Untreated Hay Research Articles

Alternative particleboards based on treated and untreated hay

Agricultural resources have a great potential to be a supplement or replacement for wood, especially in countries lacking wood resources, or during times of economic turmoil of wood markets, for manufacturing panel products. Previous research has focused on various sources including wheat straw, rice straw, rapeseed, or oil palm stems, but so far hay was not considered. Hay consists of cut and dried grasses, legumes, or other herbaceous plants. It has similar structure to wheat straw with a typical waxy surface layer and poor bondability. Soaking in NaOH was employed to improve the bondability of used full-length hay, or hay particles for urea formaldehyde (UF) resin. A comparison of the physical and mechanical properties was assessed. The vertical density profile of hay panels made from treated hay reached smaller differences between surface and core density. Full-length hay panels reached the higher average values of the equilibrium moisture content (EMC), due to the structure. The bending properties of panels made of treated hay particles showed improvement, with modulus of rupture being 3.5 times higher, and modulus of elasticity 2.6 times higher than that of the untreated hay particles. Thickness swelling after 48 hours decreased for the NaOH-pretreated hay panels.

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.

Meta-analysis of the effects of chemical and microbial preservatives on hay spoilage during storage.

A meta-analysis was performed to evaluate the effects of chemical (50 articles) and microbial (21 articles) additives on hay preservation during storage. Multilevel linear mixed-effects models were fit with response variables calculated as predicted differences (Δ) between treated and untreated samples. Chemical preservatives were classified into five groups such as propionic acid (PropA), buffered organic acids (BOA), other organic acids (OOA), urea, and anhydrous ammonia (AA). Moderators of the models included preservative class (PC), forage type (FT; grass, legumes, and mixed hay), moisture concentration (MC), and application rate (AR). Dry matter (DM) loss during storage was affected by PC × FT (P = 0.045), PC × AR (P < 0.001), and PC × MC (P = 0.009), relative to the overall effect of preservatives (-0.37%). DM loss in PropA-treated hay was numerically reduced to a greater extent in grasses (-16.2), followed by mixed hay (-1.76), but it increased (+2.2%) in legume hay. Increasing AR of PropA resulted in decrease in DM loss (slope = -1.34). Application of BOA, OOA, PropA, and AA decreased visual relative moldiness by -22.1, -29.4, -45.5, and -12.2 percentage points, respectively (PC; P < 0.001). Sugars were higher in treated grass hay (+1.9) and lower in treated legume hay (-0.8% of DM) relative to their untreated counterparts (P < 0.001). The application of all preservatives resulted in higher crude protein (CP) than untreated hay, particularly urea (+7.92) and AA (+5.66% of DM), but PropA, OOA, and BOA also increased CP by 2.37, 2.04, and 0.73 percentage points, respectively. Additionally, preservative application overall resulted in higher in vitro DM digestibility (+1.9% of DM) relative to the untreated hay (x¯=58.3%), which increased with higher AR (slope = 1.64) and decreased with higher MC (slope = -0.27). Microbial inoculants had small effects on hay spoilage because the overall DM loss effect size was -0.21%. Relative to untreated (x¯=4.63% DM), grass hay preserved more sugars (+1.47) than legumes (+0.33) when an inoculant was applied. In conclusion, organic acid-based preservatives prevent spoilage of hay during storage, but their effectiveness is affected by FT, MC, and AR. Microbial inoculants had minor effects on preservation that were impaired by increased MC. Moreover, legume hay was less responsive to the effects of preservatives than grass 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.

Effects of Watering/Steaming of Large Square Hay Bales on Particulate Matter Generation

One of the factors strongly influencing air quality in horse stables is the release of airborne particulate matter (APM) from roughage. This study examined the effects of a new system of steaming whole hay bales on the release of APM from hay. The hay bales were first watered from above and then placed in a specially constructed box and steamed with water vapor. To determine the effect of steaming the bales on the release of APM <10 μm (PM 10) and <2.5 μm (PM 2.5), samples of untreated and treated (watered and steamed) hay were examined under standardized conditions using a gravimetric particle analyzer (TEOM 1400a). In addition, the moisture content of the samples was measured. The average moisture content of the untreated samples was 13%. After watering/steaming the average moisture content rose to 31%, with a gradient from the surface to the center of the bale. Compared to untreated hay, watering/steaming of whole hay bales showed a nearly 90% decrease in PM 10 and PM 2.5 release and a mean decrease in bacteria and mold content in the hay dry matter (DM) of 49.70% and 34.53%, respectively. However, the quality of the watering/steaming process and hay bale texture has to be considered. Furthermore, an exponential relationship between the moisture content of the hay samples and their PM 10 and PM 2.5 release could be shown. A reduction in PM 10 and PM 2.5 release was determined for a moisture content of up to 25%.

Steam explosion pretreatment for enhancing biogas production of late harvested hay.

Grasslands are often abandoned due to lack of profitability. Extensively cultivating grassland for utilization in a biogas-based biorefinery concept could mend this problem. Efficient bioconversion of this lignocellulosic biomass requires a pretreatment step. In this study the effect of different steam explosion conditions on hay digestibility have been investigated. Increasing severity in the pretreatment induced degradation of the hemicellulose, which at the same time led to the production of inhibitors and formation of pseudo-lignin. Enzymatic hydrolysis showed that the maximum glucose yields were obtained under pretreatment at 220 °C for 15 min, while higher xylose yields were obtained at 175 °C for 10 min. Pretreatment of hay by steam explosion enhanced 15.9% the methane yield in comparison to the untreated hay. Results indicate that hay can be effectively converted to methane after steam explosion pretreatment.

Fibrolytic enzymes and a ferulic acid esterase‐producing bacterial additive applied to alfalfa hay at baling: effects on fibre digestibility, chemical composition and conservation characteristics

AbstractThis study evaluated the effect of two fibrolytic enzyme products, applied at baling, on the chemical composition and digestibility of alfalfa hay. Three replicate bales of alfalfa hay (82% dry matter) were produced with the application of one of five treatments including an untreated control and one of two fibrolytic enzyme products (DYC and ECO), either applied alone or in combination with a ferulic acid esterase‐producing bacterial additive. The enzyme products were applied on the basis of endoglucanase activity. The neutral detergent fibre (NDF) concentration and accumulated temperature after storage of hay produced using DYC‐ or ECO‐based treatments were greater (P &lt; 0·05) than untreated hay, except for hay bales produced using ECO alone. Bales produced using ECO‐based treatments had a greater (P &lt; 0·05) in vitro NDF digestibility compared with untreated bales. The application of fibrolytic enzymes at baling may potentially improve NDF digestibility without negatively affecting chemical composition or increasing aerobic deterioration. However, the effects of fibrolytic enzymes varied depending on the product applied. Combining ferulic acid esterase‐producing bacterial additives with fibrolytic enzymes did not improve the nutritive value of hay after storage.

Production and economic performance of F1-crossbred dairy cattle fed non-conventional protein supplements in Zimbabwe

The effects of supplementing crossbred cows with non-conventional protein sources on dry matter intake, milk yield parameters and economic returns were investigated. Twenty-five lactating F1 Holstein-Mashona crossbreds averaging 115 ± 24 days in milk were used. Five treatments, total mixed ration (TMR), urea-treated maize stover, untreated maize stover, Macroptilium atropurpureum (Siratro) hay and veld hay, were randomly assigned to cows and replicated five times in a completely randomised design. Nutrient composition, intake, milk yield and economic returns were determined. M. atropurpureum hay, urea-treated maize stover and TMR had equal crude protein content. Daily dry matter intake and yield differed significantly among the treatment diets (P < 0.05). Cows on TMR, urea-treated maize stover and M. atropurpureum consumed more (P < 0.05) than cows on untreated maize stover and veld hay. Supplementing with TMR, urea-treated maize stover and M. atropurpureum hay increased (P < 0.05) milk yields. Mean daily milk yield was highest for cows supplemented with urea-treated maize stover. Percent fat, protein and total solids in milk from cows fed urea-treated stover compared favourably to that of milk for cows supplemented with TMR. Income over supplement cost was highest for cows supplemented with M. atropurpureum hay and urea-treated maize stover. Urea-treated maize stover and M. atropurpureum can therefore be used as a replacer protein supplements for dairy cattle in Zimbabwe.

Enzimas exógenas fibrolíticas afectan la composición química, consumo voluntario y digestibilidad de nutrientes de heno de pasto guinea {Panicum maximum Jacq.

Se realizaron dos experimentos para determinar el efecto de la aplicación de enzimas exógenas de tipo fibrolíticas sobre la composición química, consumo voluntario (CV), digestibilidad de varias fracciones químicas y degradabilidad de la materia seca aparente (DIVMSJ y verdadera (DIVMSV) de heno de pasto guinea (HPG) [Panicum maximum Jacq. (= Urochloa maxima (Jacq.) R. Webster)]. Los productos enzimáticos utilizados fueron PromoteNET y BiocellulaseA-20derivados de Trichoderma longibratum y Aspergillus reesei, con potencia principalmente de celulasas y xilanasas. En el primer experimento, nueve carneros cruzados Blackbelly x criollo, de 26.8 kg peso vivo (PV) promedio se usaron en un diseño de Cuadrado Latino 3 x 3 con tres periodos experimentales de 18 días de duración. Los tratamientos consistieron de heno sin aditivo (testigo), heno tratado con Promote NET y heno tratado con BiocellulaseA-20, aplicado por rociada 24 h antes de ofrecerse a los animales. El ofrecimiento diario de heno fue al 4% del PV en base seca (BS). Los tratamientos enzimáticos aumentaron los contenidos de materia seca (MS) y proteína bruta (PB) en el HPG respecto al testigo (P &lt; 0.05); también se observó una tendencia a reducir las concentraciones de fibra detergente neutro (FDN), fibra detergente ácido (FDA) y hemicelulosa, pero la misma no fue significativa (P &gt; 0.05). El CV de MS de los HPG tratados con BiocellulaseA-20 y PromoteNET (1,139 y 938 g/d, respectivamente) superaron al testigo (921 g/d). Los consumos de PB, FDN y FDA de HPG tratado con BiocellulaseA-20 fueron mayores (P &lt; 0.05) que los de HPG sin aditivo o tratado con PromoteNET. El consumo diario de MS como porcentaje del PV fue mayor (P &lt; 0.05) en corderos alimentados con HPG tratado con ambos productos enzimáticos respecto al testigo (4.06% con BiocellulaseA-20, 3.15% con PromoteNET vs. 2.86% con el testigo). La digestibilidad aparente de la MS aumentó (P &lt; 0.05) por 5.89 y 4.24 puntos porcentuales en los henos tratados con BiocellulaseA-20 y PromoteNET respecto al testigo (50.12%). Se observaron aumentos significativos en la digestibilidad de otras fracciones para HPG tratado con BiocellulaseA-20 y PromoteNET (PB, 3.23 y 3.18; FDN, 7.96 y 4.31; FDA, 7.69 y 7.9 unidades porcentuales, respectivamente). La digestibilidad de MS, de PB y de FDA no difirieron (P &gt; 0.05) entre los dos tratamientos enzimáticos, mientras que la digestibilidad de FDN fue mayor para el HPG tratado con BiocellulaseA-20 En el segundo experimento se encontró que las DIVMSA y DIVMSV fueron mayores (P &lt; 0.05) para el HPG tratado con ambas enzimas respecto al testigo (DIVMSA por 2.75 y 2.12 unidades porcentuales para BiocellulaseA-20 y PromoteNET; DIVMSV por 2.42 y 1.73 unidades, respectivamente). Estos resultados indican que la aplicación de complejos enzimáticos fibrolíticos a henos de gramíneas tropicales de baja calidad puede mejorar la calidad nutritiva sustancialmente.

Chemical treatment of post-harvest Marandu grass seed residues with different moisture contents

The objective of this was to evaluate the effect of chemical treatments with urea (3 or 5% DM) and anhydrous ammonia (3% DM) applied to the post-harvest hay residues of Brachiaria brizantha cv. Marandu that contained different moisture contents (15, 25 or 30%). A randomized block design was used with eight treatments and four replications (defined as the bale layers within the hay stacks). The hay treated with 3% anhydrous ammonia and 15% moisture content reduced the levels of neutral detergent fiber (NDF) from 84.3 to 79.1% and increased the in vitro digestibility of the dry matter (DM) from 37.3 to 55.5% compared to the control group. The variation in the moisture content did not significantly alter the action of ammonia, with mean values of 77.6% NDF and 57.3% in vitro digestibility of DM. The hay with 5% urea reduces the NDF content from 84.3 to 79.6% compared to the untreated hay, so the hay moisture content has to be increased to 30% to achieve a greater effect on the DM digestibility, which subsequently increases by 12 percentage units.

Performance and carcass characteristics of beef cattle fed with ammoniated marandugrass hay

This trial was conducted aiming to evaluate the effects of Brachiaria brizantha vegetative seed harvest residues hay treated with anhydrous ammonia (NH3) or urea, and protein sources on the steers performance, and carcass quality. Twenty-four male beef cattle were (12 F1 Nellore X Aberdeen Angus and 12 F1 Nellore X Red Angus), distributed in four treatments, with six replications. Animal crossbreed type and initial body weight were considered blocks. The diets were: Untreated hay supplemented with non-protein nitrogen (UHNPN); untreated hay supplemented with cottonseed meal (UHCM), hay treated with 5% urea (HTU), hay treated with 3% anhydrous ammonia (HTA) of DM%. Diets were formulated to be isoproteic and isoenergetic. The initial body weight (kg), daily DM intake (kg), and percentage of body weight (% BW) did not differ among treatments, and the average values observed were 422.6 kg, 10.24 kg, and 2.16% BW, respectively. Animals fed with HTA showed better daily weight gain, feed efficiency, 1.336 kg/day, and 7.78 kg/kg of weight gain, followed by the UHCM, 1.161 kg/day, and 8.98 kg/kg, respectively. Animals of the HTA showed highest NDF, ADF and cellulose intake. Carcass fat thickness was highest on the HTA animals, 6.3 mm.

Leaf tissues degradation of signalgrass hay pretreated with urea and submitted to in vitro digestion

An experiment using signalgrass hay treated with increasing urea levels (0, 20, 40, and 80 g/kg of dry matter), and submitted to in vitro digestion times (0, 6, 12, 24 or 72 hours) was conducted to evaluate the effects of ammoniation rates and digestion times on leaf blade tissue degradation. A completely randomized design with a 4 × 5 factorial treatment arrangement, with three replicates was used. Data were submitted to multivariate analysis. Urea-treated hay presented smaller proportion of remaining tissues measured in leaf blades cross-sections after in vitro digestion. Tissues more affected by urea treatment degradation were parenchyma bundle sheath and sclerenchyma. The hay treated with 80 g urea/kg DM and in vitro digested for 24 or 72 hours showed smallest proportion of tissues with thick and lignified cell walls such as parenchyma bundle sheath and sclerenchyma. The treatment with urea also reduced the time necessary to tissue degradation. The urea-treated hay in vitro digested for 12 hours, showed the same tissue proportion found in untreated hay submitted to 24 or 72 hours of in vitro digestion. The epidermis and lignified vascular tissue showed the smallest degradation following in vitro digestion. Results indicated that treatment of signalgrass hay with urea contributed to cell wall structure disruption, enhancement of tissues microbial degradation and reduction of the time necessary to digestion.

Ecological characterization of three different phylogenetic groups belonging to the cellulolytic bacterial species Fibrobacter succinogenes in the rumen

ABSTRACTTo study the group‐dependent ecology of Fibrobacter succinogenes in the rumen, real‐time polymerase chain reaction assays for two phylogenetic groups (groups 2 and 3) of F. succinogenes were newly established and applied to rumen samples. Both the assays targeting the bacterial 16S rDNA were sensitive and accurate, showing wide quantifiable ranges (104−109 and 102−109 copies of 16S rDNA) and high recoveries of known amounts of added DNA (96.9 and 98.0%). The quantity of group 1 was confirmed to be numerable by subtracting assay values of groups 2 and 3 from that of F. succinogenes species (groups 1–3). By using the developed assays and the above subtractive calculation, the quantities of all three groups were evaluated in solid and liquid fractions of the rumen content and also on hay stems. In the solid fraction, groups 1 and 2 were abundantly present, compared with group 3 (P &lt; 0.05). On untreated hay stems, group 1 was dominant throughout 48 h. In addition, group 1 showed growth even on the cellulase‐treated hay stems, unlike the other two groups. These results suggest that F. succinogenes group 1 greatly contributes to rumen fiber digestion, even for less degradable materials.

Improving nutritive value of a North African range grass ( Stipa tenacissima): Effect of dung ash and urea treatment on digestion by goats

In arid zones of North Africa, hays formerly harvested from native range forages such as Alfa ( Stipa tenacissima), can provide alternative diets for livestock during periods of forage scarcity. However, they usually constitute low-quality forages. Soaking Alfa hay in alkaline solutions prepared from dung ash, with the addition of urea, was evaluated as a potential economic treatment for improving rumen digestibility. A digestion trial was conducted using 3-year-old male goats to compare digestibility of untreated Alfa hay with a treatment containing a 200 g/L solution of dung ash from dromedary, and 30 g/kg urea. A second experiment was conducted in order to evaluate the effectiveness of dung ash source (dromedary or goat), concentration of dung ash solution (0, 100, 200 or 300 g/L) and urea (0 or 30 g/kg) on in vitro digestibility of Alfa amongst goats. Results of digestion trials showed that treated Alfa hay had higher (P<0.01) digestion coefficients for dry matter (0.483 versus 0.420), organic matter (0.558 versus 0.487), neutral detergent fiber (0.664 versus 0.531) and acid detergent fiber (0.620 versus 0.545) than untreated hay. Crude protein apparent digestibility presented no significant different values (P>0.05) between untreated and treated hay (0.356 versus 0.402). Daily dry matter intake ranged from 40.8 to 46.2 g/kg BW 0.75 for untreated and treated hay, respectively (P<0.05). This resulted in an increase of the daily digestible dry matter intake of about 31% for treated hay as compared with the untreated hay. Results of the second experiment showed that in vitro organic matter digestibility coefficient (IVOMD) raised from 0.271 for untreated hay to 0.499 for Alfa hay treated with a 300 g/L solution of dung ash from goats and with 30 g/kg urea. Dung ash from goats appeared to have a higher effect than those from dromedary. Meanwhile, IVOMD of Alfa hay only treated with 30 g/L urea was intermediary (0.403). It is concluded that treating Alfa hay with a 200 g/L solution of dung ashes and 30 g/kg urea can provide an average quality forage which meets the nutritional maintenance requirements of livestock. The significance of these findings is discussed in relation to feeding management strategies for low-input livestock systems.

Valor nutritivo do feno de braquiária amonizado com uréia ou inoculado com Pleurotus ostreatus

Verificou-se, mediante análises de composição química e ensaio de digestibilidade com ovinos, o efeito dos tratamentos químico (amonização com uréia) e biológico (inoculação com o fungo Pleurotus ostreatus) sobre o valor nutritivo do feno de Brachiaria decumbens. Ambos os tratamentos duraram 42 dias; após esse período, o feno foi seco e moído para fornecimento aos animais. As dietas experimentais foram: feno não tratado (FNT); feno não tratado + uréia (FNT + U); feno inoculado com fungo + uréia (FTB + U); e feno amonizado + feno não tratado (FTQ + FNT). As dietas FNT + U, FTB + U e FTQ + FNT foram isonitrogenadas. Tanto o tratamento químico como o biológico causaram mudanças na composição química do feno. A amonização elevou os teores de proteína bruta (PB) e fibra em detergente ácido (FDA) e reduziu os teores de hemicelulose (HEM) e a proporção de hemicelulose na parede celular (HEM-FDN). Já o tratamento biológico tendeu a aumentar o teor de PB; elevou os teores de FDA, lignina (LIG), a proporção de celulose na parede celular (CEL-FDN) e a proporção de lignina na parede celular (LIG-FDN); e reduziu os teores de fibra em detergente neutro (FDN), HEM e HEM-FDN. Entretanto, diminuiu a digestibilidade da matéria seca (MS), FDN, celulose (CEL) e FDA, mas aumentou o consumo, provavelmente em decorrência do menor teor de FDN e menor tamanho médio de partículas, o que causou maior velocidade de passagem. Os tratamentos biológico e químico são alternativas importantes no incremento do valor nutritivo de materiais lignocelulósicos, todavia, os resultados obtidos neste ensaio não foram satisfatórios.

Avaliação de fontes de amônia para conservação do feno de alfafa (Medicago sativa L.) armazenado com alta umidade

O estudo foi desenvolvido com o objetivo de avaliar duas fontes de amônia (amônia anidra-NH3 ou uréia) para conservação do feno de alfafa (Medicago sativa L.) armazenado com alta umidade. Foram estudados os seguintes tratamentos: A - feno com 12 a 15% de umidade e não-tratado; B - feno com 24 a 27% de umidade e tratado com 1,0% de NH3 na MS; C - feno com 24 a 27% de umidade e tratado com 0,9% de uréia na MS; D - feno com 24 a 27% de umidade e tratado com 1,8% de uréia na MS; E - feno com 34 a 37% de umidade e tratado com 0,9% de uréia na MS; e F - feno com 34 a 37% de umidade e tratado com 1,8% de uréia na MS. Os fenos permaneceram sob lona plástica, hermeticamente fechada, por 60 dias. Foram realizadas amostragens para identificação de fungos nos fenos, aos 0 e 60 dias pós-tratamento, e determinação da composição química, avaliando-se os teores de proteína bruta (PB) e dos constituintes da parede celular. Nas quantidades testadas, somente a NH3 foi eficiente no controle dos fungos. Nos tratamentos com uréia, apesar de haver controle dos gêneros Aspergillus e Penicillium, os demais gêneros presentes foram suficientes para deterioração dos fenos. Merece destaque o gênero Paecilomyces, que apresentou alta incidência em todos os fenos tratados. A quantidade utilizada de NH3 foi insuficiente para promover mudanças significativas na composição química dos fenos, exceto nos teores de PB, que aumentaram com o uso de 1,0% de NH3, quando comparados com o não-tratado.

Airborne microflora in Quebec dairy farms: lack of effect of bacterial hay preservatives.

Pediococcus pentosaceus is a lactic-acid producing bacterium inoculated in hay to prevent hay deterioration. This study sought to verify the effect of this treatment on the barn microenvironment. Air samples were obtained from 19 barns using bacterial hay treatment and from 18 control barns with six-stage Andersen samplers and all-glass impingers. Appropriate culture media were used for the recovery and identification of microorganisms. Endotoxins were measured with chromogenic Limulus amoebocyte lysate assay. Median values (respectively for treated and untreated hay barns) were: 5.28 x 10(5) and 3.84 x 10(5) colony-forming units (CFU)/m3 for total bacteria; 3.18 x 10(6) and 4.5 x 10(6) CFU/m3 for molds; 1.36 x 10(3) and 1.74 x 10(3) endotoxin units/m3 for endotoxin levels; and 1.03 x 10(3) and 3.00 x 10(3) CFU/m3 for Saccharopolyspora rectivirgula. No viable P. pentosaceus were recovered. The presence of S. rectivirgula, the causative agent for farmer's lung, was not influenced by the hay treatment. Since no significant difference was observed in any of the airborne contaminants, this type of hay treatment probably does not protect farmers from the respiratory effect of ambient microbial contaminants.

Bioassay Evaluation of Insecticides on Strawberry Fruit and Foliage, 1997

Abstract Four insecticides were evaluated for efficacy against pest species listed above. A 5-year-old Allstar strawberry planting located at Moreland, OH was utilized for this study. Plots consisted of an 18-ft2 area, with 4 replicates per treatment in a randomized block design. Treatments were applied as foliar spray at the rate of 100 gpa (935 1/ha) on 17 July, using a hand-held constant-pressure CO2 sprayer operating at 45 psi (3.2 kg/cm2) and equipped with a 9505-E-Tee Jet nozzle. Once the foliage dried, 3 leaves and 2 berries were sampled from the middle of each replicate and placed in ventilated 450-ml plastic containers. Five adults of each insect were added to each container. Tarnished plant bugs and spittle bugs utilized in this study were obtained from an untreated hay field. Strawberry sap beetles were obtained from laboratory-reared colonies. The number of dead insects was recorded after 24 hrs. of exposure to the treated fruit and foliage.

Lipid-induced depression of methane production and digestibility in the artificial rumen system (RUSITEC)

An artificial rumen (RUSITEC) equipped with eight fermenters was used to examine the effects of canola oil (CA), cod liver oil (CD) and coconut oil (CO) on methane production, dietary digestibility and rumen microbial populations. The experiment, repeated three times, involved two diets (100% grass hay or a 90%:10% wheat:hay mixture) either untreated (controls) or sprayed with CA, CD or CO (10%, wt/wt) in a 2 × 4 factorial arrangement. Dry matter disappearance and CH4 production were greater (P &lt; 0.05) from untreated concentrate diet than from untreated hay. There were significant interactions (P &lt; 0.05) between diet and lipid type for DM digestion and several of the fermentation parameters. Coconut oil decreased (P &lt; 0.05) DM and neutral detergent fibre disappearance of hay but did not affect digestion of concentrate. All oils, especially CO, depressed (P &lt; 0.05) CH4 production (mmol g−1 digestible DM) and methanogenic populations regardless of diet. Methanogens on CO-treated diets numbered less than 1% of those on CA- and CD-treated diets. Total viable, amylolytic, and cellulolytic bacterial numbers were also substantially reduced (P &lt; 0.05) by CO, but not by CA or CD for both diets. Bacterial colonization and digestion of CO-treated hay was markedly less extensive than that observed on untreated, CA- or CD-treated hay. The molar proportion of propionate produced was increased (P &lt; 0.05) by CA and CD, for the hay diet, but not for the concentrate diet. Coconut oil decreased (P &lt; 0.05) the molar proportion of propionate produced on the hay diet and increased (P &lt; 0.05) it on the concentrate diet. Of the three oils, CO was most inhibitory to CH4 production and depressed fibre digestion. The CA and CD also decreased CH4 production, but did not affect feed digestion in either diet. Consequently, the amount of metabolizable energy of feeds may be increased when diets are supplemented with these oils. Key words: Lipids, methane, digestibility, artificial rumen, bacteria, VFA

Effects of organic solvent extracts from herbage on feeding behavior in goats

The effects of organic solvent extracts from perennial ryegrass (Lolium perenne L. cv. Friend), orchardgrass (Dactylis glomerata L. cv. Akimidori) andLolium ×Festuca hybrid on the hay consumption of goats were measured by simple two-choice feeding assays. Orchardgrass hay treated with methanol extracts (resuspended in water) of perennial ryegrass showed an increased intake by goats compared to untreated hay (P < 0.01). The palatability of hay tended to be slightly decreased by spraying it with pentane extract of perennial ryegrass and orchardgrass. Furthermore, extracts of hybrid with pentane inhibited goats from feeding (P < 0.05). Methanol extract stimulated hay consumption whereas the pentane extracts did not change or reduce intake.