Abstract:
A shortage in winter grazing is the major problem on most farms in South Africa. Animals loose
weight in winter, which leads to low reproduction, production of milk, mutton and meat. The
emphasis of this study was to look into the effect of cutting stages on re-growth dry matter
production and nutritional value of five different cultivars. The study was conducted 2007. Two
planting dates were used February in Mpumalanga and April in Gauteng respectively. Cultivars
(Witteberg oats, Overberg oats, LS 35 rye, LS 62 stooling rye and Cloc 1 Triticale) were planted
in three replications. Each main plot was divided in five split-plots with different cutting
treatments. Five cutting treatments were applied in five split plots: Sub-plot A was cut 8 weeks
after planting, and after that re-growth was cut every six weeks. (Ct 8), Sub-plot B was cut 10
weeks after planting, and after re-growth was cut every six weeks. (Ct 10), Sub-plot C was cut 12
weeks after planting, and after re-growth was cut every six weeks. (Ct 12), Sub-plot D was cut
14 weeks after planting, and after re-growth was cut every six weeks. (Ct 14), Sub-plot E was cut
when more than 50% of plants were in the reproductive stage (RS). The study found, planted in
April LS 62 stooling rye and Cloc 1 triticale can be described as a late winter/spring producing
cultivars. LS 62 and Cloc 1 triticale were on average the highest producers (Above 6.0 t/ha)
when defoliated initially 14 weeks after planting and two re-growth cuts was achieved in very
treatment.. On average, this defoliation treatment (Ct 14) resulted in the highest production for
all cultivars. The acid detergent fibre (ADF %) of all five cultivars was below 30%, in the young
stages. During the mature stage the ADF percentage of LS 62 stooling rye, Witteberg and
Overberg oats rose higher than 30%. The neutral detergent fibre (NDF %) of all five cultivars
was below 45% in the young stage. During the mature stage, the NDF percentage of LS 62
stooling rye, Witteberg and Overberg oats were higher than 50%. The crude protein content was
in most cases above 14 %, except Witteberg and Overberg oats, in a young stage and Overberg
oats and LS 62 stooling rye in a mature stage. These high nutritional values are indicators that
animals grazing this winter fodder will be able to gain weight and increase their production in
winter. Under the cool climate of Mpumalanga, LS 35 and LS 62 cultivars could be classified as
early to mid-winter producers, loc 1 triticale and Witteberg oats as mid-winter producers and
Overberg oats as late winter producer. |
