Spreminjanje kakovosti mleziva v prvih petih dneh po telitvi pri kravah rjave pasme na dveh kmetijah v Sloveniji

Tomšič, Tone (avtor), Klopčič, Marija (mentor)

Reja krav molznic je postala vse bolj specializirana. V odnosu do tega žal premalo pozornosti namenjamo vzreji telet. Predvsem na področju kakovosti mleziva v Sloveniji nismo naredili veliko raziskav. Cilj naloge je bil analizirati mlezivo z dveh slovenskih kmetij, kjer se ukvarjajo s prirejo mleka. Analizirali smo kemijsko sestavo mleziva (suha snov, maščobe, imunoglobuline, skupno število somatskih celic,…). Proučili smo tudi vpliv sezone na kakovost mleziva. Vzorce mleziva, zbrane v poletnih mesecih, smo primerjali z vzorci mleziva odvzetih v zimskih mesecih. Dobljene rezultate smo primerjali z rezultati, ki jih navaja literatura in izdelali priporočila za vzrejo telet. Skupno smo zbrali 137 vzorcev od 20 krav rjave pasme, ki smo jih jemali prvih pet dni po telitvi. V povprečju je bilo v mlezivu, zbranem v sedmih zaporednih molžah, 6,43 ± 3,40 % beljakovin od tega 4,77 ± 2,36 % kazeina. V mlezivu je bilo 4,90 ± 1,88 %, maščob in 3,63 ± 0,71 % laktoze. Povprečna vsebnost suhe snovi v analiziranih vzorcih je bila 16,14 ± 4,11 %. Gostota mleziva se je gibala med 1,017 do 1,052 g/cm3. Največjo variabilnost smo ugotovili pri zaščitnih snoveh v mlezivu: pri imunoglobulinih, lizocimu, laktoferinu, alfa laktoglobulinu in beta laktoglobulinu (KV > 60 %), saj se njihove koncentracije najhitreje zmanjšujejo z zaporedno molžo po telitvi. Naši rezultati se niso bistveno razlikovali od rezultatov drugih avtorjev. Samo pri koncentraciji imunoglobulinov smo ugotovili precejšna odstopanja od navedb v literaturi, saj smo izmerili 14,26 g imunoglubulinov g/l, medtem ko v literaturi navajajo, da mora kakovostno mlezivo vsebovati najmanj 50 g imunoglobulinov/l. Razlog za tako odstopanje sicer ni znan, vendar pa menimo, da je do takih odstopanj prišlo zaradi napak pri zamrzovanju, shranjevanju in pripravi vzorcev mleziva.

• Jezik: Slovenski jezik
• Ključne besede: govedo, pasme, rjava pasma, teleta, mlezivo, kakovost, Slovenija
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: BF - Biotehniška fakulteta
• Leto izida: 2020
• PID: 20.500.12556/RUL-121225
• COBISS.SI-ID: 30992131
• Datum objave v RUL: 02.10.2020

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Changing of colostrum quality in the first five days after calving of Brown Swiss cows on two farms in Slovenia

Izvleček

Rearing of dairy cows has become increasingly specialized. Unfortunately, less emphasis was put on calf rearing. There has not been much research done on the quality of colostrum in Slovenia. The aim of this thesis was to analyse colostrum from two Slovenian dairy farms. We analysed the chemical composition of the colostrum (dry matter, fats, immunoglobulin, somatic cell counts, etc.). We also studied how the seasons affected the colostrum quality. Colostrum samples collected in summer months were compared to those collected in winter months. The obtained results were then compared to those stated in the literature. Based on this comparison and our own results we made recommendations for raising calves. In total, 137 samples from 20 cows Brown breed were collected in the first five days after calving. On average, the colostrum (collected in seven consecutive milking’s) contained 6.43 ± 3.40 % proteins, of which 4.77 ± 2.36 % was casein. Colostrum contained on average 4.90 ± 1.88 % fats and 3.63 ± 0.71 % lactose. The average content of dry matter in the analysed samples was 16.14 ± 4.11 %. The density of colostrum ranged from 1.017 to 1.052 g/cm3. The highest variability was found in the protective components of colostrum: immunoglobulins, lysosomes, lactoferin, alpha-lactoglobulin, and beta-lactoglobulin (CV > 60 %), as their concentrations decrease in a higher rate after calving. Our results did not significantly differ from those found in that published in the literature. The concentration of immunoglobulins was the only one that showed significant deviations from the literature: we measured 14.26 g immunoglobulins g/l, while the literature stated that quality colostrum must contain at least 50 g immunoglobulins/l. The reason for such deviations is not known however, we conclude, they happened due to mistakes in the collecting samples, storage of colostrum and preparing samples for analysis.

• Ključne besede: cattle, breeds, brown breed, calves, colostrum, quality, Slovenia