Urinary calcium excretion in non-lactating dairy cows in relation to intake of fat-coated rice bran.
At calving, many older cows fail to compensate the sudden demand of calcium by an adequate activation of intestinal absorption. This results in a variable degree of hypocalcaemia. Reducing intestinal availability of calcium during the close-up period can prevent milk fever. Fat-coated rice bran (FCRB) was investigated for its potential to reduce Ca availability in pre-calving cows. Fat-coated rice bran was incubated in situ to estimate ruminal degradation of dry matter and phytic acid. Also, seven dry multiparous dairy cows were used for a feeding trial in three periods of approximately 1 week each: P1: adaptation; P2: feeding of 2 kg of FCRB and P3: withdrawal of FCRB. Feed intake was recorded and daily urine samples were analysed for pH, Ca and creatinine. The bypass fraction of phytic acid (passage rate: 5%/h) was 30%. Fat-coated rice bran depressed dry matter intake in P2, resulting in a lower Ca intake. In P2 urine pH and calcium excretion were lower. Daily calcium excretion decreased after introduction of FCRB, peaked after withdrawal and dropped 2 days later. Changes in urinary Ca excretion by feeding FCRB indicate that FCRB affected Ca homeostasis in dry multiparous dairy cows.
Martín-Tereso
J
J
Nutreco Ruminant Research Centre, Boxmeer, The Netherlands. javier.martin-tereso@nutreco.com
Derks
M
M
van Laar
H
H
Mulder
K
K
den Hartog
L A
LA
Verstegen
M W A
MW
D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002118:Calcium / Q000378:metabolism / Q000652:urine*; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control* / Q000652:urine; D003612:Dairying; D004032:Diet / Q000662:veterinary*; D004041:Dietary Fats; D005260:Female; D012275:Oryza; D000073878:Palm Oil; D010319:Parturient Paresis / Q000517:prevention & control; D010938:Plant Oils; D011247:Pregnancy
D004041:Dietary Fats; D010938:Plant Oils; D000073878:Palm Oil; D002118:Calcium