Effects of low phosphorus diets on phosphorus balance and plasma concentrations of 25-hydroxyvitamin D3, and carboxy-terminal collagen crosslinks during the transition period in dairy cows.

Our aim was to determine the effects of P intake on P balance, serum parathyroid hormone (PTH) levels and bone resorption during the final 4 weeks prepartum and the first 8 weeks of lactation. Sixty pregnant multiparous Holstein Friesian dairy cows were assigned to a randomized block design with repeated measurements and dietary treatments arranged according to a 2 × 2 factorial design. The experimental diets contained 3.

Feed additives for methane mitigation: A guideline to uncover the mode of action of antimethanogenic feed additives for ruminants.

This publication aims to provide guidelines of the knowledge required and the potential research to be conducted in order to understand the mode of action of antimethanogenic feed additives (AMFA). In the first part of the paper, we classify AMFA into 4 categories according to their mode of action: (1) lowering dihydrogen (H) production; (2) inhibiting methanogens; (3) promoting alternative H-incorporating pathways; and (4) oxidizing methane (CH). The second part of the paper presents questions that guide the research to identify the mode of action of an AMFA on the rumen CH production from 5 different perspectives: (1) microbiology; (2) cell and molecular biochemistry; (3) microbial ecology; (4) animal metabolism; and (5) cross-cutting aspects.

Feed additives for methane mitigation: Modeling the impact of feed additives on enteric methane emission of ruminants-Approaches and recommendations.

Over the past decade, there has been considerable attention on mitigating enteric methane (CH) emissions from ruminants through the utilization of antimethanogenic feed additives (AMFA). Administered in small quantities, these additives demonstrate potential for substantial reductions of methanogenesis. Mathematical models play a crucial role in comprehending and predicting the quantitative impact of AMFA on enteric CH emissions across diverse diets and production systems.

The farnesoid X receptor activates transcription independently of RXR at non-canonical response elements.

The farnesoid X receptor (FXR) is a nuclear receptor (NR) known to obligately heterodimerize with the retinoid X receptor (RXR). FXR is expressed as four isoforms (α1-α4) that drive transcription from IR-1 (inverted repeat-1) response elements (REs). Recently, we found that FXR isoforms α2/α4 also activate transcription from non-canonical ER-2 (everted repeat-2) REs, mediating most metabolic effects of general FXR activation.