Amélioration des bilans d'excrétion d'azote dans deux exploitations laitières de la région wallonne par un suivi raisonné des rations

Improvements after precision dietary management of nitrogen rejection in two commercial dairy farms in Wallonia. Two dairy farms located in Pays de Herve and in Ardennes were followed at regular intervals in order to assess levels of nitrogen rejection. In Farm 1, the cows were divided into two groups: group HP contained high production cows and group BP contained cows with a lower production yield. Each group was offered a specific basal diet. In Farm 2, only one group of cows was assessed. The feed rations on both farms were characterized by a imbalance between the yields allowed by the ener... Mehr ...

Verfasser: Knapp, E.
Istasse, L.
Hornick, JL.
Dufrasne, I.
Dokumenttyp: Artikel
Erscheinungsdatum: 2013
Reihe/Periodikum: Biotechnologie, Agronomie, Société et Environnement, Vol 17, Iss s1, Pp 259-270 (2013)
Verlag/Hrsg.: Presses Agronomiques de Gembloux
Schlagwörter: Animal nutrition / dairy cows / nitrogen / nitrogen content / excretion / urea / livestock management / Biotechnology / TP248.13-248.65 / Environmental sciences / GE1-350
Sprache: Englisch
Französisch
Permalink: https://search.fid-benelux.de/Record/base-29281090
Datenquelle: BASE; Originalkatalog
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Link(s) : https://doaj.org/article/1feea6d543024d4486d74da70d12813b

Improvements after precision dietary management of nitrogen rejection in two commercial dairy farms in Wallonia. Two dairy farms located in Pays de Herve and in Ardennes were followed at regular intervals in order to assess levels of nitrogen rejection. In Farm 1, the cows were divided into two groups: group HP contained high production cows and group BP contained cows with a lower production yield. Each group was offered a specific basal diet. In Farm 2, only one group of cows was assessed. The feed rations on both farms were characterized by a imbalance between the yields allowed by the energy or the nitrogen supplies and by an extremely high OEB balance of 794, 582 and 726 g, respectively, in groups HP and BP and in the Farm 2 group. Dietary changes were proposed in order to balance milk yields and to reduce the hypothesized nitrogen balance. The yield and urea content data from each milk record, along with data regarding nitrogen rejection, were statistically analyzed using a mixed model, which included an autoregressive covariance. The data from records 2, 3, 4 and 5 were then compared to the data from record 1. The advised changes implemented in the feeding management plan maintained milk yields at values similar to the yields observed in record 1 – 36.2, 24.3 and 23.0 l of 4% fat-corrected milk expressed for fixed days in milk produced by groups HP and BP and the Farm 2 group. The changes induced a significant reduction in the milk urea content (220 vs 300 mg·l-1) and a significant reduction in nitrogen rejection, whether expressed in terms of g per day per cow, g·l-1 or kg per year per cow. The cows in the Farm 2 group rejected less nitrogen in absolute terms (217.9 vs 260.1 g per day). However, it is interesting to note that the management approach in Farm 1 was more efficient in terms of nitrogen rejection since the level was on average 9 g·l-1 in comparison with 10 g·l-1 in Farm 2. In conclusion, it appears that, for either farm, whether an intensive or extensive management regime was being employed, ...