Korduvpoeginud lehmade vereplasma insuliinisarnase kasvufaktor-1 kontsentratsiooni diagnostiline väärtus seoses tiinestuvuse, haigestumuse ja prakeerimisega
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Kuupäev
2022
Kättesaadav alates
09.09.2022
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Viimastel aastakümnetel on lehmade piimatoodang suurenenud, mis on kaasa toonud sigivus- ja
ainevahetusprobleeme. Somatotroopsesse telge kuuluv insuliinisarnane kasvufaktor-1 (IGF-1) on
maksas sünteesitud hormoon, mis mõjutab lehmade sigivust ja on seotud negatiivse
energiabilansi, haigestumise ja prakeerimisega. Lõputöö eesmärk oli hinnata IGF-1 diagnostilist
väärtust seoses sigivuse, haigestumuse ja prakeerimisega, leida muutujaspetsiifilised optimaalsed
IGF-1 piirmäärad ja selgitada IGF-1 mõju tiinestuvuse ajale. Selleks analüüsiti varem kogutud
andmeid 118 korduvpoeginud holsteini lehma kohta. IGF-1 kontsentratsiooni mõõdeti kokku
kolmel korral, kaks nädalat enne poegimist ning üks ja kolm nädalat pärast poegimist. IGF-1
optimaalsed prognostilised piirmäärad leiti ROC-kõvera analüüsiga. IGF-1 seoseid
sigivusnäitajate, haigestumise ja prakeerimisega analüüsiti logistilise regressioonanalüüsiga ja
ajast sõltuvaid muutujaid elumusanalüüsiga. Enne ja pärast poegimist mõõdetud IGF-1 oli seotud
sigivusnäitajatega ning tugevaim seos esines üks nädal pärast poegimist, kui IGF-1 piirmäär oli
33 ng/ml. Pärast poegimist mõõdetud IGF-1 oli seotud haigestumise ja prakeerimisega. Vastavast
piirmäärast väiksema IGF-1 kontsentratsiooniga lehmade šanss tiinestuda vähenes, aga šanss
haigestuda ja prakeeritud saada suurenes. Aega poegimisest tiinestumiseni mõjutasid IGF-1
kontsentratsioon, haiguste esinemine ja aeg poegimisest esimese seemendamiseni. IGF-1
määramiseks tuleks proove võtta kindlal ajal, sest piirmäär sõltub proovivõtuajast. IGF-1 olulise
mõju tõttu tuleks leida viise selle hormooni kontsentratsiooni tõstmiseks organismis.
Milk yield per cow has increased in the last decades and it has caused a rise in metabolic and fertility problems. Insulin-like growth factor 1 (IGF-1) belonging to the somatotropic axis is synthesised in the liver and affects fertility and is associated with negative energy balance, disease, and culling. The aim of the thesis was to evaluate the diagnostic value of IGF-1 in association with fertility, disease and culling. The aim was to also find variable specific optimal IGF-1 thresholds and the effect of IGF-1 on fertility. Previously collected data on 118 multiparous Holstein cows were analyzed. IGF-1 concentrations were measured a total of three times, two weeks before calving and one and three weeks after calving. IGF-1 optimal prognostic thresholds were found with ROC-curve analysis. The association of IGF-1 with fertility variables, disease and culling was analyzed by logistic regression analysis and with time-dependent variables by survival analysis. IGF-1 measured before and after calving was associated with fertility variables, with the strongest association occurring one week after calving when the IGF1 threshold was 33 ng/ml. IGF-1 measured after calving was associated with occurrence of disease and culling. Cows with lower IGF-1 concentrations than the corresponding threshold had a lower chance of becoming pregnant, but an increased chance of disease and culling. The variables affecting time to pregnancy were IGF-1 concentration, disease, and time from calving to first insemination. IGF-1 samples must be taken at a specific time as the threshold depends on the sampling time. Due to the significant effect of IGF-1, ways should be found to increase its concentration.
Milk yield per cow has increased in the last decades and it has caused a rise in metabolic and fertility problems. Insulin-like growth factor 1 (IGF-1) belonging to the somatotropic axis is synthesised in the liver and affects fertility and is associated with negative energy balance, disease, and culling. The aim of the thesis was to evaluate the diagnostic value of IGF-1 in association with fertility, disease and culling. The aim was to also find variable specific optimal IGF-1 thresholds and the effect of IGF-1 on fertility. Previously collected data on 118 multiparous Holstein cows were analyzed. IGF-1 concentrations were measured a total of three times, two weeks before calving and one and three weeks after calving. IGF-1 optimal prognostic thresholds were found with ROC-curve analysis. The association of IGF-1 with fertility variables, disease and culling was analyzed by logistic regression analysis and with time-dependent variables by survival analysis. IGF-1 measured before and after calving was associated with fertility variables, with the strongest association occurring one week after calving when the IGF1 threshold was 33 ng/ml. IGF-1 measured after calving was associated with occurrence of disease and culling. Cows with lower IGF-1 concentrations than the corresponding threshold had a lower chance of becoming pregnant, but an increased chance of disease and culling. The variables affecting time to pregnancy were IGF-1 concentration, disease, and time from calving to first insemination. IGF-1 samples must be taken at a specific time as the threshold depends on the sampling time. Due to the significant effect of IGF-1, ways should be found to increase its concentration.
Kirjeldus
Lõputöö
Veterinaarmeditsiini õppekaval
Märksõnad
magistritööd, piimalehm, prognostiline piirmäär, sigivus, somatotroopne telg, negatiivne energiabilanss