Lactational performance effects of 3-nitrooxypropanol supplementation to dairy cows: A meta-regression.

A meta-regression was conducted to determine the production effects of 3-nitrooxypropanol (3-NOP) and investigate their associations with dose, dietary nutrient composition, and supplementation length in dairy cows. Forty treatment and control mean comparisons extracted from 21 studies conducted or published between 2014 to 2024 were used in the meta-regression. Response variables were DMI, milk yield (MY), ECM yield, ECM feed efficiency, BW, BW change, and concentrations of milk fat, true protein, lactose, and MUN.

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: Recommendations for testing enteric methane-mitigating feed additives in ruminant studies.

There is a need for rigorous and scientifically-based testing standards for existing and new enteric methane mitigation technologies, including antimethanogenic feed additives (AMFA). The current review provides guidelines for conducting and analyzing data from experiments with ruminants intended to test the antimethanogenic and production effects of feed additives. Recommendations include study design and statistical analysis of the data, dietary effects, associative effect of AMFA with other mitigation strategies, appropriate methods for measuring methane emissions, production and physiological responses to AMFA, and their effects on animal health and product quality.

Effects of different doses of 3-nitrooxypropanol combined with varying forage composition on feed intake, methane emission, and milk production in dairy cows.

The objective of this study was to investigate the effect of combining different doses of 3-nitrooxypropanol (3-NOP) with varying forage composition on gas emission and production performance of dairy cows. Seventy-two lactating Danish Holstein cows (36 primiparous and 36 multiparous) were enrolled in a continuous randomized block design with an initial 2-week covariate period followed by application of treatments for 12 consecutive weeks. Initial DMI and ECM yield were 23.

Milk production and methane emissions from dairy cows fed silages from different grassland species and harvesting frequencies.

The aim of this study was to examine how silages from different grassland species and harvesting frequencies affect feed intake, milk production, and methane (CH) emission in dairy cows. We hypothesized that cows consuming silages of more frequent harvest, grass species with greater organic matter digestibility and legumes with lower NDFom concentration would have greater silage dry matter intake and milk yield and thereby lower CH yield and intensity. Forty Norwegian Red cows were allocated to 5 treatments in a cyclic changeover design with 4 21-d periods (14 d of adaptation, 7 d of data collection).