Milk, an essential source of offspring nourishment, varies in it’s composition and properties significantly across species. In human nutrition, fresh milk and dairy products are valuable sources of protein, fat and energy, and are an important part of daily meals. Most of the world’s milk production (85 %) comes from cows followed by buffaloes, goats, ewes, mares and donkeys. However milk related food allergies in infants may be a reason for health problems and may cause a decrease in milk. The objective of this paper was to give an overview of the overall composition of milk and fat from different species in comparison to women milk. Regarding the overall milk composition remarkable differences in energy content, fat, lactose, protein and ash of the various milks were found, but also some similarities among milk from ruminants and non-ruminants were detected. The structures of fat globule membranes were similar among non-ruminants and women milk, while the milk fat globule structure in ruminants differed significantly. The size of fat globules was significantly different between species and highly correlated to the milk fat content, regardless of the specie. The amount of triacylglycerols was notably higher, while the amount of free fatty acids and phospholipids was notably lower in milk from ruminants and women compared to milk from mares and donkeys. The triacylglycerol structure in women and non-ruminantsˈ was similar. The percentage of saturated and monounsaturated fatty acids was lower, while the unsaturated fatty acid content was higher in milk from non-ruminants, with a remarkably higher percentage of C-18:2 and C-18:3. The cholesterol content was similar in women and ruminantsˈ milk, but lower in that of non-ruminants. This review indicates that milk from non-ruminants could be more suitable for human nourishment than milk from ruminants.

The feeding of domestic animals with diets in which polyphenols are present is increasingly attracting the attention of nutritionists and scientists. This review summarizes the knowledge regarding polyphenols’ possible positive and negative effects and their bioavailability. The bioavailability of substances is a prerequisite for any postabsorption effect in vivo. Positive and negative properties have been confirmed in previous studies on the diets of domestic animals rich in polyphenols, such as secondary metabolites of plants. Free radicals are formed in every organism, leading to oxidative stress. Free radicals are highly reactive molecules and can react in cells with macromolecules and can cause damage, including in reproductive cells. Some polyphenols at specific concentrations have antioxidant properties that positively affect animal reproduction by improving the quality of male and female gametes. The intake of phytoestrogens that mimic estrogen function can induce various pathological conditions in the female reproductive tract, including ovarian, fallopian, and uterine dysfunction. The metabolism of genistein and daidzein yields the metabolites equol and p-phenyl-phenol, leading to a decline in cow fertilization. The findings so far confirm that numerous questions still need to be answered. This review points out the importance of using polyphenols that have both benificial and some unfavorable properties in specific diets.

The objectives were to evaluate the effect of heat stress on daily milk traits (yield, fat and protein content, F/P ratio) as well as to determine the differences in metabolic disorders (acidosis, ketosis) prevalence risk regarding the heat stress conditions. For statistical analysis 1,187,781 test-day records of milk, fat, and protein from 89,030 Holsteins reared on 6,388 farms provided by the Croatian Agricultural Agency, were used. Based on the results it could be concluded that heat stress condition causes decline of daily milk yield and components as well as increase of acidosis risk regardless of the lactation stage and increase of ketosis risk during mid-lactation. The research results point out that the test-day records and environmental measurements collected in regular milk recording could be used as a tool for dairy herd monitoring enabling the early detection of unfavourable environmental conditions and the subclinical disorders. Since environmental conditions significantly affect daily milk yield and components, and consequently F/P ratio, further research with the purpose of detailed formulation of metabolic disease risk in relation to the environmental conditions is needed.

The composition and properties of the milk fat of mares’ milk is interesting from a nutritional standpoint. The aim of this study was to determine the nutritional value of Lipizzaner mare’s milk for possible human consumption and identity the influence of the parity and stage of lactation on its fatty acid (FA) composition. This study was conducted on 17 Lipizzaner mares from a state stud farm in the Slavonian region (eastern Croatia). Mares were hand-milked twice during lactation in the fourth and sixth months. Significantly higher contents of MUFAs (monounsaturated fatty acids) and PUFAs (polyunsaturated fatty acids) and lower ratios of n-6/n-3 were found in the fourth month of lactation. This parity significantly affected the PUFA/SFA ratio (polyunsaturated fatty acids/saturated fatty acids), with lower values found in older mares. The fatty acid composition of mare’s milk that is especially high in UFAs (unsaturated fatty acids) is considered to be beneficial for consumers.

Since there is not enough data about milkability of the Jersey cows, the aim of this paper is to show basic milkability traits of this cattle breed depending on the parity and milk flow curve types. Cows had average daily production (DMY) of 22.23 kg, milk yield per milking (MYM) of 9.72 kg, and average and maximum milk flow about 1.66 and 2.49 kg/min, respectively. Statistical analysis showed that DMY and MYM of the cows in 4th parity was significantly (p<0.05) higher comparing to cows in 1st and 3th parity. The duration of entirely milking is similar regarding the paritiesand only the cows in 3th and 4th differ significantly (p<0.05). Regarding the effect of milk flow curve, the significant (p<0.05) difference between unspecified and rectangular milk flow curve has been found for the average milk flow (AMF) and descending phase of the milk flow curve (TD). Cows with unspecified milk flow curve, have significantly (p<0.05) lower AMF and longer TD compared to cows with rectangular curve. Cows with bimodal milk flow curve have significantly (p<0.05) longer duration of the ascending phase compering to: unspecified, descending and rectangular. The results of this study have shown that Jersey cows have lower production and milk flow compared to other dairy cattle breeds. Nonetheless, they have uniform milkability traits, and a large representation of desirable milk flow curves which are associated with a beneficial effect on the udder health.