Diurnal variation in fecal concentrations of acid-detergent insoluble ash and alkaline-peroxide lignin from cattle fed bermudagrass hays of varying nutrient content

Abstract

BackgroundThe effect of time of fecal sampling on the accuracy of acid-detergent insoluble ash (ADIA) and alkaline-peroxide lignin (APL) for the prediction of fecal output (FO) in cattle was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 bermudagrass [Cynodon dactylon (L.) Pers.] hay diets markedly different in crude protein concentration (79–164 g/kg) with 2 replicates per diet for 3 periods. Cows were offered hay individually at 20 g DM/kg of body weight daily in equal feedings at 08:00 and 16:00 h for a 10-d adaptation period followed by 5-d of total fecal collection. Fecal grab samples also were taken each day during the fecal collection period at 06:00, 12:00, 18:00, and 24:00 h either directly from the rectum or from freshly voided feces. Samples were composited within cow and time across the 5 d total fecal collection period. Additionally, forage, ort, and fecal samples were analyzed for concentrations of APL and ADIA.ResultsFecal concentrations of ADIA and APL were not affected by sampling time (P ≥ 0.22), even though diet affected (P < 0.01) fecal ADIA and APL concentrations. There were no diet × sampling time interactions (P ≥ 0.60). Estimates of FO and dry matter digestibility (DMD) from ADIA and APL were not affected (P ≥ 0.16) by sampling time or the diet × sampling time interaction (P ≥ 0.74). Estimates of FO and DMD from markers from different sampling times or all different combinations of sampling time were not different (P ≥ 0.72) from those of total collection among internal markers.ConclusionLittle variation in concentrations of ADIA and APL in daily fecal excretion across time increases flexibility in fecal grab sampling schedules for predicting FO and DMD.

Characterization of the variation in the daily excretion of faecal constituents and digestibility predictions in beef cattle fed feedlot diets using near-infrared spectroscopy

“…Estimated TTD of nutrients using ADL as a marker was calculated using the ratios of nutrient and ADL concentration in faeces of each heifer and in the TMR consumed (Merchen 1988) using 4-h interval, as well as the 4-d-24-h composite faecal samples. Estimated faecal output (kg DM d −1 ) was assessed according to the same calculations as Kanani et al (2012). The recovery rate of ADL was assessed according to Krysl et al (1988).…”

“…There has been limited work to characterize the diurnal excretion patterns of dietary constituents in ruminants, with most studies describing variation in the excretion of starch (Leonard et al 1989;Caetano 2008;Fredin et al 2014) and digestibility markers such as lignin (Kane et al 1952;Kanani et al 2012). Fredin et al (2014) sampled faeces from lactating cows fed alfalfa silage and corn silage in equal proportions ad libitum, and two different types of grain mixes containing dry ground shelled corn either at 15.4% or 24.4% of the diet DM as described in Akins et al (2014).…”

“…Because faecal fibre concentrations were more variable over 24 h in cattle fed only once versus twice per day (Table 4), faecal samples collected from cattle fed multiple times per day at any time point will more accurately represent fibre levels in a 4-d-24-h faecal composite samples. Kanani et al (2012) fed cattle bermudagrass hay twice daily with a 9-h interval between meals and measured daily excretion of alkaline peroxide lignin at 6-h intervals. Alkaline peroxide lignin concentrations in faecal samples were similar across sampling times, which is consistent with our observations of the excretion of ADL with 4-h intervals in the backgrounding period.…”

“…Similar studies have not been conducted with feedlot cattle fed high grain diets or for nutrients other than starch. Kanani et al (2012) characterized the excretion pattern of alkaline peroxide lignin and acid detergent insoluble ash in faeces every 6 h from cattle fed a forage diet and found no differences in their concentrations over 24 h, suggesting that a single faecal sample may represent the excretion of these markers over the course of a day. In contrast, Kane et al (1952) found that lignin concentration in faeces varied over a 24-h period in dairy cattle fed high forage diets twice daily and concluded that multiple samples or designated sampling periods are required for accurate estimates of lignin excretion.…”

Replacing alfalfa hay with dry corn gluten feed alters eating behavior, nutrient digestibility, and performance of lactating dairy cows

“…Milk samples were collected on days 15-17 of each period, preserved with potassium dichromate, and stored at 4 C for analysis of milk fat, true protein, lactose, and MUN concentrations using a CombiScope FTIR 600 Dairy analyser (Delta Instruments, Netherlands). Yield of 3.5% fat-corrected (FCM) and energy-corrected (ECM) milk were calculated using the following equations (Tyrrell and Reid 1965 (Kanani et al 2015) after the 0800 feeding and stored at À20 C until analysis. Samples were dried in a forced-air oven at 60 C for 72 h, ground to pass through a 1-mm screen, and analysed for DM, ash, NDF, ADF, and CP, as described previously.…”