University of Veterinary Science

About: University of Veterinary Science is a education organization based out in Pyinmana, Myanmar. It is known for research contribution in the topics: Population & Receptor. The organization has 597 authors who have published 650 publications receiving 14262 citations.

Scaling and intermittency in animal behaviour

Abstract: Scale-invariant spatial and temporal patterns have been observed in a large variety of biological systems. It has been argued that animals in general might perform Levy flight motion with power law distribution of times between successive changes of the direction of motion. Here we study the temporal behaviour of nesting gilts. The time spent by a gilt in a given form of activity has a power law probability distribution without a finite average. Further analysis reveals intermittent occurrence of certain periodic behavioural sequences which are responsible for the scaling behaviour and indicates the existence of a critical state. This is in close analogy with temporal sequences of velocity found in turbulent flows, where random and regular sequences alternate and form an intermittent sequence. The source of this complex behaviour can come only from the neural system forced by hormonal stimulus due to nesting instincts. This is the first carefully examined case, where complex scaling behaviour of animals is related to the self-organization and possibly to some unstable critical state of the nervous system.

Postpartal ovarian function in Holstein and crossbred cows on large scale farms in Hungary.

Abstract: Summary The post partum resumption of cyclic ovarian activity was followed up by regular rectal palpation and milk progesterone assay on 249 Holstein-Friesian and crossbred cows under Hungarian large scale farm conditions. The most frequent abnormalities were delayed start of cycling (36.1%), cycles of irregular length (17.3%), cystic degeneration of the ovaries (16.5%), cessation of cyclicity (7.6%) and persistent corpus luteum (2.4%). Sometimes more than one abnormality occurred in the same animal. The duration of the post partum acyclic period correlated with the daily milk production at the peak of lactation. An increased acyclic period after calving was more frequent among heifers and cows after their fourth calving, while the occurrence of other abnormalities increased parallel to age. Ovarian dysfunction was more frequent in high yielding cows and, except for cystic ovarian degeneration, after involutional disturbances. The disturbed resumption of ovarian cyclicity had a detrimental effect on the re-conception. Zusammenfassung Postpartale Ovarfunktion bei Holstein- und Kreuzungs-Kuhen in einem Grosbetrieb in Ungarn Der Wiederbeginn der zyklischen Ovaraktivitat post partum wurde bei 249 Holstein-Friesian-und Kreuzungs-Kuhen in einem Grosbetrieb in Ungarn verfolgt. Die haufigsten Storungen waren verzogertes Einsetzen des Zyklus (36,1%), irregulare Zyklusdauer (17,3%), cystische Degeneration der Ovarien (16,5%), Sistieren des Zyklusgeschehens (7,6%) und persistierender Gelbkorper (2,4%). Manchmal traten mehr als eine Storung beim gleichen Tier auf. Die Dauer der postpartalen Azyklie war mit der Tagesmilchleistung wahrend des Laktations-Peaks korreliert. Eine verlangerte Azyklie nach dem Kalben trat bei Kalbinnen sowie bei Kuhen nach dem 4. Kalben gehauft auf, wahrend andere Storungen mit dem Alter zunahmen. Dysfunktionen des Ovars traten bei Hochleistungskuhen und, abgesehen von der cystischen Ovardegeneration, nach Involutionsstorungen gehauft auf. Storungen der Wiederaufnahme der zyklischen Ovartatigkeit hatten eine negative Auswirkung auf die anschliesende Konzeption.