Corn Silage Dry Matter Research Articles

MODELING THE EFFECTS OF PROPIONIC ACID BACTERIA IN SILAGE

A simulation model of the growth and fermentation of propionic acid bacteria (PAB) in silage was developed from literature data with pure cultures or mixed cultures with lactic acid bacteria (LAB). Effects of temperature, pH, water activity, and lactate, acetate, and propionate concentrations on growth rate and end product formation were included. The PAB were assumed to grow in succession to the LAB in silage and to ferment only lactate. A three-stage simulation was performed: LAB fermentation using a previous silage-fermentation model, PAB fermentation using the present model, and aerobic deterioration using a previous fungal-growth model. Inoculation with PAB was predicted to increase the aerobic stability of alfalfa silages of 20, 35, or 45% dry matter (DM), but to effect only minor improvements in 35% DM corn silage. Inoculation of PAB in combination with LAB at ensiling had a synergistic effect on aerobic stability. Comparison with two silage studies from the literature suggests uncertainty in the pH sensitivity of PAB in silage which may reduce the effect of LAB and PAB inoculation. In general, inoculation of PAB was predicted to have the smallest potential benefit for silages most prone to aerobic deterioration.

Eastern Gamagrass Silage Fermentation Characteristics and Quality under Different Nitrogen Rates

Perennial grass silages are needed as alternatives to corn (Zea mays L.) silage on erosive cropland. Eastern gamagrass [Tripsacum dactyloides (L.) L.] may offer an alternative to corn for silage production, but it's fermentation characteristics and quality under different rates of N have not been evaluated. A 5-yr-old stand of «PMK-24' eastern gamagrass was treated in 1991 and 1992 with ammonium nitrate at 0, 100, and 200 Ib N/acre and harvested for silage. Corn was grown adjacent to the eastern gamagrass stand in 1992 for comparison. First harvest eastern gamagrass forage was ensiled at the seed development stage in 1991 and inflorescence emergence stage in 1992, and regrowth forage at the vegetative stage both years. Eastern gamagrass silage pH was not influenced by stage of maturity or N rates, and averaged 0.4 to 0.8 pH units greater than corn silage

The effects of corn silage dry matter content and sodium bicarbonate addition on nutrient digestion and growth by lambs and calves.

One lamb and three calf trials were conducted to determine if interactions existed between the effects of dry matter (DM) content of corn silage at harvest and sodium bicarbonate supplementation on diet digestibility, nitrogen balance, rate and site of digestion and feedlot performance. Corn plants were harvested from the same field when DM content was approximately 31% (early; E) or 44% (late; L). Sodium bicarbonate (1.2% of DM intake) was added in a completely mixed ration. When lambs were offered diets ad libitum, (trial 1), intakes were greater (P less than .05) for L-silage diets, but apparent digestibilities were similar. Nitrogen balance was greater for sodium bicarbonate-supplemented diets, and was a reflection of greater (P less than .10) DM intakes for these diets. At similar diet DM intakes, N balance was greater for L-silage diets, with no effects measured due to sodium bicarbonate addition. When growing, abomasally cannulated heifers (trial 2) were offered diets 12 times per day, a significant interaction among treatments was measured for total tract and acid detergent fiber (ADF) digestion. Adding bicarbonate to the E-silage diet increased (P less than .05) digestion by 9.1 percentage units (66.4 vs 75.5%) but decreased digestibility of the L-silage diet by 4.2 percentage units (73 vs 68.8%). Grams of ADF apparently digested in the rumen followed the same pattern as for total tract digestion. In trial 3, ruminal rates of liquid and particulate passage and in situ rats of NDF digestion were determined using four rumen-cannulated heifers calves.(ABSTRACT TRUNCATED AT 250 WORDS)

Labile magnesium reserves in beef cows subjected to different prepasture supplementation regimens.

Thirty pregnant beef cows were utilized to determine the effects of winter Mg supplementation regimen on blood minerals after cows were turned to a spring tetanigenic tall fescue pasture. The winter Mg treatments were (1) tall fescue hay with free access to a Mg-deficient salt-mineral mix, (2) 6.4 kg of corn silage dry matter plus 114 g MgO/d and (3) tall fescue hay with free access to a salt-mineral mix containing 40% MgO from January 1 to February 15. All cows were then placed on the same tetanigenic pasture from February 15 to April 17 with free access to a Mg-deficient salt-mineral supplement. Forage Mg remained below .2% during the experiment. Forage Ca, P and Al changed throughout the spring, attaining maximum values of .35%, .46% and 415 ppm, respectively. Forage N and K also increased throughout the spring, reaching values of 3.5 and 3.8%, respectively, at the April 3 sampling. The forage K:(Ca + Mg) ratio approached 2.2 by March 26, which coincided closely with the average tetany date (March 29). Serum Mg averaged 1.97, 3.58 and 2.06 mg/dl for treatments 1, 2 and 3, respectively, on February 15 before turning cows to pasture. There were no treatment differences for serum Ca, P and K during the experiment. Eight cows exhibited symptoms of grass tetany (collapse) on an average date of March 29. Winter Mg supplementation provided little long-term protection against hypomagnesemia after turning cows to tetanigenic pasture, indicating that cows must have a supplemental source of Mg during this critical period.

Additive-treated corn silage, harvestore cornlage, and sodium bicarbonate supplement for yearling steers (1983)

Steers fed Silo Guard II® treated corn silage gained 3.5% faster and were 8.3% more efficient than those fed the control silage. Cornlage (54% dry matter corn silage in an oxygen-limiting structure) produced numerically slower and less efficient gains than either treated or untreated silage, but differences in silages were not statistically significant. Steers fed sodium bicarbonate throughout the trial consumed 8.5% more silage, gained 14% faster (P<.05), and were 3% more efficient than those not fed bicarbonate; performance of steer fed bicarbonate for the first half of the trial was intermediate. Steers fed cornlage had a higher rumen fluid acetate:propionate ratio (P<.05) than those fed the control or Silo Guard II silages but there were no significant differences due to bicarbonate in rumen fluid volatile fatty acids.

Influence of NPN Treatment, Oven Temperature and Drying Time on Error in Determining True Corn Silage Dry Matter

SUMMARY An experiment was conducted to determine the effect of NPN treatment of corn silage on magnitude of error in dry matter (DM) determined by oven drying. Oven drying at 60 C underestimated true DM by 8.4% and oven drying at 100 C underestimated true DM by 11.5%. Drying samples for 24 or 48 hr or NPN treatment did not affect the magnitude of this error. A summary of similar data in the literature indicated oven dry matter values could be corrected by multiplying whole plant grain silage DM values between 27 and 39% by 1.056 for 60 C oven and 1.093 for 100 C oven temperature. Similar values for high moisture corn oven DM values between 62 and 72% are 1.03 and 1.047 respectively. Without these adjustments, DM intake is underestimated and feed nutrient and efficiency of utilization values are overestimated.

Organic Acid Treatment of High Dry Matter Corn Silage Fed Lactating Dairy Cows1,2

In four experiments, lactating Holstein cows were used to evaluate the nutritive value of corn silages treated with organic acids. Propionic, formic, and acetic acid treatment of silage with medium dry matter (34 to 39%) in two experiments slightly increased silage intake but had little effect on milk yields. However, addition of propionic acid to silages with high dry matter (42 to 47%) in three experiments increased silage intake 12%, total intake 6%, and milk yields 5%. Formic acid added to high dry matter silages was less effective than propionic in increasing intakes. Decreasing dry matter of silage from 43% to 36% with water added at ensiling did not improve intakes or milk yields. Propionic treatment decreased silage temperatures during fermentation and feeding and lowered fungal counts of silage exposed to air. Normal concentrations of lactic and acetic acids and pH values resulted from propionic treatment. Propionic treatment of high dry matter silage appeared profitable.

YIELD AND NUTRITIVE VALUE OF CORN, BARLEY, WHEAT, AND FORAGE OATS AS SILAGE FOR LACTATING DAIRY COWS

Whole crops of corn, barley, wheat, and forage oats were ensiled and fed as the sole forage to 48 milking cows in two 12-wk feeding trials. In the first experiment corn (25.1% dry matter (DM)) harvested in the early dent stage, barley (34.2% DM), and forage oats (27.6% DM) harvested in the dough stage were compared. Holstein cows fed the three silages averaged 22.6, 19.7, and 18.7 kg of 4% fat-corrected milk per day and consumed 1.67, 1.82, and 1.85 kg of silage DM per 100 kg body weight, respectively. In the second experiment, cows fed wheat (35.7% DM), barley (29.8% DM), or forage oat (27.0% DM) silage harvested in the dough stage produced 21.2, 23.3, and 22.1 kg fat-corrected milk daily and consumed 1.75, 1.71, and 1.62 kg silage DM per 100 kg body weight, respectively. Corn silage DM intake was lower (P &lt; 0.01) but more efficiently utilized for milk production (P &lt; 0.01) than barley or forage oats, whereas wheat, barley, and forage oat silages were similar in feeding value. In experiment I, rumen acetate increased and butyrate decreased with corresponding increases in forage fiber content. Propionate levels were unaffected by the kind of forage, whereas blood urea nitrogen was highest for cows fed forage oats in both experiments.

EFFECTS OF SUPPLEMENTAL HAY ON CONSUMPTION OF LOW AND MEDIUM DRY MATTER CORN SILAGE BY HIGH-PRODUCING DAIRY COWS

The effects of supplementing low (23.9%) dry matter (DM) and medium (28.9%) DM corn silage roughage rations fed ad libitum to high-producing dairy cows, with orchard grass hay at 0.7% of their body weight on milk production and composition, was determined in a double reversal feeding trial using 24 lactating cows. Cows fed medium DM corn silage consumed 15.2% more DM/100 kg body weight daily than those cows fed low DM silage (P &lt; 0.05). Supplemental hay fed with either low or medium DM silage resulted in equal consumption of total forage DM/100 kg body weight by cows on the two treatments. Each kilogram of hay DM consumed by cows offered low DM corn silage reduced silage DM intake by 0.47 kg, whereas hay DM intake reduced silage DM intake by 0.79 kg for cows offered medium DM silage. Daily production of 4% fat-corrected milk (FCM), percent nonfat solids (SNF), and daily body weight gain were lower for cows consuming low DM corn silage than for those on the other treatments (P &lt; 0.05). Cows consuming low DM corn silage plus orchard grass hay at 0.7% of their body weight produced milk at the same level and of similar protein, lactose, and SNF content as those fed medium DM silage plus hay. Supplemental hay fed with medium or low DM corn silage increased FCM production over feeding silage alone, independent of DM or moisture content of the silage fed (P &lt; 0.05).

Loss of Nutrients Through Passage of Corn Grain by Cows Fed All Roughage as Corn Silage

An assessment was made of the nutrients lost through voiding of kernel by lactating cows fed 26.8% dry matter corn silage as the sole source of roughage. The kernel was 34% of total dry matter of the corn at harvest but only 16.1% on a hand-separated basis after ensiling. The kernel voided averaged 0.11kg of dry matter per cow per day. Most of the dry matter lost consisted of kernel particles, pericarp with only the upper portion containing endosperm, and a small proportion of whole kernel. Dry matter lost represented 7.1% of the kernel dry matter and 1.2% of the whole silage dry matter fed.Average digestibility of the whole ration dry matter was 66.2% by lactating cows compared with 67.9 and 65.8% by in vitro analysis for the whole silage and silage grain, respectively. In vitro method was used to determine the loss of digestible dry matter in the voided kernel. Slightly over 4.8% of the in vitro digestible dry matter in the silage kernel was lost in the voided kernel, but this loss was only 0.9% of the in vitro digestible dry matter of the whole silage.The water-soluble carbohydrates of the harvested whole corn were reduced during ensiling, whereas the soluble carbohydrates of the kernel increased from 26.8 to 51.3%. The loss of soluble carbohydrate in the voided kernels was only 6.0% of the soluble carbohydrate in the silage kernel and 3.1% of that in the whole silage.

Consumption of Corn Silage Dry Matter by Bred Heifers and Its Correlation with Subsequent First-Lactation Production1,2

Twenty Brown Swiss, 28 Holstein, 25 first-generation, and 14 second- and third-generation crossbred heifers were fed all the corn silage they would consume during a 28-day experimental period. The silage was supplemented with 0.65 or 0.68kg of soybean oilmeal per day and salt free-choice. Regression coefficients between the log of average weight, and logs of average daily intake of silage and dry matter for the 28-day period were 0.49 (P<0.001) and 0.34 (P<0.05), respectively. The model used to analyze the data included breed group, W0-49, per cent dry matter, days pregnant, and season. All except season significantly affected (P<0.01) silage and dry matter intake. Least-squares means of daily intake of silage and dry matter adjusted for all significant factors were used to compare breed groups. Both groups of crossbreds consumed more silage and dry matter than the Brown Swiss or Holsteins. The second- and third-generation crossbreds showed significant heterosis for the consumption of silage.Correlations between adjusted dry matter intake for the 28-day period and milk and milk constituents produced in the first lactation were inconsistent from one breed group to another, and none of them was significant.

Feeding Value of High Dry Matter Corn Silage for Dairy Cattle

Two feeding trials using 20 cows each compared high dry matter corn silage (HDMCS) with corn silage of medium dry matter content (MDMCS). A continuous design was employed in Trial I and a double-reversal design in Trial II. The high dry matter corn silage was ground before ensiling and both silages stored in gas-tight units.Significant differences associated with the harvesting of high dry matter corn silage when compared with the medium dry silage include: lower dry matter yields; greater field dry matter losses; higher percentage of ear losses; lower carotene content; lower total acid concentration during fermentation; and a higher pH. Voluntary dry matter consumption, milk production, and body weight gains were greater for cows fed the high dry matter corn silage, but differences were significant only for Trial II. There were no significant differences in per cent milk fat or solids-not-fat between treatments. No consistent difference in chemical composition of the silages between years was found.The digestibility of the dry matter, energy, and protein for the medium and high dry matter silages was 66.9, 66.7, and 54.7; and 64.7, 65.4, and 51.1%, respectively. The silages were nearly equal in feed value; however, the disadvantages suggest that general recommendations for delaying harvest were not warranted.

EVALUATION OF CORN AND SORGHUM-SUDAN SILAGES ON THE BASIS OF DRY MATTER INTAKE, DIGESTIBILITY AND MILK PRODUCTION

Sorghum-sudan (S-S) silage and corn silage were compared on the basis of dry matter intake and milk production when fed to lactating cows and on the basis of digestibility when fed to wether Iambs. Although dry matter percent was lower for the S-S silage, 21.5 vs. 27.4, average daily dry matter intake was nearly the same, 63.4 vs. 64.4 g/kg W0.75 when compared with corn silage. Average daily milk production and total body weight change were significantly less (P &lt; 0.05), 218.7 vs. 234.4 g/kg W0.75 and − 7.0 vs. + 10.7 kg, respectively, for cows fed S-S silage. Rumen fluid from cows fed corn silage contained a significantly lower molar percent acetic acid and higher butyric acid (P &lt; 0.01) than rumen fluid from cows fed S-S silage. Digestibility coefficients were greater (P &lt; 0.01) for corn silage dry matter, nitrogen-free extract, fiber and energy, but significantly less for protein (P &lt; 0.01) when compared with S-S silage. The high nitrogen content and protein digestibility suggest that sorghum-sudan hybrids may be usefully employed in ruminant rations, although they are low in digestible energy content when compared with corn.