Vpliv vročinskega stresa na plodnost krav

diplomsko delo

Jana Homšek (Author), Andrej Lavrenčič (Reviewer), Silvester Žgur (Mentor)

Abstract

Vročinski stres močno vpliva predvsem na plodnost visokoproduktivnih krav molznic. Ker pa je s plodnostjo močno povezana uspešnost prireje mleka, smo v nalogi najprej pripravili literaturni pregled vpliva vročinskega stresa na plodnost krav in nato prikazali še vpliv meseca telitve na dobo med telitvama (DMT) za molznice rjave, lisaste in črno-bele pasme v Sloveniji. Vročinski stres vpliva na koncentracije hormonov in posledično na izražanje estrusa, folikulogenezo, prezgodnjo atrezijo jajčnih foliklov, zrelost oocit, zamrtje zarodka in uspešnost ugnezditve. Ker vročinski stres zmanjša zauživanje suhe snovi, se poruši bilanca energije v telesu, kar povzroči presnovne bolezni in poslabša plodnost. Posledice vročinskega stresa lahko omilimo s prehrano, genetskimi izboljšavami, embriotransferjem, načrtovano ovulacijo, aplikacijo hormonov ter gradnjo hlevov z zunanjo klimo, ventilacijo ali sistemom za škropljenje. Analizirali smo podatke o DMT krav, ki so v obdobju od leta 2010 do leta 2022 telile v Sloveniji in prikazali trajanje DMT glede na mesec telitve za rjave, lisaste in črno-bele molznice. Krave, ki so telile v poletnih mesecih, od junija do avgusta, so imele krajšo DMT, kot krave, ki so telile pozimi, od meseca decembra do februarja. Razlike v trajanju DMT med posameznimi meseci telitve so bile večje pri rjavi in črno-beli pasmi in manjše pri lisasti pasmi. Pri rjavi in lisasti pasmi je bil večji vpliv meseca telitve na trajanje DMT v prvi laktaciji kot pa v drugi in poznejših laktacijah.

Keywords

govedo;krave molznice;vročinski stres;plodnost;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2024
Typology:	2.11 - Undergraduate Thesis
Organization:	UL BF - Biotechnical Faculty
Publisher:	[J. Homšek]
UDC:	636.2(043.2)
COBISS:	208684035
Views:	30
Downloads:	4
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Effects of heat stress on the cow fertility
Secondary abstract:	Heat stress has a significant impact on the cattle fertility, especially on high-producing dairy cows. However, as fertility of dairy cows correlates well with optimum maximum milk production, we first conducted a literature review on the effects of heat stress on fertility of three breed Brown Swiss, Simmental and Holstein dairy cows and then showed the effects of calving month on calving interval (CI) in dairy cows in Slovenia. Heat stress affects hormone concentration and thus oestrus expression, folliculogenesis, premature atresia of ovarian follicles, oocyte maturation, premature embryonic death and implantation success. Since heat stress reduces the consumption of dry matter, the energy balance in the body is disturbed, which provokes metabolic diseases and fertility. The effects of heat stress can be mitigated by nutrition, genetic improvement, embryo transfer, planned ovulation, hormone administration and the construction of barns with an outdoor climate, ventilation or spraying. We analysed the calving interval (CI) for dairy cows that calved between 2010 and 2022 in Slovenia. The CI for Brown Swiss, Simmental and Holstein dairy cows is presented according to the month of calving. Cows that calved in the summer months, from June to August, had the shortest CI and cows that calved in winter, from December to February, had the longest CI. The differences in CI between the individual calving months were greater in the Brown Swiss and Holstein cows and lower in the Simmental cows. The calving month has a greater influence on the CI in the first lactation than in the second and subsequent lactations in Brown Swiss and Simmental cows.
Secondary keywords:	cattle;dairy cows;heat stress;fertility;
Type (COBISS):	Bachelor thesis/paper
Study programme:	0
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Biotehniška fak., Oddelek za zootehniko
Pages:	1 spletni vir (1 datoteka PDF (VIII, 14 str.))
ID:	25124185