Rumen-protected choline for dairy cows: the in situ evaluation of a commercial source and literature evaluation of effects on performance and interactions between methionine and choline metabolism

Abstract

-The interactions were investigated between methionine and choline metabolism due to interchangeable methyl groups. Feeding trials on dairy cows with choline administration were re-evaluated with a focus on methionine balance and the possible effects of supplementary choline on methionine metabolism. In addition, in situ ruminal stability was estimated for a commercial choline supplement. We examined six experiments that included 11 dietary treatments. The Cornell net carbohydrate and protein system was used to estimate nutrient supply and requirements as well as methionine balance; further methionine supply was assessed according to the ideal protein concept. The re-evaluation of feeding trials confirmed the positive effects of supplementary abomasally available choline on milk yield and health of dairy cows. Although these effects were mainly attributed to an elevated export of triglycerides from the liver, beneficial effects may be further caused by an exoneration of methionine metabolism by sparing S-adenosylmethionine. Therefore, the effects on milk yield or other response variables of additional, abomasally available choline could serve as an indicator of methyl group deficiency and thus methionine shortage. Since from theoretical considerations the demand for methyl groups in dairy cows is related to the stage of lactation, requirements for methionine and methyl groups should be taken as separate entities and the latter should be expressed in relation to energy balance or days in milk. Our in situ data indicate that Reashure choline was effectively protected against ruminal degradation because at least 600 g·kg −1 of choline were in a rumen-protected form. In conclusion, (I) supplementary choline may improve the yield of dairy cows by elevating the export of triglycerides from the liver and by sparing methionine as a methyl donor, and (II) the demand for methyl groups still lacks adequate consideration in the design of diets for dairy cows. Résumé -Apport de choline protégée aux vaches laitières : évaluation in situ d'une source commerciale, et évaluation bibliographique de ses effets sur les performances et sur le méta-bolisme de la méthionine. Des essais dans lesquels de la choline avait été administrée à des vaches laitières ont été réévalués en portant une attention particulière au bilan de la méthionine et aux effets de la choline apportée en supplément sur le métabolisme de la méthionine. De plus, la stabilité dans le rumen d'un supplément commercial de choline a été évaluée in situ. Six essais incluant 11 traitements alimentaires ont été étudiés. Le système d'alimentation énergétique et azoté de Cornell a été utilisé pour estimer l'apport et le besoin de nutriments, et le bilan de la méthionine. En outre, l'apport de méthionine a été évalué selon le concept de la protéine idéale. La réévaluation des essais d'alimentation a confirmé l'effet positif de l'apport de choline disponible dans la caillette sur la quantité de lait produite et la santé des vaches laitières. Bien que ces effets aient...

Effect of herbal choline and rumen-protected methionine on lamb performance and blood metabolites

“…It has been suggested that the response to RPM and RPC may be positive in dairy cattle because of their high methylation requirements (Brusemeister & Sudekum, 2006), but their effects on production have not been consistent (Davidson et al, 2008;Sun et al, 2016;Zhou et al, 2016). In this experiment, the lack of response in lamb growth to RPM may have been owing to the low Lys content in the basal diet (Table 1).…”

“…The results obtained for the half time to reach Vmax suggest that the biocholine source contains fractions of rumen-protected choline. An evaluation of commercial sources of RPC indicated that in vitro or in situ degradation in rumen from encapsulated products varied from 40 to 80% (Brusemeister & Sudekum, 2006;Jayaprakash et al, 2016). The results of Godinez-Cruz et al (2015), who compared biocholine and an encapsulated choline chloride, indicated that the two sources resulted in the same final degradation, providing more bypass choline than that observed for the unsupplemented control.…”

Protected methionine as a methyl-group donor for dairy cows fed diets with different starch sources in the transition period

“…in the blood, which in turn may stimulate higher DM intake. Methionine, being a donor of methyl groups, could hypothetically provoke more effective triglyceride oxidation or stimulate VLDL synthesis (Drackley, 1999;Brusemeister and Südekum, 2006). ) on daily intake of DM (A), UFL (B) and PDI (C) Supplementation of protected methionine did not infl uence, in any analysed period after calving (Table 4), total or basal diet daily DM intake and, consequently, protein and energy intake, which is in line with other authors (Sloan, 1997;Pisulewski et al, 2002).…”

“…The higher serum glucose content may testify to more effective gluconeogenesis in the liver of methionine-supplemented cows. It is possible that methionine stimulating VLDL synthesis in the liver (Bauchart et al, 1998;Brusemeister and Südekum, 2006) decreased liver lipidosis, causing better conditions for glucose synthesis. Unfortunately, such an increase in blood glucose did not affect DM intake and milk production.…”

“…In this study, the methionine hydroxo-analogue was dosed from day 21 before calving to day 84 of lactation. Brusemeister and Südekum (2006) hypothesize that ruminally protected methionine may positively affect choline metabolism and by this means stimulate VLDL synthesis in the liver.…”