Silage Source Research Articles

Effect of carbohydrate type in silages and concentrates on feed intake, enteric methane, and milk yield from dairy cows

Dietary carbohydrate manipulation can be used to reduce enteric CH4 emission, but there is a lack of studies on the interaction of different types of carbohydrates that can affect feed intake and ruminal fermentation. Understanding this interaction is necessary to make the most out of CH4 mitigation feeding strategies using different dietary carbohydrates. The aim of this study was to test the effect on enteric CH4 emission, feed intake and milk production response when cows were fed either grass-clover (GCS) or corn silage (CS) as the sole forage source (55% of dry matter, DM), in combination with either barley (BAR) or dried beet pulp (DBP) as a concentrate (21.5% of DM). Twenty-four (half first and half second parity) cows were used in a crossover design with 2 periods of 21 d each, receiving 2 of 4 diets obtained from a 2 × 2 factorial arrangement of the experimental diet. Feed intake, CH4 emission metrics and milk production were recorded at the end of the experimental periods. The diets had NDF concentrations between 258 and 340 g/kg of DM, and starch concentrations between 340 and 7.45 g/kg of DM (CS-BAR and GCS-DBP, respectively). The effects of silage and concentrate on dry matter intake (DMI) were additive, with the highest feed intake in cows fed COR-BAR, followed by cows fed COR-DBP, GCS-BAR, and GCS-DBP (21.2, 19.9, 19.1, and 18.3 kg/d). Energy corrected milk (ECM) yield was not affected by silage source in first parity cows, but it was higher for cows fed CS than cows fed GCS in second parity. The effects of silage and concentrate on CH4 production (g/d), yield (g/kg of DMI) and intensity (g/kg of ECM) were not additive as cows fed GCS had similar responses regardless of the concentrate used, but cows fed CS had lower CH4 production, yield and intensity, when fed BAR instead of DBP. The lower CH4 production, yield and intensity in cows fed CS-BAR compared with other diets could be partially explained by the nonlinear relationship between ruminal VFA and carbohydrates (NDF and starch) concentration reported in literature, however, we observed a linear relationship between acetate:propionate ratio and CH4 yield, suggesting possible other effects. The effects of silage and concentrate on the ruminal VFA were additive in first parity cows, but not in second parity cows. The interaction between dietary CHO type and parity might indicate an effect of feed intake or the energy balance of the cow. Feeding cows silage and concentrate both rich in starch can result in the lowest enteric CH4 emission.

Crop rotation for management of plant‐parasitic nematodes in forage corn production

AbstractCorn (Zea mays L.) is an important silage source for dairy cattle production in the southeastern United States. Silage corn is often grown continuously, which frequently results in severe pressure from plant‐parasitic nematodes such as sting nematode (Belonolaimus longicaudatus). Crop rotation is one of the few nematode management options available in forage production. The research objective was to assess summer‐planted rotation crops, preceding spring silage corn, for management of plant‐parasitic nematodes. Rotation crops included field corn, pearl millet [Cenchrus americanus (L.) Morrone]—with or without fertilizer—, sorghum‐sudangrass [Sorghum bicolor (L.) Moench × Sorghum sudanense Piper], and sunn hemp (Crotalaria juncea L.), which was either incorporated into soil or harvested. Rotation crops were assessed in a 3‐year field study in central Florida. Sunn hemp treatments significantly reduced sting nematode soil abundances relative to corn by 84%, 90%, and 84% before spring corn planting in 2019–2020 and 2020–2021 and at rotation crop termination in 2021–2022, respectively. Abundances of other plant‐parasitic nematodes were not consistently influenced by rotation. Biomass of winter rye (Secale cereale L.)—a bridge cover crop between summer and spring crops—was consistently increased following sunn hemp with significant increases of 87%, 106%, and 186% relative to following corn in 2019–2020, 2020–2021, and 2021–2022, respectively. Similarly, sunn hemp significantly increased spring corn yield by 70% and 136% relative to double‐cropped corn in 2020–2021 and 2021–2022, respectively. Overall, rotation with sunn hemp improved plant‐parasitic nematode management in forage corn production relative to rotations with only gramineous crops.

Evaluation of carinata meal or cottonseed meal as protein sources in silage-based diets on behavior, nutrient digestibility, and performance in backgrounding beef heifers.

Changing climatic conditions are imposing risks and diminishing yields in agriculture. Sorghum (Sorghum bicolor) silage is a feasible option for backgrounding beef cattle in terms of economic risk management and animal productivity when compared with corn (Zea mays) silage, due to its drought adaptability. Similarly, Brassica carinata meal has proven to be a viable alternative as a protein supplement in forage-based beef cattle systems, when included at 10% of the diet dry matter (DM). However, research is scarce regarding its inclusion in silage-based diets for backgrounding animals. The objective of this trial was to compare a processor-chopped sorghum silage (SS) against a typical corn silage (CS) in a digestibility and performance trial while supplementing two protein sources; one traditionally used like cottonseed meal (CSM) and one novel like B. carinata meal (BCM). A total of 84 Angus crossbred heifers (307 ± 33 kg BW) were evaluated in a randomized block design with a 2 × 2 factorial treatment arrangement with type of silage and protein source as factors. Diets were fed ad libitum, consisting of 89% silage source plus 10% protein source, and 1% mineral inclusion on DM basis. The experimental period consisted of 14 d of adaptation followed by 5 d of apparent total tract digestibility measurements and 56 d of animal performance and intake behavior measurements. Heifers fed SS showed greater number of daily meals but decreased meal sizes (P ≤ 0.05), not differing in meal length (P > 0.10) when compared with CS. Dry matter and organic matter (OM) digestibility showed a silage type × protein source interaction (P ≤ 0.01), where in CS diets, OM tended to be more digestible with CSM vs. BCM, and it did not differ between protein sources in SS based diets. There was an effect of protein (P ≤ 0.01) on ADF digestibility, where CSM was greater than BCM. No effect of treatment was observed (P ≥ 0.10) on DM intake. Average daily gain (ADG) and gain-to-feed ratio were greater for CS than SS (P ≤ 0.01) regardless of protein source. Although heifers fed CS had greater feed efficiency and digestibility, SS can still be considered a viable option for backgrounding beef heifers, obtaining adequate ADG rates of 0.945 kg/d. Lastly, BCM did not differ from CSM in terms of feed efficiency and animal performance, proving to be a viable alternative protein source in silage-based diets.

Using rose pulp silage instead of sugar beet pulp silage in lambs fed with total mixed ration

The aim of this study was to determine the effects of using rose pulp (Rosa damacena) silage instead of sugar beet pulp silage on fattening performance, carcass yield, and some ruminal fluid parameters in lambs fed with total mixed ration. For this purpose, a total of 16 (average 30 ± 5 kg) 6-month-old Pırlak lambs, 8 in each group, were randomly divided into two groups. Total mixed rations were formulated by using concentrate, wheat straw and rose pulp silage (RPS) (Group 1) or sugar beet pulp silage (SBPS) (Group 2) in the experiment. Due to the low dry matter content of rose pulp, 7% wheat bran was added to its silage (RPS). The physical and chemical properties of both silages were evaluated, and rations were formulated as isocaloric and isonitrogenic. The study lasted 8 weeks after 2 weeks of the animals' adaptation to the ration. Live weight, live weight gain, feed consumption, feed conversion ratio, hot-cold carcass yield and ruminal parameters such as volatile fatty acids, protozoan number, pH, and ammonia nitrogen concentration were measured in the experiment. It was determined that the acetic acid level (12.4% DM) of RPS was approximately 6 times higher than SBPS, and the butyric acid level (3.83% DM) was 3 times higher. At the end of the study, it was determined that the difference between the performance parameters of both groups was not significant. Apart from acetic and butyric acid, rumen fluid parameters were not affected by the usage of RPS in the ration. It was concluded that the rose pulp silage consisting of wheat bran (7%) can be used as an alternative silage source to feed small ruminants instead of sugar beet pulp silage without any adverse effects.

Milk production, rumen function, and digestion in dairy cows fed diets differing in predominant forage and concentrate type

The objective was to determine the effect of dietary ratio of neutral detergent fibre (aNDFom) to starch within diets differing in grass to maize silage ratio on rumen function, diet digestion, serum haptoglobin, and production of lactating dairy cows. Four isonitrogenous diets were formulated with a forage to concentrate ratio of 50:50, with the forage proportion containing either a high or low ratio of grass silage to maize silage (82:18 [GS] or 18:82 [MS] on a dry matter [DM] basis, respectively) and the concentrates containing either a high (F) or low (S) aNDFom to starch ratio, giving 4 dietary ratios of aNDFom to starch. Diets were fed to 4 early lactation Holstein dairy cows in a 4 × 4 Latin square design with 28-d periods. Feed intake, eating behaviour, milk production and composition, total tract digestion, nitrogen (N) excretion, aNDFom passage rate and in-situ degradation, rumen pH, and serum haptoglobin were measured during the last week of each period. Cows fed the MS diets consumed 1.34 kg/d more DM (P = 0.047) and 2.38 kg/d more starch (P = 0.001) compared to GS diets and produced 2.46 kg/d more milk (P = 0.038). Milk fat concentration was higher (+2.88 g/kg) for cows fed GS diets compared to MS diets (P = 0.007), while cows fed S concentrates had a higher milk fat concentration (+1.8 g/kg) irrespective of forage source (P = 0.033). Digestibility of aNDFom was higher (+0.106 kg/kg) for GS diets than for MS diets (P = 0.004). Similarly, aNDFom digestibility was higher (+0.057 kg/kg) for F concentrates (P = 0.031). Rumen and total-tract particle retention times were higher (+11.9 and +9.1 h, respectively) for cows fed GS diets (P = 0.009 and P = 0.037, respectively). Milk N yield/N intake was higher for the MS diets versus GS diets (P = 0.045), due to a greater (+130 g/d) milk protein yield (P = 0.015). Cows fed the MS diets spent 187 min/d more with rumen pH below 5.8 compared to GS diets (P = 0.006). Serum haptoglobin concentration, a purported marker of gut inflammation, was 5.3 ng/ml higher for cows fed S concentrates versus F concentrates (P = 0.023). In conclusion, changes in concentrate aNDFom:starch ratio had little effect on DM intake, milk yield and composition, rumen function, and eating behaviour compared to effects of silage source (MS vs GS), where replacing a portion of diet GS with MS increased feed intake, milk yield, rumen passage rate, and N digestion, but also reduced fibre digestion and milk fat concentration. These observations suggest a greater effect of forage type on lactation performance than concentrate type per se under the conditions of the current study.

PSXIV-11 Silage source, physically effective neutral detergent fiber, and undigested neutral detergent fiber concentrations affect eating behavior, ruminal pH and reticular motility of finishing heifers

Abstract This study evaluated the effects of silage source, physically effective neutral detergent fiber (peNDF), and undigested neutral detergent fiber (uNDF) concentrations on eating behavior, ruminal pH, and reticular contractions for finishing beef heifers. Six Hereford′Simmental heifers (579±51.2 kg) were used in a replicated 6×6 Latin square (21-d periods) balanced for carry-over effects with 2×2 + 2 factorial treatment arrangement. Barley grain-based diets included barley (BarS) or wheat silage (WhS) at 10% of dietary DM. Silages were harvested at two chop lengths to yield low (LpeNDF) vs. high peNDF (HpeNDF) silage. For both BarS and WhS, chopped wheat straw was included (5% of DM) by replacing an equal proportion of LpeNDF silages to evaluate low vs. high uNDF (7.3 vs. 8.2% dietary DM) concentrations. Heifers fed HpeNDF WhS had greater DMI (silage′peNDF; P < 0.01) than those fed HpeNDF BarS, but DMI did not differ for LpeNDF treatments. Ruminating and eating time increased for heifers fed HpeNDF WhS relative to LpeNDF WhS, but were not different for BarS (silage′peNDF; P ≤ 0.02). Increasing uNDF increased eating and ruminating times for heifers fed WhS, but not BarS (silage′uNDF; P ≤ 0.03). Mean ruminal pH averaged 5.97 and was not affected by silage, peNDF, uNDF, or the interactions (P ≥ 0.12). Feeding BarS increased the duration (384 vs. 256 min/d; P = 0.02) and area (84.5 vs. 43.8 pH×min/d; P = 0.02) that pH was < 5.5 relative to WhS. Increasing peNDF numerically reduced the frequency of reticular contractions when fed BarS but numerically increased them when fed WhS (silage′peNDF; P < 0.01). Reticular contractions were not affected by dietary uNDF concentration (P ≥ 0.13). These data highlight that at a constant inclusion rate, silage source and chop length interact to affect DMI, eating behavior, ruminal pH, and reticular motility indicating the need to account for silage type, peNDF, and uNDF in diet formulation for finishing cattle.

Nutritive value of sorghum silage for sheep.

This study compared ensiled sorghum (ES) from two varieties (first and second cuts) with corn silage (CS) for chemical analysis, total-tract nutrient digestibility, ruminal variables and blood biochemistry metabolites in sheep. Five experimental silages representing first cut ES var. Pegah (PS1), second cut ES var. Pegah (PS2), first cut ES var. Speedfeed (SS1), second cut ES var. Speedfeed (SS2) and CS were assessed for chemical analysis, silage fermentation and anti-quality compounds. Diets consisted of lucerne hay, silage and a premix (at the ratio of 53.5:46:0.5 on a dry matter [DM] basis). Feed consumption, total-tract nutrient digestibility, microbial nitrogen supply (MNS), ruminal variables and blood biochemistry metabolites were determined in a Latin square design of five periods with five male sheep. Compared to sorghum, CS had lower (p<0.01) concentrations of ash, water-soluble carbohydrates and crude protein, but higher starch, lignin (sa), non-structural carbohydrates and apparent nutrient digestibility. The measurements of pH, lactic acid, NH3 -N and volatile fatty acids (VFA) confirmed that all silages were well-preserved. The anti-quality compound levels in the silages were below the safe limits for ruminants. No differences were observed in feed consumption (p>0.05) and total-tract digestibility of DM and nutrients (p>0.05). Rumen pH, NH3 -N, VFA concentrations and acetate to propionate ratio showed no difference among treatments (p>0.05). Sheep fed on sorghum silage showed a decrease (p<0.01) in total protozoa, and particularly in the Entodiniae population. There were no differences in cellulolytic bacteria counts (p>0.05) among treatments. Urinary N, MNS and blood biochemistry metabolites showed no difference among treatments (p>0.05). Silages from both cuts of sorghum had comparable total-tract nutrient digestibility to CS, therefore, these varieties could be used as a more drought resilient silage source in the feeding of sheep.

Effect of silage source, physically effective neutral detergent fiber, and undigested neutral detergent fiber concentrations on performance and carcass characteristics of finishing steers.

This study was designed to evaluate the effect of silage source (barley vs. wheat silage) when harvested at two chop lengths (low vs. high physically effective neutral detergent fiber [peNDF]) and when barley silage was partially replaced with straw to increase the undigested neutral detergent fiber (uNDF) concentration on performance and carcass characteristics of finishing steers. Four hundred and fifty yearling commercial crossbred steers with an initial body weight (BW) of 432 ± 30.5 kg were allocated to 30 pens and fed diets containing 90% concentrate:10% forage for 123 d in a completely randomized block design with a 2 × 2 + 1 factorial arrangement. Treatments included 1) barley silage (BarS) with low peNDF (LpeNDF); 2) BarS with high peNDF (HpeNDF); 3) BarS with straw to yield a diet with LpeNDF + uNDF; 4) wheat silage (WhS) LpeNDF; and 5) WhS HpeNDF. There were no silage × peNDF interactions for dry matter intake (DMI), average daily gain (ADG), or gain to feed ratio (G:F), but cattle fed WhS LpeNDF had a lower (P < 0.01) proportion of yield grade 3 and a greater proportion in yield grade 2 carcasses than cattle fed BarS LpeNDF or HpeNDF and WhS HpeNDF. Cattle fed WhS LpeNDF had greater (P = 0.02) incidence of severe liver abscesses when compared with cattle fed BarS LpeNDF or HpeNDF and WhS HpeNDF. Cattle fed BarS consumed less (P < 0.01) uNDF as a percentage of BW, had increased (P = 0.02) ADG, heavier (P = 0.02) hot carcass weight, with greater (P = 0.01) back fat thickness, and (P < 0.01) incidence of minor liver abscesses when compared with cattle fed WhS. Feeding HpeNDF did not affect DMI, ADG, or G:F, but increased (P = 0.02) marbling score and reduced (P < 0.01) the proportion AA quality grade and increased (P < 0.01) those classified as AAA when compared with cattle fed LpeNDF. Cattle fed low uNDF had lesser (P < 0.01) uNDF intake as a percentage of BW, greater dressing percentage (P = 0.01), had a lower (P < 0.01) proportion of carcasses in yield grade 2, and a greater (P < 0.01) proportion of carcasses in yield grade 3 when compared with cattle fed high uNDF. Thus, silage source, peNDF, and uNDF content do not impact DMI or G:F when diets contain 10% forage, but BarS relative to WhS as well strategies increasing the peNDF concentration may increase ADG, HCW, back fat thickness, dressing percentage, marbling score, and carcasses classified as quality grade AAA. Future research is needed to evaluate the usefulness of peNDF and uNDF in rations for finishing cattle.

4 Effect of Inclusion Rate of Silage With or Without the Presence of Alpha-Amylase on Feedlot Performance, Carcass Characteristics, and Efficiency Measures

Abstract One hundred ninety-two Continental × British steers (initial BW 420 kg [SD 24.7]) were used in a randomized complete block design finishing study to evaluate the effects of feeding two types of silage germplasm at two inclusion rates. A 2 × 2 factorial arrangement of treatments was used with either a conventional (CON) or increased expression of alpha-amylase (Enogen, Syngenta Seeds, LLC, ENO) hybrid fed at either 12% (12SIL) or 24% (24SIL) of diet DM. Steers were blocked (n = 5) and assigned randomly within block to treatments, resulting in five pens and 48 steers per treatment. Steers were harvested after 126 (12SIL) or 140 (24SIL) days on feed. There were no silage source by inclusion rate interactions detected for live growth performance. Silage source did not affect live based average daily gain (ADG), gain to feed ratio (G:F), or final BW (FBW; P ≥ 0.35). Feeding 24% silage reduced ADG (P = 0.04) and G:F (P = 0.01) but increased FBW (P = 0.02) compared to 12SIL. A source by inclusion rate interaction was detected (P = 0.04) for calculated yield grade (YG) with steers fed 24% silage having increased YG within CON but not ENO. Hot carcass weight and ribfat were unaffected by silage source (P ≥ 0.81), but were increased by feeding 24% silage (P = 0.03 and P = 0.02, respectively). Feeding increased amounts of silage increased beef produced per hectare (P = 0.05). Conventional silage produced more beef per hectare (P &amp;lt; 0.01) due to differences in silage yield, but source of silage did not affect feedlot performance independent of silage yield. Feeding increased amounts of silage reduced DM efficiency on a live animal basis but increased beef produced per hectare which is of major value to cattle feeders who produce the majority of their own feedstuffs.

Changes in the fatty acid composition of steer subcutaneous fat, including biohydrogenation products, are minimal when finished on combinations of corn and barley grains and silages

Corn production in Western Canada has increased with development of short-season varieties partially offsetting the use of barley as a silage and grain source. The current study evaluated effects of silage and cereal-grain source on subcutaneous fat (SCF) composition of finishing cattle. Steers (465 ± 28.0 kg) were assigned to 24 pens (12 steers per pen) in a 2 × 3 factorial design for an 89 d finishing study. Diets contained corn silage or barley silage at 8% [dry matter (DM)] combined either dry-rolled barley grain (BG; 86% of DM), corn grain (CG; 85% of DM), or an equal blend of BG and CG (85% of DM). Bone-in ribeyes were collected from four steers per pen, and subcutaneous fatty acids were analyzed by gas chromatography. Feeding dry-rolled CG increased dietary fat and 18:2n-6 concentrations, resulting in small increases in 18:2n-6, total n-6 fatty acids, and n-6/n-3 ratios in SCF (P &lt; 0.05). There were no changes in proportions of major trans-18:1 isomers (t10-18:1 or t11-18:1), the main natural isomer of conjugated linoleic acid (cis9,t11–18:2), or n-3 fatty acids. Substitution of dry-rolled CG for BG in finisher diets can, therefore, be done without substantially altering the fatty acid composition of beef fat, including polyunsaturated fatty acid biohydrogenation products.

Effect of feeding barley or corn silage with dry-rolled barley, corn, or a blend of barley and corn grain on rumen fermentation, total tract digestibility, and nitrogen balance for finishing beef heifers.

Five ruminally cannulated heifers were used in an incomplete 6 × 6 Latin square design to determine the effects of cereal silage (barley vs. corn), cereal grain (barley vs. corn vs. a 50:50 blend of barley and corn), and their interaction (S × G) on dry matter intake, ruminal fermentation, total tract digestibility, nitrogen balance, and in situ degradation. Corn silage (CS) or barley silage (BS) was included at 8% of dietary dry matter (DM). Within each silage source, diets contained (DM basis) either dry-rolled barley (BG; 86%), dry-rolled corn (CG; 85%), or an equal blend of barley and corn (BLEND; 85%). Periods were 25 d, with 5 d of dietary transition, 13 d of dietary adaptation, and 7 d of data and sample collection. Samples collected included feed and refusals, total urine and feces, and ruminal fluid. All data were analyzed using the Mixed model of SAS with the fixed effects of silage, grain, and the S × G. Dry matter intake (P ≥ 0.19) and mean ruminal pH (P ≥ 0.096) were not affected by the silage, grain, or S × G. Total short-chain fatty acid concentrations were greater for BLEND than BG or CG (grain, P = 0.003) and for CS (silage, P = 0.009) relative to BS. The molar proportion of acetate was greater for BS-BG and BS-CG (S × G, P < 0.001), while molar proportion of propionate was greater for CS-BG (S × G, P < 0.001) relative to other silage and grain source combinations. Rumen ammonia-N concentration was greater for CG than BG, or BLEND (grain, P < 0.001), and greater for CS compared to BS (silage, P = 0.023). Apparent total tract digestibility of DM, organic matter, neutral detergent fiber, starch, and gross energy were greatest for BG (grain, P ≤ 0.035). Digestible energy content (Mcal/kg) was greater for BG (grain, P = 0.029) than CG and BLEND. Total nitrogen retention (g/d and % of intake) was greatest for CS-BG (S × G, P ≤ 0.033) relative to all other treatments. In situ degradation rates of DM, crude protein, and starch were greater for BG than CG (P ≤ 0.004). The potentially degradable fraction of DM, crude protein, and starch was greater for CG (P ≤ 0.031), while the undegradable fraction was greater for BG (P ≤ 0.046). For silage sources, CS had greater 24 h in situ DM digestibility (P = 0.009) and starch digestibility (24, 48, and 72 h incubations, P ≤ 0.034) relative to BS. Results suggest that while feeding a combination of CS and BG promotes propionate production and greater N retention; few other additive effects were observed.

Use of barley or corn silage when fed with barley, corn, or a blend of barley and corn on growth performance, nutrient utilization, and carcass characteristics of finishing beef cattle.

The objective of this study was to evaluate the effects of the source of silage, cereal grain, and their interaction on growth performance, digestibility, and carcass characteristics of finishing beef cattle. Using a completely randomized design within an 89-d finishing study, 288 steers were randomly assigned to 1 of 24 pens (12 steers/pen) with average steer body weight (BW) within a pen of 464 kg ± 1.7 kg (mean ± SD). Diets were arranged in a 2 × 3 factorial with corn silage (CS) or barley silage (BS) included at 8% (dry matter [DM] basis). Within each silage source, diets contained dry-rolled barley grain (BG; 86% of DM), dry-rolled corn grain (CG; 85% of DM), or an equal blend of BG and CG (BCG; 85% of DM). Total tract digestibility of nutrients was estimated from fecal samples using near-infrared spectroscopy. Data were analyzed with pen as the experimental unit using the Mixed Model of SAS with the fixed effects of silage, grain, and the two-way interaction. Carcass and fecal kernel data were analyzed using GLIMMIX utilizing the same model. There were no interactions detected between silage and grain source. Feeding CG increased (P < 0.01) DM intake by 0.8 and 0.6 kg/d relative to BG and BCG, respectively. Gain-to-feed ratio was greater (P = 0.04) for BG (0.172 kg/kg) than CG (0.162 kg/kg) but did not differ from BCG (0.165 kg/kg). Furthermore, average daily gain (2.07 kg/d) and final body weight did not differ among treatments (P ≥ 0.25). Hot carcass weight (HCW) was 6.2 kg greater (372.2 vs. 366.0 kg; P < 0.01) and dressing percentage was 0.57 percentage units greater (59.53 vs. 58.96 %; P = 0.04) for steers fed CS than BS, respectively. There was no effect of dietary treatment on the severity of liver abscesses (P ≥ 0.20) with 72.0% of carcasses having clear livers, 24.4% with minor liver abscesses, and 3.6% with severe liver abscesses. Digestibility of DM, organic matter, crude protein, neutral detergent fiber, and starch were greater for BG (P < 0.01) than CG or BCG. As expected, grain source affected the appearance of grain kernels in the feces (P ≤ 0.04). Feeding CS silage increased the appearance of fractured corn kernels (P = 0.04), while feeding BS increased fiber appearance in the feces (P = 0.02). Current results indicate that when dry rolled, feeding BG resulted in improved performance and digestibility compared with CG and BCG. Even at low inclusion levels (8% of DM), CS resulted in improved carcass characteristics relative to BS.

343 Feedlot performance and carcass characteristics of steers fed diets containing steam-flaked grain and corn silage from Enogen® Feed Corn

Abstract Enogen Feed Corn (EFC; Syngenta Seeds, LLC) is genetically modified to express high concentrations of amylase. Our objective was to evaluate EFC as corn silage and as steam-flaked corn in diets fed to finishing cattle. A 2 x 2 factorial experiment was conducted with steers (n = 960; 388 ± 7.4 kg initial body weight), with factors consisting of silage source (Control or EFC) and grain source (Control or Enogen). Steers were blocked by initial body weight, assigned randomly within block to treatments, housed in 48 pens with 15 or 25 cattle per pen, and harvested after 138, 152, or 166 days on feed. Grains were steam flaked to densities of 360 or 386 g/L for Control and EFC, respectively. Diets (dry basis) consisted of 8% corn silage, 2% alfalfa hay, 74.5% flaked corn, 12% Sweet Bran, and supplement. Incidences of liver abscesses and carcass weights were recorded at harvest, and longissimus muscle area, 12th-rib subcutaneous fat thickness, marbling score, and USDA yield and quality grades were determined after 36 h of refrigeration. There were no interactions between grain source and silage source (P &gt; 0.05) for feedlot performance. Cattle fed diets containing EFC silage consumed less dry matter (P &lt; 0.01) and efficiency of gain was improved by approximately 5.3% (P &lt; 0.01) compared to cattle fed Control silage. Average daily gain and dry matter intake were unaffected by grain source, but cattle fed EFC grain were less efficient (P = 0.02) compared to cattle fed control grain. Carcass weight was greater for cattle fed the combination of EFC silage and Control grain compared to other treatments (P &lt; 0.05), but liver abscess incidence and other carcass measurements were unaffected by grain or silage source. Feeding Enogen Feed Corn as corn silage, but not as grain, improved feedlot performance of steers. Keywords: Enogen, corn silage, amylase

Short communication: Lysine retained among 2 lipid-coated lysine products after exposure to alfalfa or corn silage with different amounts of acidity

We conducted 2 experiments to determine lysine loss from 2 lipid-coated lysine products after mixing with silage. In our first experiment, we mixed 2 lipid-coated lysine products, crystalline lysine or crystalline lysine and amounts of lipid identical to amounts included in lipid-coated lysine products, with alfalfa or corn silage that had 2 different amounts of acidity. Lysine appeared to disassociate from lipid-coated lysine products in a nonlinear manner after mixing with either alfalfa or corn silage at different amounts of acidity. Additionally, silage source and acidity affected amounts of lysine released from lipid-coated lysine products after mixing. In a corresponding experiment, in vitro estimates of lysine available to ruminal microbiota after mixing with alfalfa or corn silage at different amounts of acidity were measured by ammonia release. In vitro measures were conducted with or without monensin to allow estimates of effects of monensin on amounts of lysine released from the 2 lipid-coated lysine products. It is unclear whether in vitro estimates of lysine fermentation from lipid-coated lysine are truly reflective of ruminal degradation of lysine from lipid-coated lysine because amounts of time needed to measure differences between different lysine sources were greater than typical estimates of mean ruminal particulate retention time. Nonetheless, monensin apparently reduced ammonia release from lysine, but ammonia release from lipid-coated lysine did not differ from crystalline lysine. Clearly, methods of manufacture together with physical and chemical characteristics of diet can affect amounts of lysine provided from lipid-coated lysine products to ruminants.

Effect of harvesting time on forage yield and quality of maize

Maize is the very important silage source in the world. Timely harvesting ensure high maize forage yield and quality. Therefore, the study focused on the effects of four harvesting times (starting at the 12 August every 7 days) on yield and qualitative parameters of forage green mass of maize hybrid ZP 677. The experiment was set in Vojvodina Province, Serbia, during the 2013 and 2014 growing seasons. Plant height, stem diameter, number of leaves per plant, ear percentage, forage yield, dry matter content and crude protein content were higher, while stem percentage was lower in 2014 with favorable climatic condition. Forage yield, crude protein content, ADF and NDF decreased, while dry matter content significantly increased with delay in harvesting. The maize hybrid should be harvested when the milk line is three-quarter of the way down the grain that is in the third decade of August.

Effects of dietary combination of corn and rice as whole crop silage and grain sources on carbohydrate digestion and nitrogen use in steers

Four Holstein steers were used to evaluate the combination effects of whole crop corn (Cs) or rice (Rs) silage with steam-flaked corn (Cg) or rice (Rg) grain (four dietary treatments) on ruminal carbohydrate digestion, duodenal nitrogen (N) flow and plasma essential amino acid (EAA) concentration. The ruminal digestibility of starch and nonfiber carbohydrate (NFC) for Rs and Rg diets compared with Cs and Cg diets was greater, but that of neutral detergent fiber (aNDFom) was less. Because the ruminal disappearance of NFC plus aNDFom was similar across four dietary treatments, microbial N flow was not affected by the diets. There was an interaction of methionine (Met) flow by silage and grain sources: greatest for CsRg and least for RsRg diet, and blood plasma concentration of Met after feeding was lower for Rg than Cg diets. Postprandial reduction degree of plasma EAA varied with the diets and individual EAA. The Cs diets compared with the Rs diets tended to be greater in N retention because of greater digestible organic matter (OM) intake. These results suggest that silage source combined with corn or rice grain affects N use in steers through the digestible OM intake, and the kinds of limiting AA may differ among the combination of silage and grain sources.

Replacing alfalfa or red clover silage with birdsfoot trefoil silage in total mixed rations increases production of lactating dairy cows1

The objective of this study was to compare milk production and nutrient utilization in dairy cattle fed silage made from alfalfa (AL) or red clover (RC) versus birdsfoot trefoil (BFT) selected for low, normal, and high levels of condensed tannins. Condensed tannin contents of the 3 BFT silages were 8, 12, and 16g/kg of DM by butanol-HCl assay. Twenty-five multiparous Holstein cows (5 fitted with ruminal cannulas) were blocked by days in milk and randomly assigned within blocks to incomplete 5×5 Latin squares. Diets contained [dry matter (DM) basis] about 60% AL, 50% RC, or 60% of 1 of the 3 BFT; the balance of dietary DM was largely from high-moisture corn plus supplemental crude protein from soybean meal. Diets were balanced to approximately 17% crude protein and fed for four 3-wk periods; 2wk were allowed for adaptation and production data were collected during the last week of each period. No differences existed in DM intake or milk composition due to silage source, except that milk protein content was lowest for RC. Yields of milk, energy-corrected milk, fat, protein, lactose, and solids-not-fat were greater for the 3 BFT diets than for diets containing AL or RC. Feeding BFT with the highest condensed tannin content increased yield of milk, protein, and solids-not-fat compared with BFT containing the lowest amount of condensed tannin. Moreover, milk-N/N-intake was higher, and milk urea nitrogen concentration and urinary urea-N excretion were lower for diets with normal levels of BFT than for AL or RC diets. Feeding RC resulted in the highest apparent digestibility of DM, organic matter, neutral detergent fiber, acid detergent fiber, and hemicellulose and lowest ruminal concentrations of ammonia and free amino acids. Ruminal branched-chain volatile fatty acid levels were lowest for RC diets and diets with high levels of BFT and highest for the AL diet. Overall, diets containing BFT silage supported greater production than diets containing silage from AL or RC. The results indicated that feeding BFT or other legume silages containing condensed tannins can enhance performance and N utilization in lactating dairy cows.

Ammonia and Greenhouse Gas Flux from Manure in Freestall Barn with Dairy Cows on Precision Fed Rations

Two lactating cow trials were conducted to evaluate the impact of diets differing in silage source (alfalfa/maize vs. grass/maize or maize/hay) and maize grain particle size (fine vs. coarse) on ammonia (NH3), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions from a freestall barn floor with two groups of 60 cows each. In addition, the effects of environment (temperature, humidity) and management (manure depth, time since manure removal) factors were evaluated. Manure (feces and urine), spilled feed, bedding, and spilled drinking water were allowed to collect on the solid concrete, sloped barn alleys and were scraped twice a day. Gas fluxes from the freestall floor were measured at 64 locations over a 12 h period using a fast-response, non-steady-state flux chamber and an infrared photoacoustic gas analyzer during 18 trial days over a 9-month period. Fluxes of ammonia from manure on the barn floor were within average reported values for these 165 g kg-1 crude protein diets. All gas fluxes were similar (p = 0.253 to 0.977) regardless of silage source and maize grain particle size. The highest average ammonia emissions coincided with higher environmental temperature at 30 NH3 g AU-1 d-1, while the highest average greenhouse gas emissions from the manure on the floor were 10 g AU-1 d-1 for CH4 and 580 g AU-1 d-1 for CO2. Time in hours since scraping the floor had little impact on the production of ammonia, but greenhouse gas loss from the barn floor was reduced after scraping. Air and manure temperatures were positively correlated with emissions of NH3, CO2, and CH4 (p = <0.0001). NH3 (g AU-1 d-1) = (R2 = 0.38) for indoor air temperatures (Tair, C) over the range from -5C to 32C (AU = 500 kg animal unit). Ammonia emissions were positively correlated with CO2 and CH4 gas emissions, suggesting that NH3 release from the manure was controlled to some extent by microbial activity and similar environmental factors. Nitrous oxide emissions remained <0.1 g AU-1 d-1 and were relatively constant for all diets and trials.

Effects of Essential Oils on Digestion, Ruminal Fermentation, Rumen Microbial Populations, Milk Production, and Milk Composition in Dairy Cows Fed Alfalfa Silage or Corn Silage

Four Holstein cows fitted with ruminal cannulas were used in a 4×4 Latin square design (28-d periods) with a 2×2 factorial arrangement of treatments to investigate the effects of addition of a specific mixture of essential oil compounds (MEO; 0 vs. 750mg/d) and silage source [alfalfa silage (AS) vs. corn silage (CS)] on digestion, ruminal fermentation, rumen microbial populations, milk production, and milk composition. Total mixed rations containing either AS or CS as the sole forage source were balanced to be isocaloric and isonitrogenous. In general, no interactions between MEO addition and silage source were observed. Except for ruminal pH and milk lactose content, which were increased by MEO supplementation, no changes attributable to the administration of MEO were observed for feed intake, nutrient digestibility, end-products of ruminal fermentation, microbial counts, and milk performance. Dry matter intake and milk production were not affected by replacing AS with CS in the diet. However, cows fed CS-based diets produced milk with lower fat and higher protein and urea N concentrations than cows fed AS-based diets. Replacing AS with CS increased the concentration of NH3-N and reduced the acetate-to-propionate ratio in ruminal fluid. Total viable bacteria, cellulolytic bacteria, and protozoa were not influenced by MEO supplementation, but the total viable bacteria count was higher with CS- than with AS-based diets. The apparent digestibility of crude protein did not differ between the AS and CS treatments, but digestibilities of neutral detergent fiber and acid detergent fiber were lower when cows were fed CS-based diets than when they were fed AS-based diets. Duodenal bacterial N flow, estimated using urinary purine derivatives and the amount of N retained, increased in cows fed CS-based diets compared with those fed AS-based diets. Feeding cows AS increased the milk fat contents of cis-9, trans-11 18:2 (conjugated linoleic acid) and 18:3 (n-3 fatty acid) compared with feeding cows CS. Results from this study showed limited effects of MEO supplementation on nutrient utilization, ruminal fermentation, and milk performance when cows were fed diets containing either AS or CS as the sole forage source.

Desempenho de bezerros de corte alimentados com diferentes fontes protéicas associadas à silagem de sorgo colhida em duas alturas de corte

Foram avaliadas três fontes protéicas (uréia - U, farinha penas - Fp e farelo soja - Fs) associadas a duas silagens de sorgo (silagens de sorgo corte alto - SCA e corte baixo - SCB) por intermédio do desempenho de bezerros de corte, confinados por 84 dias. Foram utilizados 36 bezerros mestiços (Charolês/RedAngus/Nelore), castrados, com cinco meses de idade e pesando em média 146,44 kg. Avaliaram-se o ganho de peso médio diário (GMD); o consumo de matéria seca expressos em kg/dia (CMS), percentagem de peso vivo (CMSPV) e peso metabólico (CMSPM); e a conversão alimentar (CA). O delineamento foi inteiramente casualizado por intermédio de um fatorial 3x2. Houve efeito significativo na interação silagem versus fonte protéica para a variável GMD, com o maior GMD para SCAFp (1,61 kg/animal/dia) versus a SCBFs (1,32 kg/animal/dia). Os demais parâmetros não diferiram estatisticamente quando analisada a interação ou isoladamente a silagem ou fonte protéica. A silagem de sorgo corte alto promoveu numericamente um maior GMD e CMS.