Influence of stage of growth at cutting on lucerne production
Abstract A 5-year field trial confirmed that for maximum production lucerne should not be mown frequently when it is growing vigorously. Lucerne repeatedly cut when 20 cm high had 73% of the yield and 115% of the percentage leaf of lucerne cut at early flowering, but continuous mowing at a vigorous growth stage caused severe reduction in lucerne vigour and delayed its recovery growth. This in turn reduced lucerne stand longevity and favoured ingress of weeds.
Yields of protein extracted from irrigated lucerne
Abstract When grown under irrigation in Canterbury, New Zealand, lucerne whole herbage gave total nitrogen yields and leaf and stem percentages which were similar for 5-weekJy (preflowering) harvests and early-flowenng harvests. Yields of extractable protem were also similar. although total herbage dry-matter yields were significantly higher from the longer intervals between harvests (195q kg/ha protein from 17 200 kg/ha dry herbage at preflowenng stage; 1880 kg/ha protem from 21 340 kg/ha dry herbage at early-flowering stage). Extractable protein yielded by herbage cut at 4-weekly intervals to a stubble of 10 em length was similar to that obtained from a crop cut less frequently and to a shorter stubble. Total N yield of lucerne was higher when the crop was grazed at 5-weekly intervals than when it was cut at the same mtervals. The yield of extractable protein from a treatment which was cut at 5-weekly intervals, then stocked. with sheep fed chopped green lucerne ad lib. on the. same area for the subsequ...
On the fractionation of β-lactoglobulin and α-lactalbumin
Abstract Existing methods for the preparation of α-lactalbumin and β-lactoglobulin are examined critically. It is proposed that the most satisfactory method for the preparation of the whey protein fraction from bovine milk is (NH 4 ) 2 SO 4 fractionation. A number of new gentle procedures for the fractionation of the whey proteins are compared with some existing methods. The distribution of total protein at various stages is determined by total Kjeldahl nitrogen and the kind of protein by starch-gel electrophoresis. The effect of variables, such as pH, salt concentration and temperature on the separation of α-lactalbumin and serum albumin from β-lactoglobulin is studied. Differences in the behavior ( e.g. solubility) of genetic variants of β-lactoglobulin are noted. The solubility of each of the major whey proteins, under similar conditions to those used in the fractionation, is compared with its solubility in the whey protein mixture. The understanding gained of factors important in the fractionation is used in recommending new procedures for α-lactalbumin and β-lactoglobulin isolation.