Passage of large plastic particles through the digestive tract of lactating and dry cows

Abstract

In five trials carried out on two lactating and two dry cows three sets of particle sizes were used: in the first set particles with a diameter of 9 mm and length of 4, 6, 8 and 10 mm, in the second set particle sizes of 8/8,11/11,14/14and 17/17 (diameter/length) mm, and the third set 8/8,9/9,10/10,11/ 11 and 12/12 mm particles. In the first set the lactating cows had a significantly higher mean recovery (97.8 vs 75.9 %) and a significantly shorter total tract mean retention time (TMRT) (53.0 vs 96.6 h) than the dry cows (P<0.05). In the second trial with lactating cows the main differences in recovery were found between 11/11 and 14/14 mm particles, significant at 48 h after administration (63.8 vs 31.3 %; P<0.05). Regurgitation of 17/17 mm particles was 27.5 % in lactating cows and 80% in dry cows in the course of384 h. In the third set did not yield significant results, except 36 h (P<0.05) after placing. It is concluded that relatively good recovery and TMRT can be achieved in lactating cows with plastic particles of a size larger than 11/11 mm but smaller than 14/14 mm.

Post-ruminal delivery systems

“…Most of the data on the effects of specific gravity on ruminal passage and digestibility have been obtained by feeding inert pellets (usually plastic or rubber) and recovering them either from the duodenum or the faeces (wELCH, 1990;DESBORDES, wELCH, 1984;TŘINÁCTý, �IMEK, ZEMAN et al, 1999 a;TŘINÁCTý, �IMEK, HOMOLKA, 1999 b;TŘINÁCTý, SCHMEISEROVÁ, SUCHý, 1999 c;TŘINÁCTý, HOMOLKA, RICHTER et al, 2002). By varying the types of plastics used (polyethylene, polypropylene, nylon, acetal, polyvinylidene fluoride and teflon) and by mixing them with barium sulfate, the range of specific gravity can be varied from less than 1 to more than 2 g.cm -3 .…”

Postruminal Delivery System for Amino Acids and Proteins in Cattle

“…Nylon bags with the delivery system, placed either directly in the rumen (in situ) or in vitro rumen system containing active rumen microbes and simulating rumen function, allow free inflow of the rumen fluid and exit of solubilized active ingredients. The loss of active ingredients in samples is determined (Třináctý et al 1999(Třináctý et al , 2003.…”