Eriksson, Torsten
- Institutionen för tillämpad husdjursvetenskap och välfärd, Sveriges lantbruksuniversitet
Sammanfattning
In change-over trials, mid-lactation dairy cows were fed concentrate-supplemented, isonitrogenous and isofibrous perennial ryegrasslegume silage diets that satisfied energy requirements but were suboptimal with respect to metabolizable protein supply. Legumes were either birdsfoot trefoil with low levels of condensed tannins (typical for hemiboreal conditions), or white clover. Averaged over two experimental years, birdsfoot trefoilbased silage resulted in lower digestibility (P < 0.001) of dry matter (50 g kg(-1)), organic matter (52 g kg(-1)), neutral detergent fibre (120 g kg(-1)) and nitrogen (24 g kg(-1)) and lower rumen total volatile fatty acid concentration (7 mm; P = 0.009). Milk protein yield was 36 g d(-1) higher with birdsfoot trefoil silage (P = 0.002), while raw milk yield tended to be 0.8 kg d(-1) higher (P = 0.06). Rumen ammonia concentration was similar between diets, but milk urea concentration (P < 0.001), urinary urea excretion (P = 0.002) and faecal-N proportion (P = 0.001) were higher with birdsfoot trefoil silage. The results suggest that grassbirdsfoot trefoil silage produced in hemiboreal areas exhibits a protein-sparing effect in dairy rations, despite a low condensed tannin content that is further diluted by companion grasses and ration concentrate proportion.
Nyckelord
birdsfoot trefoil; white clover; silage; dairy cows; condensed tannins; nitrogen balance
Publicerad i
Grass and Forage Science
2012, volym: 67, nummer: 4, sidor: 546-558
Utgivare: WILEY-BLACKWELL
SLU författare
Nilsdotter-Linde, Nilla
- Institutionen för växtproduktionsekologi, Sveriges lantbruksuniversitet
- Institutionen för växtproduktionsekologi, Sveriges lantbruksuniversitet
UKÄ forskningsämne
Jordbruksvetenskap
Publikationens identifierare
- DOI: https://doi.org/10.1111/j.1365-2494.2012.00882.x
Permanent länk till denna sida (URI)
https://res.slu.se/id/publ/43421