Protein Profile Characterization of Donkey Milk

This chapter would be a further contribution to increase the characterization of donkey milk, evaluating the nutritional qualities of donkey milk using different proteomic approaches

QUALITY AND NUTRITIONAL CHARACTERISTICS OF DONKEY MEAT

Meat has exerted a crucial role in human evolution and is an important component of a healthy and well balanced diet due to its nutritional richness. The aim of the present chapter is to shed light on the nutritional composition of donkey meat and the implications for human health. Donkeys are not perceived as multi-use animals. Cattle, buffaloes and camels are usually kept for their milk and their meat as well as for work. In many areas donkeys are not sold for their meat. One of many exceptions is Lesotho where donkeys are culled for meat when they are considered too old to work, and for this reason donkeys are relatively expensive in this Country. In the rest of the world, the lower cost of donkeys makes them more affordable to small farmers. On the other hand, donkey meat can be considered a good alternative in red meat consumption, being a dietary meat. Donkey meat is in fact characterized by low fat, low cholesterol content, a favourable fatty acid profile and is rich in iron. Today consumers are health conscious and demand high quality food products; they require leaner meat, with less fat (the minimal fat level required to maintain juiciness and flavour) and a consistent quality. Ultimately, the success of any food product is determined by the consumer’s acceptance. Meat quality and acceptability is determined by its physico-chemical characteristics, although consumer preferences for meat are difficult to define. In this context, this chapter will describe the quality of donkey carcass and donkey meat quality parameters, showing its chemical and sensorial characteristics (when possible in different muscles) and evaluating the effects of the age of slaughtering

Milk Production and Characteristics of the Milk of the Jenny

Milk is a biological fluid designed to contain all nutritional requirements of a specific mammalian newborn; therefore, the composition of milk differs by the needs of the neonate of different species. Although much research has been devoted to milk composition in the domestic horse, donkey’s milk has recently aroused scientific interest, above all among paediatric allergologists and nutritionists

THE USE OF ELECTRICAL STIMULATION IN MEAT PRODUCTION

The present chapter describes what is known about the effects of the use of electrical stimulation of carcasses of meat animals, including the effects on meat tenderness and meat sensorial characteristics. Electrical stimulation as a process involves passing an electric current through the carcass of freshly slaughtered animals. Electrical stimulation has been extensively used since the 1950s to hasten the onset of rigor mortis and to modify steps of the glycolytic pathway. Many studies conducted in the USA, in New Zealand, Australia and Europe have involved a variety of electrical stimulation methods on different types of meat animals. Data reported in many studies suggest that electrical stimulation, through hastening rigor changes, can significantly reduce in the carcasses of meat animals the phenomenon of cold shortening, one of the major cause of meat toughness. Although it is well established that electrical stimulation increases the rate of post mortem glycolysis, other biochemical and biophysical effects have been implicated with the use of this technology, including the possibility that electrical stimulation also results in physical disruption of muscle structure. Electrical stimulation can be considered as a part of the total meat production chain from slaughter to final sale, and has particular advantages for hot boning, where the shortening and toughening conditions that would occur for non stimulated muscles during chilling are avoided

Use of faba bean as a replacer of soybean meal in diet of Fabrianese lambs

Most of the lamb diets are based on soybean meal as the main protein source, often imported and derived from genetically modified varieties, which is not pos-sible to use in organic meat production. Use of faba bean to replace soybean meal as main pro-tein source in the diet of Fabrianese lambs was inves-tigated. Growth performance, dressing percentage, physical and chemical characteristics of longissimus thoracis and its fatty acid composition were investi-gated. Twenty-four Fabrianese entire male lambs were weaned at 59±5 days of age and were divided into two homogeneous groups (n = 12), then fed for 78 days with two different experimental diets. One group re-ceived a concentrate including 242 g/kg of faba bean (FB), the other group was fed on concentrate includ-ing 160 g/kg of soybean meal (SBM). Carcass quality, meat chemical composition and meat tenderness were not influenced by dietary treatment. The total amount of n-3 fatty acids was significantly (P < 0.05) higher in lambs fed with FB, with a conse-quent more favourable n-6/n-3 ratio. Conjugated Lin-oleic Acids (CLA) content was significantly (P < 0.05) higher in meat obtained from lambs fed FB diet. FB can replace SBM in concentrate mixtures for fat-tening lambs without adverse effects in growth perfor-mances and in carcass quality, causing a significant improvement of meat acidic profile, particularly con-sidering n-3 fatty acids and CLA content

Mule carcass characteristics and meat quality

Donkey carcass parameters and donkey meat quality character¬istics have been determined in previous studies, while mule carcass and meat quality traits have scarcely been evaluated. The aim of the present study was to compare the carcass data and meat quality parameters obtained from 10 mules slaughtered, respectively, at an age of 5 ± 1 years and at an age of 10 ± 1 years. All the animals were weighed before their arrival at abattoir; the carcasses were transferred to a cold room at a temperature of 4 °C and stored suspended by the hind legs. 24 h after slaughter¬ing, the cold carcass weights and the dressing percentages were recorded. From each carcass, 24 h after slaughtering samples of the muscle Longissimus thoracis (LT) were collected. Chemical composition was determined 24 h after slaughtering, while colour parameters were measured 48 h after slaughter using a Minolta CM-3600 D spectrophotometer in order to determine the L* (light¬ness), a* (redness), and b* (yellowness). Meat samples for tenderness determination, weighting approxi¬mately 30 g, were stored in the cold room at 4 °C for 7 days post slaughter before evaluating the shear force values, determined using a Warner-Bratzler device. The shear force values were expressed in kg/cm2. Analysis of variance was used to determine the significant differences in the values determined in this study; significant differences were shown when p &lt; 0.05. Carcass char¬acteristics determined in both groups of animals did not show significant differences. Meat sampled in animals slaughtered at an age of 10 years showed significant (p &lt; 0.05) higher content of fat (5.22% vs 4.09%) and cholesterol levels (0.88 mg/100 g vs 0.52 mg/100 g) compared to younger mules. Meat produced by older mules was significantly (p &lt; 0.05) darker (L* 31.09 vs 39.71, a* 13.8 vs 17.1) compared to the values determined in younger mules. Meat tenderness evaluation found not significant differ¬ences in both the groups of mules, obtaining values of shear force not particularly appreciated by the consumers. The results obtained in this study confirmed the need of adequate feeding strategies and good farm practices in mules breeding in order to produce a more tender mule meat

DNA methylation dynamics in the functional régulation of human T lymphocytes

In mammals, the 5’ methylation of the cytosine base (5mC) in the genomic DNA is intimately linked with the regulation of gene expression. Despite its stability and heritability across cell division, 5mC erasure is required for the activation of developmental programs associated with extensive functional reprogramming. Once deposited in the genome, 5mC can be removed either through passive dilution during DNA replication, or through active mechanisms characterized by enzymatic oxidation of the methyl mark to 5’-hydroxymethylcytosine (5hmC), which can persist as such or undergo further oxidation and enzymatic removal. However, it is still unclear what is the relative contribution of each mechanism to the epigenetic control in evolving biological systems. Therefore, the overall aim of this thesis is to investigate the contribution of active and passive mechanisms to 5mC and 5hmC removal in a cellular system. To explore this critical issue we used primary human T helper (TH) lymphocytes, in which two cellular states can be clearly identified: quiescent naive T cells, which are slowly or rarely proliferating, and rapidly proliferating activated T cells upon antigen recognition. First, we found that the 5hmC is dynamically modulated during T cell activation, indeed unstimulated naive T cells maintained higher levels of 5hmC compared to those of all other antigenexperienced T lymphocytes, highlighting that DNA demethylation is a process linked to the activation and not to specific effector T cell subsets. Using compounds that inhibit methylation or enhance demethylation, we found an increased ability of the cells to produce effector cytokines, suggesting that DNA methylation-related processes are required for the efficient differentiation of T cells to effector and memory subsets. By optimizing methods to uncouple T cell activation from proliferation, naive T lymphocytes showed a significant loss of genomic 5hmC upon activation, even in the complete absence of proliferation. These results point towards a role for active processes of DNA demethylation in the first activation of naive T cells. On the other hand replication-dependent dilution was the driving force leading to 5hmC reduction in highly proliferative and already differentiated cells. Finally, by analyzing genome-wide DNA methylation and hydroxymethylation we found that these modifications change dynamically during T cell activation, and 5hmC in particular appeared to be differentially associated with regulatory regions of early and late response immune genes. Our data suggest that the usage of active vs. passive mechanisms of DNA demethylation is differentiation and activation stage-dependent. Specifically, active demethylation mechanisms are selectively involved in quiescent naive T lymphocytes prior to cell-cycle entry to maintain regulatory regions poised for rapid responses to physiological stimuli, while passive, replication-dependent dilution of the modified cytosines primarily is at work in memory T lymphocytes. -- Chez les mammifères, la méthylation en 5’ de la base cytosine (5mC) de l’ADN génomique est intimement liée à la régulation de l’expression des gènes. Malgré sa stabilité et son héritabilité au cours des divisions cellulaires, la suppression de 5mC est requise pour l’activation de programmes de développement. Une fois déposée sur le génome, 5mC peut être éliminée soit par dilution passive lors de la réplication de l’ADN soit par des procédés actifs caractérisés par l’oxydation enzymatique du groupe méthyl générant la 5’-hydroxyméthylcytosine (5hmC) qui peut persister en tant que tel ou bien subir ultérieurement oxydation et élimination enzymatique. Toutefois, la contribution relative de chacun de ces mécanismes dans le contrôle épigénétique des systèmes biologiques évolutifs demeure incertaine. Dès lors, l’objectif de cette thèse est d’étudier la contribution des mécanismes actifs et passifs de la suppression de 5mC et 5hmC dans un système cellulaire. A cette fin, nous avons utilisé des lymphocytes humains T « helper » (TH) primaires dans deux états cellulaires distincts: les cellules T naives quiescentes proliférant rarement ou très lentement et les cellules T activées par l’antigène et proliférant vigoureusement. Nous avons établi que la 5hmC est dynamiquement modulée durant l’activation des cellules T, les cellules naives non stimulées maintenant des niveaux de 5hmC plus élevés que ceux de tous les autres lymphocytes T ayant rencontré leur antigène, mettant ainsi en évidence que la déméthylation de l’ADN est un procédé lié à l’activation et non pas à une sous-population de cellules T effectrices spécifiques. Grace à des composés inhibant la méthylation ou augmentant la déméthylation, nous avons pu montrer une capacité accrue des cellules à produire des cytokines effectrices, suggérant ainsi que les procédés relatifs à la méthylation de l’ADN sont requis pour une différentiation efficace des cellules T effectrices et mémoire. Après optimisation des méthodes pour découpler l’activation de la prolifération, les lymphocytes T naifs ont montré une perte significative de la 5hmC génomique lors de l’activation et ce même en totale absence de prolifération, pointant vers un rôle des procédés actifs de déméthylation lors de l’activation des cellules T naives. D’autre part, la dilution dépendant de la réplication de l’ADN est le procédé principal menant à la réduction de la 5hmC pour les cellules hautement prolifératives et déjà différenciées. Enfin, en analysant l’entier du génome, nous avons découvert que ces modifications sont dynamiques durant l’activation des cellules T et que 5hmC en particulier semble être associée à des régions régulatrices de gènes de la réponse immunitaire initiale. Nos résultats suggèrent que l’usage des mécanismes actifs vs passifs de la déméthylation de l’ADN dépend de l’état d’activation et de différentiation. Plus précisément, les mécanismes actifs sont impliqués sélectivement chez les lymphocytes T naïfs avant l’entrée dans le cycle cellulaire afin de maintenir les régions régulatrices prêtes pour une réponse rapide alors que la dilution passive des cytosines modifiées dépendant de la réplication opère principalement chez les lymphocytes T mémoire

Protein fraction characterization of sheep milk from the Comisana breed

This study investigated on the protein fractions characterization of sheep milk obtained by Comisana breed. Milk samples collected by 94 sheep were subjected to RP-HPLC analysis, in order to determine caseins and seroproteins contents. A total seroproteins content of 17.0 g/l was determined, while the total casein content was 39.0 g/l. The seroproteins content was further investigated by RP-HPLC, determining an α-lactalbumin content of 1.6 g/l, higher if compared to dairy cow’s milk, and two variants of β-lactoglobulin, with a content respectively of 16.7 g/l and 11.0 g/l. Since the RP-HPLC did not permit an accurate separation of the different variants of caseins, other studies are currently in progress using a proteomic approach

Dietary Intake of Vitamin D from Dairy Products Reduces the Risk of Osteoporosis

Background: Vitamin D and calcium are important dietary compounds that affect bone mass, even if other minerals (potassium, zinc, etc.) and vitamins (A, C and K) are also involved. Vitamin D and certain minerals, in fact, play an important role in calcium homeostasis and calcium absorption. Hip fracture incidence is higher in Europe and the United States, where calcium is frequently included in the human diet; while the occurrence of these fractures is lower in developing countries, where diets are often poor in calcium. This condition is named the "calcium paradox", and may be partially explained by phosphate toxicity, which can negatively affect mineral metabolism. It is important to maintain correct dietary calcium-phosphate balance in order to have a healthy life, reducing the risk of osteoporotic fractures in older people. Vitamin D can also act as a hormone; vitamin D2 (ergocalciferol) is derived from the UV-B radiation of ergosterol, the natural vitamin D precursor detected in plants, fungi, and invertebrates. Vitamin D3 (cholecalciferol) is synthesized by sunlight exposure from 7-dehydrocholesterol, a precursor of cholesterol that can also act as provitamin D3. Dietary intake of vitamin D3 is essential when the skin is exposed for short periods to ultraviolet B light (UV-B), a category of invisible light rays such as UV-A and UV-C. This can be considered the usual situation in northern latitudes during the winter season, or the typical lifestyle for older people and/or for people with very white delicate skin. The actual recommended daily intake of dietary vitamin D is strictly correlated with age, ranging from 5 mu g for infants, children, teenagers, and adults-including pregnant and lactating women-to 15 mu g for people over 65 years

Donkey milk production: state of the art

Milk is one of the most common causes of food allergies among children under one year of age. No specific therapy exists for this allergy, and thus the only feasible response is to avoid assumption of milk and derived products. Studies conducted on the serum of children with hypersensitivity to milk have shown that caseins are the proteins with the greater allergenic potential. However, in some cases, children have also shown hypersensitivity to the β-lactoglobulines and to the α-lactalbumins. When food intolerance is diagnosed in an infant, it is often necessary to impose a period of total parenteral feeding, followed by breast feeding, considered the most correct method of re-feeding. When human milk can not be given, alternative food sources must be sought. Clinical studies have demonstrated that donkey milk could substitute breast feeding in infants affected by severe Ig-E mediated milk allergies. In these subjects, donkey milk is not only useful, but also safer than other types of milk. In fact donkey milk composition in lipids (high levels of linoleic and linolenic acid) and proteins (low caseins content) is very close to human milk. Lysozyme content in donkey milk resulted to be very high (mean value 1.0 mg/ml) if compared to bovine (traces), caprine (traces) and human milk. The high lysozyme content of donkey milk may be responsible of the low bacterial count reported in literature and also makes this milk suitable to prevent intestine infections to infants. Among seroproteins, β-lactoglobulin and α-lactalbumin content in donkey milk was respectively 3.75 and 1.80 mg/ml and remained substancially the same during the different stages of lactation