Evaluation of titanium dioxide and chromic oxide as digestibility markers in ponies fed alfalfa hay in relation to marker dosing frequency

Abstract

In equines, Cr2O3 is widely accepted as an indigestible marker, but there are health concerns regarding the carcinogenic properties of Cr2O3. Recently, TiO2 has been suggested to be an alternative digestibility marker in equines. However, a comparison between Cr2O3 and TiO2 has not been made in equines. Six Welsh pony geldings (initial BW: 254±3 kg; 7 years of age) fed chopped alfalfa hay were used to evaluate the use of TiO2 (Ti) and Cr2O3 (Cr) as markers for calculating apparent digestibility and to investigate the effect of frequency of marker administration on the measurement of digestibility values. Diets contained 4.65 kg dry matter (DM) chopped alfalfa hay supplemented with minerals, vitamins, TiO2 (3.3 g Ti/day) and Cr2O3 (3.2 g Cr/day). Ponies were dosed with either 3.3 g Ti and 3.2 g Cr once daily (DF1) or with 1.65 g Ti and 1.60 g Cr twice daily (DF2). After adaptation to the diets and procedures for 14 days, voluntary voided faeces were collected quantitatively over 7 days and analysed for moisture, ash, Ti and Cr. Apparent total tract DM digestibility (DMD) and organic matter digestibility (OMD) were calculated using the total faecal collection (TFC) and marker method (Ti and Cr). The overall mean cumulative faecal recovery of Cr and Ti (as % of intake) were 102.0% and 96.6%, respectively. Mean daily faecal recoveries of Cr as well as of Ti were not different (P=0.323; P=0.808, respectively) between treatments. Overall daily faecal recovery of Cr differed (P=0.019) from 100% when the marker was dosed once daily, whereas overall daily faecal recovery was similar to 100% for both administration frequencies when Ti was used as a marker. For both markers, the coefficient of variation of the mean faecal marker recovery between horses was lower when the markers were administrated twice per day. Across treatments, cumulative DMD and OMD estimated with Ti were similar (P=0.345; P=0.418, respectively) compared with those values determined by TFC method. When Cr was used, the calculated cumulative DMD tended (P=0.097) to be greater compared with those estimated with TFC, and cumulative OMD values were overestimated (P=0.013). Orally supplemented Ti recovery in the faeces of ponies fed chopped alfalfa hay with Ti administered once or twice daily was close to 100%, making it the preferred marker for digestibility trials in equines.

Age-dependent response to fasting during assessment of metabolizable energy and total tract digestibility in chicken

“…Though it has been previously shown that the digestibility marker was controversial in recovery rate ( Schaafstra et al., 2019 ), it was found that the values of GE and nitrogen obtained by IM in non-fasted broilers were very close to the results observed by TCM in this study. However, we found that the total tract digestibility of energy and nitrogen calculated by TCM was greater than results obtained by the IM in non-fasted adult roosters.…”

Impact of Storage Conditions on Equine Fecal Inoculum for Estimating In Vitro Digestibility

“…In vitro digestibility studies provide a faster, more accessible, and more cost-effective way of evaluating the digestibility of equine diets than traditional methods using in vivo techniques. Additionally, in vitro batch culture techniques allow for the simultaneous study of multiple feedstuffs with less labor than in vivo digestibility trials [ 5 ]. Previous studies have used fresh fecal material, collected via rectal palpation for microbial inoculum, that was transported to the laboratory in anaerobic conditions at 39 °C [ 1 , 2 , 3 ].…”

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).…”