Linear regression approach to study amino acid digestibility in broiler chickens

Rodehutscord, M.; Kapočius, Marius; Timmler, R; Dieckmann, A.

doi:10.1080/00071660410001668905

Cited by 95 publications

(111 citation statements)

References 16 publications

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“…A mixed microbial fraction was isolated from the liquid effluent by differential centrifugation according to Boguhn et al (2006), freezedried and ground. Amino acid (AA) concentrations in the microbial fraction were measured as described by Rodehutscord et al (2004). The concentrations of tryptophan, histidine and tyrosine were not determined.…”

Section: Digestibility and Energy Concentrationmentioning

confidence: 99%

Effects of pressed beet pulp silage inclusion in maize-based rations on performance of high-yielding dairy cows and parameters of rumen fermentation

Boguhn

Kluth

Bulang

et al. 2010

Animal

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Beet pulp contains high amounts of pectins that can reduce the risk of rumen disorders compared to using feedstuffs high in starch. The objective was to study the effects of inclusion of ensiled pressed beet pulp in total mixed rations (TMR) for highyielding dairy cows. Two TMR containing no or about 20% (on dry matter (DM) basis) beet pulp silage were used. The beet pulp silage mainly replaced maize silage and corn cob silage. The TMR were intentionally equal in the concentrations of energy and utilisable crude protein (CP) at the duodenum. TMR were fed to 39 and 40 dairy cows, respectively, for 118 days. The average daily milk yield was about 43 kg/day. No significant differences in milk yield and milk fat or milk protein content were detected. DM intake of cows was significantly reduced by the inclusion of beet pulp silage (23.0 v. 24.5 kg/day). However, a digestibility study, separately conducted with sheep, showed a significantly higher organic matter digestibility and metabolisable energy concentration for the TMR that contained beet pulp silage. In vitro gas production kinetics indicated that the intensity of fermentation was lower in the TMR that contained beet pulp silage. In vitro production of short-chain fatty acids, studied using a Rusitec, did not differ between the TMR. However, the inclusion of beet pulp silage in the ration caused a significant reduction in the efficiency of microbial CP synthesis in vitro. The amino acid profile of microbial protein remained unchanged. It was concluded that beet pulp silage has specific effects on ruminal fermentation that may depress feed intake of cows but improve digestibility. An inclusion of beet pulp silage of up to 20% of DM in rations for high-yielding dairy cows is possible without significant effects on milk yield and milk protein or milk fat.

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Section: Digestibility and Energy Concentrationmentioning

confidence: 99%

Effects of pressed beet pulp silage inclusion in maize-based rations on performance of high-yielding dairy cows and parameters of rumen fermentation

Boguhn

Kluth

Bulang

et al. 2010

Animal

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“…Rodehutscord et al (2004) found that supplementing phytase did not improve the ileal AA digestibility of CM, as determined by the regression method with practical CP levels (17.0 to 25.6%) in the diets, whereas Newkirk and Classen (2001) reported that purified phytase improved the ileal AA digestibility of broilers fed diets containing pretreated CM. In view of the dearth of data, the current study was designed to determine the effect of phytase supplementation on ileal digestibility of AA and protein utilization in CM for broilers.…”

Section: Introductionmentioning

confidence: 99%

“…Several approaches have been used to correct this underestimated digestibility in poultry (Adedokun et al, 2007), with each of these methods having some advantages and disadvantages. Rodehutscord et al (2004) suggested that the regression method could be used to estimate ileal AA digestibility without separate determination of endogenous AA losses in broilers.…”

Section: Introductionmentioning

confidence: 99%

Protein utilization and amino acid digestibility of canola meal in response to phytase in broiler chickens

Kong

Adeola²

2011

Poultry Science

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The regression method was used in a 14-d broiler chicken study to determine the true ileal digestibility of amino acid (AA) and protein utilization in canola meal (CM, 388 g of CP/kg) without or with added phytase. Experimental treatments consisted of 2 factors, phytase at 2 levels (0 or 1,500 phytase units/ kg) and CM at 3 levels (125, 250, or 375 g/kg). Birds received a standard starter diet from d 1 to 8 and the assay diets from d 8 to 22 posthatch. On d 8, a total of 384 birds were allocated to 6 dietary treatments in a randomized complete block design; excreta were collected from d 12 to 14 and d 19 to 21, and ileal digesta were collected on d 22 posthatch. True ileal indispensable AA digestibility of CM were derived from the regression of AA flow (mg/kg of DM intake) at the terminal ileum against the intake of AA (mg/kg of dietary DM) of birds fed diets without or with phytase.Body weight gain (BWG), protein gain, and protein intake increased linearly (P < 0.001) with increasing CM level, regardless of phytase supplementation. Effects of phytase (P < 0.05) were observed on BWG and the protein efficiency ratio from d 8 to 15, whereas effects of phytase (P < 0.05) were observed on BWG and protein gain from d 15 to 22. There was no effect of phytase on protein intake and net protein utilization from d 8 to 22. Phytase supplementation at 1,500 phytase units/kg did not affect true ileal digestibility of any AA in CM. In conclusion, the results of this study indicated that phytase supplementation improved the protein efficiency ratio of birds fed diets containing CM as the sole protein source from d 8 to 15 posthatch but did not affect the true ileal digestibility of AA in CM as determined by the regression method.

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“…Amino acid contents in the RSM and in the 8 and 16 h in situ incubation residues were measured with an amino acid analyser L8900 (VWR/Hitachi). After oxidation with performic acid, samples were hydrolysed with 6 M HCl for 24 h at 1108C (Rodehutscord et al, 2004). The AA were separated with ion-exchange chromatography and quantified by post-column derivatisation with ninhydrin using photometric detection at 570 nm (440 nm for proline).…”

Section: Analytical Proceduresmentioning

confidence: 99%

Variation of in situ rumen degradation of crude protein and amino acids and in vitro digestibility of undegraded feed protein in rapeseed meals

Steingaß

Kneer

Wischer

et al. 2013

Animal

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In this study, 10 samples of rapeseed meal (RSM) from 10 different oil plants in Germany were examined. In situ rumen degradation of CP was determined by incubation over 1, 2, 4, 8, 16, 32 and 72 h in duplicate per time point using three rumen fistulated dry cows. Degradation kinetics were estimated by an exponential model and effective CP degradation was calculated. Degradation was corrected for small particle loss as the difference between washing loss and water-soluble fraction. Amino acid analysis was carried out in the samples and in the residues after 8 and 16 h of incubation in situ and degradation of individual amino acids was calculated for these incubation times. In vitro pepsin-pancreatin digestibility of CP (IPD) was determined in the samples as well as in the 8 and 16 h residues. Effective CP degradation for a rumen outflow rate of 8%/h (ED8) averaged 54.3% with a considerable variation among samples ranging from 44.3% to 62.7%. A multiple regression equation containing acid detergent insoluble N, total glucosinolates and petroleum ether extract as independent variables predicted ED8 with satisfying accuracy (R 2 5 0.74; RSD 5 6.4%). Degradation of amino acids was different from that of CP for most amino acids studied, especially after 8 h of incubation. Compared with CP, degradation of essential amino acids was predominantly lower while degradation of non-essential amino acids was higher in most cases. However, for lysine and methionine no distinct difference with CP degradation was found. Degradation of individual amino acids was predicted from CP degradation with high accuracy using linear regression equations. Average IPD of RSM was 79.8 6 2.6%. IPD was lower in the incubation residues and decreased with longer incubation time and increasing rumen degradation, respectively.Keywords: protein evaluation, ruminants, prediction, degradation, pepsin-pancreatin solubility ImplicationsThis study demonstrates, that rapeseed meal (RSM) is a good source of rumen undegradable protein (RUP), however, considerable variation of RUP among meals was observed mainly because of different process technologies in the oil plants. Equations for prediction of degradation of CP and amino acids have been developed that help farmers and feed manufactures estimate protein and amino acid degradation and improving precision of formulation of diets and compound feeds. It was demonstrated, that digestibility of RSM-RUP is lower compared with the meal which may lead to an overestimation of the contribution of RUP to amino acid supply.

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Linear regression approach to study amino acid digestibility in broiler chickens

Cited by 95 publications

References 16 publications

Effects of pressed beet pulp silage inclusion in maize-based rations on performance of high-yielding dairy cows and parameters of rumen fermentation

Effects of pressed beet pulp silage inclusion in maize-based rations on performance of high-yielding dairy cows and parameters of rumen fermentation

Protein utilization and amino acid digestibility of canola meal in response to phytase in broiler chickens

Variation of in situ rumen degradation of crude protein and amino acids and in vitro digestibility of undegraded feed protein in rapeseed meals

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