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141.
142.
N. I. Nielsen H. Volden M. Åkerlind M. Brask A. L. F. Hellwing T. Storlien 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(3):126-130
AbstractA data-set with 47 treatment means (N = 211) was compiled from research institutions in Denmark, Norway, and Sweden in order to develop a prediction equation for enteric methane (CH4) emissions from dairy cows. The aim was to implement the equation in the Nordic feed evaluation system NorFor. The equation should therefore be based on input variables available in NorFor. The best equation to predict CH4 (MJ/d) was based on dry matter intake (DMI, kg/d), and content of (g/kg DM) fatty acids (FA), crude protein (CP), and neutral detergent fiber (NDF). The equation was CH4 = 1.36 (±0.10) × DMI – 0.125 (±0.039) × FA – 0.02 (±0.012) × CP + 0.017 (±0.005) × NDF (RMSE = 3.00 MJ CH4/d; CV = 13.8%; R2 = 0.77), where RMSE is the root mean square error and CV is the coefficient of variation. However, CP was on the borderline of being significant and did not quantitatively explain much variation in CH4 emission. Based on the present research, we concluded, therefore, that the equation CH4 = 1.23 (±0.08) × DMI – 0.145 (±0.039) × FA + 0.012 (±0.005) × NDF (RMSE = 3.10 MJ CH4/d; CV = 14.3%; R2 = 0.75) is most suited for being implemented in NorFor. However, the ability of the proposed equation to predict enteric methane emissions is uncertain until evaluated on an independent data-set. 相似文献
143.
T.S. AAS B.F. TERJESEN T. SIGHOLT M. HILLESTAD J. HOLM S. REFSTIE G. BAEVERFJORD K.‐A. RØRVIK M. SØRENSEN M. OEHME T. ÅSGÅRD 《Aquaculture Nutrition》2011,17(6):657-670
Rainbow trout with initial body weight 1144 g were fed two diets with high (feed A) or low (feed B) water stability for 6 weeks. During the last 2 weeks either stable or fluctuating oxygen saturation, salinity and temperature was introduced. High water stability of the feed was associated with harder pellets, less dust formation and less broken pellets compared to feed with low water stability. During the first 4 weeks, feed intake was 23% higher in trout fed diet B than in those fed diet A. Fluctuating environment resulted in a severe drop in feed intake for both dietary groups. At termination of the trial, stomachs of trout fed feed B contained mashed pellets and free water and oil. Stomachs of trout fed feed A contained more intact pellets and little fluid. The apparent digestibility of protein, starch, dry matter and energy was highest in feed A. The apparent digestibility of P and Zn was highest at stable environment, and the absorption of P was highest from feed A. In conclusion, physical quality affected the nutritional value of the feeds, and differences in nutritional value at stable or fluctuating environment appeared to be related to feed intake. 相似文献