Evaluation of internal and external markers to estimate faecal output and feed intake in sheep fed fresh forage

Abstract

The objectives of the present study were to estimate dry-matter intake and output of faeces using two external and four internal markers in sheep fed Brachiaria brizantha cv. Marandu on an ad libitum basis over 3- and 5-day periods. Six sheep fitted with ruminal cannulas were randomly assigned in a crossover design experiment to receive either of two treatments of external markers, namely titanium dioxide (TiO2) and chromic oxide (Cr2O3). Faecal output was obtained by total faecal collection and faecal grab sampling. Faeces were collected for 3- or 5-day periods, and, for each collection period, two sampling methods were compared; grab samples were collected directly in the rectum once daily, and a second sample was taken at the same time directly in faecal collection bags after having determined the daily total output of faeces. Faecal concentrations of the internal markers, indigestible dry matter, indigestible neutral detergent fibre, indigestible acid detergent fibre and indigestible acid detergent lignin (iADL), were determined. Faecal output was not accurately predicted with indigestible dry matter, indigestible neutral detergent fibre, indigestible acid detergent fibre and iADL. Dry-matter intake was predicted with iADL and TiO2 when faeces were collected for 5 days as grab samples once daily, or as total collection and with Cr2O3 when faecal grab samples were collected for 5 days. The results using external markers indicated that TiO2 is not a marker equivalent to Cr2O3 for estimating intake and faecal output. TiO2 was the only external marker to accurately estimate faecal output, independent of the method (total or grab) and time period (3 or 5 days) used; this suggests that TiO2 is the best marker tested for predicting the faecal output of sheep that are fed a diet of fresh Brachiaria brizantha (cv. Marandu) grass ad libitum.

Different Grass Availabilities of Tropical Pasture on Performances and Carcasses of Lambs

“…Grazing simulation was performed by analyzing the way an animal was fed and the grazing site was monitored in order to obtain a representative sample of its natural and behavioral grazing habits. Monthly samples were collected manually without using scissors (Costa et al, 2019). Fecal sampling and grazing simulation were performed to obtain a sample composed of animal/treatment.…”

“…After drying in an oven at 55 o C, the samples were processed in a sieve mill with sieves of 1 mm for subsequent laboratory analysis. Internal indicator (iNDF) on forage and feces were determined using 0.5 g of samples packed in TNT bags (cut and sealed to a size of 5 × 5 cm with the porosity of 100 microns), previously dried, weighed, and incubated for 144 hours to represent the indigestible portion of the food (Costa et al, 2019), in the in vitro incubator for degradability testing (MA443 Marconi®). Next, 1600 mL of buffer solution and 400 mL of rumen inoculum were added and CO 2 was purged to maintain anaerobic conditions.…”

Ovinos OPC alimentados con ensilado de Pennisetum purpureum suplementados con afrecho de yuca

“…Al ensilado, al AY y a las heces se les determinó materia seca (MS), cenizas, proteína cruda (PC) (17), FDN, FDA, lignina (18), carbohidratos no estructurales (CNE) (estimación según 11), extracto etéreo (EE) (17). La materia orgánica (MO) se estimó con la diferencia entre la MS y las cenizas (19). A las heces también se les cuantificó Cr por absorción atómica (20) con un espectrofotómetro de absorción atómica Shimadzu ® modelo AA 7000.…”

Use of indigestible markers to estimate the apparent dry matter digestibility of diets containing a cocoa by-product

“…The external marker (EM) chromium oxide (CO) is the most used in the literature (COSTA et al, 2018;SCHAAFSTRA et al, 2019). Studies on the EMs titanium dioxide (TD) (COSTA et al, 2018;SCHAAFSTRA et al, 2019) and isolated, purified, and enriched lignin nanoparticles (NANOLIPE ® ) (MOSS et al, 2017) are promising; however, further studies with different animal species and diets are needed. The EM Isolated, Purified, and Enriched Lignin (LIPE ® ) was used in several animal species (MARCONDES et al, 2008;FERREIRA et al, 2009;LANZETTA et al, 2009).…”