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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. [ABSTRACT FROM AUTHOR]

Adapting Ca homeostasis of dairy cows before calving can prevent milk fever. Rice bran, treated with formaldehyde to prevent ruminal degradation of phytic acid, was fed to heifers to study its effect on Ca homeostasis. For 3 weeks 18 heifers were supplemented 3 kg of two feeds: placebo (PF) and rice bran (RBF), defining three treatments: control (CRT), low dose (LD) and high dose (HD). In weeks 1 and 3, all animals received 3 kg of PF and in week 2: CRT received 3 kg of PF, LD received 1.5 kg of PF and 1.5 kg of RBF and HD received 3 kg of RBF. Treatments did not affect dry matter intake (DMI). Feed intakes and growth rates indicated that all heifers had nutritional requirements that exceeded their Ca intakes. Serum Ca, urinary Ca, calcitriol or hydroxyproline remained unaffected. Urinary Ca was consistently low indicating high renal Ca reabsorption, which is indicative of insufficient Ca supply. Rice bran feed influenced P, Mg and Zn intakes and serum and urine presence of these minerals. Most heifers already presented an upregulated Ca metabolism, being inadequate to study adaptive changes in Ca homeostasis of multiparous dry cows. This metabolic difference can be explanatory to the very low susceptibility of heifers to milk fever, further supporting the induction of homeostatic adaptation before calving to prevent milk fever. Rice bran feed did not reduce DMI, and was not detrimental to P, Mg or Zn status. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Animal Physiology & Animal Nutrition is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Animal Physiology & Animal Nutrition is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Three batches of weanling pigs (total n=310 pigs) were used in a 34-day experiment to validate the use of an IVOG® feeding station as a tool for monitoring individual feed intake of group-housed weanling pigs. An IVOG® feeding station for weanling pigs consists of a single-space dry feeder placed on a load cell in combination with electronic identification. Data of 192 weanling pigs (18 pens) fed by IVOG® feeding stations were used to develop a protocol for the screening of IVOG® data. To assess the quality of the IVOG® data, the feed intake per pen computed from the screened IVOG® data was compared with the feed intake calculated from feed weighing. To assess the suitability of the use of IVOG® feeding stations under practical pig husbandry conditions, performance of 96 weanling pigs fed by the IVOG® feeding stations was compared with that of 118 weanling pigs that were fed using commercial single-space dry feeders (11 pens). Feed intake per pen computed from the IVOG® data was similar to the feed intake calculated from feed weighing (average recovery 101.1%) for all test periods (p > 0.1). Furthermore, feed recovery did not differ among feeding stations (p > 0.1). During the first 13 days after weaning, the average daily feed intake (ADFI) of weanling pigs fed by the single-space dry feeders was higher (p < 0.05) than that of weanling pigs fed by the feeding stations. Average daily gain and gain to feed ratios did not differ (p > 0.1) between both feeding systems. During the remaining 21 days and averaged over the entire experimental period, performance did not differ between the feeding systems (p > 0.1). It can be concluded that IVOG® feeding stations for weanling pigs are a suitable tool to monitor individual feed intake of group-housed weanling pigs. [ABSTRACT FROM AUTHOR]