Panorama des démarches qualité : à chaque stratégie son outil.

in Quatrième Carrefour des Productions animales : Les démarches de qualité en production de viandes : Pourquoi ? Pour qui ? (1999, January 27)

The Use Of N-15-Labeled Dietary Proteins For Determining True Ileal Amino Acid Digestibilities Is Limited By Their Rapid Recycling In The Endogenous Secretions Of Pigs

in Journal of Nutrition (1996), 126(9), 2188-2198

We assessed the use of 15N-labeled dietary proteins as a possible tool for the determination of the true ileal amino acid (AA) digestibility in pigs. The first experiment was designed to study the dietary ... [more ▼]

We assessed the use of 15N-labeled dietary proteins as a possible tool for the determination of the true ileal amino acid (AA) digestibility in pigs. The first experiment was designed to study the dietary N excretion pattern at the ileum subsequent to the ingestion of a single 15N-labeled meal. In a second experiment, we compared ileal endogenous AA outputs and true AA digestibility estimates obtained in pigs ingesting 15N-labeled dietary proteins in a single meal vs. intravenous infusion of 15N-leucine for 10 d during the ingestion of a pea-based diet and a protein-free starch diet. The proportion of endogenous N found in the ¡leal digesta differed when the label was delivered orally (50%) vs. intravenously (72%) and changed with time. As a consequence, the true ileal AA digestibilities measured with labeled diets were lower. A third experiment demonstrated that this was due to the rapid recycling of labeled dietary N in endogenous moieties, because 15N was found in blood within 10 min of consuming the labeled meal, within 50 min of consumption in pancreatic enzymes, 90 min in bile and 4 h in ¡leal mucins. We conclude that the use of 15N-labeled meals for determination of true ¡leal AA digestibilities is limited by the fast recycling of dietary N in endogenous secretions following a single 15N-labeled meal. The accuracy of results will depend on meaningful estimates of AA flow during a limited period and accurate estimates of 15N in AA. [less ▲]

Studies On The In-Situ Nitrogen Degradability Corrected For Bacterial-Contamination Of Concentrate Feeds In Steers

in Journal of Animal Science (1995), 73(1), 220-227

Stable 15N was used to evaluate the influence of bacterial contamination on in situ DM and N degradabilities (Dg) of meat and bone meal (MBM), soybean meal (SBM), and wheat bran (WB) in two steers ... [more ▼]

Stable 15N was used to evaluate the influence of bacterial contamination on in situ DM and N degradabilities (Dg) of meat and bone meal (MBM), soybean meal (SBM), and wheat bran (WB) in two steers. Bacterial DM and N contamination ranged from 2.4 to 28.6% and 2.1 to 56.8% of residual DM and N, respectively. Effective N degradability increased when bacterial contamination was taken into account ( P < .05). The difference was low for MBM (2.4%) and for SBM (3.4%) but high for WB (12.2%). Theoretically, using solid-associated bacteria should give the most accurate correction for bacterial contamination; however, results showed that Dg of N based on liquid-associated bacteria were identical for MBM and SBM ( P > .05) and different for WB ( P .05). In a second experiment, five treatments were applied to incubated feeds to remove bacteria fxed to the residues and consequently to determine directly the Dg of DM and N corrected for the bacterial contamination without the need for a marker. These treatments involved chilling for 6 h at 4°C in saline solution alone ( T l ) or with a commercial detergent (T2), or with sodium dodecyl sulfate (T3) or with methylcellulose (T4), followed by pummeling in a stomacher for 5 min. The last treatment was only machine washing twice (T5). The Dg of DM can be directly determined following the first four treatments, nevertheless their application to MBM and SBM led to higher Dg of N than that corrected for the bacterial contamination determined in the frst experiment ( P < .05). This overestimation was higher than the observed underestimation when the correction for bacterial contamination was omitted. However, two treatments (T1 and T4) were able to dislodge bacterial N fixed to incubated WB and so the Dg of N could be measured directly. In conclusion, bacterial contamination of concentrate feeds incubated in the rumen may be extensive. In this case Dg must be corrected for this contamination or treatments for decontamination can be applied to residues before determining the Dg of N. [less ▲]

Effect of the carbohydrate fractions of pea seeds on the endogenous amino acid flow at the ileum of the pig.

in Proceeding of the 6th International Symposium on Digestive Physiology in Pigs, n°80. (1994, October)

The true ileal digestibility of pea amino acids measured with 15N labelled diets or animal in pigs.

in The 45th Annual Meeting of the EAAP, Edinburgh, 5-8 September, paper n°5 (1994, September)

In situ N degradability of fresh forages corrected for the microbial contamination determined by 15N labelling of feedstuffs or of liquid and solid associated bacteria.

Conference (1994)

Determination of the true ileal digestibility of amino acids in pigs by means of 15N-labelled diets or animals.

Conference (1993, August)

The Use Of N-15 For The Determination Of In-Sacco Bacterial-Contamination Of 3 Concentrate Feeds And N-Degradability Of Feeds In The Rumen

in Annales de Zootechnie (1993, March)

Determination of the true ileal digestibility of amino acids in pigs by means of 15N-labelled diets. Preliminary results.

in Nitrogen flow in pig production and environmental consequences: Proceedings of the First International Symposium. (1993)

Toepassing van 15N-gelabelde veevoedergrondstoffen voor de bepaling van de endogene fractie in nylon zakjes verzameld aan het einde van de dunne darm van varkens.

in XVIst Studiedag Nederlandstaligen Voedingsonderzoeckers, Gent, 12 april 1991 (1991, April)