Glutamate is one of the most abundant amino acids in nature, accounting for up to 8-10% of most dietary proteins and peptides and most tissues. Only the free form of glutamate has taste-enhancing ...properties as a unique umami taste, and when glutamate is bound to proteins, it is tasteless with no umami taste. Fermentation, ageing, ripening and heat cooking are typical natural processes of protein hydrolysis during which free glutamate is released. The food industry most commonly uses it in the form of monosodium glutamate (MSG) in amounts between 0.1 and 0.8% as a flavour enhancer. Since the beginning of the 21st century, its use as a flavour enhancer in meat and meat products with reduced salt content has become more widespread. The sodium content of MSG (12.28 g/100 g) is one-third that of salt (39.34 g/100 g), making MSG a promising salt alternative in sodium reduction strategies. There is no one-sided and conclusive scientific information reporting adverse human health effects of MSG in the general population, and it is still considered safe. However, in the wake of "clean label" initiatives, many consumers would prefer not to have additives or flavour enhancers such as glutamates in their food. This can be overcome by the known synergistic effect of natural 5'-ribonucleotides and glutamates found in seaweed, cheese, fish sauce, yeast extract, soy sauce, fermented soybeans and tomatoes, as they enhance the overall perception of umami flavour.
The aim of this study was to determine effect of diet-based seasonal changes on fatty acid composition of Jersey milk in mountain region of Croatia. Bulk milk samples (200 mL) were collected during ...total-mixed ratio (TMR)-based, intermediate and pasture-based diet. Fatty acid composition of milk was determined by gas-chromatography. We found that pasture-based diet has positive effect on fatty acid composition of Jersey milk considering human nutrition. During pasture-based diet, Jersey cows produced milk with lower (P<0.05) saturated fatty acid and higher (P<0.05) polyunsaturated fatty acid content. Namely, regarding individual fatty acids, milk produced during pasture-based diet had lower (P<0.05) C16:0 and higher (P<0.05) C18:2n-6, C18:3n-6 and conjugated linoleic acid (CLA) content than milk produced during TMR and intermediate diet. Milk produced during pasture-based diet can be valuable source of health-beneficial PUFA in diet.
Milk urea concentration (MU) has been extensively studied and is often used to evaluate energy and protein balance in dairy cattle diets, but not to this extent in dairy goat diets. The aim of this ...study was to determine the relationship between MU concentration and crude protein content (CP) in the diet of Alpine goats in order to reduce excessive nitrogen excretion from the organism. For this purpose, 72 goats were randomly divided into three equal groups (24 animals) and fed a concentrate mix containing 14%, 16%, and 18% CP, respectively. The chemical composition of milk samples was determined and the ratio of milk fat to protein was calculated. Statistical analysis of the data was performed using the MIXED procedure (SAS V8 software package). Increasing CP from 14% to 16% in the diet increased daily milk yield by 0.4 kg (p<0.001), and MU concentration from 35.01 to 41.24 mg/100 mL (p<0.001). Based on the calculated inflection point of daily milk yield and protein content in milk, the range of MU concentration from 40.00 to 45.00 mg/100 mL can be considered optimal and is a good indicator of a balanced diet for goats.
In recent years there has been an increasing trend in research of sheep and goat udder morphology, not only from the view of its suitability for machine milking, but also in terms of milk yield and ...mammary gland health. More precisely, herds consisting of high-yielding sheep and goats as a result of long-term and one-sided selection to increase milk yield, have been characterised by distortion of the udder morphology caused by increasing the pressure of udder weight on its suspensory system. Along with the deteriorated milking traits, which is negatively reflected on the udder health, some udder morphology traits are often emphasized as factor of production longevity of dairy sheep and goats. Since the intention of farmers and breeders nowadays is to increase the milk yield of sheep and goats while maintaining desirable udder morphology and udder health, the aim of this paper is to give a detailed overview of the current knowledge about the relationship of morphological udder traits with milk yield, and the health of the mammary gland of sheep and goats. External measures of udder size (circumference, width and depth of the udder) are strongly correlated with milk production in sheep and goats. The morphological udder traits determining its suitability for machine milking (such as teat position and teat angle, udder depth, teat size, cistern height) are related to the mammary gland health in sheep and goats. Thus, the incidence of mastitis is noticeably higher in the udders of unsuitable shape for machine milking (deep and hung udders, unfavourable position of teats, etc.). Consequently, the morphological udder traits that affect the milkability of sheep and goats are indirectly related to milk yield.
The optimal concentration of urea in cow's milk is known and is often used to assess the balance of energy and protein in diets. While in goat (and sheep) milk it is not controled nor defined. Main ...determinants of urea formation in milk are the amount of crude protein intake and the ratio betwwen protein and energy proportion in diet. Goat diet with excessive amount of crude protein and energy unbalanced diet cause the excess of nitrogenous substances in rumen along with release of ammonia and rise in concentration of urea in blood and milk, which adversely affects the production, milk coagulation propreties, environmental pollution and reproductive capabilities of goats. However, besides diet, there are other factors that influence milk urea concentration: breed, stage of lactation, parity, season, body mass, litter size, production and chemical composition of milk. Numerous studies conducted on cow milk included the influence of sources of variability listed above, while there are only few studies available for goat milk due to its less economic importance, seasonal polyesterity and different way of breeding and keeping goats. The aim of this paper is to comparatively and critically combine the previous research results on the importance of determining the milk urea concentration as well as on individual sources of variability of urea concentration in goat milk.
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.
Cilj ovog rad bio je utvrditi utjecaj sezone na koncentraciju retinola, β-karotena, luteina i zeaksantina u mlijeku Jersey krava, te njihovu povezanost s pokazateljima boje mlijeka. Krave (n=77) su tijekom šestomjesečnog razdoblja držane u staji i hranjene kompletno miješanim obrokom (TMR; farmska sezona), tijekom tri mjeseca boravile se četiri sata na pašnjaku i ostatak dana u staji te hranjene TMR-om (prijelazna sezona), dok su tri mjeseca cijeli dan držane na paši uz dohranu koncentratom (pašna sezona). U razdoblju od svibnja 2018. do travnja 2019. godine tijekom zadnjeg tjedna svakog mjeseca prikupljani su skupni
uzorci mlijeka (200 mL). Koncentracije retinola i karotenoida u mlijeku
su kvantificirane primjenom tekućinske kromatografije visoke djelotvornosti, dok je kemijski sastav mlijeka određen primjenom uređaja
MilkoScan FT 120. Sezona je imala značajan (P<0,05) utjecaj na kemijski sastav mlijeka te je najveći (P<0,05) prosječni sadržaj mliječne masti, bjelančevina i bezmasne suhe tvari u mlijeku utvrđen tijekom farmske sezone Prosječne koncentracije (μg/100 mL) retinola, β-karotena, luteina i zeaksantina u mlijeku su iznosile: 2,56±0,29; 4,15±0,27; 4,43±0,40; i 0,97±0,04. Utvrđen je značajan (P<0,05) utjecaj sezone na koncentracije luteina i retinola pri čemu je najveća koncentracija luteina utvrđena je tijekom pašne sezone, dok je najveća koncentracija retinola utvrđena u mlijeku tijekom farmske sezone. Umjerene i pozitivne korelacije (P<0.05) utvrđene su između kon-centracije β-karotena, odnosno koncentracije luteina i b* parametra boje mlijeka što se očituje u žućoj boji mlijeka, odnosno većoj vrijednosti parametra boje b*. Stoga, boja mlijeka može poslužiti u procjeni koncentracije karotena u mlijeku.
The aim of this study was to determine the prevalence of individual udder shapes in three dairy sheep breeds, as well as the relationship of udder shape with the production and chemical composition ...of sheep's milk. For this purpose, the research included 111 Pag sheep, 93 Istrian sheep and 80 East Friesian sheep. During the milking period in all flocks included in the research, milking control was carried out using the AT method, while the udder shape assessment in all studied ewes was carried out by the same person once during lactation when conducting the first milking control (after weaning of lamb(s)). In Pag sheep four distinct forms or types of udder (types I, II, III and IV) were clearly identified, in Istrian sheep the existence of three udder shapes (types II, III and IV) was determined, while in East Friesian sheep were found two udder shapes (type II and III). In all three breeds the most frequent were ewes with the udder type III. in all three breeds, higher production of milk was observed in sheep with low and (almost) vertically positioned teats and with a pronounced longitudinal furrow between the udder halves (udder types III and IV) than in sheep with highly placed and horizontally positioned teats (udder types I and II). However, differences in milk production between sheep of different udder shapes were found to be statistically significant (P<0.05) only in East Friesian sheep. Irrespective to breed, the poorest average milk chemical composition was found in ewes (udder types) with the highest average daily and lactation milk yield.
Livestock industry, with dairy sector as one of the fastest growing, largely contributes to the atmospheric/soil pollution and greenhouse gases emissions (i.e. methane, carbon dioxide, and nitrous ...oxide) on the global scale. The goal of this paper is to present a short synthesis of published scientific works aiming to reduce dairy ruminants’ environmental footprint by mitigating land degradation, water pollution and depletion, and greenhouse gasses emissions (GHG) by implementing novel nutritional, biotechnological, microbiological, animal management, and manure management strategies. In order to mitigate land degradation, suggested strategies include the introduction and adjustment of grazing fees and lease rents, and addressing pollution by establishing a “provider gets - polluter pays”. Improving water use efficiency is the most important in animal feed production. Contamination of water with microorganisms and parasites from manure should be prevented to avoid a public health hazards. With respect to methane and nitrous oxide emissions, the most common nutritional strategy for mitigating GHG emissions is using forages with lower fiber and higher soluble carbohydrates content or grazing less mature pastures. Although many of feed additives (organic acids, secondary plant components, and lipids) can be effective to some extent in reducing rumen methanogenesis, much in vivo research is still needed to clarify which amounts and combinations of additives are the most effective in mitigating methane emission. In order to successfully respond to the increasing global demand for raw milk and milk products, the dairy industry will have to mitigate future negative impacts on the environment, modifying the current production systems, and maintain at the same time high quality of final products at an economic price acceptable for the consumers.
The aim of this study was to determine relationship between litter size and milk yield, udder morphology, and udder health of East Friesian ewes. For that purpose a total of 80 East Friesian ewes, ...from 2nd to 4th lactation, with symmetrical udders, without visible (clinical) signs of mastitis were involved in this study. Until weaning at average age of 60±5 days lambs suckled their mothers exclusively. During milking period regular milking controls (on a monthly basis) were carried out (AT method) and, on these occasions, individual milk samples for chemical composition analysis were taken. Three times per lactation (1st, 3rd and 5th milking control), prior to the milking, evaluation and measuring of udder morphology traits were performed. Also, during above-mentioned test-day controls (three times per lactation) one sample of half udder milk was taken with purpose of bacterial and somatic cell counts (SCC) tests. Ewes with twin and triplet lambs had significantly (P<0.05) higher milk yield (daily and lactation milk yield) and lower (P<0.05) average milk fat content and total solids content than ewes with single lamb. Ewes with twins and triplets had bigger and more developed udder than ewes with singles, i.e. their udders were of larger circumference (P<0.05), larger width (P>0.05) and depth (P>0.05). Besides that, udders of ewes with twins and triplets had higher cistern, greater teat angle and larger teat dimensions than ewes with singles, although those differences were not statistically significant. Ewes with single lamb had teats more (P<0.05) cranially oriented than ewes with twins and triplets. Significant (P<0.05) differences in somatic cell count (log10SCC) between ewes of different litter sizes were determined, regardless of the health status of mammary gland. The higher (P<0.05) prevalence of subclinical mastitis was observed in ewes with twin and triplet lambs than in ewes with singles. In 46% of mammary glands (udder halves) of sheep with twins and triplets a subclinical mastitis was established and even 65.8% of them undergone an infection of one or both halves of the udder during the milking period.
The aim of this paper was to determine basic technological traits and sensory acceptance of dry game sausages with addition of bay leaf (Laurus nobilis L.) essential oil. For that purpose, three ...treatments were established: controlled C, L1 with addition of 0.005% of bay leaf essential oil, and L2 with addition of 0.01% of bay leaf essential oil. Measurement of pH, water activity and thiobarbituric acid reactive substances (TBARS) values were performed at the end of production, while after storage for 2 months in vacuum and cold sensory hedonic test on 106 subjects was done. It was found that sausages with added bay leaf essential oil had significantly lower pH values (L1 and L2 treatment), water activity (L1 treatment) and TBARS values (L1 and L2 treatment) compared to control treatment C. Statistical analysis of sensory data revealed that sausages from C treatment were rated with significantly higher acceptability and willingness to buy than L1 and L2 treatments. It was established that sensory traits of sausages from treatment C were liked in 98.61% of consumers, from treatment L1 in 90.93%, while sausages from treatment L2 were liked in 85.71% of consumers. The highest proportion of consumers willing to buy sausages were in treatment C (91.11%), followed by sausages in treatment L1 (84.31%), and the lowest proportion were in treatment L2 (66.67%). Although beneficial impact of addition of bay leaf essential oil on technological traits was found, there was an unfavorable effect on sensory traits and willingness to buy sausages possibly due to the consumers’ existing expectation of sensory characteristics of dry game sausages.
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