Near infrared reflectance spectroscopy (NIRS) was used to predict quality parameters in Cajanus cajan used as forage for animals. Crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), crude lipid (CL) and organic matter (OM) were determined by chemical methods. The set of samples for analysis was selected using the software SELECT on the basis of the NIR spectra of samples from field plots and consisted of branches and leaves of Cajanus cajan, harvested in two contrasting locations in Zimbabwe. The samples were scanned and screened using an NIR Systems Model 5000 monochromator; 48 samples were used to calibrate and to cross-validate the equations derived. Equations for predicting chemical composition of the species under study were calculated using scores from partial least squares (PLS) as independent variables. Cross-validation procedures indicated good correlations between laboratory values and NIRS estimates. NIRS calibrations obtained from this study could be utilised in current and future programmes for evaluating the quality of Cajanus cajan forage for animal nutrition.
Tag: animal
Population dynamics of Hippophae rhamnoides shrub in response of sea-level rise and insect outbreaks
The coastal vegetation of islands is expected to be affected by future sea-level rise and other anthropogenic impacts. The biodiverse coastal vegetation on the eastern part of the Dutch Wadden Island of Ameland has experienced land subsidence caused by gas extraction since 1986. This subsidence mimics future sea-level rising through increased flooding and raising groundwater levels. We studied the effects of this relative sea-level rise and other environmental factors (i.e. insect outbreaks, temperature and precipitation) on the population dynamics (i.e. cover and age structure and annual growth) of the shrub seabuckthorn (Hippophae rhamnoides L.) in young (formed after 1950) and old (formed before 1950) dune areas over a period of 56 years (1959–2015). We found an increase in seabuckthorn cover in the young dune areas since 1959, while over time the population in the old dunes decreased due to successional replacement by other species. With the increasing age of the young dunes, we found also a decrease in sea-buckthorn after 2009. However the sharp decrease indicated that other environmental factors were also involved. The most important determinant of annual shrub growth appeared to be five outbreaks of the brown-tail moth (Euproctis chrysorrhoea L.), in the last decade. Relative sea-level rise caused more frequent flooding and reduced growth at lower elevations due to inundation or soil water saturation. This study clearly indicates that sea-buckthorn is affected by relative sea-level rise, but that other ecological events better explain its variation in growth. Although shrub distribution and growth can be monitored with robust methods, future predictions of vegetation dynamics are complicated by unpredictable extreme events caused by (a)biotic stressors such as insect outbreaks.