Effects of the isopropylester of the hydroxylated analogue of methionine (HMBi) on production performance of dairy cows in early lactation - INRA - Institut national de la recherche agronomique Accéder directement au contenu
Communication Dans Un Congrès Année : 2006

Effects of the isopropylester of the hydroxylated analogue of methionine (HMBi) on production performance of dairy cows in early lactation

Résumé

Thirty six Holstein cows (26 multiparous, 10 primiparous) were assigned to one of two treatments 17 to 24 days after calving. A basal diet consisting of (DM basis) 61.5 % corn silage, 6.7% wheat straw, 14.9% cracked wheat, 15.6% soybean meal, 1.3 % minerals was fed for 17 weeks as a control diet (treatment 1: T1), or was supplemented with 0.12 % of diet DM with HMBi (treatment 2: T2). The control diet contained an estimated (per kg DM) 1.61 Mcal Net Energy, 100g metabolizable protein (MP), 46g digestible undegraded protein (PDIA from PDI system), 6.91 metabolizable lysine (%MP) and 1.78 metabolizable methionine (%MP). Treatment 2 contained 2.25 metabolizable methionine (%MP), HMBi supplying 0.47 metabolizable methionine (%MP). Results were analysed through an ANOVA using the mixed procedure of SAS with the repeated time option. The covariance structure between the different weekly averages was de ned as compound symmetric. No signi cant differences were observed between treatment groups for DMI, milk yield, milk fat (content and yield) and body weight variations. Milk protein content was higher for T2 vs T1 (%3.36 vs 3.24, p<0.10) and lactose content increased signi cantly for T2 vs T1 (% 5.13 vs 5.02, p<0.01). Total nitrogen content in milk did not vary significantly (g/L, 5.37 and 5.20 respectively for T2 and T1). Protein nitrogen and casein nitrogen increased signi cantly for T2 vs T1: respectively (g/L) 5.10 vs 4.91 (p<0.10) and 4.33 vs 4.12 (p<0.05). Non protein nitrogen content and proportion in total nitrogen decreased signi cantly for T2 vs T1: respectively (mg/L) 274 vs 293 and (%) 5.12 vs 5.68. HMBi supplementation improved N use by partitioning a greater proportion of absorbed N into milk protein N. Moreover, N losses in nonvalorised form as NPN were reduced. This result is in agreement with metabolizable methionine optimization of the ration through HMBi supply.
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Dates et versions

hal-02756295 , version 1 (03-06-2020)

Identifiants

  • HAL Id : hal-02756295 , version 1
  • PRODINRA : 18586

Citer

Stefan Jurjanz, J.C. Robert, François Laurent. Effects of the isopropylester of the hydroxylated analogue of methionine (HMBi) on production performance of dairy cows in early lactation. American Dairy Science Association - American Society of Animal Science 2006 Joint annual Meeting, Jun 2006, Minneapolis, United States. ⟨hal-02756295⟩
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