This study assessed the effects of farm management during rearing practices in the first months of a calf’s life on growth performance and meat quality traits during the fattening period. A total of 48 Simmental calves were divided into two groups at a commercial cattle feedlot. In the first group were calves from the same farm and herd (n = 12 male and n = 12 female). The second group included calves from several different herds and farms (n = 12 male and n= 12 female). Calves were transferred to a feedlot and fed with a commercial feedlot ration at three to four months of age. The aim was to determine if identical fattening conditions at feedlot can reduce initial calf rearing differences between cattle during the fattening period. Bulls grew faster than heifers reaching higher total gain and showed significantly higher slaughter weight than heifers. Meat samples of heifers from the same herd had the highest intramuscular fat content and reddest color with significant differences among cattle groups. The most abundant fatty acid was oleic acid (C18:1), followed by palmitic (C16:0), stearic (C18:0), linoleic (C18:2), and myristic acid (C14:0). Meat samples of heifers from different herds were darkest with highest content of iron (Fe) with significant differences among cattle groups.

The objective of this research was to determine the association between age at first calving (AFC) and milk production in the first lactation of longevity traits for Holstein cows. The research was conducted on 2307 cows raised on 4 farms in AP Vojvodina. The cows were culled in the period from 2017 to 2018. The cows belonged to the group of Holstein Friesian breed of cattle. Cow longevity was observed using three parameters: number of lactations (NL), lifetime milk yield (LMY) and length of productive life (LPL). The research involved the influence of the farm on which the animals realized their production, the season of first calving. A mean value obtained for the length of productive life in the analysed population was 1207 days (3.30 years on average). During this period the animals on average realized 2.45 lactations and produced on average 18798 kg milk. All studied traits showed a high level of variability. From these data, the study sought to determine the influence of factors on the traits of longevity, our research present that studied factors showed high statistical significance on these traits except in the case of the season of first calving where a statistical significance effect wasn?t observed. The season of first calving did not affect the animal traits for longevity and, generally, didn?t affect the calving interval. Regarding the obtained correlation data between age at first calving and length of productive life, it can be concluded that belated AFC leads to reduced reproductive performance.

The aim of this research was to determine the influence of lactation number and parity on milk yield of Saanen goat’s breed. It has been concluded that milk yield was higher for goats that had given birth to twins and three kids than for goats that had given birth to a single kid (P<0.05). The longevity has a great positive impact on production, given that goats in the fifth lactation produced more milk than goats in first or second lactation (P<0.05), while goats in the sixth lactation still produced more milk than goats in first lactation (P<0.05). During the period from 2014- 2019, the research was conducted on a farm of multiparous Saanen goats in Vojvodina (northern part of Serbia). In the observed period, the farm had between 350 and 400 goats per milking, and the research included a total of 1,628 concluded lactations, within which the first lactations were the most 484, then the second 381. According to the number of lactations, goats were grouped into classes from one to seven and from one to three for parity. By comparing each individual lactation, it was determined that in first lactation goats produced significantly lower milk than goats in the rest lactations(P<0.05), except the seventh. Research has shown that lactation number has a significant influence on milk yield (P=0.00). Increasing the fertility of goats significantly affects the production capacity of dairy goats, since does with a larger number of kids in the litter had a significantly higher milk production (P<0.05). Due to the larger number of kids in the litter, milk production also increases. Likewise, it is assumed that the increase in milk yield of goats with two and three kids is a consequence of a larger placenta, i.e. stronger lactogenic activity during pregnancy.

The European Green Plan and its implementation strategies defined very demanding and ambitious goals for establishing the first "climate neutral continent" in the world. The implementation of the "Farm to Fork Strategy" (F2F) strategy will have an extremely immense effect on quantitative changes in the area of animal production (reduction in the number of animals and volume of production), increase in prices of beef and products of animal origin, the decrease in citizens' standards and increase in inflation. The appearance of the so-called "leakage effects" can be expected in NON-EU regions with the lowest population density (LU/ha), such as Serbia and the countries of the Western Balkans. At the same time, this effect represents a development opportunity for organizing extensive to semi-intensive production of organic beef based on the Cow-calf system - grass-fed beef production. In addition to the production of organic meat, these systems will contribute to improving biodiversity, maintaining the microbiological and pedological structure of the soil, regulating the carbon cycle, preventing erosion and forest fires, stopping population migration from villages to cities, reducing the use of artificial fertilizers and biocides, etc.

Summary: Nutrition is considered the primary paragenetic factor influencing the milk urea (MU) concentration in ruminants. In addition to diet, various other factors (including season, milk yield, stage of lactation, etc.) have also been shown to affect the urea concentration in ruminant milk. While the physiological concentration of MU has been well-defined for cow's milk, with an optimal range of 15 to 30 mg/dl, such parameters have yet to be established for goat's milk. The objective of this study was to determine the urea concentration in the milk of Alpine goats and to assess its correlation with the daily milk yield and the contents of fat, protein, lactose, and solids-not-fat (SNF). A total of 3,009 samples of Alpine goat milk, collected from two farms in 2021, were analyzed. The average MU concentration was 37.3 ± 8.9 mg/dl, with a range from 13.8 to 110.7 mg/dl. The average daily milk yield was 1.15 ± 0.49 kg, whereas the average milk fat and protein contents were 3.28 ± 0.97% and 3.35 ± 0.50%, respectively. The study found a positive and statistically significant correlation between the MU concentration and the contents of milk fat, protein, and SNF. Conversely, an increase in the MU concentration was negatively correlated with the daily milk yield. Monitoring the MU concentration in dairy goat herds enables the optimization of feed rations, particularly their protein and energy contents, thus improving nitrogen utilization in milk production.