Mikrolevät lypsylehmien ruokinnassa : 2. Valkuaisen hyväksikäyttö

Non peer reviewe

Different microalgae species as a substitutive protein feed for soya far bean meal in grass silage based dairy cow diets

This experiment was conducted to evaluate different microalgae species as protein supplements in the nutrition of lactating dairy cows in comparison to soya bean meal. Four multiparous lactating Finnish Ayrshire cows (112 days in milk) were used in a balanced 4 × 4 Latin square study. Cows were fed separately fixed amount of cereal-sugar beet pulp based concentrate (12.5 kg/d) and grass silage ad libitum. Experimental treatments consisted of four isonitrogenous protein supplements: soya bean meal (SOY), Spirulina platensis (SPI), Chlorella vulgaris (CHL) and a mixture of C. vulgaris and Nannochloropsis gaditana (1:1 on dry matter (DM) basis; CHL-NAN). The substitution of soya bean meal by microalgae did not affect the quantity of total DM intake (DMI), but changed the composition of DMI by decreasing the concentrate:forage ratio of the diet (P=0.054) owing to the poorer palatability of microalgae. Intake of methionine was increased (P<0.01) and that of histidine decreased (P<0.01) with microalgae diets compared to SOY, but no significant changes in arterial concentrations were observed. The digestibility of nutrients, milk or energy corrected milk (ECM) yield were not affected by dietary treatments. Though, owing to SPI, algae diets resulted in numerically +2.2 kg/d higher ECM yield than SOY. Microalgae diets tended to result in higher milk fat (P=0.073), arterial acetic acid (P=0.055) and non-esterified fatty acid (P=0.060) concentrations than SOY. Milk fat (P<0.05) and arterial acetic acid (P=0.010) concentrations were increased and milk fat yield tended to increase (P=0.098) on SPI compared to CHL and CHL-NAN. Urinary nitrogen excretion was also lower (P<0.05) for microalgae diets than for SOY. Microalgae diets resulted in higher secretion of Δ16:2 (P<0.05), cis-9, cis-12, cis-15 18:3 (α-linoleic acid; ALA) (P<0.05), cis-6, cis-9, cis-12 18:3 (P<0.05) and polyunsaturated fatty acids (PUFA) (P<0.05) in milk than SOY. Secretion of cis-5, cis-8, cis-11, cis-14, cis-17 20:5 (eicosapentaenoic acid; EPA) in milk tended to be higher on CHL and CHL-NAN than on SPI (P=0.060), and was higher on CHL-NAN than on CHL (P<0.05). Also the omega-6:omega-3 ratio was lower (P<0.05) for CHL-NAN than for CHL. The results suggest that microalgae are likely comparable protein feed to soya bean meal in dairy cow nutrition, especially if palatability of microalgae can be improved.Peer reviewe

Comparison of microalgae and rapeseed meal as supplementary protein in the grass silage based nutrition of dairy cows

Two experiments were conducted to evaluate microalgae as a protein supplement in the nutrition of lactating dairy cows in relation to unsupplemented and rapeseed meal supplemented diets. In both experiments multiparous Finnish Ayrshire cows were fed separately fixed amount of cereal-sugar beet pulp based concentrate (11 kg/d in Exp. 1 and 12 kg/d in Exp. 2), and grass silage ad libitum. In Exp. 1, six cows (212 days in milk; DIM) were used in a replicated 3 × 3 Latin square. Diets were supplemented isonitrogenously with rapeseed meal (pelleted rapeseed supplement, RSS), mixture of Spirulina platensis and Chlorella vulgaris microalgae (1:1 on dry matter (DM) basis; ALG) or a mixture of RSS and ALG (1:1 on crude protein (CP) basis; RSS-ALG). In Exp. 2, four intact cows and four rumen cannulated cows (190 DIM) were used in a replicated 4 × 4 Latin square. Treatments consisted of basal diet without protein supplement (NEG) or supplemented similarly as in Exp. 1 with the exception of RSS-ALG and ALG containing only S. platensis. Protein supplementation increased fibre and N digestibility but did not affect dry matter intake (DMI) or milk yield. The substitution of rapeseed by microalgae did not affect total DMI or milk yield in neither of the experiments, but changed the quality of DMI in Exp.2 by linearly decreasing concentrate:forage ratio of the diet due to poorer palatability of microalgae. The efficiency of N utilisation (NUE) in milk production varied from moderate (Exp. 1) to high (Exp. 2), and in Exp. 2 was decreased by both protein supplementation and microalgae inclusion in the diet. Protein supplementation or microalgae inclusion in the diet did not affect ruminal pH or major volatile fatty acids in Exp. 2, but both increased ruminal NH3-N concentration. There was likely a shortage of N for rumen microbes on NEG in Exp. 2 as indicated by low milk urea N and increased microbial N flow on protein supplemented diets. In both experiments, only minor differences were observed in plasma metabolites when microalgae substituted rapeseed. Even though arterial histidine concentrations were high, arterial histidine and carnosine concentrations (Exp. 1 and 2) and milk protein yields (Exp. 2) decreased by microalgae inclusion suggesting that histidine supply may become suboptimal on microalgae supplemented diets. Experiments demonstrated the suitability of microalgae as protein supplement for dairy cows, however, the protein value of microalgae is likely slightly lower than that of rapeseed meal.Two experiments were conducted to evaluate microalgae as a protein supplement in the nutrition of lactating dairy cows in relation to unsupplemented and rapeseed meal supplemented diets. In both experiments multiparous Finnish Ayrshire cows were fed separately fixed amount of cereal-sugar beet pulp based concentrate (11 kg/d in Exp. 1 and 12 kg/d in Exp. 2), and grass silage ad libitum. In Exp. 1, six cows (212 days in milk; DIM) were used in a replicated 3 × 3 Latin square. Diets were supplemented isonitrogenously with rapeseed meal (pelleted rapeseed supplement, RSS), mixture of Spirulina platensis and Chlorella vulgaris microalgae (1:1 on dry matter (DM) basis; ALG) or a mixture of RSS and ALG (1:1 on crude protein (CP) basis; RSS-ALG). In Exp. 2, four intact cows and four rumen cannulated cows (190 DIM) were used in a replicated 4 × 4 Latin square. Treatments consisted of basal diet without protein supplement (NEG) or supplemented similarly as in Exp. 1 with the exception of RSS-ALG and ALG containing only S. platensis. Protein supplementation increased fibre and N digestibility but did not affect dry matter intake (DMI) or milk yield. The substitution of rapeseed by microalgae did not affect total DMI or milk yield in neither of the experiments, but changed the quality of DMI in Exp.2 by linearly decreasing concentrate:forage ratio of the diet due to poorer palatability of microalgae. The efficiency of N utilisation (NUE) in milk production varied from moderate (Exp. 1) to high (Exp. 2), and in Exp. 2 was decreased by both protein supplementation and microalgae inclusion in the diet. Protein supplementation or microalgae inclusion in the diet did not affect ruminal pH or major volatile fatty acids in Exp. 2, but both increased ruminal NH3-N concentration. There was likely a shortage of N for rumen microbes on NEG in Exp. 2 as indicated by low milk urea N and increased microbial N flow on protein supplemented diets. In both experiments, only minor differences were observed in plasma metabolites when microalgae substituted rapeseed. Even though arterial histidine concentrations were high, arterial histidine and carnosine concentrations (Exp. 1 and 2) and milk protein yields (Exp. 2) decreased by microalgae inclusion suggesting that histidine supply may become suboptimal on microalgae supplemented diets. Experiments demonstrated the suitability of microalgae as protein supplement for dairy cows, however, the protein value of microalgae is likely slightly lower than that of rapeseed meal.Peer reviewe

Härkäpapusäilörehun ja rypsitason vaikutukset maitotuotokseen ja ravintoaineiden hyväksikäyttöön

Non peer reviewe