei jų reikšmingumo lygį. Darbo uždaviniai: 1. Mokslinės literatūros apie riebaluose tirpius vitaminus piene ir jo produktuose analizė ir apibendrinimas. 2. Nustatyti piene ir jo produktuose esantį riebaluose tirpų vitaminą E. 3. Įvertinti veiksnius įtakojančius piene ir jo produktuose esančio riebaluose tirpaus vitamino E dinamiką. 4. Nustatyti piene ir pieno produktuose esančio riebaluose tirpaus vitamino E dinamiką įtakojančių veiksnių reikšmingumo lygį. Tirti iš 3 Lietuvoje esančių pieno ūkių paimti pieno mėginiai ir iš šio pieno pagaminti produktai: pasterizuotas pienas, acidofilinis pienas, raugintas pienas, kefyras, grietinėlė, grietinė, sviestas, išrūgos. Prekybos centre tyrimams įsigyti fermentiniai puskiečiai sūriai ir saldintas sutirštintas pienas. Tyrimai atlikti Lietuvos sveikatos mokslų universiteto Lietuvos veterinarijos akademijos biochemijos katedroje ir maisto tyrimų laboratorijoje. Atliktas tiriamojo pieno cheminės sudėties nustatymas. Vitamino E kiekio piene ir pieno produktuose nustatymas didelės skyros skysčių chromatografijos metodu. Išvados: 1. Atlikus vitamino E kiekio tyrimą iš pieno ūkių paimtuose pieno mėginiuose didžiausią vitamino E kiekį nustatėme Lietuvos žalųjų karvių ūkyje vasarą 0,85 mg/kg, žiemą – 0,80 mg/kg. Mažiausią vitamino E kiekį vasaros piene nustatėme mišriame karvių ūkyje 0,72 mg/kg, žiemos... [toliau žr. visą tekstą] / The aim of the work – determine the milk fat–soluble vitamin E, and evaluate the dynamics influencing factors and their significance levels. Objectives: 1. Analysis and generalization of scientific literature about the fat-soluble vitamins in milk and its products. 2. To detect the fat-soluble vitamin E in milk and milk products. 3. To access the factors influencing the fat-soluble vitamin E dynamics in milk and its products. 4. To determine significance of fat-soluble vitamin E dynamics influencing factors in milk and milk products. Milk samples and dairy products from this milk: pasteurized milk, acidophilic milk, acidified milk, kefir, cream, sour cream, butter, were investigated which have been taken from dairy farms in Lithuania. The research was carried out in the Biochemical department of Lithuanian Health Science University Veterinary Academy and laboratory of food analysis; Lithuanian fermented semi-hard cheese and sweetened condensed milk from trade centers were investigated. The chemical composition of milk has been determinated. Vitamin E content in milk and milk products were determinate by high performance liquid chromatography. Conclusions: 1. During examination of vitamin E content in milk from farms, the highest content of vitamin E was found in the third cows farm: at summer 0,85 mg/kg, at winter 0,80 mg/kg. The lowest content of vitamin E at summer was found in the second farm 0,72 mg/kg and the lowest content of vitamin E at winter was found... [to full text]