The differences in production of Holstein Friesian and Holstein Friesian x Norwegian Red F1 crossbreeds

The aim of this study was to compare the production, health and fertility traits of Holstein Friesian (HF) and their F1 crosses with Norwegian Red cows (HF x NRF F1). Only the production data’s from finished first lactations of the total 57 HF x NRF F1 crosses and 401 HF cows, and for health and fertility traits of 120 HF x NRF F1 crosses and 255 HF cows, were used. The differences in production traits were tested by a least square means using the GLM procedure in SAS. The milk yield in both lactation (standard 305 days and full lactation) were higher in HF x NRF F1 crosses for approximately 400 kg, but without significance. The differences in production traits (fat and protein (kg and %)) were significant (p<0.001; p<0.05) with higher values for HF x NRF F1 crosses comparing to HF cows, with exception of protein in full lactation. Regarding the fertility traits, HF x NRF F1 crosses had a better conception rate (+1.58 %), a lower number of the insemination per pregnancy (-0.43) and a shorter duration of the service period (-22.2) comparable to HF cows. F1 crosses had better health traits (with except for hoofs problem) comparing to HF cows, they had less cows with mastitis (-11.9 %), ketosis (-0.5 %), retained placenta (-4.8 %) and dislocation of the abomasum (-1.0 %), respectively. Because of the fact that all results were obtained on the basis of data from the first lactation cows, it is necessary to do more analyses of all studied traits in subsequent lactations, in order to get a much clearer insight into the studied issues.

Concentrations of retinol and carotenoids in Jersey milk during different seasons and possible application of the colour parameter as an indicator of milk carotenoid content

The aim of this study was to determine concentrations of retinol, β-carotene, lutein and zeaxanthin in Jersey milk during different seasons and their correlation with milk colour parameters. During a sixmonths period the Jersey cows (n=77) were kept free-stall and fed with total mixed ratio (TMR; farm season), for the next three months the cows were kept for four hours on pasture and the rest of the day free-stall fed with TMR (transition season), and for the remaining three months they were kept predominantly on pasture (grazing season). A bulk milk samples (200 mL) were collected during the last week of each month in the period between May 2018 and April 2019. Retinol and carotenoids concentrations in cow milk were quantified using high performance liquid chromatography, while milk chemical composition was analysed by a MilkoScan FT 120 infra-red analyser. The season significantly (P<0.05) affected chemical composition of milk, and the highest (P<0.05) content of milk fat, protein and non-fat dry matter was found during the farm season. Retinol, β-carotene, lutein and zeaxanthin concentrations (μg/100 mL) were as follows: 2.56±0.29, 4.15±0.27, 4.43±0.40 and 0.97±0.04. Lutein and retinol concentrations in Jersey milk were affected (P<0.05) by the season. The highest lutein concentration was found during the grazing season, while the farm season yielded the highest retinol concentration. Moderate and positive correlations (P<0.05) were found between β-carotene and lutein concentrations and colour parameter b*, resulting in a more intense yellow colour i.e. high values of colour parameter b*. The obtained results suggest that milk colour could be used to estimate carotenoid concentrations in milk.

Biochemical changes during ripening of cheeses in an animal skin

A few types of cheeses ripened in an animal skin sack are produced around the world: Sir iz mišine (Croatia), Sir iz mijeha (Bosnia and Herzegovina and Montenegro), Tulum and Divle Cave (Turkey), Bouhezza (Algeria) and Darfiyeh (Lebanon). Pronounced and piquant taste, flavour and aroma of these cheeses originate from intensive lipolysis and proteolysis as a result of specific anaerobic conditions inside the skin sack, autochthonous microorganisms from raw milk and skin, as well as their manufacturing procedure. The specific and complex biochemical changes that occur during ripening of cheeses in animal skin sacks have become of great interest to researchers, and numerous studies have been conducted over the last decade. Therefore, the aim of this paper is to review the specificities of proteolytic and lipolytic changes that occur during ripening of cheese in the animal skin sack, which cause the characteristic volatile compounds profile. Moreover, the manufacturing procedures and physico-chemical properties of cheeses is shown due to their relationship with biochemical reactions during cheese ripening. As biochemical changes during ripening directly influence sensory attributes of cheese, which determine consumer preference, this review could provide practical data for cheesemakers to prevent negative consequences of overly intensive biochemical changes during cheese ripening, and so improve the quality of this kind of cheeses.

The influence of plant addition to some physicochemical, textural, microstructural, melting ability and sensory properties of Mozzarella cheese

Mozzarella cheese is produced by kneading the curd, which has a fibrous structure with melting and elongation properties, in hot water. The present study aimed to investigate the impact of the addition of some plants on certain properties of Mozzarella cheese. Rosemary (Rosmarinus officinalis L.), basil (Ocimum basilicum L.), mint (Mentha piperita L.) and Turkish Oregano (Origanum onites L.) were added to Mozzarella cheese at the curd kneading stage, and physicochemical, textural, microstructural, meltability and sensory properties were investigated during the storage period. No plants were added to the control group cheese. Plant addition to Mozzarella cheese affected some physicochemical properties such as pH, acidity, free fatty acids, as well as textural and microstructural properties. Furthermore, it affected sensory properties, especially Turkish Oregano and mint addition provided high general acceptability and taste-aroma scores. While higher pH and lower titration acidity were determined in rosemary-added cheese samples, the lowest free fatty acid (ADV) levels were determined in the mint-added cheese sample. Rosemary-added cheeses had higher hardness and a more even microstructure, while the highest sensory scores were obstained for cheeses that included Turkish Oregano and mint. In conclusion, the present study findings demonstrated that the short shelf life of Mozzarella cheese could be extended with the addition of various plants due to their effects on pH, acidity and free fatty acids.

Texture, colour and sensory properties of non-fat yoghurt as influenced by tara gum or combinations of tara gum with buttermilk powder

The texture, colour and sensory properties of non-fat yoghurts prepared with different tara gum concentrations (0.25, 0.50 and 1.0 gL-1) and different tara gum (TG) with buttermilk powder (BP) combinations (0.25+10, 0.50+10 and 1.0+10 gL-1) were investigated during storage. While addition of 0.25 and 0.50 gL-1 of tara gum caused an increase in firmness, consistency, cohesiveness, viscosity index of yoghurt samples, use of 1 gL-1 of tara gum and combinations of tara gum with buttermilk powder led to a decrease in these properties. During the storage period, increasing the concentration of tara gum resulted in significant decrease in L* and a* values, significant increase in b* value in yoghurt. Sensory properties of non-fat yoghurts supplemented with 0.25 and 0.50 gL-1 did not significantly differ from those of control yoghurts. In contrast, use of 1 gL-1 of tara gum and combinations of tara gum and buttermilk powder caused a significant decrease of sensory properties of non-fat yoghurt.

Relationship of milking traits and somatic cell count with electrical conductivity of goat milk during different milking phases

The aim of this study was to estimate the relation between milking traits and somatic cell count with electrical conductivity of goat milk during different milking phases. The research was carried out in the herd of Czech White Shorthaired and Saanen goat breeds (n=323) with the help of the electronic milk flow meter LactoCorder®. The milk yield, milking duration, milking flow rate and electrical conductivity of milk in the different phases of milking showed the significant mean differences between the breeds. Almost all (except electrical conductivity during the initial time) investigated indicators of electrical conductivity had a significant positive correlation with SCC. The bimodality of milk flow was determined in 9.69 % of goats and associated with milk yield decrease and SCC increase (P<0.05). The results confirm that the milk flow curve data is a good tool to control milking traits of goats, to predict the prevalence of mastitis and, thus, to improve the health of the udder of goats.

Consumers’ attitudes towards functional dairy market in Croatia - a cross-sectional study

Modern consumers ask for foods that have beneficial effects beyond the traditionally known nutritional role. This is the core definition of functional foods, however, many consumers are confused with what functionality represents. Milk and dairy products stand out as the largest segment of functional foods. Given the diversity of Croatia’s functional dairy market, the aim of this study was to conduct market analysis and to analyse whether consumers’ attitudes towards functional foods in general, and specifically functional dairy products, changed throughout years (by comparing year 2011/12 to 2019). Market analysis was done according to the standardized methodology while for consumer’s attitudes an online, study-specific questionnaire was used. The same questionnaire was used for both study years. Total of 231 participants in 2011/12 and 221 in 2019 completed the questionnaire. In comparison to 2011/12, statistically less people are buying functional foods (44.3 % in 2019 vs 63.5 % in 2011/12, p=0.026) but the awareness improved over time, especially regarding probiotics. Within eight years, two new growing categories of functional dairy were identified; yoghurt with chia seeds and high-protein products, while the range of lactose-free products bloomed. Cross-sectional analysis showed that the only consistent independent indicator of consumer’s decision to buy a functional over a regular product is the self-care for health, which increases the likelihood by 50.2 %. Unlike eight years ago, pre-existence of a medical condition increases the likelihood to buy a lactose-free product (by 47.4 %), regardless of what the medical condition is. Despite some positive shifts observed, general awareness of what functionality represents and what is the intended purpose of a product is fragmentary. Our findings support the need for stronger, specifically targeted evidence-based communication towards the consumers.

Evaluation of lactation models in pasture-based dairy ewes in Bosnia and Herzegovina

Milk of Kupres, Privor and Stolac dairy ewe breeds is used for the production of the fine cheese varieties. To the best of our knowledge there are no information about milk production and milk composition of these pasture-based dairy ewes. The aim was to determine the best lactation curve model in autochthonous pasture-based dairy ewes in Bosnia and Herzegovina. Milk production was recorded and milk composition sampled (milk fat and protein) during early, mid and late lactation in 129 Kupres, 141 Privor and 129 Stolac pramenka ewes. Four lactation models (Wilmink, Cubic, Ali-Shaeffer and Guo-Swalve) were compared and selected based on the lowest coefficient of determination and root mean square error. The Guo-Swalve model described all of the measured variables most successfully. Kupres pramenka dairy ewe was the highest producing breed with 139 kg of milk during 175 days of lactation (0.79 kg/d; between lactation day 50 to 225) and showed the standard lactation curve. Privor pramenka produced 118 kg of milk during 175 days of lactation (0.67 kg/d) and Stolac pramenka 101 kg of milk during 175 days of lactation (0.58 kg/d). Both showed atypical constantly decreasing shape of the lactation curve common in low producing dairy ewes. The prediction of milk yield and milk composition from the Guo-Swalve model could be used by the national breeding program for the Kupres, Privor and Stolac pramenka sheep breeds. Additional research during a more stable management conditions is recommended for Privor and Stolac pramenka.

The effect of in vitro digestion on antioxidant properties of water-soluble and insoluble protein fractions of traditional Serbian white- brined cheeses

The influence of simulated in vitro digestion on antioxidant potential of protein fractions of traditional Serbian white-brined cheeses was investigated. Water-soluble (WSF) and water-insoluble fractions (WINF) of three cow’s and three ovine white-brined cheeses were fractionated. Total antioxidant capacity, reducing power and iron (II) chelating properties of these fractions before and after in vitro digestion were assayed. The investigated protein fractions had different antioxidant properties. WSFs had a better total antioxidant capacity and reducing power and less pronounced iron (II) chelating properties than WINFs. A strong negative correlation (-0.818, P<0.05) between the total antioxidant capacities of undigested WSF and WINF of traditional cheeses were observed. In vitro digestion greatly improved the total antioxidant capacities of WINFs (by 16.61-34.18 times), their reducing power (up to 95.77 %) and except in the case of Svrljig ovine cheese, the iron (II) chelating ability as well. A less pronounced increase (up to 71.29 %) of the total antioxidant capacity of WSFs was induced by in vitro digestion. In vitro digestion reduced reducing power of WSF of investigated ovine cheeses as well as reducing power of WSF of Homolje cow’s cheese. Since there was no significant correlation between the investigated antioxidant properties of digested WSFs and their free amino acids and mineral contents the observed differences should be attributed to different composition and properties of low molecular weight peptides. Thus, further investigations related to their isolation and characterization needs to be conducted. However, these results indicate that Serbian white-brined cheeses have great potential as source of antioxidant peptides.

Microstructure of kajmak skin layer made during kajmak production

Kajmak is a unique dairy product with a long tradition in Balkan countries and the Middle East. Kajmak skin layers are formed during 60 minutes of kajmak production, influencing the quality and determining the structure of the final product. The influence of milk composition and heat treatments (75-95 °C/5min) on the composition, microstructure and protein distribution of kajmak skin layers was investigated in this study. Microstructure was determined using scanning electron microscopy (SEM), while the distribution of protein fractions was studied by SDS PAGE in reducing and non-reducing conditions. Kajmak skin layers obtained from milk treated at common intense heat regime were characterized with β-LG and α-LA mainly as disulfide-linked complexes, while lower temperature (75 °C) caused the presence of whey proteins in dominantly individual form. More severe treatments (85 °C, 90 °C and 95 °C) caused the full involvement of β-LG in the complexes, since a certain amount of α-LA was found as a monomer. The kajmak skin layer composition, severity of the applied milk heat treatment and the linked whey proteins exhibited a very strong influence on kajmak skin layer microstructure. The microstructure of kajmak skin layer with a low fat content and fat/protein (F/P) ratio was characterized by a compact structure with a dense protein matrix. High fat content and F/P ratio resulted in a dispersive form of the stretched protein network. Kajmak skin layers produced from milk with added whey proteins were characterized by fibrous, thread-like segments, due to the incorporated denatured whey proteins, especially linked β-LG.