Influence of two feed supplements on technological properties of goat’s milk

Hranidba koza na dnevnoj bazi sastoji se od ispaše, sijena i/ili suplemenata. Suplementi su neophodni u hranidbi visokoproduktivnih pasmina koza u svrhu postizanja genetskog potencijala i uzgajivači moraju odabrati režim hranidbe koji osigurava proizvodnju velikih količina mlijeka bez neželjenih promjena u tehnološkoj kvaliteti mlijeka. U ovom istraživanju određivan je utjecaj dva komercijalno dostupna suplementa na sposobnost koagulacije kozjeg mlijeka te na reološka svojstva jogurta od kozjeg mlijeka. Ukupno 61 koza pasmine slovenska alpska koza hranjena je s dva suplementa tijekom tri godine. Prvi suplement (FS1) imao je viši udjel ječma i lucerne, dok je drugi suplement (FS2) imao dodane mineralne tvari i vitamine te više udjele pšenice i suncokretove pogače. Posljedično, FS1 je imao više sirovih vlakana, što je vrlo vjerojatno rezultiralo 15 % većom čvrstoćom, konzistencijom i kohezivnosti (P<0,05) jogurta iz skupine FS1 u odnosu na jogurte iz skupine FS2. K tomu je i vrijeme koagulacije (r) bilo kraće (P<0,05) kod jogurta iz skupine FS1 u usporedbi s jogurtima iz skupine FS2. Čvrstoća gruša 30 min nakon dodatka enzima (a30) također je bila veća u skupini FS1, iako te razlike nisu bile statistički značajne. Uzimajući sve navedeno u obzir, dobiveni rezultati ukazuju kako su koze hranjenje suplementom FS1 proizvodile mlijeko boljih tehnoloških svojstava nego koze hranjene suplementom FS2, unatoč činjenici da nisu utvrđene statistički značajne razlike u kemijskom sastavu mlijeka iz obiju navedenih skupina. Ova studija pokazala je da se pažljivim odabirom suplementa u hranidbi mogu poboljšati tehnološka svojstva kozjeg mlijeka. Međutim, potrebno je provođenje daljnjih istraživanja u svrhu određivanja specifičnih mehanizama koji su doveli do prethodno navedenih razlika.Goat’s daily diet is usually based on grazing, hay and/or feed supplements. Feed supplements are crucial in the diet of high productive goats to achieve their genetic potential and breeders must choose balanced feeding regime to produce large quantities of milk without affecting the technological quality of milk. In the present study, we evaluated the influence of two commercially available feed supplements on goat milk coagulation properties and rheological properties of yoghurts. Goats of the Slovenian Alpine breed (61) were fed with two feed supplements during the 3-year experiment. Feed supplement 1 (FS1) had higher proportions of barley and alfalfa, while feed supplement 2 (FS2) had added premix of minerals and vitamins and had higher proportions of wheat and sunflower meal. Con¬sequently, FS1 had more crude fibres, which is the most probable reason for approximately 15 % higher firmness, consistency and cohesiveness (P<0.05) of yoghurts in FS1 group, compared to the FS2 group. Moreover, the rennet coagulation time (r) was shorter (P<0.05) in the FS1 group, compared to the FS2 group. Curd firmness 30 min after enzyme addition (a30) was also higher in FS1 group although the results were not statistically significant. Taking together, our results indicate that goats fed with FS1 produced milk with better technological properties compared to those fed with FS2, despite the fact that there were no significant differences in chemical composition of milk from each group. We showed that careful selection of feed supplement’s constituents could improve technological properties of goat milk. However, further studies are needed to evaluate the mechanisms of the observed differences

How Can We Advance Integrative Biology Research in Animal Science in 21st Century?:Experience at University of Ljubljana from 2002 to 2022

In this perspective analysis, we strive to answer the following question: how can we advance integrative biology research in the 21st century with lessons from animal science? At the University of Ljubljana, Biotechnical Faculty, Department of Animal Science, we share here our three lessons learned in the two decades from 2002 to 2022 that we believe could inform integrative biology, systems science, and animal science scholarship in other countries and geographies. Cultivating multiomics knowledge through a conceptual lens of integrative biology is crucial for life sciences research that can stand the test of diverse biological, clinical, and ecological contexts. Moreover, in an era of the current COVID-19 pandemic, animal nutrition and animal science, and the study of their interactions with human health (and vice versa) through integrative biology approaches hold enormous prospects and significance for systems medicine and ecosystem health

Comparison of different types of reconstructions of burnt forest in the area ʺTrstelj - Šumkaʺ

Na območju Šumka % Trstelj je bilo leta 2006 v požaru zajetih 720 ha gozda, od tega je 75 % gozda zajel vršni požar. V zadnjih letih se uveljavlja izkoriščanje sečnih ostankov za sekance, kar vodi v osiromašenje tal z organskimi snovmi. Raziskovalni objekt se nahaja v Kraškem gozdnogospodarskem območju na rastišču jesenske vilovine s črnim gabrom (Seslerio-Ostryetum), kjer je bilo postavljenih 12 večjih raziskovalnih ploskev, porazdeljenih po tri na štirih različnih lokacijah požarišča glede na način izvedbe sanacije. Ugotovili smo, da je bil vpliv rastiščnih, edafskih in reliefnih dejavnikov na uspešnost naravne in umetne obnove mnogo večji kot sam način izvedbe sanacije v posameznem stratumu. Odkrili smo tudi, da je bila uspešnost naravne obnove zadovoljiva v nasprotju z umetno obnovo, kjer je bilo mladje zelo redko. Glede na naše ugotovitve sklepamo, da bodo na teh ploskvah v prihodnosti prevladovali mešani sestoji termofilnih listavcev, predvsem črni gaber, hrasti in mali jesen, ki se jim bosta na boljših rastiščih pridružila v skupinah poljski brest in posamezno gorski javor. Tem avtohtonim vrstam bo ostajala primešana robinija, ki pa ji v primerjavi z avtohtonimi vrstami življenjska moč močno pojema.In the area Šumka % Trstelj in the year 2006 the fire covered 720 ha of the forest, of which 75% was crown fire. In recent years, exploitation of logging residues for wood chips is applied, which leads to the impoverishment of the soil with organic matter. The research facility is located in the Kras forest management area, at the site of the autumn moor grass (Sesleria autumnalis) and black hornbeam (Seslerio-Ostryetum), where 12 major research plots were formed. The research plots were separated in 3 groups and set on 4 different locations of the burnt area, depending on the mode of salvage logging. The results indicated that site, edaphic and relief factors had a greater impact on the performance of natural and artificial regeneration, as the mode of salvage logging in each stratum itself. The effectiveness of the natural regeneration was satisfactory in contrast to the artificial regeneration, where the number of seedlings was low. According to our findings, we expect that in the future, the plots will be dominated by mixed stands of thermophilic deciduous species, mainly hornbeam, oak and flowering ash. In the future, they will be joined on better sites by groups of field elm and individually sycamore. This native species will remain being mixed with black locust, whose vitality is in comparison with native species, decreasing

Evaluation of human milk microbiota by 16S rRNA gene next-generation sequencing (NGS) and cultivation/MALDI-TOF mass spectrometry identification

The aim of the present study was to characterize human milk microbiota (HMM) with 16S rRNA gene amplicon next-generation sequencing and cultivation/matrix-assisted laser desorption/ionization (MALDI)-time of flight (TOF) mass spectrometry (MS) identification approaches. We analyzed 31 human milk samples from healthy Slovenian mothers. To check the accuracy of MALDI-TOF MS identification, several colonies representing most abundant genera and those, which could not be reliably identified by MALDITOF, were subjected to Sanger sequencing of their 16S rRNA gene. We showed that cultivation/MALDI-TOF MS was a suitable tool for culture-dependent determination of HMM. With both approaches, Staphylococcus and Streptococcus were found as predominant genera in HMM and the abundance of Staphylococcus was associated with decreased microbial diversity. In addition, we characterized factors that might influence HMM. The use of a breast pump was significantly associated with composition of HMM, higher microbial load, and lower abundance of cultivable staphylococci. Moreover, our study suggests that administration of probiotics to the suckling infant might influence HMM by increased abundance of lactobacilli and the presence of viable probiotic bacteria in human milk. However, since our study was observational with relatively small sample size, more targeted studies are needed to study possible transfer of probiotics to the mammary gland via an external route and the physiological relevance of these events

Correlations of goat milk coagulation properties between dams and daughters

Goat milk coagulation properties (gMCP) are important trait for the cheesemaking industry but are rarely included in national breeding programs. In the present study, we monitored goat milk quality traits and gMCP of Slovenian Alpine goats within a single flock (N = 77), reared in the same common environment over three-year period. In addition, using pedigree data, we looked for correlations among dams, daughters (N = 32 pairs) and gMCP. Traditional gMCP measurements were introduced into a 4-parameter curd firmness over time (CFt) model. Several gMCP parameters were associated with parity and stage of lactation. Most notably, estimated rennet coagulation time (RCTeq), curd firmness at 15 (a15eq) and 20 min (a20eq) after rennet addition were strongly correlated between dams and their daughters. These results support further research of genetic parameters for gMCP and the inclusion of breeding value predictions for gMCP in national breeding programs

Evaluation of dietary supplements containing viable bacteria by cultivation/MALDI-TOF mass spectrometry and PCR identification

The insufficient quality of products containing beneficial live bacteria in terms of content and viability of labelled microorganisms is an often-reported problem. The aim of this work was to evaluate the quality of dietary supplements containing viable bacteria available in Slovenian pharmacies using plate counting, matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) and species- or subspecies-specific PCR with DNA isolated from consortia of viable bacteria, from individual isolates, or directly from the products. Twelve percent of the products (3 of 26) contained insufficient numbers of viable bacteria. Eighty-three of the labelled species (111 in total) were confirmed by PCR with DNA from the product; 74% of these were confirmed by PCR with DNA from viable consortium, and 65% of these were confirmed by MALDI-TOF MS analysis of colonies. Certain species in multi-strain products were confirmed by PCR with DNA from viable consortia but not by MALDI-TOF MS, suggesting that the number of isolates examined (three per labelled strain) was too low. With the exception of Lacticaseibacillus casei and closely related species (Lacticaseibacillus rhamnosus and Lacticaseibacillus zeae), PCR and MALDI-TOF identification results agreed for 99% of the isolates examined, although several MALDI-TOF results had lower score values (1.700–1.999), indicating that the species identification was not reliable. The species L. zeae, which appeared in 20 matches of the Biotyper analysis, was identified as L. rhamnosus by PCR. The MALDI-TOF MS analysis was also unsuccessful in detecting Lactobacillus acidophilus La-5 and Bacillus coagulans due to missing peaks and unreliable identification, respectively. Mislabelling was detected by both methods for two putative L. casei strains that turned out to belong to the species Lacticaseibacillus paracasei. PCR remains more successful in subspecies-level identification as long as the database of MALDI-TOF MS spectra is not expanded by building in-house databases. The lack of positive PCR results with viable consortia or colonies, but positive PCR results with DNA isolated directly from the products observed in 10% (11/112) of the labelled strains, suggests the presence of non-culturable bacteria in the products. MALDI-TOF MS is a faster and simpler alternative to PCR identification, provided that a sufficient number of colonies are examined. Generation of in-house library may further improve the identification accuracy at the species and sub-species level

Lactic acid bacteria and bifidobacteria deliberately introduced into the agro-food chain do not significantly increase the antimicrobial resistance gene pool

Lactic acid bacteria (LAB) and bifidobacteria may serve as reservoirs of antimicrobial resistance, but the risk posed by strains intentionally introduced into the agro-food chain has not yet been thoroughly investigated. The aim of our study was to evaluate whether probiotics, starter and protective cultures, and feed additives represent a risk to human health. In addition to commercial strains of LAB and bifidobacteria, isolates from human milk or colostrum, intestinal mucosa or feces, and fermented products were analyzed. Phenotypic susceptibility data of 474 strains showed that antimicrobial resistance was more common in intestinal isolates than in commercial strains. Antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs) were characterized in the whole genome sequences of 1114 strains using comparative genomics. Intrinsic ARGs were abundant in enterococci, bifidobacteria, and lactococci but were considered non-risky due to the absence of MGEs. The results revealed that 13.8% of commercial strains contained acquired ARGs, most frequently for tetracycline. We associated 75.5% of the acquired ARGs with known or novel MGEs, and their potential for transmission was assessed by examining metagenomic sequences. We confirmed that ARGs and MGEs were not as abundant or diverse in commercial strains as in human intestinal isolates or isolates from human milk, suggesting that strains intentionally introduced into the agro-food chain do not pose a significant threat. However, attention should be paid especially to individual probiotic strains containing elements that have been shown to have high potential for transferability in the gut microbiota