Seasonal Variations in Voluntary Intake and Apparent Digestibility of Forages in Goats Grazing on Introduced Leymus chinensis Pasture
The nutrient composition of pasture, voluntary intake and digestibility of diet ingested by goats grazing on an introduced Leymus chinensis pasture were measured across spring (May), summer (July), autumn (October) and winter (March). In each season, 12 Inner Mongolian Cashmere goats (6 wethers and 6 does with an average live weight of 22.2±1.3 kg and 19.5±0.8 kg, respectively) were used to graze on a 2 hectares size paddock. Diet selection was observed and the plant parts selected by grazing goats and whole plant L. chinensis were sampled simultaneously. The alkane pair C32:C33 and C36 were used to estimate intake and digestibility, respectively. The results showed that the plant parts selected by goats had higher crude protein (CP) and lower acid detergent fiber (ADF) and neutral detergent fiber (NDF) than the whole plant, especially in the autumn and winter. The voluntary intake of dry matter (DM), CP, ADF, NDF, and metabolizable energy (ME) by goats was highest in summer (p<0.05). The goats ingested more CP, ME, and less ADF in spring than in autumn (p<0.05). The intakes of DM, CP, and ME were lowest in winter (p<0.05). There were significant differences in nutrient intake between wethers and does in each season, except for the ADF and ME intake per metabolic weight (LW0.75). The nutrient digestibilities were higher in spring and summer, and decreased significantly during the autumn and winter (p<0.05). Goats, especially wethers, had a relative constant NDF digestibility across seasons, however, the apparent digestibility of CP in both wethers and does, decreased to negative values in winter. The grazing goats experienced relatively sufficient nutrients supply in spring and summer, and a severe deficiency of CP and ME in winter.
Geographical Variation in Nutrient Composition of Lotus tenuis (Waldst.&Kit.) Populations from Seeds Collected from Different Locations
To investigate the effect of seed origin on the nutritive value of narrowleaf birdsfoot trefoil (NBT, Lotus tenuis Waldst.&Kit.), seeds of 86 NBT populations were collected from plants spontaneously occurring in natural pastures and rangelands located at different geographical gradients of the Black Sea Region, Turkey. Some nutrient contents of these populations regrown under the same conditions were determined. Minimum and maximum values with regard to the crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), Ca, P, Mg, K and condensed tannin contents, relative feed value, Ca P-1 and K (Ca+Mg)-1 ratios were found as 176.83 and 238.87, 201.00 and 351.61, 307.19 and 435.48, 15.01 and 21.60, 2.18 and 3.77, 3.03 and 4.02, 8.43 and 16.69, 20.00 and 31.50 g kg-1 dry matter, 189.70 and 263.41, 4.73 and 9.57, 0.35 and 0.88, respectively. The effects of seed genotype from different altitudes (Ca P-1), latitudes (digestible dry matter and ADF) and longitudes (CP and Mg) on some nutrient contents and feed values were found significant (P<0.05). The correlations between altitude and NDF, P and Mg or between latitude and P and Mg contents of populations were significant. There were no specific trends in chemical composition and the nutritive value of tested NBT populations due to geographical variation. Thus, the results suggested that all studied geographical populations can be selected to obtain the nutritionally superior forage.
D'une application pratique des indices bio-météorologiques
Abstract The purpose of the author is to determine statistically in what part of Switzerland maize could be cultivated with certain chance of rentability. The author gives first the method he used for determining the biometeorological index of four species of maize which were selected by the Swiss agronomical research stations. He has considered two possibilities for the growing period: ( a ) raising-ripening (l'approche globale); ( b ) raising-flowering, flowering-ripening (l'approche fractionee). From the biometeorological index, he calculated retrospectively the ripening time of these four species in the years 1901–1965. Assuming a priori that maize should be harvested before October 15th at the latest, he calculated, for a number of meteorological stations, the relative number of years when such conditions were fulfilled. Dividing the country in regions of similar mesoclimates and sorting these stations per region, it is possible to average the maximum altitude where maize can ripen at least 7, 8, 9 and 10 times within 10 years. Finally, taking into account the exposure and ground slope, he draws maps of the theoretically possible extension area, which maps are more reliable and detailed than the ones derived from actual means.