@conference {40310,
	title = {The effects of oxytocin and bovine somatotropin on production of cows milked once a day},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {51},
	year = {1991},
	month = {Jan},
	pages = {197-202},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	abstract = {Milk from normally lactating goats contains on average 11 ng/ml  IGF-I and 106 ng/ml IGF-II, as determined by specific radioimmunoassay.  The present study was an attempt to determine whether IGFs in milk could  have originated from the blood. 125 I labelled IGF-I or IGF-II was  infused directly into one gland via a pudic arterial catheter for 60  mins and their appearance in milk followed for 720 min. A total of  5.2\% of [125 I]IGF-I infused and 10.0\% of [125I]IGF-II was recovered  from milk from both glands. Radioactivity consisted of TCA precipitable  material, which eluted from Sephacryl S-200 as free and protein-bound  IGF, and TCA soluble material which probably represents degraded  products of the peptides. The amount and time course of secretion of  TCA soluble radioactivity in milk from both glands was similar,  indicating degradation of infused peptide at textra-mammary sites.  Maximum specific activity in milk from the infused gland occurred at  80-120 min for IGF-I and 120 min for IGF-II and was 2.5 fold higher than  milk from the non-infused gland. The lower milk/plasma ratio for  immunoreactive IGF-I compared with 125I labelled IGF-I suggests all milk  IGF-I might be derived from the circulation whereas similar calculations  with IGF-II suggests only 78\% of milk IGF-II could be accounted for by  its transfer from blood.  },
	issn = {1176-5283},
	author = {Carruthers VR and Davis SR and Norton DH}
}
