Transit time ultrasound measurement of portal blood flow in cattle
Autor: | Arg Wylie, DJ Devlin, J. D. McEvoy, P. D. Mcgrattan |
---|---|
Rok vydání: | 1996 |
Předmět: | |
Zdroj: | Proceedings of the British Society of Animal Science. 1996:239-239 |
ISSN: | 1752-7570 1752-7562 |
Popis: | Portal blood flow (PF) is central to the quantitative characterisation of dietary nutrient uptake. Dilution of PAH (p-aminohippurate) is unsuited to rapidly changing flow and visceral studies often use frequent-feeding to encourage “steady-state” digestion and absorption and minimise postprandial PF variation. Such data is of limited value to understanding nutrient flux and visceral responses to conventional feeding (once/twice daily) eg. insulin levels did not differ on similar ME intakes of frequently-fed (12x2h) forage or concentrates (Reynolds and Tyrrell, 1991) whereas in steers fed once daily, insulin was higher (Pet al., 1996). Transit-time ultrasound (TTU) gives real-time, continuous flow but the steer portal vein was regarded as anatomically unsuitable for TTU (Huntington et al., 1990) with PF of less than half those by PAH (20 vs 42ml/min/kg LW). The current study was initiated to monitor temporal PF changes by TTU in steers fed once-daily. |
Databáze: | OpenAIRE |
Externí odkaz: |