Íslenskar landbúnaðarrannsóknir - 01.03.1979, Blaðsíða 32

30 ÍSLENZKAR LANDBÚNAÐARRANNSÓKNIR
and c were at the beginning of shooting of
Phleum pratense. In the first two experim-
ents Phleum pratense (Engmo) was the
dominant species but in the third exper-
iment Alopecurus geniculatus, Agrostis spec-
ies, Poa pratensis and Deschampsia caespitosa
were most prominent in the sward. The
yield of digestible dry matter and conser-
vation losses were measured and subseq-
uently the different hays were fed to a total
of 62 ewe lambs, 7—12 months of age, to
study voluntary feed intake and body
weight gain. In the feeding trials 10 ewe
lambs were used for each treatment in the
first experiment and 4 per treatment in the
other two experiments. The feeding per-
iod averaged 138 days (winter).
The results are summarized in the foll-
owing paragraps:
1. The yield of dry matter per hectare
increased on average by 25—40 hkg/
day with advancing stage of maturity
but the number of harvested feed units
per hectare remained relatively con-
stant after the beginning of shooting of
Phleum pratense.
2. The total conservation losses of dig-
estible dry matter ranged from 8 to
31 %, the highest losses being in treat-
ments b and c.
3. The feeding value (quality) of the hay
had a negligible effect on the voluntary
feed intake of Phleum pratense where as
the feeding value of the mixed species
(third experiment) was positively cor-
related with intake.
4. There was a close relationship between
the growth rate of the lambs and the
feeding potential of the hay measured as
F.U./W0-56. Some 20% of the variation
in the feeding potential was accounted
for by different feed intake and 80% by
different feeding value (DMD) of the
hay.
5. Only the lambs fed the early cut barn
dried hay (treatment a) gained body
weight at a satisfactory rate. The poor-
est weight gains were recorded in tre-
atments c and d.
6. The advancing stage of maturity seem-
ed to have a greater effect on the feed-
ing potential of the hay than the le-
aching in the field during a prolonged
exposure to rain. It is concluded that
prolonging the field drying period by x
days had the same effect on the feeding
potential of the hay as delaying the
time of cutting by 2 x days. Heating of
the hay (treatment c), reduced the fe-
eding potential by 15-39% compared
with the best cured hay (treatment a).
7. The results indicate that the most ef-
ficient utilization of grass for hay-
making (DM yield), taking into acco-
unt its feeding potential for growing
sheep, was obtained by early cutting
(when Phleum pratense begins shooting)
and barn drying of the hay.