Browsing IJAFR, volume 51, 2012 by Title
Now showing items 4-6 of 6
Digestible lysine levels in low-protein diets supplemented with synthetic amino acids for nursery, growing, and finishing barrowsTo investigate the effect of lysine level in low-protein diets (LPD) an experiment was conducted with 36 barrows fed 174, 140 and 118 g/kg of crude protein (CP), and three digestible lysine levels. Low-protein diets were supplemented with crystalline amino acids (AA) to the same concentration as in the standard CP diet. Growth performance, carcass characteristics and plasma urea nitrogen concentration were evaluated. In nursery pigs, the addition of lysine to LPD quadratically increased backfat thickness (BF; P < 0.01), longissimus muscle area (LMA; P < 0.001), and lean meat percentage (LMP; P < 0.05). In the growing phase, reducing dietary protein decreased average daily gain (ADG; P < 0.09), final body weight (BW; P < 0.09), fat free lean gain (FFLG; P < 0.09), and LMA (P < 0.038); and increased BF (P < 0.05). Addition of lysine to LPD quadratically increased ADG (P < 0.01), average daily feed intake (ADFI; P < 0.05), final BW (P < 0.006), and FFLG (P < 0.002). In the finishing period, pigs fed LPD had lower ADFI (P < 0.03) and feed:gain ratio (FGR; P < 0.003). Addition of lysine to LPD linearly increased BF (P < 0.04), and quadratically increased ADFI (P < 0.02), FGR (P < 0.009), BF (P < 0.08), and LMA (P < 0.08). The plasma urea nitrogen concentration was reduced (P < 0.05) in all phases in pigs fed LPD. Lysine requirement for fattening barrows fed LPD may be higher than the recommended concentration for standard CP diets.
A note on the fermentation characteristics of red clover silage in response to advancing stage of maturity in the primary growthThis study investigated the silage fermentation characteristics of red clover (Trifolium pratense L., var. Merviot) harvested at five dates in the primary growth (at two week intervals from 12 May to 7 July). Despite the challenging herbage ensilability characteristics pre-ensiling [i.e. low dry matter (DM) concentration (142 to 178 g/kg), low water soluble carbohydrate concentration (51 to 118 g/kg DM) and high buffering capacity (552 to 639 mEq/kg DM], the silages preserved successfully and showed little evidence of clostridial activity (i.e. low concentration of butyric acid and ammonia-N). Stage of maturity at harvest had little effect on silage fermentation characteristics.
Physical and mechanical properties of soil for ridge formation, ridge geometry and yield in new planting and ridge formation methods of potato productionIn 2008 and 2009, a trial was performed to enhance the physical and mechanical properties of light soil for ridge formation, to increase the cross-sectional area of loose soil in the ridge, to improve the marketable yield and time efficiency, and to lower the percentage of green tubers. Three different planting and ridge formation methods applied to potato production were compared. The first method involved simultaneous planting and small ridge formation, followed by final ridge formation with a PTO-driven potato cultivator immediately before potato emergence (CL method). The second method combined planting and simultaneous final ridge formation (P+FR method), while, in the third method (BF+P+FR method), a special bed former attached to the front of a tractor that pushed the loose soil off the tractor wheels was used. The trial design was a randomised complete block with three repetitions. The BF+P+FR method produced the best physical and mechanical properties of the soil for ridge formation, while the CL method produced the poorest. Due to greater distance of the seed tuber from the ridge centre, the CL method resulted in the largest yield and percentage of green tubers. In comparison with the other two methods, the CL method gave a lower percentage of marketable tubers and a higher percentage of non-marketable tubers. Moreover, the BF+P+FR and P+FR methods were more time-efficient during planting and ridge formation than the CL method.