Corn Silage Dry Matter Research Articles

128 Bromoform metabolites from Asparagopsis taxiformis: Formation and impact on in vitro rumen fermentation parameters and microbial composition dynamics

Abstract The aim of the experiment was to study the formation and impact of bromoform metabolites from Asparagopsis taxiformis on in vitro rumen fermentation parameters and microbial composition over time. Rumen fluid from three rumen fistulated lactating Holstein-Friesian dairy cows was collected and after buffering used as inoculum. Cows were fed a total mixed ration of grass silage, corn silage and concentrate. In total 0.5 g dry matter (DM) of substrate was incubated, consisting of either 0.3 g DM grass silage and 0.2 g DM corn silage (Control) or 0.295 g DM grass silage, 0.195 g DM corn silage and 0.01 g DM A. taxiformis (ASP). Substrates were incubated for 72 h. Total gas production (TGP) was measured continuously and methane (CH4) at 0, 1, 2, 4, 8, 12, 24, 36, 48, 60 and 72 h. After 72 h, volatile fatty acids (VFA), ammonia (NH3), and pH were determined. Substrates (Table 1) and contents of additional bottles at specific timepoints were analyzed for bromoform (CHBr3), dibromomethane (CH2Br2), bromomethane (CH3Br), dibromochloromethane (CHBr2Cl), arsenic (As), bromine (Br) and iodine (I). RNA was isolated and sequenced with specific primers for bacteria, archaea and protozoa. Data were averaged per inoculum and analyzed with an ANOVA to test for differences between treatments. Preliminary results revealed no difference between Control and ASP in TGP (mL/g organic matter; OM) after 72 h (P = 0.102), whereas CH4 (mL/g OM) was 78% less in ASP than in Control (P = 0.005). Total VFA (tVFA) did not differ between Control and ASP (P = 0.435). Acetate (% tVFA) was lower in ASP (49.2 vs 56.6; P = 0.011), and branched VFA (% tVFA) greater in ASP than in Control (5.8 vs 3.8; P = 0.001). At 72 h, NH3 (mg/L) and pH did not differ between ASP and Control (P = 0.183 and 0.519, respectively). After 1 h of incubation CHBr3 concentration was 118 ng/mL, rapidly decreasing below detection limit by 8 h of incubation. At 1 h of incubation CH2Br2 concentration was 22 ng/mL, reaching 40 ng/mL at 4 h of incubation and remained relatively stable thereafter. At any timepoint, CH3Br concentration was below detection limit. At 12 h of incubation CHBr2Cl concentration was 3.7 ng/mL and remained relatively stable. Mineral concentrations (As, I, Br) were constant throughout incubation. Addition of 2% DM A. taxiformis effectively reduced CH4 production without negative effects on TGP and tVFA in vitro. While CHBr3 disappeared quickly and CH2Br2 concentration increased, substantial formation of CH3Br in hydrogenation reactions by methanogens seemed absent. Levels of Br did not change, suggesting no substantial Br vaporization through secondary metabolites. Microbial composition data are pending analyses and will be presented at the symposium.

Effects of Grape Pomace on Growth Performance, Nitrogen Metabolism, Antioxidants, and Microbial Diversity in Angus Bulls.

Polyphenol-rich grape pomace (GP) represents a valuable processing by-product with considerable potential as sustainable livestock feed. This study aimed to investigate the effects of different levels of GP on the growth performance and nitrogen utilization efficiency, antioxidant activity, and rumen and rectum microbiota of Angus bulls. Thirty Angus bulls were allocated three dietary treatments according to a completely randomized design: 0% (G0), 10% (G10), and 20% (G20) corn silage dry matter replaced with dried GP dry matter. The results showed that the average daily gain (ADG) of the G0 group and G10 group was higher than that of the G20 group (p < 0.05); urinary nitrogen levels decreased linearly with the addition of GP (linear, p < 0.05). In terms of antioxidants, the levels of catalase (CAT) in the G10 group were higher than in the G0 and G20 groups (p < 0.05), and the total antioxidative capacity (T-AOC) was significantly higher than that in the G20 group (p < 0.05). In addition, in the analysis of a microbial network diagram, the G10 group had better microbial community complexity and stability. Overall, these findings offer valuable insights into the potential benefits of incorporating GP into the diet of ruminants.

Effects of the types of sealing on chemical-fermentation characteristics of corn silage from the feed out face of trench silos

The objective of this study was to evaluate the efficiency of different types of sealing on the physical losses of dry matter, chemical and fermentation characteristics and in situ digestibility of the dry matter of corn silage stored in the feed out face (ramp) of trench silos. The experimental design used randomized blocks, composed of three treatments, namely: T1 - corn silage preserved with double-sided polyethylene of 110 μm thickness (conventional seal); T2 - corn silage preserved with double-sided polyethylene of 200 μm thickness (double-sided); and T3 - corn silage preserved with oxygen-impermeable film composed of double-sided polyethylene of 80 μm thickness on a translucent vacuum polyamide film of 20 μm thickness (double sealing), with four repetitions each. The use of double-sided polyethylene with 200 μm thickness (double-sided) and oxygen impermeable film composed of double-sided polyethylene and polyamide (double sealing), were effective in preserving the chemical composition, fermentation profile, raw protein composition and fiber quality, in addition, the use of these polymers resulted in greater ruminal digestibility of dry matter and reduced the pH, temperature, temperature gradient and physical losses of corn silage from the feed out face (ramp) of trench silos compared to the conventional sealing.

6 Feed intake variability and performance implications of adjusting for dry matter content of cattle feedlot feed ingredients exposed to the elements

Abstract Objectives of this study were: 1) validate on-farm dry matter (DM) testing methods, and 2) determine how as-fed dietary composition adjustment to respond to DM content changes affected performance. One-hundred fifty-one crossbred steers (n = 85; 404 kg initial BW) and heifers (n = 66; 384 kg initial BW) were allocated randomly (4 to 6 hd/pen), within truck load and sex, to one of two 15-pen rows in a deep-bedded confinement barn. Treatments included control (n = 15 pens), where diets were only modified to account for changes in ingredient DM every 28 d or adjusted (ADJ; n = 15 pens), in which diets were modified daily to account for changes in ingredient DM. Target composition of diets was (DM basis) hay (3.73%), corn silage (CS; 8.28%), high moisture corn (HMC; 50.86%), dry distillers grains with solubles (DDGS; 11.83%), dry rolled corn (DRC; 20.07%), and a liquid supplement (5.23%). Cattle were fed for 84 d. Dry matter content of hay was determined daily using a microwave oven and that of CS and HMC were determined using a forced-air dryer every other day upon removal from bunker silos; these methods were validated against DM determination using a forced-air oven set at 105 °C. Hay or corn silage DM measured indirectly was similar (P &amp;gt; 0.10) to that measured using a forced-air oven at 105 °C. Adjusting as-fed dietary composition daily to compensate for changes in ingredient DM had no effect on DMI, ADG, feed conversion or final BW. Within-pen feed delivery residual variance tended to be greater (P = 0.06) for pens managed under ADJ. Within-pen and between-treatment residual DMI variance was not different (P &amp;gt; 0.10). Under the conditions of this study, exposure to the elements did not precipitate in large changes in diet DM composition or content. This resulted in similar performance response whether dietary as-fed composition was adjusted or not.

Soybean oil modulates the fatty acid synthesis in the mammary gland, improving nutritional quality of the goat milk

Abstract The objective of this study was to evaluate the productive performance, macro compounds and fatty acid (FA) profile of goats’ milk receiving diets supplemented with three amounts of soybean oil. Additionally, we tested to which extent lactating goats can positively respond to the influence of the soybean oil supplementation. Our hypothesis is that the FA profile in the milk will change with the increasing doses of soybean oil, i.e., the healthy FAs concentrations will increase and the concentration of harmful FAs will reduce. Eight primiparous Saanen goats weighing 39 ± 3.5 kg, with approximately 35 days of lactation and daily production of 1.8 ± 0.30 kg were evaluated. The experimental design was arranged as a double Latin Square 4 × 4. Goats were allocated in individual tie-stall pens and submitted to the following diets: control = 400 g/kg of dry matter (DM) of corn silage and 600 g/kg DM of concentrate without oil addition; 15 = 400 g/kg DM of corn silage and 585 g/kg DM of concentrate with addition of 15 g of soybean oil/kg of the diet’s DM; 30 = 400 g/kg DM of corn silage and 570 g/kg DM of concentrate with addition of 30 g of soybean oil/kg of the diet’s DM; 45 = 400 g/kg DM of corn silage and 555 g/kg DM of concentrate with addition of 45 g of soybean oil/kg of the diet’s DM. The soybean oil intake reduced daily milk production in all diets, except for diet 30. Production efficiency was not influenced by the diets. When compared to control, diet 45 resulted in an increase in the concentration of fat (29.1 %), lactose (4.9 %), total solids (10.4 %) and non-fat solids (5.7 %) in the milk, although it did not provide protein increase. Diet 45, when compared to the control, reduced the concentration of C8:0 and C10:0 FA by more than 60 %. Diet 45 also reduced by more than 26 % the total concentration of saturated FA (C12:0, C14:0, C15:0, C16:0 and C18:0), especially those with atherogenic properties such as C12:0 (97 %), C14:0 (40 %) and C16:0 (33 %). In addition, the inclusion of soybean oil increased the concentration of those FA that are beneficial to health, such as C18:1 cis-9, C18:2 cis-9, cis-12, C18:3 cis-9, cis-12, cis-15, C18:2 trans-10, cis-12 (antiobesity factor), C18:1 trans-11 (precursor for endogenous synthesis of rumenic acid), omega-3, unsaturated: saturated and PUFA: saturated ratios. The results corroborated our hypothesis that the healthy FAs concentrations increase and the concentration of harmful FAs will reduce with increasing oils doses in goats’ diet, in doses as high as 4.5 %. As far as we know, this is the first study that includes three concentrations of oil supplemented in the feed (accessing in more details the progressive changes in the FA milk profile) and that used a concentration as high as 4.5 % of oil.

Hepatic metabolomics and transcriptomics to study susceptibility to ketosis in response to prepartal nutritional management

BackgroundKetosis in dairy cows is associated with body fat mobilization during the peripartal period. Sub-clinical and clinical ketosis arise more frequently in cows that are overfed energy during the entire dry (last 50 to 45 days prior to parturition) or close-up period (last ~ 28 days prepartum).MethodsA retrospective analysis was performed on 12 cows from a larger cohort that were fed a higher-energy diet [1.54 Mcal/kg of dry matter (DM); 35.9% of DM corn silage and 13% of DM ground corn] during the close-up dry period, of which 6 did not develop clinical ketosis (OVE, 0.83 mmol/L plasma hydroxybutyrate; BHB) and 6 were diagnosed with clinical ketosis (KET, 1.4 mmol/L BHB) during the first week postpartum. A whole-transcriptome bovine microarray (Agilent Technologies) and metabolomics (GC-MS, LC-MS; Metabolon® Inc.) were used to perform transcript and metabolite profiling of liver tissue harvested at − 10 days relative to parturition which allowed to establish potential associations between prepartal transcriptome/metabolome profiles and susceptibility to clinical ketosis postpartum.ResultsCows in KET had greater (P = 0.01) overall body weight between − 2 and 1 week around parturition, but similar body condition score than OVE. Although dry matter intake (DMI) did not differ prepartum, KET cows had lower (P < 0.01) DMI and similar milk yield as OVE cows during the first week postpartum. Transcriptome analysis revealed a total of 3065 differentially expressed genes (DEG; P ≤ 0.05) in KET. Metabolomics identified 15 out of 313 total biochemical compounds significantly affected (P ≤ 0.10) in KET. Among those, greater concentrations (P ≤ 0.06, + 2.3-fold) of glycochenodeoxycholate in KET cows also have been detected in humans developing non-alcoholic fatty liver disease. Bioinformatics analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database and the DEG revealed that, among the top 20 most-impacted metabolic pathway categories in KET, 65% were overall downregulated. Those included ‘Metabolism of cofactors and vitamins’, ‘Biosynthesis of other secondary metabolites’, ‘Lipid’, ‘Carbohydrate’, and ‘Glycan biosynthesis and metabolism’. The lower relative concentration of glucose-6-phosphate and marked downregulation of fructose-1,6-bisphosphatase 2 and pyruvate dehydrogenase kinase 4 support a strong impairment in gluconeogenesis in prepartal liver of cows developing KET postpartum. Among the top 20 most-impacted non-metabolic pathways, 85% were downregulated. Pathways such as ‘mTOR signalling’ and ‘Insulin signalling’ were among those. ‘Ribosome’, ‘Nucleotide excision repair’, and ‘Adherens junctions’ were the only upregulated pathways in cows with KET.ConclusionsThe combined data analyses revealed more extensive alterations of the prepartal liver transcriptome than metabolome in cows overfed energy and developing ketosis postpartum. The causative link between these tissue-level adaptations and onset of clinical ketosis needs to be studied further.

The effect of corn silage quality on usage for digestion and balance of the body of sheep (first message)

The article presents the results of studies on the effect of corn silage conditions on its quality, eating and digestion in the body of sheep. It is established that the ratio of individual particles of corn weight depends on the degree of ripeness of the corn mass. In the case of maize waxy degree of ripeness, the weight of stems, on average, is 27.30%, which is 5.41% more than when maize waxy degree of ripeness is used. The volume of foliage in the first version of the experiment was at the level of 40.5%, which is 1.19 times more than when using corn waxy ripeness of grain. At the same time, the weight of the grain in the silage was 1.31 times less than when it is used for silage corn of milky-wax degree of ripeness. It has been proved that increasing of the size of grinding corn with milk-waxy ripeness of grain to 2.0 - 3.0 cm and under conditions of reducing the parameters of silage weight consolidation from 400 to 600 kg / m3 is accompanied by the accumulation of oil acid from 0.13 to 3.40%. With the use of corn waxy degree of ripeness of the grain and grinding it from 2.0 to 3.0 cm and the seal from 400 to 600 kg / m3, the content of butyric acid in the silo ranged from 0.02 to 0.18%. Carotene content of corn silage of milky-waxy degree of ripeness of grain, grinding from 1.0 to 2.0 cm was 1, 68, 1.77, 1.65, 1, 46 and 2.75 times more than in corn silage of waxy ripeness of grain (p ≤ 0,01 - 0,001). The digestibility of organic and dry matter of corn silage in the body of sheep was quite high. The most significant differences we found in digestion of crude protein, namely the increase of this figure 36.24 ± 1.04% in animals of the first group to 47.26 ± 2.24% in sheep of the second group and to 44.66 ± 1.86 % in animals of the third group under conditions of feeding of silage from corn of milk – wax degree of ripeness of grain. In animals fed corn silage with a waxy degree of ripeness of grain, the digestibility of crude protein was 9.29%, 19.89% and 2.01% less than in those who fed corn silage with milky – waxy degree of ripeness of grain. In the future, these studies will allow the effective use of corn silage of milky - waxy degree of ripeness of grain in feeding sheep.

Silage yield, organic carbon content and physical attributes of a chiseled Ferralsol under an integrated crop-livestock system

The aim of this study was to evaluate the physical attributes and the silage production of a soil submitted to chiseling under an integrated crop-livestock system (ICLS) for nine years. The experiment was performed with clayey Ferralsol with three treatments (no-tillage, no-tillage with chiseling every other year, and conventional tillage) and three blocks. Corn was grown for silage in the summer, and ryegrass for pasture in the winter. The sampled soil layers each year were: 0.00-0.05 m; 0.05-0.10 m; 0.10-0.20 m; and 0.20-0.30 m, in order to determine total organic carbon, particle density, texture, porosity, bulk density and resistance to penetration. Compaction was evaluated by the relative density and the structure by the structural index. Dry matter corn silage yield and ryegrass forage were determined. Chiseling did not provide higher silage yield compared to other treatments. However, chiseling provided improvements in the physical attributes of the Ferralsol conducted over nine years on ICLS with the physical attributes of the soil detected 12 months after chiseling management.

Impact of corn silage moisture at harvest on performance of growing steers with supplemental rumen undegradable protein, finishing steer performance, and nutrient digestibility by lambs.

Three experiments evaluated delaying corn silage harvest, silage concentration, and source of supplemental protein on performance and nutrient digestibility in growing and finishing diets. Experiment 1 used 180 crossbred yearling steers (body weight [BW] = 428; SD = 39 kg) to evaluate corn silage dry matter (DM) (37% or 43%) and replacing corn with silage (15% or 45% of diet DM) in finishing diets containing 40% modified distillers grains with solubles. Experiment 2 used 60 crossbred steers (BW = 271; SD = 32 kg) to evaluate corn silage harvest DM (37% or 43%) and response to rumen undegradable protein (RUP) supplementation (0.5%, 1.4%, 2.4%, 3.3%, or 4.2% of diet DM) in silage growing diets. Experiment 3 used 9 crossbred lambs (BW = 30.1; SD = 4.1 kg) to evaluate nutrient digestibility of 37% or 43% DM corn silage in silage growing diets fed ad libitum or restricted to 1.5% of BW. In experiment 1, as corn silage concentration increased from 15% to 45%, average daily gain (ADG) and gain-to-feed ratio (G:F) decreased (P ≤ 0.04). Carcass-adjusted final BW and hot carcass weight (HCW) were lower (P ≤ 0.04) for steers fed 45% corn silage compared to 15% when fed for equal days. As DM of corn silage was increased from 37% to 43%, no differences (P ≥ 0.30) in dry matter intake (DMI), ADG, G:F, or HCW were observed. In experiment 2, as DM of corn silage increased from 37% to 43%, ADG and G:F decreased (P ≤ 0.04). Increasing supplemental RUP in the diet increased (P ≤ 0.05) ending BW, DMI, ADG, and G:F linearly as supplemental RUP increased from 0.5% to 4.2%. In experiment 3, there were no differences (P ≥ 0.56) in DM digestibility and organic matter digestibility between silage harvest DM and intake level. Neutral detergent fiber (NDF) intake was reduced (P < 0.01) for lambs fed the delayed harvest corn silage compared to earlier corn silage harvest. As silage harvest was delayed from 37% to 43% DM, NDF digestibility decreased (P < 0.01) from 64.39% to 53.41%. Although increasing corn silage concentration in place of corn in finishing diets reduced ADG and G:F, delayed silage harvest did not affect performance of finishing cattle. Delayed silage harvest in growing cattle resulted in lower ADG and G:F, possibly due to increased starch or maturity leading to decreased NDF digestibility. The addition of RUP to silage-based, growing diets improves performance by supplying more metabolizable protein and suggests RUP of corn silage is limiting.

Cactus [Opuntia stricta (Haw.) Haw] cladodes and corn silage: How do we maximize the performance of lactating dairy cows reared in semiarid regions?

This study aimed to investigate the effect of replacing corn silage with cactus Opuntia stricta (Haw.) Haw. cladodes (cactus Opuntia) (0, 18.5, 37.0, and 55.5%, on a DM basis) in the diets for lactating dairy cows. Twelve Holstein cows (20 ± 2.7 kg/day milk, 530 ± 35 kg of body weight, 84 days in milk) were distributed in three (4 × 4) Latin squares. There was an increase in the intake of dry matter (DM), organic matter (OM), non-fiber carbohydrate (NFC) and net energy for lactation (NEl) with the replacement (17.68 to 18.58; 16.38 to 16.91; 5.32 to 7.28; 25.1 to 27.01 kg/day, respectively). The intake of crude protein (CP; 2.80 kg/day) and the digestibility of DM, OM, CP, NFC and neutral detergent fiber (NDF) were not changed by the replacement (623.4; 642.4; 641.6; 519.6; 763 g/kg DM, respectively). The milk yield and fat-corrected milk yield (FCMY) to 3.5% fat increased linearly with the replacement (20.8 to 22.1; 21.4 to 23.3 kg/day, respectively). The fat, protein, lactose, and total solids milk content remained unaltered (37.6; 31.6; 45.1; 124.4 g/kg, respectively). There was a linear decrease in the urea nitrogen excretion in urine (298 to 221.4 mg/kg BW) and the urea nitrogen concentration in milk (16.8–13.04 mg/dL). We recommend a diet composed of 366.0 g/kg DM of cactus Opuntia 290.0 g/kg DM of corn silage and 344.0 g/kg DM of concentrate.

Inclusion of brown midrib dwarf pearl millet silage in the diet of lactating dairy cows

Brown midrib brachytic dwarf pearl millet (Pennisetum glaucum) forage harvested at the flag leaf visible stage and subsequently ensiled was investigated as a partial replacement of corn silage in the diet of high-producing dairy cows. Seventeen lactating Holstein cows were fed 2 diets in a crossover design experiment with 2 periods of 28 d each. Both diets had forage:concentrate ratios of 60:40. The control diet (CSD) was based on corn silage and alfalfa haylage, and in the treatment diet, 20% of the corn silage dry matter (corresponding to 10% of the dietary dry matter) was replaced with pearl millet silage (PMD). The effects of partial substitution of corn silage with pearl millet silage on dry matter intake, milk yield, milk components, fatty acid profile, apparent total-tract digestibility of nutrients, N utilization, and enteric methane emissions were analyzed. The pearl millet silage was higher in crude protein and neutral detergent fiber and lower in lignin and starch than the corn silage. Diet did not affect dry matter intake or energy-corrected milk yield, which averaged 46.7 ± 1.92 kg/d. The PMD treatment tended to increase milk fat concentration, had no effect on milk fat yield, and increased milk urea N. Concentrations and yields of milk protein and lactose were not affected by diet. Apparent total-tract digestibility of dry matter decreased from 66.5% in CSD to 64.5% in PMD. Similarly, organic matter and crude protein digestibility was decreased by PMD, whereas neutral- and acid-detergent fiber digestibility was increased. Total milk trans fatty acid concentration was decreased by PMD, with a particular decrease in trans-10 18:1. Urinary urea and fecal N excretion increased with PMD compared with CSD. Milk N efficiency decreased with PMD. Carbon dioxide emission was not different between the diets, but PMD increased enteric methane emission from 396 to 454 g/d and increased methane yield and intensity. Substituting corn silage with brown midrib dwarf pearl millet silage at 10% of the diet dry matter supported high milk production in dairy cows. When planning on farm forage production strategies, brown midrib dwarf pearl millet should be considered as a viable fiber source.

Evaluation of blood metabolites in dairy cows grazing under two pasture allowances and supplemented with corn silage under restricted grazing conditions

This study was conducted to evaluate the influence of management tools - daily pasture allowance and corn silage supplementation - during periods of forage shortage on the metabolism of dairy cows grazing low-mass pasture in temperate regions. Forty lactating Holstein cows were used during an experimental period of seventy days (April 15 to June 23, 2012). Blood metabolites and milk production were determined in fall-calving dairy cows grazing under two daily pasture allowances (PA) (moderate, 17 kg vs. high, 25 kg dry matter (DM)) and supplemented with corn silage (CS) (low, 4.5 kg vs. high, 9.0 kg DM). All cows received 3 kg DM of concentrate. Plasma concentrations of β-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFA), and urea were determined using an automated spectrophotometer, and milk production was electronically measured at each milking time during the trial. The experimental design was completely randomized using a 2 × 2 factorial arrangement of treatments. The increase in daily PA decreased plasma concentrations of BHBA (0.91±0.36 vs. 1.12±0.43 mmol L−1), provided an increase in milk yield (23.18±3.26 vs. 21.99±3.37 kg d−1), and did not modify the concentrations of NEFA and urea. The increased CS supplementation increased mildly the plasma concentrations of BHBA (1.07±0.36 vs. 0.96±0.44 mmol L−1) and NEFA (92.77±54.14 vs. 92.77±55.31 µmol L−1), and decreased the concentrations of urea (4.08±1.40 vs. 4.64±1.30 mmol L−1), but did not change milk production. The positive effect of increasing PA was associated with a high herbage intake, while the lack of response to increasing CS supplementation was attributed to a high substitution of pasture intake (0.9 kg DM pasture/kg DM CS). Low corn silage supplementation is recommended.

Harvester Modifications to Alter Composition and Dry Matter of Corn-Silage

Two common variants to conventional whole-plant corn silage (WP) are high-cut silage (HC) and snaplage (SNPL) which are harvested to alter DM content, fiber, and starch contents compared to WP silage. A conventional ear-snapper (ES) header is used to harvest SNPL which creates a low-fiber, starch-rich feed. However, the plant fractions in SNPL can dry quickly, creating issues with digestibility, palatability, fermentation, and aerobic stability. Stalk cut-off knives were added to the ES header to harvest more leaves and upper stalk to increase SNPL fiber content, yield and moisture. The DM content, yield and nutrient composition of the resulting material, referred to here as “toplage” (TPL), was between that of HC and SNPL. TPL yield averaged 72% to 77% of WP yield. Compared to HC or WP silages, TPL starch concentration was greater but the concentrations of fiber and lignin were less. To offset the loss in yield with harvesting only TPL, the biomass remaining after TPL was then harvested as a high-fiber roughage feed, referred to here as “stalklage” (STKL). STKL was either direct harvested or windrowed and then wilted to greater DM content before final harvest. The combination of TPL followed by STKL resulted in total yield 3% to 8% less than achieved with conventional WP silage. Windrowing increased STKL yield by collecting more leaves that had been dropped during TPL harvest compared to direct cutting, resulting in STKL with greater protein and lower fiber content. STKL had similar or better nutrient composition than reported values for corn stover harvested after grain harvest. Both TPL and STKL fermented well in mini-silos across a wide range of DM contents. The stalk cut-off knives are simple to adapt to the ES header, and by altering the number of knives, producers can easily change corn silage yield, DM content, and nutrient composition, offering an alternative to conventional SNPL or WP silages.

Use of fibrolytic enzymes additives to enhance in vitro ruminal fermentation of corn silage

Two experiments were conducted to evaluate the effect of four enzyme additives on ruminal fermentation of corn silage using a 48h batch culture in vitro assay with buffer and ruminal fluid. Experiment 1 (Exp. 1) and Experiment 2 (Exp. 2) were conducted as completely randomized designs each with two runs and four replicates. The enzyme additives (E1, E2, E3, and E4) were commercial products that provided a range in endoglucanase, exoglucanase, and xylanase activities. For both xylanase (birch wood and oat spelt substrate) and endoglucanase (carboxymethylcellulose substrate), the enzyme products (per ml) were ranked E4>E1>E2>E3. In Exp. 1, the four enzymes were added at 0, 2, 4, and 8μl/g of corn silage dry matter (DM), whereas in Exp. 2 enzymes were added at 0, 0.5, 1, 2, and 4μl/gDM. Gas production (GP) was measured at 3, 6, 12, 18, 24, and 48h after incubation. Disappearance of DM (DMD), neutral detergent fiber (NDFD), and acid detergent fiber (ADFD), and volatile fatty acid concentrations (VFA; total and individual molar proportions) were determined after 24 and 48h. In Exp. 1, E1 and E2 had higher NDFD and ADFD at 24 and 48h of incubation (P<0.001) compared with E3 and E4. Increasing dose rate increased NDFD and ADFD for all enzymes (except ADFD for E4 at 48h), with the optimum dose rate dependant on the enzyme additive (dose×enzyme; P<0.01). There were some treatment effects on DMD and total GP at 24 and 48h, but these responses were not consistent with responses in NDFD and ADFD. Experiment 2 was conducted to confirm the effects and optimum dose rate of each enzyme additive. In Exp. 2, DMD was not affected by enzyme after 24 and 48h incubation. There were no enzyme×dose interactions for DMD, NDFD, or ADFD after 24 or 48h of incubation (except for ADFD at 48h). After 24h, DMD, NDFD, and ADFD increased linearly with increasing dose (P<0.05); after 48h DMD increased linearly, whereas NDFD increased quadratically with increasing enzyme dose (P<0.05). The ADFD increased linearly after 48h for E3 and E4, but after 48h ADFD increased quadratically for E1 and E2. Total GP was consistently lowest for E4 at both incubation times (P<0.05). There were no enzyme×dose interactions (P>0.05) for any of the fermentation variables at either 24 or 48h of incubation in Exp. 2. There were differences amongst the additives for total VFA at 24 and 48h (P≤0.05); increasing enzyme dose decreased total VFA after 24h but increased total VFA at 48h, such that all doses were higher than the control (P<0.001). Overall, the enzyme additives increased NDFD and ADFD of corn silage in vitro; however, E1 and E2 were more effective than E3 or E4. Responses to increasing dose of enzyme were generally linear or curvilinear, and the optimum dose rate differed amongst the products evaluated. Evaluation of the enzymes at 24 and 48h generally led to the same ranking of the additives, and the degradation of NDF and ADF was more useful in differentiating the enzymes compared with DM and total GP.

Effect of vitamin E on milk composition of grazing dairy cows supplemented with microencapsulated conjugated linoleic acid

The objective of this study was to evaluate the effect of vitamin E on the fat content and fatty acid profile of grazing dairy cows supplemented with microencapsulated conjugated linoleic acid. Eight New Zealand Holstein cows in a rotational grazing system were used, in a crossover design, randomly assigned to four treatments: control (base diet with microencapsulated conjugated linoleic acid) and three levels of vitamin E (control with 4,000; 8,000; and 12,000IU/cow per day). All the cows received a supplement apportioning 5g of cis-9, trans-11, and 5g of trans-10, cis-12 of conjugated linoleic acid. Moreover, they each received 4-kg dry matter (DM) concentrate and 3.2-kg DM corn silage every day. There were no differences in dry matter intake, milk production, milk composition (fat, protein, and lactose), or fatty acid profile as an effect of vitamin E, and fat content remained under 3% in all treatments. Therefore, under the conditions that this experiment was carried out, high concentrations of vitamin E in the diet of grazing dairy cows do not inhibit milk fat depression associated with conjugated linoleic acid. It also has no effect on the fatty acid profile of the milk.

Effects of homo-fermentative bacterial inoculants on fermentation characteristics and nutritive value of low dry matter corn silage

Summary This study was conducted to evaluate the effects of inoculation of homo-fermentative lactic acid bacteria (LAB) on ensiling characteristics and nutritive value of low dry matter corn silage (LDMCS). Corn forage was harvested at milk stage (22.8 ± 0.9% DM), chopped at theoretical length of cut (TLC) 2.5 cm, and stored in eighteen 3.8 L mini silos for each treatment. The following treatments were used, 1) control (uninoculated), 2) ecosyl (treated with ecosyl TM corn silage inoculants containing Lactobacillus plantarum), and 3) biotal (treated with biotal TM corn silage inoculants containing Lactobacillus plantarum, Pediococcus pentosaceus and Propionibacter freudenreichii). Triplicate silos for each treatment were opened and sampled for chemical analyses after 3, 6, 12, 16, 21 and 90 days of ensiling. Neither ecosyl nor biotal improved fermentation characteristics of LDMCS compared to the control silage. Neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), water soluble carbohydrate (WSC) contents and lactic acid (LA) concentration were not affected significantly by inoculants (P>0.05). Acetic acid concentration of control silages was higher; however, ethanol concentration was lower than the other silages. Biotal treated silages had the highest ammonia-N (NH3-N) concentrations compared to the control (P<0.05). In vitro dry matter disappearance (IVDMD) of control silage was higher than treated silages (P<0.05). In conclusion, the results showed that homo-fermentative LAB inoculants used in this experiment did not improve the fermentation characteristics and nutritive value of LDMCS.

Effects of different lipid levels on protozoa population, microbial protein synthesis and rumen degradability in cattle

Protozoa population, microbial synthesis efficiency and rumen degradability of dry matter and neutral detergent fiber in cattle fed on diets with different lipid rates were evaluated. Nine 16-month- old Nelore young bulls, cannulated in the rumen and duodenum, weighing 232 ± 35 kg, were used in the trial. Experimental design consisted of a 3 x 3 square in triplicate, comprising the following treatments: 2, 4 and 6% lipid in diet. In situ degradability was assessed by rumen incubation of corn silage, soybean, soybean meal and citrus pulp during 0, 3, 6, 12, 24, 48, 72 and 96h. The flow of microbial nitrogen and microbial efficiency were not influenced (p > 0.05) by the inclusion of lipid levels in the diet. When the animals received diet with 4% lipid, there was a reduction (p < 0.05) in the potential and effective degradation of dry matter of corn silage (64.10 and 55.04%, respectively), soybean meal (94.55 and 60.83%, respectively) and soybeans (98.45 and 76.44%, respectively). Since the degradability of neutral detergent fiber was not affected, 4 and 6% lipid levels in the diet may be used without altering the parameters of rumen degradation of fiber.

Evaluation of catfish oil as a feedstuff for lactating Holstein cows

The objective of this study was to evaluate catfish oil (CFO) as a dietary ingredient for lactating Holstein cows. Twelve multiparous Holstein cows (6 fitted with a rumen cannula and 6 noncannulated cows), arranged in a 3×3 Latin square design replicated 4 times, were used to evaluate CFO as a dietary ingredient for lactating Holstein cows. Each period lasted 27 d with the last 13 d used for data collection. Dietary treatments were 0, 1.5, and 3% CFO (dry matter basis). Orally dosing with chromium oxide powder was used as an external inert marker for calculation of apparent dry matter and nutrient digestion coefficients. Ruminal fluid was collected hourly for 8h after feeding to measure pH and volatile fatty acids. Intake of dry matter increased as intake of CFO increased (23.0, 24.4, and 25.4kg/d). Production of milk was unchanged by the feeding of CFO (29.0, 29.0, and 29.4kg/d). Concentrations of milk fat (3.57, 3.60, and 3.48%) and protein (3.21, 3.18, and 3.23%) were unchanged by feeding CFO. Concentrations of plasma glucose (57.8, 55.1, and 56.0mg/100mL), urea nitrogen (11.6, 11.0, and 12.0mg/100mL), and insulin (0.55, 0.53, and 0.57ng/mL) were not affected by dietary treatments. Average ruminal fluid pH decreased (6.40, 6.20, and 6.15), as did the molar proportions of acetate (64.5, 64.2, and 63.4%), as dietary concentration of CFO increased. The molar proportions of propionate increased (19.4, 20.0, and 20.4%) as did that of butyrate (12.0, 12.4, and 12.5%) as intake of CFO increased. Ruminal protozoa numbers were unchanged by treatments. Apparent digestibility coefficients of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber were increased by addition of CFO. In situ lag, rate, and extent of corn silage dry matter digestion were not affected by the inclusion of CFO. However, in situ digestion rate of neutral detergent fiber was increased (0.023, 0.024, and 0.029h−1) with increasing intake of CFO. In a second study involving 190 Holstein cows, those fed CFO at 1.8% of dietary dry matter produced 1.2kg more milk/d than those not fed CFO, along with an increase in milk protein concentration. Catfish oil can be a viable lipid source for dairy cows when fed at up to 3% of the dietary dry matter.

Soil Tests for Predicting Corn Response to Nitrogen Fertilizer in New York

The presidedress nitrate test (PSNT) is currently the best tool available for Northeastern producers to determine if corn (Zea mays L.) will benefit from sidedress N. The PSNT requires 0‐ to 30‐cm soil samples, which can be difficult to obtain on stony soils, and samples need to be taken in late‐spring, an inopportune time for dairy (Bos taurus) farmers. Additionally, the in‐season nature of the PSNT prevents its use by producers who apply preplant broadcast N. The Illinois soil N test (ISNT) is a simple test that estimates a potentially mineralizable fraction of soil organic N, amino sugar N. The test was able to identify sites that are nonresponsive to sidedress N fertilization in Illinois. From 2002 to 2004, 33 field trials were conducted to assess the effectiveness of the ISNT as compared with the PSNT in New York. Results confirmed the ability of the PSNT to separate responsive from nonresponsive corn sites. The ISNT was not an effective predictor by itself. However, when ISNT results and soil organic matter (OM) were considered, critical values could be developed that separated fields that were responsive to sidedress N from nonresponsive sites for corn silage dry matter yield, N concentration, N uptake, and estimated milk yield (kg of milk per ha predicted based on yield and quality of the silage). Further evaluation of the ISNT with consideration for OM could improve the accessibility of soil N testing to corn producers who apply N as sidedress as well as those who fertilize with preplant broadcast applications in the Northeast.

Estimating silage energy value and milk yield to rank corn hybrids

This paper provides a revised summative energy equation and applies it to estimate the energy value of corn ( Zea mays) silage. Estimating the energy value of corn silage is important, because energy is the primary nutrient contributed by corn silage to dairy cattle rations. Estimated energy intake from corn silage was used to estimate milk yield from corn silage by dairy cows. The milk yield estimate was used to rank corn hybrids in silage evaluation and breeding programs. The revised (MILK2000) forage quality (milk Mg −1) and yield (milk ha −1) indices were evaluated relative to MILK1995 indices in corn silage hybrid performance trials. A previously published summative energy equation ( Weiss, 1996), with crude protein, fat, non-fiber carbohydrate (NFC), and neutral detergent fiber (NDF) fractions and corresponding digestibility coefficients, was adapted for corn silage as follows: the crude protein and fat fractions were not altered, the NFC fraction with constant digestibility was replaced with starch and non-starch NFC fractions, the starch digestibility coefficient was varied in relationship to whole-plant dry matter (DM) concentration and kernel processing, and the NDF digestibility coefficient based on lignin concentration was replaced by a 48 h or maintenance intake in vitro measurement of NDF digestibility (NDFD). Our summative approach integrates known differences in starch digestibility, as affected by whole-plant DM concentration and kernel processing, and NDFD into estimates of the energy value of corn silage. It also provides a framework for the future incorporation of laboratory measures of starch digestibility into estimates of the energy value of corn silage. For the MILK2000 model, we used our net energy for lactation estimates along with DM intake estimated from NDF concentration and NDFD to estimate milk Mg −1of corn silage DM. Corn hybrid checks characterized by high and low milk Mg −1 were selected on the basis of above average forage yield and either low or high NDF concentration. These low and high NDF check hybrids were then included in 61 trials conducted between 1995 and 2000. The frequency with which low NDF hybrids had greater estimated milk Mg −1 than high NDF hybrids was 0.90–0.93. Both maturity at harvest and NDFD strongly influenced the relative hybrid rankings with MILK2000 versus MILK1995. MILK2000 provides an index for evaluating relative performance among hybrids and could be applied to ranking hybrids tested in performance trials.