Autumn grazing of finishing lambs on annual lupine (Lupinus angustifolius) under subarctic conditions
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| Höfundur | Útgefandi | Útgáfuár | Útgáfustaður |
| Ólafur Guðmundsson, Sveinn Runólfsson | Búnaðarfélag Íslands, Bændaskólinn á Hvanneyri, Rannsóknastofnun landbúnaðarins, Rannsóknastöð Skógræktar ríkisins, Tilraunastöð háskólans í meinafræði, Veiðimálastofnun | 1988 | Reykjavík |
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| Rit | Árgangur | Tölublað | Bls. |
| Búvísindi | | 1 | 45-57 |
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ABSTRACT
The use of annual lupine was first studied in Iceland around 1900. However, due to a high content of alkaloids it was not suitable for animal feeding. A research program to test the suitability of annual lupines for Icelandic conditions was reinstituted in 1979. The trials indicated a great potential for annual lupines in Iceland as animal feed despite low summer temperatures. Further research with '°N has substantiated the ability of Rhizobium strains to function under these conditions. Lupinus angustifolius cv. Uniharvest from West Germany, which was the best commercially available variety of the 12 tested, was selected for two grazing trials. The lupine was seeded in May. The weather conditions during May through September were exceptionally cold in both years (8.6 and 8.4 °C with a ten year average of 9.0 °C), whereas the precipitation was 87 mm below the ten year average of 456 mm in the first year and 275 mm above average in the second year. Twin lambs of the Iceland breed were grazed on the lupine for 4 to 5 weeks in the fall. Control groups were grazed on kale and barley/ryegrass aftermath (experiment I) and on fertilized hayfield aftermath (experiment II) for the same period. The lambs in expt. I were 107 days old and weighed 31.6 kg and in expt. 11 115 days old and weighed 38.0 kg at the initiation of the trials. The lambs had been grazed on aftermath for two weeks prior to the experiments. Blood samples were collected at the beginning and the end of each trial. Higher hematocrit and lower urea levels were found in samples from lambs on the lupine than from the control lambs in expt. I. Urea, phosphorus and magnesium were higher and MCHC and glucose lower in samples from lambs on the lupine in expt. II. Lamb gains in all groups were excellent. During expt. I the lambs on both treatments gained over 450 g per day. In expt. II the lambs on lupine made less gain the first two weeks, needing some time for adjustment, but between 27 September and 14 October lambs on the lupine gained on the average 412 g per day compared to 167 g per day on the aftermath. The results indicate that lupine can play an important role in extending the period of rapid lamb growth late into the autumn.
Key words: Lupine, subarctic, grazing, growth, lambs, blood.
YFIRLIT
Haustbeit lamba á einæra fóðurlúpínu (Lupinus angustifolius) við íslenskar aðstæður
Fyrstu rannsóknir með einæra lúpínu voru gerðar hér á landi nálægt síðustu aldamótum. Hátt innihald af alkalóíðum gerði þær ónothæfar handa búfé. Þetta, ásamt auknu framboði af tilbúnum áburði um miðbik aldarinnar gerði það að verkum að tilraunum var hætt með einæra lúpínu. Tilraunir með mismunandi stofna af svo til alkalóíðlausum (sætum) lúpínum, voru hafnar aftur árið 1979. Þrátt fyrir lágan sumarhita á þessum árum lofuðu niðurstöðurnar góðu. Frekari rannsóknir með 15N hafa leitt í ljós töluverða starfsemi rótarbaktería við hérlendar aðstæður.
Af þeim 12 stofnum sem prófaðir voru, reyndist afbrigðið Uniharvest (Lupinus angustifolius) frá Vestur-Þýskalandi best af þeim tegundum sem fáanlegar voru á almennum markaði. Það var því valið í þær haustbeitartilraunir sem hér er skýrt frá. Tilraunirnar voru gerðar tvö haust. Lúpínunni var sáð í maí. Sumrin frá maí fram í september, voru bæði mjög köld ( 8,6 °C og 8,4 °C). Úrkoma á sama tíma fyrra sumarið, var 369 mm, en 731 mm það seinna.
Lömbunum var beitt á lúpínu í 4 til 5 vikur. Samanburðarhópum, með sambærilegum lömbum, var beitt á kál og há af blöndu af byggi og rýgresi fyrra árið (1. tilraun) og á áborna há seinna árið (2. tilraun). Lömbin í fyrri tilrauninni voru að meðaltali 107 daga gömul við upphaf tilraunarinnar og vógu 31,6 kg á fæti.
Lömbin í seinni tilrauninni voru aftur á móti 115 daga gömul og vógu 38,0 kg á fæti í upphafi. Lömbin höfðu verið á há í um það bil tvær vikur áður en þau voru sett í tilraunina.
Blóðsýni voru tekin við upphaf og lok tilraunanna. Hematókrít var hærra og þvagefni lægra í sýnum lamba á lúpínunni í fyrri tilrauninni heldur en hjá samanburðarlömbunum. Hærra þvagefni, fosfór og magníum ásamt lægra innihaldi af MCHC og glúkósa var í blóði lamba á lúpínunni heldur en á hánni í seinni tilrauninni.
Öll lömbin þrifust mjög vel. Bæði lömbin á lúpínunni og samanburðarlömbin þyngdust yfir 450 g á dag í fyrri tilrauninni.
INTRODUCTION
Lupine research was initiated in Iceland around 1900 (Helgason, 1902). In the following years several studies were conducted on the cultivation of lupines (Jónsson, 1939). With increased availability of artifical fertilizers and also probably due to a high content of alkaloids in the cultivars tried, the interest in lupine declined and by the middle of the century the research had ceased.
In 1945 a perennial lupine, Lupinus nootkatensis, that originated in Alaska was established in Iceland (Einarsson, 1981), though it had been tried as early as 1910 (Helgason, 1911). This lupine is a very hardy species, producing a great amount of biomass during the summer. Unfortunately it is unsuitable as animal feed because of its high alkaloid content (Arnalds and Guðmundsson, 1980). However, its high rate of production created interest in trying other varieties of lupine, especially the sweet cultivars developed originally in Germany around 1930. These varieties have spread to various countries of the world and are now especially popular in Australia, Poland and the USSR (Williams, 1984).
In 1979 a research program was initiated. Twelve cultivars of two varieties were tested, with the intention of selecting the most productive one for use as autumn green feed for fattening livestock and for milk production. Two of the best cultivars turned out to be Lupinus luteus cv. Ventus from Poland and Lupinus angustifolius cv.
Uniharvest from West Germany (Arnalds and Bjarnason, 1981) but only the latter was commercially available at the time. Uniharvest was therefore selected for further research on autumn grazing of lambs. |