 |
A comparison of the excretion rate of endogenous purine derivatives in the urine of Bos indicus and Bos taurus steers
Bowen, M. K., Poppi, D. P., McLennan, S. R. and Doogan, V. J. (2006) A comparison of the excretion rate of endogenous purine derivatives in the urine of Bos indicus and Bos taurus steers. Australian Journal of Agricultural Research, 57 2: 173-177.
|
|
|
| Author(s) |
Bowen, M. K.
Poppi, D. P.
McLennan, S. R.
Doogan, V. J.
|
| Title |
A comparison of the excretion rate of endogenous purine derivatives in the urine of Bos indicus and Bos taurus steers
|
| Journal name |
Australian Journal of Agricultural Research
|
| Publication date |
2006
|
| Volume number |
57
|
| Issue number |
2
|
| ISSN |
0004-9409
|
| Start page |
173
|
| End page |
177
|
| Total pages |
5
|
| Editor(s) |
Fegent, Jenny C.
|
| Place of publication |
Collingwood
|
| Publisher |
Csiro Publishing
|
| Collection year |
2006
|
| Language |
eng
|
| Subject |
C1
300403 Animal Nutrition
630103 Beef cattle
|
| Abstract |
Estimates of microbial crude protein (MCP) production by ruminants, using a method based on the excretion of purine derivatives in urine, require an estimate of the excretion of endogenous purine derivatives (PD) by the animal. Current methods allocate a single value to all cattle. An experiment was carried out to compare the endogenous PD excretion in Bos taurus and high-content B. indicus ( hereafter, B. indicus) cattle. Five Holstein - Friesian ( B. taurus) and 5 Brahman (> 75% B. indicus) steers ( mean liveweight 326 +/- 3.0 kg) were used in a fasting study. Steers were fed a low-quality buffel grass (Cenchrus ciliaris; 59.4 g crude protein/kg dry matter) hay at estimated maintenance requirements for 19 days, after which hay intake was incrementally reduced for 2 days and the steers were fasted for 7 days. The excretion of PD in urine was measured daily for the last 6 days of the fasting period and the mean represented the daily endogenous PD excretion. Excretion of endogenous PD in the urine of B. indicus steers was less than half that of the B. taurus steers ( 190 mu mol/kg W-0.75. day v. 414 mu mol/kg W-0.75. day; combined s.e. 37.2 mu mol/kg W-0.75. day; P< 0.001). It was concluded that the use of a single value for endogenous PD excretion is inappropriate for use in MCP estimations and that subspecies-specific values would improve precision.
|
| Keyword(s) |
rumen microbial protein
cattle
Fibrous Feeds
Ruminants
Cattle
Cows
Detergents
Infusion
Nitrogen
Protein
Rumen
|
|
|
