Acid Detergent Insoluble Crude Protein Research Articles

Evaluation of wheat-based wet distillers' grains for feedlot cattle

This study was conducted to determine the nutritive value of wheat-based wet distillers' grains (WDG) for ruminants. Chemical composition and in situ rumen degradability characteristics of WDG were compared with wet brewers' grain (WBG). The in situ trial involved three 48 h incubations utilizing one ruminally fistulated cow. Trail 2 compared the value of WDG in growing and finishing rations relative to WBG and a control based on standard feed ingredients. Relative to WBG, WDG had greater (P < 0.05) NDF and ADL and similar ADF and CP levels. Fractionation of CP indicated that WDG contained more (P < 0.05) neutral detergent and less acid detergent insoluble CP than WBG. Effective degradability of DM, CP, NDF and ADF in WDG exceeded (P < 0.05) WBG. Animal performance in the growing period was similar (P > 0.01) among treatments. During the finishing period the control fed steers grew faster (P < 0.05) than WBG fed steers. WDG fed steers exhibited more (P < 0.05) intermuscular fat than control or WBG fed steers and less (P < 0.05) subcutaneous fat than WBG fed steers. It was concluded that WDG is more degradable than WBG and thus cannot be considered as good a source of rumen undegraded protein. WDG can be used effectively as an energy and protein source for growing and finishing cattle. Key words: distillers' grains (wet), brewers' grains (wet), rumen degradability, cattle, gain, carcass

Chemical characterization and nutrient availability of high and low fiber canola meal

Tail-end dehulling separates regular canola meal (CM) into low (LFCM) and high (HFCM) fiber fractions. The study was designed to study the effects of tail-end dehulling of CM on the chemical composition, ruminal nutrient degradability, and intestinal protein availability of the resulting HFCM and LFCM fractions. Relative to LFCM and CM, HFCM had higher (P < 0.05) neutral (NDF) and acid (ADF) detergent fiber and acid detergent lignin (ADL) levels. Canola meal had higher (P < 0.05) ADF and ADL but not NDF relative to LFCM. Crude protein (CP) was lower (P < 0.05) in HFCM than in CM and was lower (P < 0.05) in CM than in LFCM. Neutral and acid detergent insoluble CP followed the pattern of NDF and ADF, respectively. Protein fractionation showed no difference in non-protein nitrogen between the three meals. True protein was lower (P < 0.05) in HFCM than CM and LFCM. Sub-fractionation of true protein resulted in a B1 fraction of 148, 145, and 129 g kg−1 for CM, LFCM and HFCM, respectively. Respective values for B2 and B3 fractions were 768, 769, and 751 g kg−1 and 84, 86, and 120 g kg−1. Results indicated that ruminal effective degradability of dry matter and ADF was lower (P < 0.05) in HFCM relative to CM and was lower in CP relative to LFCM. Ruminal effective degradability of CP and NDF was lower in HFCM than in CM and LFCM. No differences were observed between CM and LFCM. Intestinal digestibility of rumen undegraded protein was higher (P < 0.05) in LFCM than in CM and was higher (P < 0.05) in CM than in LFCM. It was concluded that tail-end dehulling of canola meal resulted in a LFCM with higher protein and lower NDF and ADF content and improved nutrient availability and a HFCM with a lower protein and a higher fiber (particularly ADF) content and reduced nutrient availability. Further studies are required to determine the effect of feeding HFCM on ruminant performance. Key words: High fiber, low fiber, canola meal, chemical composition, ruminal degradability

Storage of fresh and ensiled forages by freezing affects fibre and crude protein fractions

AbstractThe effect of freezing on fibre and crude protein fractions of forages was determined. Fresh and ensiled lucerne and fresh bromegrass were processed immediately after collection or stored at −25°C for 1 day or 1, 6 or 12 months before drying at 55°C. Samples were frozen quickly by submersion in liquid nitrogen or slowly at −25°C. Samples which were not frozen were processed immediately or after 1 h delay at room temperature. All treatments were replicated (n = 3). Samples were analysed for crude protein (CP), trichloroacetic acid soluble CP (TSCP), phosphate buffer soluble CP (BSCP), neutral detergent insoluble CP (NDCP), acid detergent insoluble CP (ADCP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent sulphuric acid lignin (lignin) and ash. Freezing decreased BSCP and increased NDCP by more than 40% for bromegrass. Freezing also changed NDF, ADF, lignin, ash, CP and ADCP in different ways depending on forage type and length of time frozen. No significant effects were observed for method of freezing or a 1‐h delay in processing. An additional experiment showed that freeze‐drying resulted in less insoluble protein than ovendrying. Prior freezing of forages appeared inconsistently to change the extent of gaseous loss during drying, and resulted in precipitation of protein. These changes also affected fibre estimates. Fresh forages should not be frozen and thawed before analysis of protein or fibre fractions.