Basal diet and indigestible marker influence apparent digestibilities of nitrogen and amino acids of cottonseed meal and soybean meal in pigs

Abstract

This study was to determine the apparent ileal nitrogen (N) and amino acid digestibilities of cottonseed meal (CSM) and soybean meal (SBM) in simple carbohydrate-based and more complex wheat-based diets. Twenty five Large White × Landrace boars (40.9 kg) were randomly allocated to one of 5 dietary treatments: a wheat diet, 40% CSM in either a sugar:starch (1:1) or wheat-based diet, or 40% SBM in either a sugar:starch or wheat-based diet for 14 d. All diets contained vitamins, minerals, and contained acid-insoluble ash (AIA) and Cr2O3 as indigestible markers. Rations were offered (1,800 g/pig per d) in 3 meals/d on d 1 – 11 and 8 meals/d on d 12 – 13. On d 14, the pigs were fed hourly for 8 h. After the 8th meal, pigs were anaesthetised with isoflurothane, and ileal and faecal digesta sampled from the terminal ileum and rectum before lethal injection of barbiturate. Apparent ileal digestibility (AID) of N was greater (12.1%) when CSM was fed in the wheat-based diet as compared to the simple carbohydrate-based diet, whereas apparent ileal N digestibility of SBM was slightly lower (−4.5%) in the wheat-based diet as compared to the sugar:starch-based diet. Apparent ileal amino acid digestibility generally respondeds similarly to N. Therefore, while there was a wide difference in apparent N and amino acid digestibilities of SBM and CSM when they were fed in the sugar:starch-based diets, these differences were less apparent when they were fed the wheat-based diet. There was an apparent net release of N into the hindgut of pigs fed CSM in both base diets. Conversely, there was quite substantial apparent digestion of N in the hindgut of pigs fed SBM in both base diets. The use of Cr2O3 as an indigestible marker resulted in lower apparent ileal and faecal digestibilities than using AIA, particularly for diets containing CSM. These data demonstrate that the basal diet and choice of indigestible marker can substantially influence the estimate of apparent N digestibility, this response can differ for different protein meals.

Acid-insoluble ash is a better indigestible marker than chromic oxide to measure apparent total tract digestibility in pigs

“…The AID and ATTD values obtained in the present experiment were in agreement with the results reported by Prawirodigdo et al. (1998 ; 2019 ) who investigated the effects of method of collection and marker on AID and ATTD. In addition, the response pattern of the pigs to the effects of basal diets on the apparent faecal digestibility of feeds in our previous ( Prawirodigdo et al., 2019 ) and present studies were also similar.…”

“…However, for diets containing SBM, the AID and ATTD of N were higher in the sugar-starch-based diet. These findings are similar to those found by Prawirodigdo et al. (2019) and other researchers who found that the AID of amino acids in CSM determined using complex cereal basal diets have generally been near the upper end of the range of normally encountered values ( Batterham et al., 1990 ; Li et al., 2000 ), whereas those determined using less complex basal diets have been towards the lower end of the range ( Knabe et al., 1989 ; Prawirodigdo et al., 1998 ).…”

“…(1998 ; 2019 ) who investigated the effects of method of collection and marker on AID and ATTD. In addition, the response pattern of the pigs to the effects of basal diets on the apparent faecal digestibility of feeds in our previous ( Prawirodigdo et al., 2019 ) and present studies were also similar. The ATTD of N varied significantly depending upon the protein source.…”

“…(2000) found that the digestibility values of feed in pigs determined using Cr 2 O 3 as a marker was lower compared with those determined using the total faecal collection method. Similarly, Prawirodigdo et al. (2019) found the use of Cr 2 O 3 as an indigestible marker resulted in lower AID and ATTD than AIA, particularly for diets containing cottonseed meal (CSM).…”

“…Several researchers have suggested acid-insoluble ash (AIA) as an alternative neutral marker to Cr 2 O 3 for determining digestibility of feeds in pigs ( McCarthy et al., 1974 ; Moughan et al., 1991 ; Rowan et al., 1991 ; Van Barneveld et al., 1995 ; Prawirodigdo et al., 2019 ) whereas others maintain that Cr 2 O 3 is more suitable as a marker than AIA ( Bakker and Jongbloed, 1994 ; Van Leeuwen et al., 1996 ). Yin et al.…”