Effect of feeding rumen protected rice bran on calcium homeostasis of non-lactating multiparous cows

Abstract

Milk fever in dairy cows can be prevented by activating Ca homeostasis before calving. Homeostatic adaptation can be achieved by reducing dietary Ca availability. Formaldehyde-treated rice bran was studied to supply rumen protected phytic acid to reduce Ca availability. Twelve multiparous dry cows were used in a 3×3 Latin square change-over design with 5-day periods to test three dietary treatments. Diets consisted of a forage mix (maize silage, grass silage and hay), being 77% of ration dry matter, supplemented with three concentrates: Control (no formaldehyde-treated rice bran), T1 (100% formaldehyde-treated rice bran) and T2 (99.5% formaldehyde-treated rice bran with 0.6% Ca carbonate, to equal Ca content of Control). Dietary treatments did not affect urine pH (8.14, 8.13 and 8.11 for Control, T1 and T2 respectively) or dry matter intake (13.9, 13.7 and 13.8 kg for Control, T1 and T2 respectively). Including formaldehyde-treated rice bran in the diet resulted in lower urinary Ca/creatinine ratio (0.970, 0.457 and 0.618 for Control, T1 and T2 respectively). A sudden increase of urinary Ca excretion took place after withdrawal of T1 and T2 at introduction of Control, peaking on the first day and coming back down progressively in the second and third days. Peak was greatest after T1 and was not observed in transitions between rice bran treatments. This is understood as indirect evidence of activation of intestinal Ca absorption during formaldehyde-treated rice bran feeding, because renal adaptations to changes in blood Ca clearance are immediate and intestinal adaptations delay 2 days. It was concluded that including formaldehyde-treated rice bran in rations before calving may represent a dietary strategy to prevent milk fever without reducing dry matter intake.

A novel model to explain dietary factors affecting hypocalcaemia in dairy cattle

“…The rapid adaptation of renal reabsorption and delayed adaptation of intestinal absorption can explain the increases in urinary Ca excretion observed by our group in cows for 2 d after the withdrawal of a restriction in dietary Ca availability (29,32) . Urinary excretion of Ca is an effective means to correct positive fluctuations in blood Ca (1) .…”

“…In rats, this adaptation has been proven to take longer than 1 d to take effect (31) . To our knowledge, this delay has not been directly observed in cattle; however, we have observed indirect indications of this delay by monitoring urinary Ca in cows, which suggest that the inactivation of gastrointestinal Ca absorption may present a 2 d delay (29,32) . Furthermore, calcitriol sustains bone Ca mobilisation, offering an extensive pool for sustaining Ca homeostasis during lactation (33) ; however, in the short term, the readily available bone Ca is limited (34) .…”

“…This effect is caused by very low Ca content and the action of lowering the dietary availability of Ca (32) . The prophylactic value of this feed against milk fever is currently under evaluation by our group, and the preliminary results indicate that rumen-protected rice bran can improve calcaemia recovery after calving (117) .…”

Feeding Solanum glaucophyllum to preparturient multiparous cows prevents postparturient hypocalcemia

“…); and formaldehyde‐treated rice bran as a supplement source of rumen‐protected phytic acid (Martín‐Tereso et al . ). Among the post‐parturient treatments are calcium propionate paste (Goff et al .…”

“…Parturient hypocalcemia is not caused by calving but by the abrupt increase in milk production (Goff et al 2002). Various preparturient treatments for preventing milk fever have been suggested: restriction of dietary calcium (Jorgensen 1974); an acidified diet that includes calcium chloride, aluminum sulfate or magnesium sulfate (Jonsson 1978); intravenous injection of bovine parathyroid hormone (PTH) (Goff et al 1986a); feeding with calcium chloride fertilized timothy hay to reduce the dietary cation-anion difference (Charbonneau et al 2008); sodium aluminum silicate as a calcium-binder (Thilsing-Hansen et al 2002); and formaldehydetreated rice bran as a supplement source of rumenprotected phytic acid (Martín-Tereso et al 2011). Among the post-parturient treatments are calcium propionate paste (Goff et al 1996) and calcium chloride gel/drench (Dhiman & Sasidharan 1999).…”