Replacing Corn Silage Research Articles

The effect of alfalfa (Medicago sativa) silage chop length and inclusion rate within a total mixed ration on the ability of lactating dairy cows to cope with a short-term feed withholding and refeeding challenge

The objectives of the study were (1) to test whether 6 h of feed deprivation followed by refeeding induces an acidosis challenge in dairy cattle and (2) to quantify the acidosis challenge mitigation potential of increased alfalfa silage concentration in the diet. Alfalfa silage constituted either 25 or 75% of forage dry matter (DM) replacing corn silage [low (LA) or high alfalfa (HA)] and was chopped to either 14 or 19 mm theoretical length [short (S) or long (L)]. Dietary treatments LAS, LAL, HAS, or HAL were offered to 4 rumen-cannulated Holstein dairy cattle (161 d in milk; 5th or 6th parity) in a 4 × 4 Latin square design study with 21-d periods. Starch concentration was 69 g/kg of DM higher for LA diets than HA diets. Feed was withheld for 6 h followed by ad libitum refeeding on d 18 of each period. Measurements of DM intake, milk yield and composition, rumen pH, and eating and rumination behavior were taken on 1 baseline day, the challenge day, and 2 further recovery days. After refeeding, rumen pH was reduced in cows fed LA diets but not HA diets. Feeding LAL resulted in the greatest subclinical acidosis risk (pH <5.8 for 355 min on the first recovery day). Animals fed LA produced 4.4 L less milk on the challenge day in comparison to baseline. It was concluded that short-term feed deprivation detrimentally affected rumen health and milk yield in dairy cattle normally fed ad libitum, but had no effect on DM intake or milk composition. Feeding alfalfa silage in place of corn silage mitigated acidosis risk due to interrupted feed supply, likely due to a combination of lower starch concentration in HA diets, greater effective fiber concentration, and higher buffering capacity of alfalfa relative to corn silage.

Comportamiento de terneras de la raza Holstein alimentadas con silaje pre-secado del pasto Tifton 85 (Cynodon spp.)

The use of pre-dried silage from Tifton 85 grass can be a good option of quality forage for animal feeding. The main objective was to evaluate the behavior of the Holstein heifers fed with pre-dried silage, the grass Tifton 85, replacing the corn silage (0, 33, 66 and 100%). Sixteen animals were distributed in four treatments and remained in feedlot system for 21 days. Behavioral assessments were carried out in the last four days of the trial period during 24 hours, through the instant collection route, with sampling intervals of 10 minutes and type scan sampling route. The frequency of urination, defecation and water intake were also recorded. A completely randomized design with four treatments (0, 33, 66 e 100% of corn silage replacement for pre-dried grass silage of Tifton 85), and four repetitions (number of animals per treatments).The rumination time was influenced by diet, being the highest values (39.76%) observed for animals fed with corn silage. Sleeping behavior influenced food, ranging from 5.81 to 9.28%, to levels of 0 and 66% corn silage replacement for pre-dried grass silage of Tifton 85, respectively. The frequency that the animals drank water, defecated and urinated showed no difference among the treatments. The replacement of corn silage by the pre-dried silage of Tifton 85 grass did not cause changes in the behavior of the animals during the studied period.

Enhancing biogas plant production using pig manure and corn silage by adding wheat straw processed with liquid hot water and steam explosion

BackgroundPig manure utilization and valorization is an important topic with tightening regulations focused on ecological and safety issues. By itself pig manure is a poor substrate for biogas production because of its excessive nitrogen content relative to available organic carbon. Such substrate is alkaline, and methanogenesis can be suppressed, and so additional substrates with high organic carbon must be added. The most promising is straw, which is available from adjacent biogas plant cultures. However, the abundant lignocellulosic biomass of wheat straw undergoes slow decomposition, and only a fraction of the chemical energy can be converted into biogas; thus economical methods for pretreatment increasing bioavailability are sought.ResultsA method was investigated to increase the methane yield in a full-scale plant for co-fermenting pig manure with corn silage, which was the default substrate in the original source reactors. Increased lignocellulosic bioavailability of wheat straw was achieved by combining liquid hot water (LHW) and steam explosion (SE). According to FT-IR analysis, the treatment resulted in hemicellulose hydrolysis, partial cellulose depolymerization, and lignin bond destruction. Low-mass polysaccharides (0.6 × 103 g mol−1) had significantly higher concentration in the leachate of LHW-SE wheat straw than raw wheat straw. The methanogenic potential was evaluated using inoculum from two different biogas plants to study the influence of microorganism consortia. The yield was 24–34% higher after the pretreatment process. In a full-scale biogas plant, the optimal conditions were ~ 165 °C, ~ 2.33 MPa, and 10 min in LHW and ~ 65 °C and ~ 0.1 MPa for SE. The processes did not generate detectable inhibitors according to GC–MS analysis, such as furfural and 5-hydroxymethylfurfural.ConclusionsThe LHW-SE combined pretreatment process increases the bioavailability of carbohydrates from wheat straw. The LHW-SE treated wheat straw gave similar biogas yields to corn silage, thus enables at least partial replacement of corn silage and is good for diversification of substrates. Surprisingly, microorganisms consortia from other biogas plant fed with other substrates may have higher efficiency in utilization of tested substrate. Thus, methanogenic consortia may be considered in the process of optimization at industrial scale. The efficiency was calculated, and the LHW-SE may be profitable at full industrial scale and further optimization is proposed.

Fermentation kinetics and ruminal parameters of animals fed diets containing Brazil nut cake inclusion levels

The inclusion effect of 0 (control), 15, 30, 45, 60, and 100% dry matter (DM) of Brazil nut (Bertholletia excelsa Bonpl.) cake (BNC) aiming at replacing corn silage was assessed on fermentation kinetics and effective degradability (ED) by means of in vitro gas production at 3, 6, 9, 12, 24, 48, 72 and 96 h. A randomized block design was used with six treatments, three blocks, and two replications per block. France’s model was fit to the data. An in vivo experiment, conducted in fistulated ovine, assessed the effects of BNC inclusion levels of 0, 15, 30, and 45% DM replacing corn silage on ruminal parameters. Ruminal fluid samples were collected postprandial at 8, 10, 12, 14, 16, and 18 h for determining the concentrations of short-chain fatty acids (SCFA), pH, and N–NH3. A completely randomized design with repeated measures in time was used, with four treatments and three replications. Results of acetate, propionate, butyrate, acetate to propionate ratio, pH, and NH3 were submitted to analysis of variance and regression (linear and quadratic) considering treatment, time and interaction of both. In addition, the F test with a 5% (P &lt; 0.05) significance level was applied to the data. Fermentation kinetics pattern and ED presented a linear decreasing (P &lt; 0.05), which means a decrease in total gas production at each coproduct inclusion level. No interaction effect between treatment and time was observed for total SCFA (P &gt; 0.40), acetic acid (P &gt; 0.41), propionic acid (P &gt; 0.85), butyric acid (P &gt; 0.62) and pH (P &gt; 0.57). BNC replacements of 0, 15, 30 and 45% did not change (P &gt; 0.05) total SCFA concentration, as well as acetic acid concentration in ovine. When including 45% DM of BNC, concentrations (mMol/100 mL) of propionic (P &lt; 0.001) and butyric (P &lt; 0.022) acids was reduced in the ruminal fluid. The highest concentrations at measurement times were observed 4 hours after feeding. The pH values presented a quadratic effect on both inclusion (P &lt; 0.001) and time (P &lt; 0.001). An interaction was observed between treatment and time for N–NH3 concentration (mg/ml) (P &lt; 0.001) and acetic to propionic acids ratio (P &lt; 0.014). Fermentation kinetics was negatively affected by Brazil nut cake inclusion to corn silage-based diet. Therefore, the use of this coproduct is recommended associated with non-structural carbohydrate sources.

Inclusion of wheat and triticale silage in the diet of lactating dairy cows.

The objective of this experiment was to partially replace corn silage with 2 alternative forages, wheat (Triticum aestivum) or triticale (X Triticosecale) silages at 10% of the diet dry matter (DM), and investigate the effects on dairy cow productivity, nutrient utilization, enteric CH4 emissions, and farm income over feed costs. Wheat and triticale were planted in the fall as cover crops and harvested in the spring at the boot stage. Neutral- and acid-detergent fiber and lignin concentrations were higher in the wheat and triticale silages compared with corn silage. The forages had similar ruminal in situ effective degradability of DM. Both alternative forages had 1% starch or less compared with the approximately 35% starch in corn silage. Diets with the alternative forages were fed in a replicated 3 × 3 Latin square design experiment with three 28-d periods and 12 Holstein cows. The control diet contained 44% (DM basis) corn silage. In the other 2 diets, wheat or triticale silages were included at 10% of dietary DM, replacing corn silage. Dry matter intake was not affected by diet, but both wheat and triticale silage decreased yield of milk (41.4 and 41.2 vs. 42.7 ± 5.18 kg/d) and milk components, compared with corn silage. Milk fat from cows fed the alternative forage diets contained higher concentrations of 4:0, 6:0, and 18:0 and tended to have lower concentrations of total trans fatty acids. Apparent total-tract digestibility of DM and organic matter was decreased in the wheat silage diet, and digestibility of neutral-and acid-detergent fiber was increased in the triticale silage diet. The wheat and triticale silage diets resulted in higher excretion of urinary urea, higher milk urea N, and lower milk N efficiency compared with the corn silage diet. Enteric CH4 emission per kilogram of energy-corrected milk was highest in the triticale silage diet, whereas CO2 emission was decreased by both wheat and triticale silage. This study showed that, at milk production of around 42 kg/d, wheat silage and triticale silage can partially replace corn silage DM and not affect DM intake, but milk yield may decrease slightly. For dairy farms in need of more forage, triticale or wheat double cropped with corn silage may be an appropriate cropping strategy.

Using brown midrib 6 dwarf forage sorghum silage and fall-grown oat silage in lactating dairy cow rations

Double cropping and increasing crop diversity could improve dairy farm economic and environmental sustainability. In this experiment, corn silage was partially replaced with 2 alternative forages, brown midrib-6 brachytic dwarf forage sorghum (Sorghum bicolor) or fall-grown oat (Avena sativa) silage, in the diet of lactating dairy cows. We investigated the effect on dry matter (DM) intake, milk yield (MY), milk components and fatty acid profile, apparent total-tract nutrient digestibility, N utilization, enteric methane emissions, and income over feed cost. We analyzed the in situ DM and neutral detergent fiber disappearance of the alternative forages versus corn silage and alfalfa haylage. Sorghum was grown in the summer and harvested in the milk stage. Oats were grown in the fall and harvested in the boot stage. Compared with corn silage, neutral detergent fiber and acid detergent fiber concentrations were higher in the alternative forages. Lignin content was highest for sorghum silage and similar for corn silage and oat silage. The alternative forages had less than 1% starch compared with the approximately 35% starch in the corn silage. Ruminal in situ DM effective degradability was similar, although statistically different, for corn silage and oat silage, but lower for sorghum silage. Diets with the alternative forages were fed in a replicated 3 × 3 Latin square design experiment with three 28-d periods and 12 Holstein cows. The control diet contained 44% (DM basis) corn silage. In the other 2 diets, sorghum or oat silages were included at 10% of dietary DM, replacing corn silage. Sorghum silage inclusion decreased DM intake, MY, and milk protein content but increased milk fat and maintained energy-corrected MY similar to the control. Oat silage had no effect on DM intake, MY, or milk components compared to the control. The oat silage diet increased apparent total-tract digestibility of dietary nutrients, except starch, whereas the sorghum diet slightly decreased DM, organic matter, crude protein, and starch digestibility. Cows consuming the oat silage diet had higher milk urea N and urinary urea N concentrations. Milk N efficiency was decreased by the sorghum diet. Diet did not affect enteric methane or carbon dioxide emissions. This study shows that oat silage can partially replace corn silage at 10% of the diet DM with no effect on MY. Brown midrib sorghum silage harvested at the milk stage with <1% starch may decrease DM intake and MY in dairy cows.

Spineless cactus associated with Tifton hay or sugarcane bagasse may replace corn silage in sheep diets.

The effect of the replacement of corn silage with spineless cactus associated with Tifton 85 hay or sugarcane bagasse was evaluated on the performance, body weight components and sheep meat quality. Twenty-one Santa Inês male sheep with initial body weight of 22.9±2.9kg were used. They were confined in individual stalls for 74days receiving the following diets: corn silage + concentrate (CS); spineless cactus + Tifton 85 hay + concentrate (TH); spineless cactus + sugarcane bagasse + concentrate (SB). After the feedlot period, the animals were slaughtered and their body components were weighed and sampled. Data were submitted to Tukey's test at 5% probability. The average daily gain (0.25 vs 0.14kg), cold carcass weight (13.3 vs 13.7kg), loin muscularity (0.6 vs 0.4kg) and liver weight (0.7 vs. 0.5kg) were higher (P<0.05) for the TH diet when compared to that for the CS. The physical-chemical parameters of meat were not influenced (P>0.05) by the treatments and presented about 20.1% of crude protein, 6.1% of crude fat and shear force of 2.0kgf/cm2. In complete diets for sheep, Tifton 85 hay associated with spineless cactus provides greater weight gain, cold carcass muscularity and organ weight when compared to those for animals fed with corn silage as exclusive roughage. Sugarcane bagasse associated with spineless cactus may replace corn silage in complete diets for sheep.

1438 Evaluation of brown midrib sudangrass silage in the diets of lactating dairy cows

Forages that use less water but are high in digestibility are sought as alternatives to traditional forages such as corn silage. Brown midrib (BMR) sudangrass is a possible alternative that can provide high-quality forage as a replacement for corn silage. The objective of this study was to evaluate the replacement of corn silage and alfalfa silage with increasing concentrations of sudangrass silage in the diets of lactating dairy cows. Forty-eight Holstein cows in mid lactation were assigned to treatments in a randomized complete block design. Cows were fed a common covariate diet for 2 wk followed by 8 wk of experimental diets. Diets were formulated to contain 40% corn silage, 20% alfalfa silage, and 40% concentrate on a DM basis. Sudangrass silage was included in experimental diets at 0, 10, 20, and 30% of the diet DM. Proportionally, sudangrass silage replaced 2 parts corn silage and 1 part alfalfa silage. All other ingredients (high-moisture corn, canola meal, roasted soybeans, soyhulls, and minerals and vitamins) were included equally for all diets. Data were analyzed using MIXED procedures of SAS. Polynomial orthogonal contrasts were used to determine the effect of increasing BMR sudangrass silage in the diets of lactating dairy cows. Dry matter intake linearly decreased as sudangrass silage replaced corn silage and alfalfa silage (P < 0.01). Similarly, milk production decreased from 43.1 kg/d for cows fed 0% sudangrass silage to 39.2 kg/d for cows fed 30% sudangrass silage. Milk fat and lactose percentage were not affected by changes in forages; however, milk protein percentage was quadratically affected (P = 0.02). Yields of milk fat, protein, and lactose linearly decreased (P < 0.05) with increasing sudangrass silage. Similarly, energy-corrected milk (ECM) linearly decreased with increasing concentrations of sudangrass silage. Feed efficiency, defined as ECM/DMI, was not affected by changes in forage because milk production changes and DMI changes were the same. Although it was expected that increased digestibility of the BMR sudangrass silage would benefit the dairy cow, it is possible that the increased fiber in the sudangrass diets limited intake, resulting in a linear decrease in milk production.

Effects of partial replacement of corn and alfalfa silage with tall fescue hay on total-tract digestibility and lactation performance in dairy cows

Our objective was to evaluate the effects of replacing either corn or alfalfa silage with tall fescue hay on total-tract neutral detergent fiber (NDF) digestibility and lactation performance in dairy cows. Twenty-four primiparous (75±35 d in milk) and 40 multiparous (68±19 d in milk) Holstein cows were blocked by parity and randomly assigned to 1 of 4 treatment groups in a pen equipped with 32 feeding gates to record intake by cow. Each gate was randomly assigned to 1 treatment group; thus, each cow had access to all 8 gates within the respective treatment and cow was the experimental unit. Treatments were formulated to replace either corn silage (CS) or alfalfa silage (AS) with tall fescue hay (TF) as follows (DM basis): 33% AS and 67% CS (control; 33AS67CS), 60% TF and 40% AS (60TF40AS), 60% TF and 40% CS (60TF40CS), and 33% TF and 67% CS (33TF67CS). The experiment was a 7-wk continuous lactation trial with a 2-wk covariate period. Milk production did not differ among treatments and averaged 40.4 kg/d. Fat yield and concentration and protein yield and concentration did not differ among treatments and averaged 1.58 kg/d, 3.94%, 1.28 kg/d, and 3.15%, respectively. Dry matter intake was greater for 33AS67CS (24.5 kg/d) compared with 60TF40CS (22.1 kg/d) and 33TF67CS (22.7 kg/d), and tended to be greater than 60TF40AS (23.2 kg/d). In vivo total-tract dry matter digestibility did not differ among treatments and averaged 66.2%. In vivo total-tract NDF digestibility was lower for 33AS67CS (37.8%) compared with 60TF40AS (44.4%) and 33TF67CS (45.3%), and similar to 60TF40CS (42.4%). In vivo total-tract NDF digestibility and an estimate of in situ total-tract NDF digestibility were similar between techniques across all treatment diets (42.3 vs. 42.6%, respectively). Inclusion of tall fescue grass hay increased the total-tract NDF digestibility of the diet and has the potential to replace corn silage and alfalfa silage and maintain milk production if economically feasible based on current market prices.

Greenhouse gases, short-chain fatty acids and ruminal pH in vitro of biodiesel byproducts to replace corn silage

SUMMARY The aim of the study was evaluate the production potential for methane (CH4) and carbon dioxide (CO2), short-chain fatty acids, ammonia nitrogen (N-NH3) and pH by semi-automated techniquein vitro from biodiesel byproducts cottonseed cake (Gossypium hirsutum), castor bean (Ricinus communis), moringa cake (Moringa oleifera), jatropha cake (Jatropha curcas) and sunflower cake (Helianthus annuus) substituting corn silage in increasing levels, 0, 30, 50 and 70%. The experimental design used was completely randomized in a 5 x 4 factorial arrangement (byproducts and substitution levels). The inoculum for the in vitro incubations was obtained from three Holstein cows with rumen fistulas. In the experiment, the conditions were verified for the differences in potential gas production among the ingredients. The byproduct of cotton was the ingredient with the greatest potential to produce acetate, butyrate, CO2 and CH4. The byproduct of moringa had the lowest potential for the production of acetate, butyrate, CO2 and CH4 from in vitro degraded dry matter and a greater potential for the production of propionate. Among the byproducts studied, moringa was distinguished for promoting mitigation of CH4 and obtaining levels of pH and N-NH3 satisfactory for maximum rumen fermentation; thus, it is recommended the byproduct of moringa to replace corn silage because reduces environmental impact without impairingin vitro rumen fermentation.

Optimizing ration formulation as a strategy for greenhouse gas mitigation in intensive dairy production systems

The study determines the extent to which ration selection can reduce GHG emissions in intensive dairy production systems. Replacing corn silage with alfalfa hay as the primary roughage component of dairy rations can lead to significant declines in GHG emissions from milk production in Ontario. Due to the higher soil organic matter of perennial forages, this change leads to the capture and storage of C in farm soils. Furthermore, alfalfa production requires less farm fieldwork and chemical inputs than corn which leads to a decline in emissions from energy consumption. The results suggest that feeding decisions have important implications for GHG emissions from intensive dairy production due to the wide variation in emissions for alternative crops that can be used in the ration. This is a notable finding, as much of the work on cost effective GHG mitigation in the dairy sector focuses on how this decision impacts enteric CH4. While our model estimates a decline in enteric CH4 resulting from the change in rations, this decline makes up only a small fraction of the total emission reductions. The ration decisions that lead to initial reductions in GHGs involve a small reduction in net farm returns but reductions beyond 5% impose a marginal abatement cost of about $550 Mg-1 CO2eq. Thus, reducing emissions by this amount through a carbon tax or market would not occur under current C prices suggesting that while intensive dairy production systems could contribute to policy efforts to reduce GHG emissions largely through cropping decisions, there may be more cost effective mitigation potential in other sectors.

Ingestive behavior of dairy goats fed increasing levels of sugarcane in replacement of corn silage

The objective of this experiment was to evaluate levels of replacement (0, 33, 67 and 100%) of corn silage with fresh sugarcane in dairy-goat diets on the ingestive behavior of these animals. Eight lactating Alpine goats (after lactation peak) with a live weight of 51.95±3.29 kg were distributed into two 4 × 4 Latin squares according to their milk production. Animals were placed in individual pens where they received diets ad libitum, twice a day, with a roughage:concentrate ratio of 40:60, during 72 days of experiment. The evaluated variables were time spent feeding (TSF), ruminating (TSR), idle (TSI) and chewing (TSC), dry matter intake (DMI), neutral detergent fiber intake (NDFI), feeding efficiency of dry matter (FEDM) and neutral detergent fiber (FENDF), rumination efficiency of dry matter (REDM) and neutral detergent fiber (RENDF), number of ruminal boli per day (NRB) and number of rumination chews per day (NRC). The different treatments had no effect on TSF or TSR. However, a linear effect was observed on TSC. There was a linear effect on TSI, in which the highest value was observed in the treatment with 0% of sugarcane inclusion. A quadratic effect was observed on dry matter intake, with minimum point of 2.14 kg/day for 68.04% of sugarcane inclusion; however, NDFI was not affected by the different treatments. There was no effect of treatments on FEDM, although a quadratic effect was observed on FENDF, wherein the lowest value was observed in the treatment with 67% of sugarcane inclusion. There was no effect of different levels of corn silage replacement on REDM, RENDF, NRB or NRC. Sugarcane can be replaced with corn silage without changing the times spending on feeding and rumination.

Replacing corn silage with different forage millet silage cultivars: Effects on milk yield, nutrient digestion, and ruminal fermentation of lactating dairy cows

This study investigated the effects of dietary replacement of corn silage (CS) with 2 cultivars of forage millet silages [i.e., regular millet (RM) and sweet millet (SM)] on milk production, apparent total-tract digestibility, and ruminal fermentation characteristics of dairy cows. Fifteen lactating Holstein cows were used in a replicated 3×3 Latin square experiment and fed (ad libitum) a high-forage total mixed ration (68:32 forage:concentrate ratio). Dietary treatments included CS (control), RM, and SM diets. Experimental silages constituted 37% of each diet DM. Three ruminally fistulated cows were used to determine the effect of dietary treatments on ruminal fermentation and total-tract nutrient utilization. Relative to CS, RM and SM silages contained 36% more crude protein, 66% more neutral detergent fiber (NDF), and 88% more acid detergent fiber. Cows fed CS consumed more dry matter (DM; 24.4 vs. 22.7kg/d) and starch (5.7 vs. 3.7kg/d), but less NDF (7.9 vs. 8.7kg/d) than cows fed RM or SM. However, DM, starch and NDF intakes were not different between forage millet silage types. Feeding RM relative to CS reduced milk yield (32.7 vs. 35.2kg/d), energy-corrected milk (35.8 vs. 38.0kg/d) and SCM (32.7 vs. 35.3kg/d). However, cows fed SM had similar milk, energy-corrected milk, and solids-corrected milk yields than cows fed CS or RM. Milk efficiency was not affected by dietary treatments. Milk protein concentration was greatest for cows fed CS, intermediate for cows fed SM, and lowest for cows fed RM. Milk concentration of solids-not-fat was lesser, whereas milk urea nitrogen was greater for cows fed RM than for those fed CS. However, millet silage type had no effect on milk solids-not-fat and milk urea nitrogen levels. Concentrations of milk fat, lactose and total solids were not affected by silage type. Ruminal pH and ruminal NH3-N were greater for cows fed RM and SM than for cows fed CS. Total-tract digestibility of DM (average=67.9%), NDF (average=53.9%), crude protein (average=63.3%), and gross energy (average=67.9%) were not influenced by dietary treatments. It was concluded that cows fed CS performed better than those fed RM or SM likely due to the higher starch and lower NDF intakes. However, no major differences were noted between the 2 forage millet silage cultivars.

Diurnal behavior of dairy cows on alfalfa pastures supplemented with corn silage and concentrate

The diurnal ingestive behavior of dairy cows on alfalfa pastures supplemented with corn silage and concentrate was evaluated. Sixteen Holstein dairy cows in mid-lactation were used in a randomized block design. The treatments were partial replacement of corn silage for limited alfalfa grazing time (LGT) or unlimited grazing time (UGT). Rotational alfalfa grazing was used and the amount of concentrate fed was the same in both treatments. Behavioral activities observed were time spent grazing, rumination and idleness, during four days, from 8:00 AM to 7:00 PM. From 2:00 to 5:00 PM grazing was intermittent and short-lasting on UGT, whereas on LGT grazing activity was longer than UGT in the morning and at the end of the afternoon. Restriction in available grazing time clearly influenced the distribution of time spent with grazing, rumination and idleness throughout the day. However, this effect was not observed in the total time spent in these activities.

Effects of Replacing Corn Silage and Alfalfa Hay with Master Graze Silage on Dairy Cows Performance

Effects of Replacing Corn Silage and Alfalfa Hay with Master Graze Silage on Dairy Cows Performance

Milk production, nitrogen balance, and fiber digestibility prediction of corn, whole plant grain sorghum, and forage sorghum silages in the dairy cow

Total mixed rations containing corn (CS), whole plant grain sorghum (WPGS), or forage sorghum (FS) silages were fed to 6 primiparous Italian Friesian cows to determine the effects on lactation performance, nutrient digestibility, and N balance. Furthermore, the relationship between in vivo total-tract neutral detergent fiber (NDF) digestibility (ttNDFD) and the ttNDFD derived by the Cornell Net Carbohydrate and Protein System (CNCPS) model was assessed. Cows were assigned to 1 of 3 diets in a replicated 3×3 Latin square with 28-d periods. The experimental treatment was silage type and 3 different silages were included in the diets. The diets were formulated to be iso-NDF. Accordingly, each diet was formulated to contain 41.5% CS silage, 36.7% WPGS silage, or 28.0% FS silage, on a DM basis. Starch content was balanced by adding the appropriate amount of corn meal. Separate collection of total urine and feces was performed. Dietary forages were analyzed for in vitro NDF digestibility (6 and 24h of incubation) to predict fiber digestion rate with 2 NDF pools (digestible and indigestible). Rumen digestibility of the potentially digestible NDF pool was predicted using CNCPS version 6.1, using the in vitro forage fiber digestion rate. The ttNDFD was predicted assuming that intestinal digestibility of the NDF amount escaping rumen digestion was 20%, according to the CNCPS model. Dry matter intake was decreased by approximately 1.8kg/d in cows fed the FS diet compared with the other diets, probably for the greater particle size of FS diet. Hence, milk yield (kg/d) was lowest for FS (23.6), intermediate for WPGS (24.6), and highest for the CS diet (25.4). Milk urea N (mg/dL) was highest for FS (12.9), intermediate for WPGS (11.9), and lowest for CS (10.7) diet. In vivo ttNDFD (%) was 51.4 (CS), 48.6 (WPGS), and 54.1 (FS); this was probably due to a higher retention time of FS diet in the rumen rather than to a better quality of the FS silage, as confirmed by in situ and in vitro results. Urinary N excretion (% N intake) was highest for FS (31.8), intermediate for WPGS (29.3), and lowest for the CS (27.5) diet. The predicted ttNDFD (37.7, 36.3, and 39.5% for CS, WPGS, and FS, respectively) were lower than the in vivo results. Providing an adequate starch supplementation, whole plant grain sorghum silage can replace corn silage in dairy cows TMR. Forage sorghum silage had rumen NDF digestibility comparable to the other silages; however, it had a negative effect on dry matter intake and milk production, probably due to an inadequate effect of processing.

Effects of feeding different levels of dietary fiber through the addition of corn stover on nutrient utilization of dairy heifers precision-fed high and low concentrate diets

The objective of this experiment was to assess the effects of manipulating dietary fiber by replacing corn silage (CS) with lower quality forage as corn stover (CST) when used in high concentrate (HC) and low concentrate (LC) diets for precision-fed dairy heifers. Eight Holstein heifers (335.6±7.41kg of body weight) were randomly assigned to 2 levels of concentrate: HC (20% forage) and LC (80% forage), and to a forage type sequence [0% of forage as corn stover (CST), 100% corn silage (CS); 20% CST, 80% CS; 40% CST, 60% CS; and 60% CST, 40% CS] within concentrate level administered according to a split-plot, 4×4 Latin square design (21-d periods). Heifers fed HC had higher apparent total-tract dry matter digestibility (DMD). Increasing the fiber level by increasing the amount of CST in the diet resulted in a linear decrease of DMD and organic matter digestibility. Heifers fed LC diets had higher neutral detergent fiber (NDF) digestibility and tended to have lower acid detergent fiber (ADF) digestibility than those fed HC diets. Substituting CS with 20% CST resulted in the highest NDF and ADF digestibilities. Digestibility of N was not different, but N retention increased for HC and decreased quadratically for LC diets. Heifers fed HC diets decreased fecal output, and CST linearly increased these parameters. Urine volume tended to be higher for HC-fed heifers, and increasing dietary fiber through CST inclusion tended to decrease urine output. This shift in water excretion resulted in similar total manure output. Total purine derivative excretion did not differ between treatments, but interacted with CST addition, resulting in a linear increase in microbial protein flow to the duodenum in HC-fed heifers and in a linear decrease in LC diets as CST increased. In conclusion, increasing dietary fiber through CST decreased DMD and organic matter digestibility linearly, whereas NDF and ADF digestibility were maximized when 20% CST was added to HC and LC diets. Microbial protein synthesis increased and decreased linearly with CST addition in HC and LC diets, respectively. Retention of N increased and decreased quadratically with CST addition in HC and LC diets, respectively. Total manure excretion was not different between HC or LC diets.

Consumo, digestibilidade total, produção de proteína microbiana e balanço de nitrogênio em dietas com subprodutos de frutas para ruminantes

Objetivou-se avaliar os efeitos da inclusão de subprodutos de frutas in natura (abacaxi, goiaba, mamão, manga e maracujá) e do nível (10 e 30%) utilizado na dieta de bovinos em substituição parcial à silagem de milho sobre o consumo e a digestibilidade total dos nutrientes, a produção de proteína microbiana (Pmic) e o balanço de nitrogênio e sobre a predição das frações digestíveis e nutrientes digestíveis totais (NDT) desses subprodutos. Todos os animais receberam silagem de milho e mistura ureia/sulfato de amônio (9:1) para que as rações se mantivessem isonitrogenadas. Os consumos de matéria seca (MS) (kg/dia), matéria orgânica (MO), proteína bruta (PB), fibra em detergente neutro (FDN) e NDT, além da digestibilidade de PB, extrato etéreo (EE) e carboidratos não-fibrosos (CNF) foram afetados pela origem do subproduto. Houve efeito para o nível de inclusão dos subprodutos na digestibilidade da PB e EE. Os subprodutos de mamão, manga e abacaxi apresentaram valor energético 23,1; 18,0 e 7,1%, respectivamente, superior ao da silagem de milho. A fonte do subproduto influenciou as excreções urinárias de derivados de purinas totais e purinas absorvidas e a produção de proteína microbiana, além da ingestão (g/dia), a excreção dos compostos nitrogenados nas fezes e na urina (g/dia) e o balanço de nitrogênio (g/dia). O nível de inclusão dos subprodutos na dieta afetou as excreções urinárias de derivados de purinas totais e purinas absorvidas e a produção de proteína microbiana. Os subprodutos de abacaxi, mamão e manga têm valor energético superior ao da silagem de milho e podem substituir parcialmente concentrados energéticos em dietas para ruminantes. O subproduto de maracujá tem potencial para substituir parcialmente volumosos em dietas para ruminantes. O subproduto de goiaba apresenta limitações para uso em dietas para ruminantes.

Desempenho de vacas leiteiras em pastagem de alfafa suplementada com silagem de milho e concentrado e viabilidade econômica do sistema

Avaliou-se o efeito da substituição parcial de silagem de milho por pastagem de alfafa no desempenho de vacas leiteiras e na viabilidade econômica do sistema. Utilizaram-se 24 vacas da raça Holandesa, em estádio médio de lactação, em delineamento em blocos ao acaso. Os tratamentos foram: dieta à base de silagem de milho em confinamento, silagem de milho substituída parcialmente por pastejo restrito (PR) e pastejo irrestrito (PI) de alfafa. O sistema de pastejo foi rotacionado, e a quantidade de concentrado igual em todos os tratamentos. A massa de forragem foi de 2.338 e de 1.878kg de MS/ha, e a oferta de 1,8 e 4,2kg de MS/100kg de peso vivo, nos tratamentos PR e PI, respectivamente. A produção de leite não diferiu entre os tratamentos, cujas médias foram de 25,9; 25,8 e 25,2 litros por vaca por dia no confinamento, no PR e no PI, respectivamente. A produção diária de leite por área foi de 59,3L/ha no PR e de 63,0L/ha no PI, enquanto no confinamento foi de 45,7L/ha. A substituição parcial de silagem de milho por alfafa em pastejo não limitou o desempenho produtivo dos animais e mostrou-se economicamente vantajosa em relação ao confinamento.

SUBSTITUIÇÃO DE SILAGEM DE MILHO POR CANA-DE-AÇÚCAR E CAROÇO DE ALGODÃO SOBRE O DESEMPENHO DE VACAS HOLANDESAS EM LACTAÇÃO

Five multiparous Holstein cows averaging 526 kg of body weight and 85 days of lactation were assigned in a 5 x 5 latin square design for the evaluation of the replacement of corn silage by sugar cane and whole cottonseed. Cows were fed a 50:50 concentrate:forage diet (dry matter basis-DM). Treatments were defined by the replacement of corn silage by chopped sugar cane (whole plant) according to the following proportions: 100:0 (control), 75:25, 50:50, 25:75, 0:100, based on dry matter roughage. In each treatment, 0, 5, 10, 15, and 20% of whole cottonseed were added to the dietary DM, respectively. Dry matter intake (DMI) of cows fed 100, 75, and 50% corn silage diets was higher (P 0.05) by inclusion of sugar cane and whole cottonseed. Corn silage can be replaced by sugar cane up to 50% of roughage level without negative effect on performance of dairy cows producing up to 18 kg milk/day. KEYWORDS: Cottonseed, dry matter intake, milk composition, milk production.