Kakovost mleziva na kmetijah, usmerjenih v prirejo mleka

Zupan, Manca (author), Lavrenčič, Andrej (mentor)

Kakovost mleziva pomembno vpliva na razvoj in zdravje telet. Ker v Sloveniji ni veliko raziskav o kakovosti mleziva, smo želeli ugotoviti, kakšna je kakovost mleziva in kateri dejavniki vplivajo na njegovo kakovost. Zato smo skupno zbrali 95 vzorcev prve, druge in tretje molže 35 krav, s treh različnih kmetij. Vzorce smo analizirali na vsebnost IgG z ELISA testom, na vsebnost surovih beljakovin in maščob, maščobno kislinsko sestavo, z refraktometrom pa smo določili lomni količnik svetlobe, ki je šla skozi vzorec (%Brix). Z analizo variance smo ocenili vplive pasme, sezone telitve, zaporedne molže in zaporedne laktacije na proučevane lastnosti. Ugotovili smo, da na vsebnost IgG in %Brix v mlezivu vplivata zaporedna molža in pasma krav, medtem ko zaporedna laktacija in sezona telitve nista imela statistično značilnega vpliva. Več kot 50 g IgG/L je imelo 88 % vzorcev prve molže, kar pomeni, da je vsebnost IgG dovolj velika, da je mlezivo primerno za prvi napoj. Mejno vrednost 22 %Brix je v 1. molži doseglo samo 37 % vzorcev. Ker mlezivo ob prvi molži ne vsebuje vedno dovolj zaščitnih snovi, bi morali njegovo kakovost redno preverjati pred začetkom napajanja telet s prvim napojem. Viške kakovostnega mleziva je priporočljivo zamrzniti za primere, ko krava nima dovolj kakovostnega mleziva za novorojeno tele.

• Language: Slovenian
• Keywords: krave, molznice, mlezivo, kakovost, dejavniki, imunoglobulini
• Work type: Master's thesis/paper
• Organization: BF - Biotechnical Faculty
• Year: 2023
• PID: 20.500.12556/RUL-144819
• COBISS.SI-ID: 145319171
• Publication date in RUL: 15.03.2023

Secondary language

• Language: English
• Title: Quality of colostrum on dairy farms

Abstract

The quality of colostrum has a great influence on the development and health of calves from birth to weaning. Since there are few studies on the quality of colostrum in Slovenia, we wanted to find out what the quality of colostrum is and what factors influence its quality. Therefore, we took 95 samples of the first, second and third milking after calving from 35 cows in three different farms. The samples were analysed for IgG content, crude protein and crude fat content, and fatty acid composition using the Elisa test, while %Brix was determined using the refractometer (%Brix). The statistical model considered the influence of breed, calving season, consecutive milking and consecutive lactation. We found that consecutive milking and cow breed had a significant effect on IgG content and %Brix in colostrum, while consecutive lactation and calving season had no effect. Eighty-eight percent of the samples of first milking colostrum contained more than 50 g IgG/L and thus had sufficient IgG to be considered suitable for first drinking. The 22% Brix threshold for first milk colostrum was met by only 37% of the samples. Since colostrum does not always contain sufficient protective substances after the first milking, its quality should be checked regularly before it is administered as the first drinker. It is recommended to freeze the surplus of high quality colostrum if a cow does not have enough colostrum or the quality does not meet the quality standards.

• Keywords: dairy cows, colostrum, quality, factors, immunoglobulins