High-moisture Alfalfa Hay Research Articles

Impact of Inoculation with Pediococcus pentosaceus in Combination with Chitinase on Bale Core Temperature, Nutrient Composition, Microbial Ecology, and Ruminal Digestion of High-Moisture Alfalfa Hay

This study evaluated the effects of Pediococcus pentosaceus (PP) and chitinase combinations on the conservation and nutritive value of alfalfa high-moisture hay (HMH). P. pentosaceus [1012 colony forming unit/g fresh forage] combined with (g/tonne of fresh forage) 1.5 (PP + LC), 7.5 (PP + MC), or 15.0 (PP + HC) g of LANiHay01 chitinase (Exp. 1) or with LANiHay02 (PP + Fe; 1.5 g), LANiHay01 (PP + Pe; 1.5 g), or Sigma (PP + Si; 55 mg) chitinase/tonne (Exp. 2) were used in 2016. In 2017, PP was applied alone or in combination with LANiHay01 at 1.5 g (PP + LC) or 7.5 g (PP + MC) chitinase/tonne (Exp. 3 and 4). Deionized water and propionic acid (4.0 L/tonne of fresh forage in Exp. 1 and 2 and at 6.0 L/tonne of fresh forage in Exp. 3 and 4) were applied as neutral (CON) and positive control (CON+), respectively. The maximum temperature (r2 = 0.66) and NH3-N concentration (r2 = 0.80) of the HMH were positively related to total microbial populations. PP + MC had lower (p ≤ 0.05) yeast and mold counts than CON in Exp. 3 and 4 while the neutral detergent fiber degradability was greater (p < 0.01) for PP + MC and PP + LC than CON in Exp. 1 and 3, respectively. P. pentosaceus in combination with chitinase has the potential in conserving the nutrient quality of alfalfa HMH.

Effect of sodium lignosulfonate and propionic acid application rate on dry matter losses, nutritional composition, in vitro gas production, and fungal populations of high moisture alfalfa hay mini bales

This study evaluated the effects of application rate (AR) of sodium lignosulfonate (MBL) and propionic acid (PRP) on high moisture alfalfa hay spoilage during storage and its nutritive value. Treatments (TRT; MBL and PRP) were applied at four AR: 0 (CON), 2.5, 5 and 10 g/kg (fresh basis) to alfalfa hay at 68.5 % dry matter (DM), packed into mini bales and stored for 33 d. Data were analyzed as a randomized complete block design (5 blocks) with a 2 TRT × 4 AR factorial arrangement. At d 33, DM losses were decreased by PRP at 5 and 10 g/kg (x¯=0.9), vs. CON (6.92) and MBL (6.63 ± 1.13 %). Visual moldiness (0–10 ranking) and mold counts were also decreased by PRP at 5 (2.4 and 5.30) and 10 g/kg (0 and 2.7) relative to CON (6.0 and 7.13) and MBL (5.85 ± 0.67 and 7.21 ± 0.31 log cfu/fresh g, respectively). Both TRT kept aNDF and ADF concentrations low at 2.5 g/kg AR (464 and 319) and to a greater extent at 10 g/kg (442 and 307), relative to CON (494 ± 8.1 and 333 ± 4.71 g/kg DM, respectively; P<0.001). Both TRT increased apparent in vitro DM digestibility at all AR relative to CON (x¯=543 vs. 501 ± 12.0 g/kg of DM, respectively), but, compared to MBL, PRP also increased the asymptotic maximal gas produced (188.4 vs. 179.7 ± 4.82 mL/g of incubated DM), the rate of gas production (9.46 vs. 8.72 ± 0.45 %/h), and total volatile fatty acids (117.5 vs. 114.8 mM, respectively; P<0.035), due to its greater concentration of nutrients. In conclusion, MBL failed to prevent spoilage of high moisture alfalfa hay while PRP was effective at doses >5 g/kg. However, MBL prevented the increase of aNDF and improved in vitro DM digestibility to the same extent as PRP, possibly due to its strong surfactant properties.

PSIII-11 Effects of Inoculation of Alfalfa Hay with Pediococcus Pentosaceus and α-Amylase on Hay Temperature, Microbial Ecology, Nutrient Composition, and Feed Value

Abstract Haying in the Midwest is challenging, with excessive spring and early summer precipitation followed by unpredictable rain events throughout the growing months, forcing farmers to be innovative and resort to novel haying practices. High moisture haying with lactic acid bacterial (LAB) inoculants allows farmers to harvest earlier with less expenditure. This study examined how inoculating high-moisture alfalfa hay with Pediococcus pentosaceus and α-amylase (Magniva for Hay; Lallemand Animal Nutrition, Milwaukee, WI) affected hay temperature, microbial ecology, nutritional content, and feed value. Alfalfa was harvested at the late flowering stage and allowed to wilt in windrows for two days until the moisture level dropped to 20-25%, at which point half of the field was baled (20 bales) with the inoculant at 1.25 L ton-1, providing 1.0 × 106 cfu g-1 fresh forage of Pediococcus pentosaceus (NCIMB 12675) and 2.5 × 106 units of α-amylase (INOC). Uninoculated alfalfa baled at 15–18% moisture (20 bales) served as control (CON). The hay bales were stored under cover and sampled using a hay corer on days 0, 60, 120, and 180 to evaluate nutrient composition, microbial ecology, and feed value. Dallas Thermochron iButton sensors (Embedded Data Systems, Lawrenceburg, KY) were inserted into the center of hay bales during day 0 sampling (20 sensors per treatment) to measure the temperature every 4 h over 180 days. The core holes were air-tightened with alfalfa hay after installing the iButton sensors. SAS (SAS Institute Inc., 2012) mixed model technique was used to assess repeated measurements with treatment (T), day (D), and T × D effects. CON had greater LAB counts (log10 cfu g-1 DM) than INOC (7.45 vs. 7.11; P = 0.03) during storage. On days 0, 120, and 180 of storage, INOC had lower yeast counts (P &amp;lt; 0.02) than CON (T × D interaction). INOC exhibited higher core temperatures (P &amp;lt; 0.03) than CON on days 14, 21, and 28 of storage, peaking at 46.7°C on day 14. INOC reported lower DM than CON on days 60 and 120 of storage (P &amp;lt; 0.03). INOC had a higher CP concentration (18.0 vs. 16.9; P &amp;lt; 0.0001) than CON throughout storage. On days 60, 120, and 180 of storage, INOC had increased ADICP and NDICP (% DM) concentrations than CON (P &amp;lt; 0.05). Results indicated that inoculation of high moisture alfalfa hay with LAB inoculants is a viable alternative for farmers in the Midwest severely impacted by unpredictable weather events due to global warming. Further studies will provide detailed information on nutrient degradability and utilization for livestock production.

Evaluating the potential of lignosulfonates and chitosans as alfalfa hay preservatives using in vitro techniques.

Our objectives were to compare the antifungal activity of 5 lignosulfonates, and 2 chitosans against fungi isolated from spoiled hay, and assess the effects of an optimized lignosulfonate, chitosan, and propionic acid (PRP) on high-moisture alfalfa hay. In experiment 1, we determined the minimum inhibitory concentration and minimum fungicidal concentration of 4 sodium lignosulfonates, 1 magnesium lignosulfonate, 2 chitosans, and PRP (positive control) against Aspergillus amoenus, Mucor circinelloides, Penicillium solitum, and Debaromyces hansenii at pH 4 and 6. Among sodium lignosulfonates, the one from Sappi Ltd. (NaSP) was the most antifungal at pH 4. However, chitosans had the strongest fungicidal activity with the exception of M. circinelloides at both pH 4 and 6. PRP had more antifungal effects than NaSP and was only better than chitosans for M. circinelloides. In experiment 2, we evaluated the effects of 3 additives (ADV): optimized NaSP (NaSP-O, UMaine), naïve chitosan (ChNv, Sigma-Aldrich), and PRP on high-moisture alfalfa hay. The experimental design was a randomized complete block design replicated 5 times. Treatment design was the factorial combination of 3 ADV× 5 doses (0, 0.25, 0.5, 1, and 2% w/w fresh basis). Additives were added to 35 g of sterile alfalfa hay (71.5 ± 0.23% DM), inoculated with a mixture of previously isolated spoilage fungi (5.8 log cfu/fresh g), and aerobically incubated in vitro for 23 d (25°C). After incubation, DM losses were reduced by doses as low as 0.25% for both NaSP-O and PRP (x¯=1.61) vs. untreated hay (24.0%), partially due to the decrease of mold and yeast counts as their doses increased. Also, hay NH3-N was lower in NaSP-O and PRP, with doses as low as 0.25%, relative to untreated hay (x¯=1.13 vs. 7.80% of N, respectively). Both NaSP-O and PRP increased digestible DM recovery (x¯=69.7) and total volatile fatty acids (x¯=94.3), with doses as low as 0.25%, compared with untreated hay (52.7% and 83.8 mM, respectively). However, ChNv did not decrease mold nor yeast counts (x¯=6.59 and x¯=6.16 log cfu/fresh g, respectively) and did not prevent DM losses relative to untreated hay. Overall, when using an alfalfa hay substrate in vitro, NaSP-O was able to prevent fungal spoilage to a similar extent to PRP. Thus, further studies are warranted to develop NaSP-O as a hay preservative under field conditions.

181 Effect of Application Rate of Sodium Lignosulfonate and Propionic Acid on DM Losses, Nutritional Composition, and Fungal Counts of High Moisture Alfalfa Hay Mini Bales

Abstract Our objective was to evaluate the effects of application rate (AR) of sodium lignosulfonate and propionic acid on high moisture alfalfa hay spoilage during storage. Treatments (TRT) were sodium lignosulfonate (NaL) and Propionic Acid (PRP), which were applied at four AR: 0 (CON), 0.25, 0.5 and 1% (w/w fresh basis) to 20% bloom alfalfa hay (second cut) at 68.5% DM and packed into mini bales (10.3x10.8x13cm; 346kg fresh/m3). The treated bales were stored for 33 days in open-top insulation boxes in a room kept at 22°C. Data were analyzed as a randomized complete block design (5 blocks) with a 2 (TRT) x 4 (AR) factorial arrangement, and differences were declared at P ≤ 0.05. At day 0, no differences were observed for DM (68.5 ± 0.61 %), CP (23.2 ± 0.31% DM), and NDF (42.6 ± 0.66% DM), but NaL had more sugars than PRP (0.99 vs. 0.87 ± 0.66% DM) and PRP at 1% reduced mold counts vs. CON (4.71 vs. 4.97 ± 0.05 log cfu/fresh g). At day 33, DM losses were decreased by PRP at 0.5 and 1% (0.9), relative to CON (6.92) and to NaL (6.63 ± 1.13%). Both TRT decreased NDF at 0.25% (46.3) and furthermore at 1% (44.2) relative to CON (49.4), but overall PRP had lower NDF (45.2) than NaL (47.2± 0.81% DM). No differences were observed for sugars and CP. Visual moldiness (0–10) and mold counts were also decreased by PRP at 0.5% (2.4 and 5.30) and 1% (0 and 2.7) relative to CON (6.0 and 7.13) and NaL (5.85 ± 0.67 and 7.21 ± 0.31 log cfu/fresh g, respectively). In conclusion, NaL failed to prevent spoilage of high moisture hay while PRP was effective at doses &amp;gt;0.5%.

PSXI-12 Effect of application rate of sodium lignosulfonate and propionic acid on in vitro digestibility and gas production kinetics of high moisture alfalfa hay mini bales

Abstract Our objective was to evaluate the effects of application rate (AR) of sodium lignosulfonate and propionic acid on the in vitro fermentation measures of high moisture alfalfa hay. Treatments (TRT) were sodium lignosulfonate (NaL) and Propionic Acid (PRP), which were applied at four AR: 0 (CON), 0.25, 0.5 and 1% (w/w fresh basis) to 20% bloom alfalfa hay (second cut) at 68.5% DM and packed into mini bales (10.3×10.8×13cm; 346 kg fresh/m3). The treated bales were stored for 33 days in open-top insulation boxes in a room kept at 22°C, after which they were dried, ground to 1 mm and incubated in vitro for 48hr with ruminal fluid from two ruminally cannulated Holstein cows in lactation. Gas kinetics were recorded using the Ankom RF Gas Production System. Data were analyzed as a randomized complete block design (5 blocks) with a 2 (TRT) x 4 (AR) factorial arrangement, and differences were declared at P ≤ 0.05. Both TRT increased apparent in vitro DM digestibility (DMD) at all AR relative to CON (54.3 vs 50.1 ± 1.20%, respectively). PRP increased asymptotic maximal (188.4) and rate of gas production (9.46) compared to NaL (179.7 ± 4.82 ml/g of incubated DM and 8.72 ± 0.45%/h, respectively). Total VFA were higher for PRP (117.5) vs NaL (114.8), and for both TRT at 1% relative to CON (118.9 vs. 113.8 ± 1.68mM). Acetate (A) was increased by both TRT at 1% (~73.5) and propionate (P) was increased by PRP at 1% (26.1) relative to CON (69.9 ± 1.10 and 24.2 ± 0.29mM, respectively), but the A:P ratio was higher for NaL at 1% (3.02) vs. CON (2.89 ± 0.04). In conclusion, NaL and PRP at 1% improved the rumen in vitro fermentation measures of high moisture alfalfa hay but PRP did so to a greater extent.

High-moisture alfalfa hay conserved with a mixture ofPediococcus pentosaceusand chitinase has a similar feed value to that conserved at optimal moisture

Two separate experiments were conducted to compare the nutrient digestion and growth performance of beef cattle fed diets containing up to 77% of two conserved alfalfa hays. The two alfalfa hays were baled either at the optimum moisture (8.6%) or at a higher-than optimum moisture (21.4%) with application of a mixture of Pediococcus pentosaceus and chitinase at baling. Digestibility of dry matter, neutral detergent fibre, acid detergent fibre, rumen parameters, and growth performance were similar (P ≥ 0.16) for cattle fed either diet. A combination of P. pentosaceus and chitinase has the potential to preserve high-moisture alfalfa hay.

In vitro screening of technical lignins to determine their potential as hay preservatives

Our objectives were to evaluate technical lignins for their antifungal properties against 3 molds and 1 yeast causing hay spoilage, and their ability to preserve ground high-moisture alfalfa hay nutritive value in vitro. In experiment 1, 8 technical lignins and propionic acid (PRP; positive control) were tested at a dose of 40 mg/mL. The experiment had a randomized complete block design (RCBD, 4 runs) and a factorial arrangement of 3 molds × 10 additives (ADV). The effects of the ADV on yeast were evaluated separately with a RCBD. Sodium lignosulfonate (NaL) and PRP were the only treatments with 100 ± 2.8% inhibition of fungi. In experiment 2, the minimum inhibitory concentration (MIC) for selected lignins and PRP were determined. At pH 4, NaL had the lowest MIC across the molds (20-33.3 mg/mL) and magnesium lignosulfonate (MgL) for the yeast (26.7) among the lignins. However, PRP had MIC values that were several-fold lower across all fungi (1.25-3.33). In experiment 3, a RCBD (5 blocks) with a 3 (ADV; NaL, MgL, and PRP) × 4 (doses: 0, 0.5, 1, and 3% wt/wt fresh basis) factorial arrangement of treatments was used to evaluate the preservative effects of ADV in ground high-moisture alfalfa hay inoculated with a mixture of the fungi previously tested and incubated under aerobic conditions in vitro. After 15 d, relative to untreated hay (14.9), dry matter (DM) losses were lessened by doses as low as 1% for NaL (3.39) and 0.5% for PRP (0.81 ± 0.77%). The mold count was reduced in both NaL at 3% (3.92) and PRP as low as 0.5% (3.94) relative to untreated hay (7.76 ± 0.55 log cfu/fresh g). Consequently, sugars were best preserved by NaL at 3% (10.1) and PRP as low as 0.5% (10.5) versus untreated (7.99 ± 0.283% DM), while keeping neutral detergent fiber values lower in NaL (45.9) and PRP-treated (45.1) hays at the same doses, respectively, relative to untreated (49.7 ± 0.66% DM). Hay DM digestibility was increased by doses as low as 3% for NaL (67.5), 1% MgL (67.0), and 0.5% PRP (68.5) versus untreated hay (61.8 ± 0.77%). The lowest doses increasing neutral detergent fiber digestibility relative to untreated hay (23.3) were 0.5% for MgL and PRP (30.5 and 30.1, respectively) and 1% for NaL (30.7 ± 1.09% DM). Across technical lignins, NaL showed the most promise as a potential hay preservative. However, its effects were limited compared with PRP at equivalent doses. Despite not having an effect on preservation, MgL improved DM digestibility by stimulating neutral detergent fiber digestibility. This study warrants further development of NaL under field conditions.

Impact of Pediococcus pentosaceus and Pichia anomala in combination with chitinase on the preservation of high‐moisture alfalfa hay

AbstractThis study assessed the effects of applying Pediococcus pentosaceus (PED) or Pichia anomala (PIC) in combination with chitinase (CH) on the conservation characteristics and rumen digestibility of large round‐bale high‐moisture alfalfa hay (HMH). Alfalfa was wilted in the field to 23%–27% moisture and baled without (Control) or with PED + CH, PIC + CH and propionic acid (PA). The study was repeated yearly from 2012 to 2014. The PED + CH‐treated HMH had the numerically lowest high degree day (bale internal temperature &gt;30°C) in all 3 years, which was less (p &lt; .05) than Control HMH and PA in 2012. Treatments had no effect on pH, but mixed effects on chemical and microbial compositions across 3 years. The PED + CH treatment had the highest water‐soluble carbohydrate (WSC) content (p &lt; .05) in 2012 and 2014, whereas PA treatment had the lowest (p &lt; .05) WSC in these years. Total bacteria were decreased (p &lt; .001) by PIC + CH and PED + CH in 2012 only. The PED + CH treatment had greater (p &lt; .01) soluble fraction of dry matter (DM) than Control HMH and PA in both 2012 and 2014, but treatments did not affect the potential degradable fraction of DM. The PED + CH and PIC + CH treatments increased (p &lt; .01) in situ neutral detergent fibre digestibility after 6, 24 and 96 hr of ruminal incubation in 2012 but not in 2014. Combinations of P. pentosaceus or P. anomala with chitinase have potential as high‐moisture hay inoculants to reduce microbial spoilage and to increase fibre digestibility.

1341 Application of Pediococcus pentosaceus and chitinase to high moisture alfalfa hay at baling: effects on nutrient digestion and on growth performance of beef cattle

The objective of this study was to assess the effect of applying a Pediococcus pentosaceus and chitinase mixture (PED+CH) at baling on nutrient digestion and on growth performance of beef cattle. Pure alfalfa was harvested and sun-cured to either 23 to 30% (HMH) or 10 to 13% (NMH) moisture. The HMH (Treatment) was baled with application of PED (6.5 × 1011 cfu/tonne)+CH (1.5 g/tonne) and NMH was baled without additives (Control). A crossover experiment (Exp 1) used eight cannulated heifers that were divided into two groups and fed diets containing 77% of control or treated alfalfa hay and 33% concentrate (DM basis). Each period consisted of a 10-d adaption, 2-d for measuring rumen fermentation products and 7-d for measuring total tract digestibility using chromium oxide (Cr2O3) as an indigestible marker. In Exp 2, fifty Angus×Hereford crossed-bred steers (270 ± 1.12 kg) were stratified by BW and allocated randomly to two groups in 10 pens, and fed diets containing 57% (DM basis) of treated or control alfalfa hay for 112 d and DMI, ADG and feed efficiency (FE) were measured. Data were analyzed as a completely randomized design using PROC MIXED procedure of SAS with cattle (Exp 1) or pen (Exp 2) as the statistical unit. Differences among means were identified using LSMEANS with the PDIFF in SAS. Cattle fed both diets had similar (P > 0.05) DM, NDF and ADF digestibility. However, HMH alfalfa treated with PED+CH had lower (P < 0.05) CP digestibility as compared with NMH alfalfa hay. Both groups of cattle had similar rumen pH, VFA and ammonia concentrations and cellulolytic enzyme activity. The two groups of cattle also had similar (P > 0.05) DMI, ADG and FE over the 112-d backgrounding period. The similar rumen fermentation characteristics, nutrient total tract digestibility and growth performance between the 2 groups of cattle indicate that alfalfa HMH preserved with PED+CH exhibited similar ruminal and total tract digestibility and feed value to NMH alfalfa. The PED+CH additive has the potential to conserve high-moisture alfalfa hay so that its nutritive and feeding value is similar to that of sun-dried alfalfa hay.

Effect of Addition of Varying Amounts of Urea on Preservation of High Moisture Alfalfa Hay

Experiments were conducted to evaluate the effects of uniformly adding urea (.8, 1.3, 1.5, and 2.6%) to alfalfa hay at baling (Experiment 1) or on the top surface of bales (1kg per bale or 2.1% of DM) subjected to water and rain damage (Experiment 2). Addition of≥1.3% urea to high moisture alfalfa hay (24 to 26%) effectively lowered bale temperatures, nonenzymatic browning, visible mold, and chitin content from those of high moisture, untreated hay. During 5 mo of storage, ADF and NDF in untreated hay increased considerably, but changes were much less when≥1.3% urea was added. Urea disappeared rapidly from hays, and, by 36 d after harvest, urea was detectable only at the 2.6% addition. Urea-treated hays, fed as 60% of diet, were eaten readily by late lactation cows; differences were not significant among treatments in DMI, milk yield, milk composition, or digestion coefficients of DM, ADF, and NDF. Urea on the top surface of hay subjected to water damage prevented heating and molding observed in untreated hay. Addition of urea to high moisture alfalfa hay resulted in higher nutritional quality through reduced heating, molding, and lower structural carbohydrate content compared with control, high moisture hay.

Effect of Microbial Inoculant on Quality of Alfalfa Hay Baled at High Moisture and Lamb Performance1,2

The effectiveness of a microbial hay inoculant in high moisture alfalfa hay was evaluated. Alfalfa (third cutting) was baled at 72% DM without or with inoculant and at 82% DM without inoculant during yr 1. In yr 2, alfalfa (second cutting) was baled at 75% DM without or with inoculant and at 82% DM without inoculant. Application rate of inoculant was 3.8 L/.98 tonne each year. At this application rate, 90 billion cfu were applied per .98 tonne of forage. Hays were core sampled at 0, 14, 30, and 60 d after baling to determine chemical composition. By d 30, all hays had DM content of 89%. In yr 2, 12 wether lambs were assigned to three treatments in a replicated 3 × 3 Latin square. Treatments were chopped, low moisture hay plus corn; chopped, inoculated high moisture hay plus corn; and chopped, high moisture hay plus corn. All diets contained 63% alfalfa hay, 35% ground corn, and 2% minerals and vitamins. In yr 1, inoculated and low moisture hays were not different in chemical composition but were higher in CP and lower in NDF than high moisture hay. Neither NDF nor CP were different among the three hays in yr 2. Average daily gain was not different on the three diets. The feed to gain ratio was lowest for the inoculated hay, intermediate for the low moisture hay, and highest for the high moisture hay diet. Daily gain and feed to gain ratio were not different for lambs fed the inoculated hay baled at 75% DM compared with lambs fed untreated hay baled at 82% DM.

Hay desiccation and preservation with potassium sorbate, potassium carbonate, sorbic acid and propionic acid

Three experiments were conducted to ascertain the effectiveness of sorbic acid or potassium sorbate in hastening the drying of cut alfalfa, thus decreasing the interval from cutting to baling, and to evaluate the effectiveness of sorbic acid or potassium sorbate compared with dry control or propionic acid as a forage preservative by measuring and comparing storage temperature, dry matter and chemical composition of treated and untreated alfalfa hay before and after storage. Second-harvest alfalfa was cut at the early bud stage, wilted in the field to approximately 30% moisture, and baled with the addition of various treatments. Treatments consisted of wet control 0.25, 0.5, 1, 2 and 4 g potassium sorbate kg −1 dry matter (DM). Addition of potassium sorbate to high-moisture alfalfa hay did not improve preservation when compared with untreated hay, with comparisons based on heating during storage, DM change, and chemical composition of hay obtained from storage. A solution containing 1, 2 or 4 g potassium sorbate kg −1 DM and 4 g potassium carbonate kg −1 DM was sprayed on third-harvest bud-stage alfalfa from a sprayboom mounted on the push-bar of a self-propelled mower conditioner. Forage loss of moisture during drying was monitored at regular intervals, and hay was baled into conventional rectangular bales when moisture reached 30%. Addition of potassium carbonate and potassium sorbate to alfalfa hay at cutting did decrease drying time and improved preservation when compared with untreated hay, with comparisons based on field drying time, heating during storage, DM change and chemical composition of hay obtained from storage. Second-harvest alfalfa was cut at the early-bud stage, wilted in the field to approximately 35% moisture and baled with the addition of various treatments. Treatments consisted of wet control, 5, 10, 15 g sorbic acid kg −1 DM and 15 g propionic acid kg −1 DM. Addition of sorbic acid to alfalfa hay at baling did not improve preservation when compared with untreated hay with comparisons based on heating during storage and DM losses. However, alfalfa hay harvested at 30% and treated with 15 g propionic acid kg −1 DM had interior bale temperatures that followed a similar pattern of dry control.

Preservation of Alfalfa Hay with Propionic Acid

Thirteen trials were conducted to evaluate propionic acid as a preservative for high-moisture alfalfa hay using spray equipment and procedures available to a farmer. An experimental device was also evaluated which injected the preservative into hay in the baling chamber of a rectangular baler. Propionic acid treatment provided a reduction in heating and dry matter loss during the first month of storage with less visible mold in the hay following storage when compared to untreated high-moisture hay. After six months of storage, dry matter loss in high-moisture hay was similar with or without the acid treatment. When compared to untreated dry hay, the treated high-moisture hay had much greater heating and dry matter loss during storage as well as more visible mold, poorer color and greater fiber and fiber bound protein concentrations following storage. Propionic acid injected into bales did not perform as well as spray application because the acid was not dispersed uniformly throughout the bale.

Preservation of Alfalfa Hay with Urea

Urea was evaluated as a preservative for high-moisture alfalfa hay through trials designed to represent a forage producers use of the treatment. A device was developed to meter and distribute granular or powdered urea into hay at baling. When compared to untreated high-moisture hay, urea treatment provided a small reduction in heating during storage with a slight improvement in hay appearance and a reduction in spore numbers on hay following storage. When compared to untreated dry hay, urea treated high-moisture hay had much greater heating and loss during storage with greater fiber and fiber-bound protein contents following storage. The only consistent improvement provided by urea was an increase in crude protein content due to the nitrogen added through urea. The small benefit obtained would not justify the use of urea as a preservative of alfalfa hay.

Nutritive Value of High Moisture Alfalfa Hay Preserved with Urea

Urea (2 and 4%) was added to high moisture hays and compared with untreated wet or dry hays. Means for bale temperatures (°C) for 1 wk postharvest were highest for wet control (41.2), lowest for dry control (31.4), and intermediate for urea treatments (36.7).By 4 wk postharvest, all temperatures were equal. Protection from molding was most effective for 4% urea, and 2% urea was superior to wet control. By 4 mo postharvest, CP for low urea had decreased due to NH3 loss, and CP for wet control had increased due to DM loss, so they were not different. Initially, ADF was similar for the hays, but after 4 mo storage the wet control was highest (41.7%), the dry control lowest (36.0%), and urea treatments intermediate. Lignin and NDF followed similar trends. In vitro DM digestibilities were highest for the wet control at harvest but lowest at 120 d with high urea and dry control greater than low urea. Feed intakes and milk yields in lactating cows fed the hays were not different. These data show that addition of 2 or 4% urea improved quality of hay baled at about 25% moisture; high urea was more effective than low urea.

Anhydrous Ammonia Injection into Baled Forage

AN injection system was mounted on the bale chamber of a rectangular-type baler to inject liquid anhydrous ammonia into baled forage. A high pressure syringe operated with the tractor hydraulic system was used to inject a stream of liquid anhydrous ammonia into the formed bale. This type of ammonia application to high-moisture alfalfa hay (20 to 30% wet basis) reduced storage temperature, increased crude protein and normally improved visual appearance of the hay. When wrapped in plastic, the ammoniated hay had a dry matter less similar to that of dry hay; otherwise, loss was similar to untreated wet hay.

Feeding Dairy Cows High Moisture Alfalfa Hay Preserved with Anhydrous Ammonia1,2

Alfalfa hay was baled either at 32% moisture and treated with 1.87% anhydrous ammonia (dry weight) or at 19.5% moisture and left untreated and fed to dairy cows. Ammonia treatment prevented molding and heating in high moisture hay, improved in vitro cell wall digestion slightly, and increased crude protein content of hay from 18.8 to 23.8%. There were no differences between hay treatments for actual and fat-corrected milk, percentages of milk fat and protein, and dry matter intake. Cows fed untreated or ammoniated hay produced 20.7 and 20.8kg fat-corrected milk per day and consumed 11.7 and 11.4kg hay dry matter daily. Increasing dietary ammonia intake did not influence urinary orotate, but it did elevate concentrations of orotate in milk. This experiment demonstrated that alfalfa hay with 32% moisture can be preserved with anhydrous ammonia and fed to dairy cows with no detrimental effects on cow performance.

Treating High-Moisture Alfalfa with Urea

ABSTRACT HIGH moisture alfalfa hay was treated with feed-grade urea. The urea broke down to ammonia and carbon-dioxide. The released ammonia acted as a pre-servative, and the hay remained free of visible mold and deterioration for over 8 wk. The nutritive value of the hay also increased. Three different moisture levels of alfalfa (30, 40 and 50 percent on wet basis) and three levels of urea (1.75, 3.5 and 5.3 percent of dry matter) were se-lected. Since the urea is non-toxic, its application is sim-ple and free of risk.