Nutritional value of seaweed for ruminants Photo: Ingrid Bay-Larsen Martin Weisbjerg, Margarita Novoa-Garrido 1, Michael Roleda 1 Department of Animal Science, Aarhus University Foulum, Denmark. 1 NIBIO, Bodø, 8049 Bodø, Norway.
Background Seaweed is a large biomass source Use of seaweeds in animal feeding is not new Knowledge on feed value is very limited 2
Aim Study feed value for ruminants of seaweed, and variation between seaweed species and seasons in chemical composition and in vitro digestibility 3
Samples 8 seaweed species 2 seasons 2014, spring and autumn Legumes and seaweeds as alternative protein for sheep (AltPro) Bodø: 67 19'00'' N, 14 28'60" E 4
Sample collection Hand picked 2 baths with sea water eliminate sand, animals and fouling organisms 1 quick bath with 30% sea water eliminate salt 1 quick bath on pure fresh water eliminate more salt 5
Red seaweeds Rhodophyta Mastocarpus stellatus Porphyra sp. Photo: M. Novoa-Garrido Palmaria palmata 6
Brown seaweeds Ochrophyta Pelvetia canaliculata Alaria esculenta Photo: M. Novoa-Garrido, M.Y. Roleda Laminaria digitata 7
Green seaweeds Clorophyta Acrosiphonia sp. Ulva sp. Photo: M. Novoa-Garrido, 8
Samples freeze dried Ash (525 o C) Analysis Acid insoluble ash as measure for sand pollution (spring samples) N (Dumas) to estimate crude protein (x 6.25) Neutral Detergent Fibre (NDF) in Fibertech including sodium sulphite and residual ash correction In vitro organic matter digestibility (Tilley & Terry), rumen fluid from 3 dry rumen fistulated cows fed standard ration at maintenance (hay, straw and concentrate) 9
Composition of seaweeds Acid insoluble ash only analysed in spring samples, however concentrations were low or below detection level No sand pollution 10
Composition of seaweeds Specie Season DM Ash CP NDF OM other In vitro dig. g/kg g/kg DM g/kg OM Brown seaweeds Alaria Spring 132 278 158 117 447 590 Autumn 237 139 127 90 644 529 Laminaria Spring 128 351 161 163 325 792 Autumn 173 233 103 201 463 852 Pelvetia Spring 229 219 105 293 383 359 Autumn 244 210 75 280 435 333 Red seaweeds Mastocarpus Spring 283 217 178 148 457 746 Autumn 254 208 178 351 264 760 Palmaria Spring 160 165 257 421 157 839 Autumn 200 108 188 501 203 863 Porphyra Spring 148 149 372 371 107 778 Autumn 105 107 321 408 164 780 Green seaweeds Acrosiphonia Spring 226 171 333 406 90 444 Autumn 194 127 286 388 199 502 Ulva Autumn 143 483 162 286 69 564 P value Species (n=8) 0.09 <0.01 <0.0001 <0.01 <0.0001 <0.0001 Season (n=2) 0.17 0.02 <0.01 0.21 <0.0001 0.7 11
NDF (g/kg DM) OM not CP or NDF (g/kg DM) Ash (g/kg DM) CP (g/kg DM) 700 600 Composition of seaweeds 700 600 500 483 500 400 300 200 100 351 238 139 217 159 107 260 127 400 300 200 100 161 122 75 372 333 249 260 178 162 0 Brown Red Green 0 Brown Red Green 700 600 700 600 644 500 501 400 406 367 360 300 293 286 200 191 148 100 90 0 Brown Red Green 500 400 300 200 100 0 450 457 325 225 199 107 119 69 Brown Red Green 12
In vitro OM digestibility (g/kg OM) 1000 Digestibility of seaweeds 900 800 700 836 863 794 745 600 500 400 300 200 100 574 333 564 503 443 0 Brown Red Green 13
Sampling and work continued in 2015 Preliminary spring data confirm 2014 effects and variation Further work has been performed on protein degradability and digestibility, and on indigestible NDF 14
Conclusions Dry matter concentrations as high as for land grown forages Very high and variable ash (not sand) Low to very high protein concentration, higher in spring than in autumn Very low to very high organic matter digestibility Non NDF non protein organic matter high in brown seaweed Some seaweed species could be highly interesting as energy (some red and brown) and protein (some red and green) feed for ruminants 15
Thank you for your attention 16
CP (g/kg DM) In situ measures of protein availability in dairy cows 400 350 300 250 200 150 100 50 0 76 26 40 77 68-11 76 30-15 61 66 53 49 80 95 36 80 174 93 138 137 37 86 39 Indigestible Digestible escape Rumen degradable -50 Species Tayyab, Novoa-Garrido, Roleda & Weisbjerg (2015) 17
indf (g/kg DM) indf (g/kg NDF) NDF (g/kg DM) 700 NDF and indf 600 500 400 300 200 100 293 191 90 501 406 367 360 286 148 0 Brown Red Green 700 600 500 400 411 337 300 200 191 181.4 144.5 100 117 95 41 0 9 Brown Red Green 1400 1200 1000 800 600 400 200 0 1422 1048 675.6 466 458.4 347.7 312 51 80 Brown Red Green 18