Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Silage”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources
PubMed2002

The effect of delayed ensiling and application of a propionic acid-based additive on the fermentation of barley silage.

Prolonged exposure to air can adversely affect the silage fermentation process. To investigate a possible method to overcome this problem, we determined if a buffered propionic acid-based additive, applied to chopped, whole-plant barley exposed to air before ensiling, would affect the subsequent fermentation. Wilted forage was chopped and treated with nothing, or with 0.1% (wt/wt wet forage) of a buffered propionic acid-based additive and ensiled immediately in quadruplicate 20-L laboratory silos. Portions of the chopped forage, untreated and treated, were left in loose piles in a barn for 24 h before ensiling. Another portion of the untreated silage exposed to air for 24 h was also treated with 0.1% of the additive just before ensiling. Prolonged exposure to air before ensiling increased the numbers of yeasts on forages by more than 1,000-fold. The concentrations of water-soluble carbohydrates decreased by more than 50%; the ammonia-N concentrations increased 40%, and pH increased by more than 1 unit as a result of exposure to air. These changes were less in forage that was treated with the additive at chopping. After 60 d, silages of forages that were exposed to air before ensiling had a higher pH, higher concentrations of ammonia-N and butyric acid, and lower concentrations of lactic and acetic acids than silages of forage that had been ensiled immediately after harvest. In situ DM digestibility was lowest in untreated silages that had been exposed to air before ensiling. In contrast, treatment with the additive, applied before or after exposure to air, prevented the reduction in in vitro digestion.

Acetic Acid↗
PubMed2003

Performance of lactating dairy cows fed corn as whole plant silage and grain produced from a glyphosate-tolerant hybrid (event NK603).

Sixteen multiparous Holstein cows averaging 74 d in milk were used in a replicated 4 x 4 Latin square to compare the effects on animal performance of feeding whole plant silage and grain from a glyphosate-tolerant corn hybrid (event NK603), a nontransgenic control hybrid, and two commercial nontransgenic hybrids (DK647 and RX740). The grain and silage from the four corn hybrids were produced using the same procedures and under similar agronomic conditions at the University of Illinois. On a dry matter (DM) basis, diets contained 30% corn silage and 27.34% corn grain produced either from event NK603, a nontransgenic control, or commercial hybrids. Apart from the DM content of silages, the chemical composition of both grain and silage produced from the four corn hybrids were substantially equivalent. Feeding diets that contained event NK603 and DK647 hybrids tended to decrease DM intake (DMI) compared with the control nontransgenic and RX740. The intakes of crude protein (CP), acid and neutral detergent fiber, and nonfiber carbohydrates were not different for cows fed event NK603 and control diets. The RX740 diet resulted in the highest intakes of fiber and CP, whereas the DK647 diet resulted in the lowest intake of CP. These differences in nutrient intake arose from small variations in both the DMI and the chemical composition of feed ingredients and experimental diets. Production of milk and 3.5% fat-corrected milk; milk fat, CP, and true protein percentage and yield; milk urea N; milk total solids percentage and yield; and somatic cell count were not affected by treatments. These data indicate that the stable insertion of the gene that confers tolerance to glyphosate (event NK603) in the corn line used in this experiment does not affect its chemical composition and nutritional value for lactating dairy cows when compared with conventional corn.

Animals↗
PubMed2003

Effects of feeding silage and grain from glyphosate-tolerant or insect-protected corn hybrids on feed intake, ruminal digestion, and milk production in dairy cattle.

Lactating dairy cows were used to determine effects of feeding glyphosate-tolerant or insect-protected corn hybrids on feed intake, milk production, milk composition, and ruminal digestibility. Corn resistant to European corn borer (Ostrinia nubilalis) infestation (Bt-MON810), or its nontransgenic control (Bt-CON), were planted in alternating fields during two successive years. One-half of each strip was harvested for whole plant corn silage and the remainder was allowed to mature and harvested as grain. Effects of feeding diets containing either Bt-MON810 or Bt-CON grain and silage were determined in two experiments (1 and 2) conducted during successive years. In experiment 3, glyphosate-tolerant Roundup Ready corn (RR-GA21) or its nontransgenic control (RR-CON) corn were grown in alternating fields during one cropping season. Diets contained 42 to 60% corn silage and 20 to 34% corn grain from Bt-MON810, RR-GA21, or the appropriate nontransgenic counterpart; treatments were applied using a switchback design. Cows were fed ad libitum and milked twice daily. There were no differences for nutrient composition between silage sources or between grain sources within an experiment. Data for experiments 1 and 2 indicated similar dry matter intake (DMI), 4% fat-corrected milk (FCM) production, and milk composition between Bt-MON810 and Bt-CON diets. There were no differences for DMI, 4% FCM production, and milk composition between RR-GA21 and RR-CON diets. There was no difference in ruminal degradability, determined separately for corn silage and corn grain, for RR-GA21 or Bt-MON810-hybrids compared with their respective controls. These data demonstrate equivalence of nutritional value and production efficiency for corn containing Bt-MON810 compared with its control and for RR-GA21 corn compared with its control.

Animal Feed↗
PubMed2003

Effects of cutting height and maturity on the nutritive value of corn silage for lactating cows.

We studied the effect of increasing the cutting height of whole-plant corn at the time of harvest from 12.7 (NC) to 45.7 (HC) cm on yield and nutritive value of silage for dairy cows. Three leafy corn silage hybrids were harvested at NC and HC at about 34% dry matter (E) and 41% DM (L) and ensiled in laboratory silos. Increasing the height of cutting lowered yields of harvested DM/ha. In addition, the concentrations of DM and starch were higher but the concentrations of lactic acid, crude protein, neutral detergent fiber (NDF), and acid detergent fiber were lower in HC than in NC. The concentration of acid detergent lignin was also lower in HC, but only in corn harvested at E. In vitro digestion (30 h) of NDF was greater in HC (50.7%) than NC (48.3%). Calculated yield of milk per tonne of forage DM was greater for HC than for NC at E but not at L. In a lactation experiment, increasing the height of cutting of another leafy corn silage hybrid, TMF29400, in general also resulted in similar changes in nutrient composition as just described. When fed to lactating dairy cows, HC corn silage resulted in tendencies for greater NDF digestion in the total tract, higher milk production and improved feed efficiency, but there were no differences in 3.5% fat corrected milk between treatments. Results of this study suggest that increasing the cutting height of whole plant corn at harvest can improve the nutritive value of corn silage for lactating dairy cows.

Animal Nutritional Physiological Phenomena↗
PubMed2003

Comparison of feeding corn silages from leafy or conventional corn hybrids to lactating dairy cows.

Three corn hybrids (Pioneer 36F30, Mycogen TMF2450, and Mycogen TMF2404) were compared for yield and quality traits, and lactation performance and apparent digestibility by Holstein cows. The three corn silages were harvested at a target of 33 to 35% dry matter. Before harvest, six corn plants were randomly selected for plant fractionation. Grain-to-stover ratios were 0.92, 0.70, and 0.95 for the 36F30, TMF2450, and TMF2404 corn plants, respectively. Fifty-two multiparous Holstein cows were placed on a 120-d lactation trial after a 21-d covariate diet. Cows were blocked by calving date and randomly assigned within block to one of three dietary treatments, containing approximately 40% (dry matter basis) corn silage. Milk yield, milk components, and dry matter intake did not differ among dietary treatments. In vitro true and neutral detergent fiber digestibilities were numerically higher for TMF2404 than the other corn silage hybrids. Apparent total-tract crude protein and neutral detergent fiber digestibilities, as measured by acid insoluble ash, were higher for TMF2450 than the other two hybrids, but starch digestibility was not different between the corn silage dietary treatments. Although small differences in nutrient content and digestibility existed among corn silage hybrids, inclusion of these leafy hybrids in lactating cow diets at 40% of the dietary dry matter did not have a significant impact on lactation performance of dairy cattle.

Animal Nutritional Physiological Phenomena↗
PubMed2003

Influence of corn silage particle length on the performance of lactating dairy cows fed supplemental tallow.

The objective of this study was to determine if the length of chop of processed corn silage influences the impact of supplemental fat on rumen fermentation and performance of dairy cows. We hypothesized that increasing forage particle length may alleviate the interference of fat on rumen fermentation. Sixteen Holstein cows averaging 120 d in milk were used in a replicated 4 x 4 Latin square design with 21-d periods. Treatments were arranged as a 2 x 2 factorial with 0 or 2% tallow (dry matter basis), and corn silage harvested at either 19 or 32 mm theoretical length of cut. The forage:concentrate ratio was 50:50, and diets were formulated to contain 18% crude protein and 32% neutral detergent fiber (dry matter basis). Cows were allowed ad libitum consumption of diets that were fed twice daily as a total mixed ration. Fat supplemented cows had lower dry matter intake and produced less milk fat relative to nonsupplemented cows. No effect of corn silage particle length was observed for dry matter intake and milk fat production. Proportion of trans-10 C18:1 and of trans-10, cis-12 conjugated linoleic acid was highest in milk fat of cows fed 2% supplemental tallow. Rumen pH was not affected by feeding tallow, and tended to be highest for cows eating the 32-mm theoretical length of chop corn silage diets. No effect of treatments was observed for rumen acetate-to-propionate ratio or rumen ammonia concentration. In this study, tallow supplementation had a negative impact on performance of dairy cows regardless of the corn silage particle length. Feeding tallow increased formation of trans-fatty acids in the rumen in the absence of significant changes in the rumen environment.

Acetic Acid↗
PubMed2003

The effect of corn silage particle size on eating behavior, chewing activities, and rumen fermentation in lactating dairy cows.

The objective of this experiment was to evaluate effects of reducing corn silage particle size on eating behavior, chewing activity, and rumen fermentation in lactating dairy cows. Four cannulated, multiparous cows averaging 110 +/- 4 d in milk and weighing 675 +/- 70 kg were randomly assigned to a 4 x 4 Latin square. During each of four 14-d periods, animals were offered one of four diets that were chemically similar but varied in corn silage particle size: short (SH), mostly short (MSH), mostly long (MLG), and long (LG), with a geometric mean particle length of 7.4, 7.8, 8.3, and 8.8 mm, respectively. Reducing particle size increased dry matter intake (DMI) linearly (28.0, 26.8, 26.8, and 25.7 kg/d for SH, MSH, MLG, and LG respectively). At 8, 16, and 24 h postfeeding, the neutral detergent fiber (NDF) concentration of feed remaining in the bunk decreased linearly with reduced particle size. Time spent eating or ruminating was not different across treatments; however, total chewing activity (TC; sum of time spent eating and ruminating) exhibited a quadratic response with highest chewing activities observed for diets with shortest and longest particle size. Eating or ruminating time per kilogram of DMI was not affected by corn silage particle size, but TC per kilogram of DMI decreased linearly with decreasing particle size. In comparison, when expressed as minutes per unit of NDF intake (NDFI), ruminating, and TC were linearly reduced as particle size decreased. Rumen pH was not affected by corn silage particle size even though total concentration of volatile fatty acids increased linearly from 89.1 mM/L to 93.6 mM/L as diet particle size decreased. A quadratic effect was observed in molar proportion of acetate and propionate with the highest concentration observed in animals consuming diets of intermediate particle size. Results of this experiment suggest that reducing corn silage particle size may increase DMI, positively affect rumen fermentation, and reduce sorting behavior. Because both chewing activity and sorting tendencies increased when proportion of TMR particles > 19.0 mm increased, results suggest that particle size measurement as estimated by the PSPS is useful in understanding some factors that affect feeding behavior.

Ammonia↗
PubMed2004

Short communication: Effects of feeding level on energy concentration in grass silage-based diets offered to dairy cattle.

Twelve grass silages were offered to sheep as a sole diet at maintenance and to lactating dairy cows ad libitum as mixed silage and concentrates diets (n = 13 diets). Fecal and urinary energy outputs were measured for silages and mixed diets. Digestible energy (DE) and metabolizable energy (ME) concentrations for mixed diets with sheep at maintenance were estimated based on the silage dry matter (DM) proportion obtained in the cattle trials, the silage energy utilization values (methane energy-predicted) determined using sheep, and tabulated concentrate values. A comparison of dietary mean data (n = 13) indicated that concentrations of ME (P < 0.01) and DE (P < 0.001) in mixed diets were significantly lower for cows at production feeding level than for sheep at maintenance. The reductions were proportionately 0.015 and 0.020 with each unit increase in feeding level above maintenance, respectively. These ME and DE data were also used to evaluate the feeding level correction factors previously proposed by Van Es (1975) (ME, 0.018) and Yan et al. (2002) (ME, 0.016; DE, 0.025) using the mean square prediction error technique. The ME correction factor proposed by Yan et al. (2002) had a greater prediction accuracy than that proposed by Van Es (1975) for the prediction of ME concentration in mixed diets offered to dairy cattle at production feeding level.

Animal Nutritional Physiological Phenomena↗
PubMed2004

Prediction of fermentation parameters in grass and corn silage by near infrared spectroscopy.

Prediction models were developed for determination of lactic acid (Lac), acetic acid (HAc), pH, NH(3) N, and ethanol (EtOH) in grass and corn silages by near infrared (NIR) spectroscopy. Generally, Lac, pH, and NH(3) N concentrations in original sample material could be determined with a better accuracy when NIR measurements were performed on dried material rather than on wet material. The difference could only partly be explained by the repeatability error of NIR measurements for compounds stable with respect to drying. The HAc concentration was determined slightly more accurately when measurements were performed on wet material. The respective ratios between analytical concentration range expressed as standard deviation and the root mean square error of cross validation (RMSECV) were 4.9, 2.0, 3.7, and 3.1 for Lac, HAc, pH, and NH(3) N measured on dried grass silage, and 3.3 for EtOH measured on wet grass silage. The corresponding standard deviation:RMSECV for corn silage were 4.7, 1.9, 2.4, 2.9, and 4.0. The content of Lac was affected only slightly by drying at 80 degrees C, whereas the effects on NH(3) N and HAc were more pronounced, depending on silage type.

Acetic Acid↗
PubMed2005

Corn grain endosperm type and brown midrib 3 corn silage: site of digestion and ruminal digestion kinetics in lactating cows.

Interactions of endosperm type of corn grain and the brown midrib 3 (bm3) mutation in corn silage on ruminal kinetics and site of nutrient digestion of lactating dairy cows were evaluated. Eight ruminally and duodenally cannulated cows (72 +/- 8 d in milk; mean +/- SD) were used in a duplicated 4 x 4 Latin square design experiment with a 2 x 2 factorial arrangement of treatments. Treatments were corn grain endosperm type (floury or vitreous) and corn silage type (bm3 or isogenic normal). Diets contained 26% neutral detergent fiber (NDF) and 30% starch. Interactions of treatments were not observed for any measure of digestibility, but digestion kinetics of starch and fiber did interact to affect digestible organic matter intake by affecting dry matter intake. Rate of ruminal starch digestion was faster and rate of ruminal starch passage tended to be slower in diets containing corn grain with floury vs. vitreous endosperm, resulting in a mean increase of 22 units for ruminal starch digestibility. Although compensatory postruminal starch digestion decreased differences among treatments for total tract starch digestibility, starch entering the duodenum was more digestible for grain with floury endosperm compared with vitreous grain, resulting in greater total tract starch digestibility for floury compared with vitreous corn grain. Fermentation rate of potentially digestible NDF was not affected by either bm3 corn silage or greater ruminal starch digestion of floury grain. Brown midrib corn silage increased total tract NDF digestibility vs. control silage by numerically increasing ruminal and postruminal digestibility of NDF. Endosperm type of corn grain greatly influences site of starch digestion and should be considered when formulating diets.

Animal Feed↗
PubMed2006

Influence of ensiling temperature, simulated rainfall, and delayed sealing on fermentation characteristics and aerobic stability of corn silage.

The aim of this study was to determine how delayed silo sealing, high ensiling temperatures, and rainfall at harvest affect the fermentation and aerobic stability of corn silage. One-half of each of 4 replicated, 6 x 1.5 m plots of a corn hybrid was harvested at 35% dry matter (Dry), and each of the other halves was harvested after they were sprinkled with sufficient water to simulate 4 mm of rainfall (Wet). Six representative (2 kg) subsamples were taken from the Wet and Dry forage piles and ensiled immediately (Prompt). Three hours later, 6 additional representative (2 kg) samples were taken from each pile and ensiled (Delay). Half of the bags from each moisture x sealing time treatment combination were stored for 82 d in a 40 degrees C incubator (Hot) and the other half were stored in a 20 degrees C air-conditioned room (Cool). A 2 (moisture treatments) x 2 (sealing times) x 2 (ensiling temperatures) factorial design with 3 replicates per treatment was used for the study. Wetting the corn silage increased concentrations of NH(3)-N, ethanol, and acetic acid. Ensiling at 40 instead of 20 degrees C increased pH, in vitro digestibility, and concentrations of NH(3)-N, residual water-soluble carbohydrates and acid detergent insoluble crude protein. The higher ensiling temperature also reduced concentrations of neutral and acid detergent fiber and lactic and acetic acid. Delayed sealing reduced concentrations of NH(3)-N and total volatile fatty acids. Wetting, high temperature ensiling, and delayed sealing each reduced yeast counts slightly, and marginally (8 h) increased aerobic stability. Hot-Wet-Delay silages were more stable than other silages but had the lowest lactic to acetic acid ratio, and total volatile fatty acid concentration. This study indicates that the fermentation of corn silage is adversely affected by wet conditions at harvest and high ensiling temperatures, whereas delayed silo sealing for 3 h caused no adverse effects.

Acetic Acid↗
PubMed1976

Plasma growth hormone and insulin during early lactation in cows fed silage based diets.

Peripheral plasma insulin, growth hormone, and blood glucose were determined in 24 dairy cows during early lactation. Blood samples were obtained at 4-day intervals during the first 56 days of experimental lactations 1 and 3 of a 3-lactation experiment. The cows were divided equally among three groups and fed one of the following forage rations for three consecutive lactations: corn silage (18.2 kg/day) plus alfalfa-timothy hay ad libitum; corn silage (18.2 kg/day) plus alfalfa-timothy silage ad libitum; or corn silage ad libitum. These diets were continued throughout the intervening dry periods except in the latter group where corn silage intake was limited if individual animals exhibited excessive body weight gain. Four animals in each group received prepartum supplemental concentrates. The remaining four animals received no prepartum concentrate supplementation. Following parturition, concentrates were fed in increasing amounts to a maximum of 14.6 kg/day during the first 56 days of lactation. Plasma insulin, growth hormone, and blood glucose were not affected by forage diet or prepartum supplemental concentrate feeding. Plasma insulin and blood glucose increased and plasma growth hormone decreased with time after parturition. These changes were correlated with nutrient intake which increased during the experiment. Changes in plasma insulin and growth hormone are related to metabolic adjustments during early lactation.

Animal Feed↗
PubMed1988

Particle size reduction of alfalfa silage did not alter nutritional quality of high forage diets for dairy cattle.

Twelve multiparous, lactating Holsteins were fed an energy adequate diet (50% wilted alfalfa silage) and two isonitrogenous diets containing 80% of the same silage. The two 80% alfalfa diets were identical in all respects except that for one diet 38% of the alfalfa silage was rechopped after fermentation to reduce the particle length from 5.63 to 3.12 mm. Feeding the 80% alfalfa diets decreased milk production due to limitation of digestible energy intake. Under conditions of energy restriction, reduction of particle size of alfalfa silage after fermentation did not result in any changes in feed intake, feed digestibility, or milk production. The results do not preclude the possibility of some changes for intake or digestibility with more extensive reductions in particle length of alfalfa silage. However, because the extent of forage particle size reduction is limited by nutritional and economic constraints, the results of this study indicate that there is no practical advantage to reducing the particle size of fermented alfalfa beyond that required for adequate fermentation.

Animal Feed↗
PubMed1995

Brown midrib sorghum silage for midlactation dairy cows.

Brown midrib sorghum silage was compared with alfalfa, corn, and normal sorghum silages for its effect on performance, ruminal metabolism, and digestive kinetics of Holstein dairy cows in midlactation. Twelve cows averaging 90 +/- 5 DIM were assigned to one of four diets in replicated 4 x 4 Latin squares with 4-wk periods. Additionally, 3 ruminally fistulated cows (95 +/- 20 DIM) were assigned to the same diets in a 3 x 4 Youden square for measurement of ruminal characteristics. Diets were fed as isonitrogenous TMR that contained 65% silage (DM basis). The DMI was greater for the corn and brown midrib sorghum (4% of BW/d) than for the alfalfa and normal sorghum diets (3.4% of BW/d). The brown midrib sorghum supported FCM production that was similar to that of cows on corn and alfalfa diets (25.8 kg/d), but cows fed normal sorghum produced less milk and fewer milk components. Source of silage had no effect on eating time, but rumination was least for the alfalfa diet. Ruminal pH and ammonia concentrations were similar for all diets. Total VFA concentrations were greatest for the corn and brown midrib sorghum diets. The brown midrib sorghum had greater in situ extent of ruminal NDF digestion than did the normal sorghum, which agreed with in vitro data. The brown midrib sorghum used in this experiment supported FCM production similar to the corn and alfalfa silages commonly fed to dairy cows in midlactation.

Animal Nutritional Physiological Phenomena↗
PubMed1997

Effects of supplementation of energy or ruminally undegraded protein to lactating cows fed alfalfa hay or silage.

Alfalfa was harvested as silage or hay and fed in two 12-wk trials with a 4 x 4 Latin square design that used 12 (trial 1) or 24 (trial 2) multiparous lactating cows (4 ruminally cannulated cows per trial). Diets contained (dry matter basis) 75 or 50% alfalfa plus 24 of 40% high moisture corn (trial 1) or 50% alfalfa, 44 or 41% high moisture corn, with (3%) or without fish meal (trial 2). Experiments were conducted to evaluate the responses of cows fed alfalfa hay or alfalfa silage diets to an increase in protein supply from microbial protein synthesis (trial 1) or from the supplementation of ruminally undegraded protein (RUP) (trial 2). In trial 1, the increase in high moisture corn in the diet increased both milk protein and microbial crude protein yields (estimated from the excretion of purine derivatives) to a greater extent for the cows fed the alfalfa silage diets (170 and 337 g/d, respectively) than for the cows fed the alfalfa hay diets (100 and 100 g/d, respectively). In trial 2, RUP supplementation (as fish meal) increased milk protein yield 100 g/d for cows fed alfalfa silage diets and 20 g/d for cows fed alfalfa hay diets. These results indicated that protein status was poorer and, thus, more responsive to absorbable protein from microbial protein (trial 1) or RUP (trial 2) for cows that consumed alfalfa conserved as silage versus those that consumed alfalfa conserved as hay.

Allantoin↗
PubMed1997

Physical effectiveness of the neutral detergent fiber of whole linted cottonseed relative to that of alfalfa silage at two lengths of cut.

The effectiveness of the neutral detergent fiber (NDF) of whole linted cottonseed to stimulate chewing was examined relative to the effectiveness of the NDF of alfalfa silage at two lengths of cut. Twelve Holstein cows (125 d of lactation) were fed diets containing alfalfa silages differing in theoretical length of cut, with or without cottonseed substituted for alfalfa silage at 27% of alfalfa NDF. The experiment was a replicated (n = 3) 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Length of cut had no effect on milk production or composition, and substitution of cottonseed increased milk production but did not affect milk composition. An interaction was observed between treatment effects for dry matter intake, total chews per day, and total chewing time (minutes per day). Physical effectiveness of cottonseed NDF was calculated by dividing the total chewing time per unit of cottonseed NDF by total chewing time per unit of alfalfa silage NDF. Physical effectiveness of cottonseed NDF was calculated to be 50% of long-cut and 127% of short-cut alfalfa silage NDF. The interaction observed between main effects for total chewing time per day indicated that the physical effectiveness of whole linted cottonseed was relative and depended on the characteristics of the forage that it replaced.

Animal Nutritional Physiological Phenomena↗
PubMed1999

True absorption of calcium and phosphorus from corn silage fed to nonlactating, pregnant dairy cows.

A crossover design was implemented using four nonlactating dairy cows [mean body weight (BW) = 678 kg] and two rations to measure the true absorption of Ca and P from corn silage. True absorption was calculated after dosing cows intravenously with 45Ca and 32P to measure endogenous fecal losses. Rations consisted mainly of corn silage and were formulated to supply 32 g/d of Ca and 20 g/d of P or 16 g/d of Ca and 12 g/d of P. The percentages of total Ca and P that came from corn silage were 95 and 77%, respectively, for ration 1, and 98 and 79%, respectively, for ration 2. Cows ate more dry matter (10.9 vs. 10.2 kg/d) when consuming the corn silage in ration 1 than when consuming the corn silage in ration 2. Calcium intake was greater for cows fed ration 1 than for cows fed ration 2 (32.6 vs. 16.1 g/d), and P intake was greater for cows fed ration 1 than for cows fed ration 2 (20.1 vs. 11.7 g/d). True absorption of Ca was 34.4 and 43.7% for rations 1 and 2, respectively, and true absorption of P was 84.5 and 93.9% for rations 1 and 2, respectively. True absorption of Ca was about equal to values currently used in the National Research Council (NRC) feeding standards, but true absorption of P was higher than values currently used by the NRC. Fecal endogenous excretion of Ca (mean = 8.23 mg/kg of BW per d) was one-half of the value currently used by the NRC, and fecal endogenous excretion of P (mean = 7.23 mg/kg of BW per d) was only slightly less than NRC values.

Absorption↗
PubMed1999

Response of dairy cows fed grass silage diets to abomasal infusions of histidine alone or in combinations with methionine and lysine.

The response of dairy cows fed grass silage-based diets to the abomasal infusion of water (control) or 6.5 g of His alone or in combination with either 6.0 g of Met or 19.0 g of Lys or both was studied in an incomplete 4 x 5 Latin square experiment with 14-d periods. Each cow received a basal diet of 8 kg/d of cereal concentrate [12.1% crude protein (CP)] and free access to grass silage (14.1% CP) ensiled with an acid-based additive. Postruminal infusions increased arterial plasma concentrations of the amino acids (AA) infused, but compared with control, only the infusion of His (18 vs. 57 mumol/L) was associated with significant increases in milk and milk protein yields. Infusions of His did not affect dry matter intake of grass silage, rumen fermentation, or diet digestibility. Milk protein content was unchanged by treatments, but His infusions decreased lactose and fat contents. The combinations of AA did not produce any further responses compared with His alone. However, milk protein percentage was slightly higher, and milk fat percentage tended to be higher when Met rather than Lys was infused with His. We concluded that His is the first-limiting AA when grass silage-based diets are supplemented with cereal concentrates, while neither Met nor Lys are the second-limiting AA with grass silage feeding.

Abomasum↗