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

Abstract

G. W. 2003. Winter weathering effects on corn grown for grazing in a short-season area. Can. J. Plant Sci. 83: 333-341. Winter grazing can reduce over-winter feeding costs of beef cows and, recently, the selection and marketing of corn (Zea mays L.) varieties for grazing has increased the interest of Alberta beef producers. The objective of this study was to compare grazing corn varieties with early conventional corn hybrids for winter grazing potential. Five corn varieties (one grazing, one short-stature and three conventional types) were compared for whole-plant yield and forage quality at Lacombe and Brooks, AB, at four harvest times (two in September, one in December and one in January), in each of 2 yr. Forage quality analyses were in vitro digestible organic matter (IVDOM), neutral (NDF) and acid detergent fiber (ADF) and crude protein concentration. Averaged over varieties and years, yield decreased (P ≤ 0.05) by 13% between September and January at Lacombe, and by 39 and 16% at Brooks in 1999 and 2000, respectively. At Brooks, yield losses from September to January, averaged over years were 38 to 18% for a grazing and a conventional variety, respectively. At Lacombe, IVDOM concentration declined (P ≤ 0.05) by 6.3 and 3.6% between September and January during 1999 and 2000, respectively; NDF concentration increased (P ≤ 0.05) by 10% over the same interval for both years. At Lacombe there were no differences among varieties for nutritive value by January harvests. Trends for reduced forage quality with harvest were not clear at Brooks but the grazing-type variety had higher (P ≤ 0.05) NDF and ADF concentrations than the other varieties after the first harvest. In general, projected energy and crude protein concentrations of corn during winter exceeded minimum requirements and were adequate, respectively, for non-lactating, pregnant beef cows. Grazing and short stature corn varieties were not superior to early conventional corn genotypes for winter grazing potential. Thus, choice of variety for winter grazing should be made on the basis of cost of production and early maturity. ) pour la paissance a éveillé l'intérêt des producteurs de boeuf de l'Alberta. L'étude devait comparer le potentiel de paissance hivernal de ces variétés à celui d'hybrides ordinaires. Les auteurs ont comparé le rendement global de la plante et la qualité du fourrage de cinq variétés (une destinée à la paissance, une naine et trois ordinaires) à Lacombe et à Brooks (Alberta) pendant deux ans, à quatre périodes de récolte (deux en septembre, une en décembre et la dernière en janvier). Pour déterminer la qualité du fourrage, ils ont dosé la concentration de matière organique digestible in vitro (IVDOM), la quantité de fibres au détergent neutre (NDF) et acide (ADF) et la teneur en protéines. Une fois la moyenne pour les variétés et les deux années établie, on constate que le rendement a diminué (P ≤ 0,05) de 13 % entre septembre et janvier à Lacombe, contre 39 % et 16 % en 1999 et 2000, respectivement, à Brooks. Après calcul de la moy...

Evaluation of Low Heat Unit Corn Hybrids Compared to Barley for Forage Yield and Quality on the Canadian Prairies

“…Protein content was higher for barley (10.3 to 14.3% CP) than the 3 corn hybrids (6.8 to 9.3% CP). The latter CP values were in agreement with those of previous work (Baron et al, 2003;Abeysekara et al, 2013) for corn forage. Taking into consideration the protein requirements of beef cattle, in the current study, only AC Ranger barley had sufficient amounts of CP required by gestating and lactating cows.…”

“…This rule says that for a mature beef cow to maintain her body condition score through the winter, the ration must have a TDN energy reading of 55% in mid pregnancy, 60% in late pregnancy and 65% after calving (Yurchak & Okine, 2004). Therefore, even accounting for weathering effects on plant material for winter grazing (Baron et al, 2003) , the result of the current study suggested that all three new corn hybrids had adequate energy needed by dry gestating cows, mid pregnancy cows, as well as late pregnancy cows at all sites. This further confirms that similar with barley, corn is a high energy feed that will normally match the nutritional needs of a dry cow in mid and late pregnancy and after calving.…”

“…Previous grazing trials at Lanigan, Saskatchewan suggested that corn can serve as an excellent winter foraging crop, left either standing or swathed (Lardner, 2002). Standing corn can also serve as an effective windbreak for grazing cattle during winter and snow depth will not limit animal access to the crop as corn stands well above the ground (Baron et al, 2003). The corn grown in the Canadian prairies is different from the corn hybrid varieties grown in warmer climates (Lassiter et al, 1958).…”

The suitability of cool- and warm-season annual cereal species for winter grazing in Saskatchewan

“…Plots were seeded directly into standing stubble using a low disturbance no-till plot seeder with a row spacing ranging from 20 to 30.5 cm except at Melfort, where the plots were seeded into tilled soil. The stubble was canola at Canora in 2003and at Indian Head in 2002, spring wheat at Indian Head in 2003, Redvers in 2002and 2003, and Scott in 2003, and barley at Loon Lake in 2003and Canora in 2002. Seeding rates were 34 kg ha -1 for pearl millet and 22.5 kg ha -1 for proso millet, foxtail millets and sorghum-sudangrass.…”

“…Swath grazing and the grazing of standing corn (Zea mays L.) are two production practices that are currently being used on the Canadian prairies (Baron et al 2003;Anonymous 2004). Several studies have shown that swath grazing will reduce feeding costs for spring-calving beef cows and wintering calves (Volesky et al 2002;).…”