Feeding Value for Beef Steers of Corn Silage as Affected by Harvest Dates and Frost

Abstract

. l9j'7. Feeding value for beef steers of corn silage as affected by harvest dates and frost. Can. J. Anim. An experiment was conducted in 3 consecutive yr with corn grown each year on a field from which silage was made of corn harvested at different dates before and after freezing. Yields of green and dry weight were recorded at each harvest.Individual whole plants and ptant parts were evaluated for dry matter (DM), total nitrogen, total available carbohydrates and in vitro digestibility of DM. Animal gains, feed consumption and carcass grades were determined by feeding the silages to yearling Hereford steers and DM digestibility determined with sheep. The total yield and contribution of the ear increased from the first to the second harvestins date. The in vivo digestibility ofDM ofthe silages declined between the second ani final harvests in all years as did animal gain in years I and 3. The This agrees with the observations of Demarquilly (1969) in France and Daynard and Hunter (1915) in Ontario where temperatures would not be expected to be high during the corn maturation period. Cummins (1970)

Apparent digestibility and nitrogen utilization of diets based on maize silage harvested at three stages of maturity and fed to steers

“…Similarly, Cartee et al (1994) and Joanning et al (1981) found N digestibility of maize silage with a low DM content (c. 250 g DM kg )1 ) to be significantly higher than that of maize silage containing more than 300 g DM kg )1 . The literature contains other reports of advancing maize maturity having a negative effect on N digestibility (Goering et al, 1969;Calder et al, 1977;St Pierre et al, 1983) although this does not appear to always be the case. Both Colovos et al (1970) and Sutton et al (2000) found no effect of crop maturity on N digestibility over a wide range of silage DM contents (c. 230-390 g DM kg )1 ).…”

“…The literature contains other reports of advancing maize maturity having a negative effect on N digestibility (Goering et al. , 1969; Calder et al. , 1977; St Pierre et al.…”

“…, 1984). However, some studies have shown negative effects of increasing maize maturity on digestibility, particularly when the crop is harvested with a high DM content (≥350 g DM kg −1 ; Byers and Ormiston, 1964; Johnson and McClure, 1968; Calder et al. , 1977).…”

“…The digestibility of dry matter (DM) and organic matter (OM) of maize silage is reported to remain relatively constant over a wide range of DM contents (Bryant et al, 1965: Wilkins andCook, 1971;Aerts et al, 1984). However, some studies have shown negative effects of increasing maize maturity on digestibility, particularly when the crop is harvested with a high DM content ( ‡350 g DM kg )1 ; Byers and Ormiston, 1964;Johnson and McClure, 1968;Calder et al, 1977). At these high DM contents, fibre, starch and crude protein digestibility can be reduced (Bal et al, 1997).…”

Winter weathering effects on corn grown for grazing in a short-season area

“…In studies from other regions, losses of whole-plant corn dry matter have ranged from 50 to 70% (Lamm and Ward 1981;Willms et al 1993). Losses for whole-plant digestibility during fall (August to mid-October) were minimal, but large losses of stalk and leaves occurred when harvest was delayed into November in New Brunswick (Calder et al 1977).…”