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Effects of grass height at the start of grazing on herbage intake and milk production under rotational grazing by lactating dairy cows
Author(s) -
Nakatsuji H.,
Nishimichi Y.,
Yayota M.,
Takahashi M.,
Ueda K.,
Kondo S.,
Okubo M.
Publication year - 2006
Publication title -
grassland science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.388
H-Index - 19
eISSN - 1744-697X
pISSN - 1744-6961
DOI - 10.1111/j.1744-697x.2006.00064.x
Subject(s) - grazing , dry matter , zoology , neutral detergent fiber , biology , agronomy , nutrient , ecology
Under rotational grazing by lactating dairy cows, effects of grass height at the start of a grazing season on herbage intake and milk production were evaluated. A 1.87 ha grass‐clover mixed sward was divided evenly into two paddocks, and a different group of six lactating Holstein cows were rotationally grazed on each paddock for 5 h a day. Grazing was commenced when mean grass height in the two paddocks reached 15 cm (S15) and 20 cm (S20), respectively. Mean grass height throughout the grazing period tended to be higher in S20 than S15, and in particular, the difference at June between the treatments was significant ( P < 0.01). However, mean crude protein and neutral detergent fiber contents of herbage, including those at June, did not significantly differ between S15 and S20. Mean daily herbage dry matter (DM) and total digestible nutrients (TDN) intake per cow were similar between S15 and S20, while mean daily total feed DM and TDN intake tended to be higher in S15 than S20, although the difference was not significant. Mean daily total 4% fat‐corrected milk (FCM) yield tended to be higher in S15 than S20, but there was no difference in mean daily FCM yield derived from herbage between the treatments. The amount of herbage DM and TDN intake per unit area throughout the grazing period was similar between the treatments, and were 8.56 and 5.61 t/ha in S15 and 8.62 and 5.54 t/ha in S20. The amount of FCM yield from pasture differed very little between the treatments, and was 11.10 and 10.81 t/ha in S15 and S20, respectively. The difference in the grass height at the start of grazing as in the present study had no obvious effect on nutritive values of herbage, herbage intake per animal, and herbage intake and milk production per unit area.