Physically effective fiber changes nutrient levels of total mixed ration and fecal parameters in beef feedlots

Abstract

This study evaluated the effects of the physically effective fiber (peNDF) content on nutrient composition of the total mixed ration (TMR), orts and fecal parameters in 15 commercial beef feedlots. The particle size distribution of TMR was measured adopting Penn State Particle Size Separator (PSPS). Samples were evaluated for dry matter (DM), ash, ether extract (EE), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and starch content. Fecal samples were also evaluated for pH and score. The feedlots were categorized into peNDF<20% and peNDF ≥ 20%. Data were analyzed by a model that included fixed effects of treatment and covariates (sex and genetic groups). Levels of DM, CP, EE and starch were lower in TMR with peNDF ≥ 20% (P<0.05). Fecal dry matter was higher and morning fecal pH was lower for TMR with peNDF<20% (P<0.05). Physically effective fiber changed nutrient levels in TMR, orts, fecal pH and DM. So, using PSPS and fecal parameters are practical and indirect tools for measuring fecal starch and assessing the effectiveness of the diet supplied to ruminants.

Detoxified castor-bean meal replaces soybean meal in the diet of pasture-finished steers

“…Despite increasing the iNDF content of the supplements, the inclusion of DCM did not influence DM intake from pasture, supplement and the total diet, or NDF intake. It is possible that the small particle size of DCM (about 3 mm) used in the supplements caused it to leave the cattle rumen by passage, contributing to less rumen distension and to the regulation of intake due to a physical limiting factor (White et al, 2017;Cunha et al, 2021). Moreover, according to Oliveira et al (2010) the alkaline treatment can improve the rumen degradation rate of the potentially degradable fraction of NDF (NDFap) by up to 7%.…”