Factors affecting the plasmin-plasminogen system in milk obtained from three Greek dairy sheep breeds with major differences in milk production capacity

dc.contributor.author	Theodorou, G	en
dc.contributor.author	Kominakis, A	en
dc.contributor.author	Rogdakis, E	en
dc.contributor.author	Politis, I	en
dc.date.accessioned	2014-06-06T06:47:45Z
dc.date.available	2014-06-06T06:47:45Z
dc.date.issued	2007	en
dc.identifier.issn	00220302	en
dc.identifier.uri	http://dx.doi.org/10.3168/jds.2006-780	en
dc.identifier.uri	http://62.217.125.90/xmlui/handle/123456789/3790
dc.subject	Ovine milk	en
dc.subject	Plasmin	en
dc.subject	Plasminogen	en
dc.subject	Plasminogen activator	en
dc.subject.other	plasmin	en
dc.subject.other	plasminogen	en
dc.subject.other	plasminogen activator	en
dc.subject.other	animal	en
dc.subject.other	article	en
dc.subject.other	breeding	en
dc.subject.other	chemistry	en
dc.subject.other	comparative study	en
dc.subject.other	cytology	en
dc.subject.other	female	en
dc.subject.other	genetics	en
dc.subject.other	Greece	en
dc.subject.other	lactation	en
dc.subject.other	milk	en
dc.subject.other	physiology	en
dc.subject.other	regression analysis	en
dc.subject.other	sheep	en
dc.subject.other	udder	en
dc.subject.other	Animals	en
dc.subject.other	Breeding	en
dc.subject.other	Female	en
dc.subject.other	Greece	en
dc.subject.other	Lactation	en
dc.subject.other	Least-Squares Analysis	en
dc.subject.other	Mammary Glands, Animal	en
dc.subject.other	Milk	en
dc.subject.other	Plasmin	en
dc.subject.other	Plasminogen	en
dc.subject.other	Plasminogen Activators	en
dc.subject.other	Sheep	en
dc.subject.other	Ovis	en
dc.subject.other	Ovis aries	en
dc.title	Factors affecting the plasmin-plasminogen system in milk obtained from three Greek dairy sheep breeds with major differences in milk production capacity	en
heal.type	journalArticle	en
heal.identifier.primary	10.3168/jds.2006-780	en
heal.publicationDate	2007	en
heal.abstract	The purpose of this study was to evaluate the effect of breed, stage of lactation, and health status of the udder on the plasmin-plasminogen system in ovine milk. A total of 38 ewes were used from 3 breeds [Boutsiko (n = 12), Chios (n = 12), and a synthetic breed (50% Boutsiko, 25% Arta, and 25% Chios, n = 14)] with major differences in their genetic potential with respect to milk yield. Milk samples were collected every 2 wk throughout the lactation period and were analyzed for fat, protein, lactose, and somatic cell count (SCC). In addition, milk plasmin (PL), plasminogen (PG), and plasminogen activator (PA) activities were determined. The Chios breed had the greatest average daily milk yield, the synthetic breed had an intermediate milk yield, and ewes of the Boutsiko breed had the lowest milk yield. Milk samples obtained from the Boutsiko breed had similar PL and PA activities, compared with those obtained from the other 2 breeds. The ratio of PG:PL was less in milk samples from the Boutsiko breed compared with the other 2 breeds, indicative of an increased rate of conversion of PG to PL for this breed. There was no correlation between PL activity and daily milk yield in ewes from all 3 breeds. Activities of PL, PG, and PA were greater in ovine milk with elevated SCC (>300,000/mL) compared with activities in milk with low SCC (<300,000/mL). The ratio of PG:PL was less in the high-SCC group compared with the low-SCC group, which indicates an increased rate of conversion of PG to PL for the high-SCC group. There was a decrease in PG and PA activities as well as in the PG:PL ratio in late lactation milk (mo 5 to 6) when compared with early or mid lactation milk (mo 1 to 4). Thus, the PL-PG system is affected by breed, stage of lactation, and the health status of the udder. No relationship was found between PL activity and daily milk yield in the 3 Greek dairy sheep breeds. Plasmin is not a marker for gradual involution in the Greek sheep breeds studied. © American Dairy Science Association, 2007.	en
heal.journalName	Journal of Dairy Science	en
dc.identifier.issue	7	en
dc.identifier.volume	90	en
dc.identifier.doi	10.3168/jds.2006-780	en
dc.identifier.spage	3263	en
dc.identifier.epage	3269	en