Chop Length Research Articles

Application of Computational Intelligence to Determine the Effect of Different Shear Bar Positions on Chopping Length and Specific Cutting Energy Consumption in the Chopping of Silage Sorghum

ABSTRACTFlail forage harvesting machines are disadvantageous compared to other silage machines because of the uneven length of the chop obtained, the low distribution of the appropriate chopping length in the entire chopped material, and the high energy consumption. This issue is tackled by employing artificial neural networks (ANN), which serve as versatile mathematical instruments capable of capturing data. In this article, six different knife peripheral speeds (KPS) and three different shear bar (SB) positions were tested to determine the combination of KPS and SB positions that increased the proportion of suitable chopping length (CL) for silage and decreased the specific cutting energy consumption (SCEC) among all chopped material. The results have shown that, depending on the increase in KPS, the average CL varied between 165.28, 127.30, 100.24, 83.55, 77.06, and 65.09 mm. Depending on no shear bar (), shear bar positioned parallel to the feed unit (), and shear bar positioned at an angle of 45° to the feed unit () the average CL was determined as 114.73, 99.65, and 94.88 mm, respectively. Depending on the increase in KPS, the SCEC values vary between 0.97, 1.49, 1.89, 2.20, 3.05, and 4.12 kWh t−1. Depending on , , and the SCEC values were determined as 1.64, 3.05, and 2.17 kWh t−1, respectively. The effects of KPS and SB positions on CL and SCEC were statistically very significant (p < 0.001). An ANN model with a 3‐(5‐5)‐1 architecture, utilizing a backpropagation learning algorithm, was developed to forecast SCEC. This model outperformed traditional statistical models and was constructed using data on KPS, SB, and CL. The ANN model exhibited the highest efficiency, outperforming the polynomial models. In this particular ANN model, key metrics such as coefficient of determination (R2), root mean square error (RMSE), and mean error (ε) (0.9970%, 0.0159%, and 3.86% respectively) are significantly positive. This research convincingly demonstrated the efficacy of ANN in accurately predicting SCEC, leveraging data on KPS, SB, and average CL.

Effect of chop length of grass silage harvested at two maturity stages, and of concentrate protein level, on feed intake and milk production in dairy cows

AbstractThis study in dairy cow feeding explored the effects of growth stage and chop length for grass‐clover silage, and of concentrate protein level, including the interactions of these three factors. The experiment was conducted with 48 Norwegian Red cows according to a cyclic change‐over design with four 4‐week experimental periods and eight dietary treatments in a 2 × 2 × 2 factorial arrangement. Round bale silage from a mixed sward of timothy, meadow fescue, and red clover was harvested at two growth stages (H1, H2) and offered to dairy cows either unchopped with median particle length of 152 mm or chopped to 19 mm median particle length before feeding. A low protein (LP) concentrate containing 7% lignosulphonate treated soybean meal (SBM) and a high protein (HP) concentrate containing 12% solvent extracted SBM were compared. Silage was offered ad libitum and supplemented with 8 kg concentrate per day. Silage dry matter intake was 2.0 kg higher for H1 than H2 silage, which supported a higher yield of milk, energy‐corrected milk and the milk constituents, fat, protein, and lactose. All these measures of milk production, as well as feed energy efficiency and N use efficiency, increased when silage was fed chopped rather than unchopped. Lignosulphonate treated SBM spared N in the diet without milk yield reductions. For efficient milk production with high energy and N utilisation, we recommend chopping to 20 mm for timothy, meadow fescue, and clover silages harvested in late stem elongation or in reproductive growth stages.

Development of a chopper with performance optimization for areca nut frond using response surface methodology

The chopper's performance is affected by the moisture content level of the material being chopped and the speed of the machine's rotation. This research aims to develop a chopper for an areca nut frond with performance optimization using RSM. RSM was utilized to assess the effect of areca nut frond moisture content (50.50 – 73.50%, w.b.) and machine rotation speed (1000 – 1600 rpm) on capacity, efficiency, chopping width, chopping length, and fuel consumption reactions. Next, the desirability formula is used to discover the moisture content and the machine rotation speed to maximize capacity and efficiency while minimizing losses. The optimum moisture content of 73.50% and machine rotation speed of 1600 rpm was performed in the highest capacity of 126.46 kg/hr at more increased efficiency (81.1%) and minimum chopping width and length (2.4 mm, 21.51 mm) and lower fuel consumption (0.91 ml). These findings showed that an appropriate machine performance could be completed by utilizing the moisture content of the areca nut frond and the machine's rotation speed.

Effect of Chop Length and Level of Molasses on Chemical Composition of Yellow Corn Stover Silage

This factorial study was carried out from 15/10/2020 to 31/6/2021 to investigate the effect of chop length (CL) and level of molasses (M) added at ensiling on chemical composition of yellow corn stover including leaves and stems. Those materials were chopped into 4 lengths, 5, 10, 15 and 20 mm and molasses was added as a source of soluble carbohydrates at 3 levels, 6, 8 and 10% of dry matter (DM). Urea was added to all samples at 2% to enhance nitrogen content. Samples of ensiled materials were packed in double plastic bags and preserved for 60 days.
 Results revealed that there was a significant (P˂0.01) increase in DM content with increasing CL and level of M, and a significant (P˂0.05) increase in crude protein (CP) content with increasing level of M. Ether extract content was significantly (P˂0.05) decreased with increasing CL but (P˂0.01) increased with increasing level of M. Regarding cell wall components, neutral and acid detergent fibers (NDF, ADF) and cellulose contents were significantly (P˂0.01) decreased in silage samples prepared at fine CL. Lower (P˂0.01) NDF and cellulose contents were associated with those prepared with addition of M at 10%. In general, it was concluded that better results were achieved when samples of yellow corn stover silages including leaves and stems were prepared at 5 mm of chop length and addition of molasses at 10%.

Issues with Tropical and Temperate Ensilage Protein and Amino Acid Feeds Utilization: A Research Note

Alfalfa protein breakdown was to soluble NPN of oligopeptide-N, AA-N, amide-N, amine-N and NH3-N. Acidity (pH) and moisture (Aw) are critical in determining extent of fermentation and changes in composition. Further changes in digestive flows and post-prandial plasma AA are indicators of protein status. Dual-purpose cropping and tree plant cropping was with ensiling management of the undergrowth. On-farm field-drying and probiotic additives are promising. It is suggested acidity with propionic acid and microbial inoculants together with field-drying and chop length are required to optimize profile qualities in silage. It is proposed use of denaturing with acid and dust cropping with a hypothetical PNA-Auxin repressor to plant protease. Further study with field-drying to follow is needed. Feeding HIS, ARG and LEU AA supplement to change GRH and GH profiles could be used to promote LBM in production. Dual-purpose cropping can expand subsistence to mixed farming with expanded livestock products and services and resources. PNA-Auxin and PNA-ARF penetrates the plant shoot tips to deliver a TF mRNA to boost proteins in residual cell tissues. Ensiled % AA-N delivery per os to per duodenum was higher; yet total AA-N flow was higher in the control. It is suggested that “bulk” flow was less but with a “tighter” conversion on TAA. FAA was 145% higher in the ensiled versus the fresh control indicating the ENU with less PFAA supplied. FAA on the ensiled diet is high inferred to be more soluble and escape lower from the rumen. WSC are less supplied in fermented forage with VFA being lower and presenting the question whether WSC should be supplied for energy and also with EFE through breaking down of polymers of lignocellulose. It was surmised, although not known, that higher dilution rate (% hr-1) was true on the fresh diet compared to the ensiled although end-products may initially detract with feed but that further digestion in the fresh feed may be higher with intake. Plasma AA before and after absorption or feeding are indicators of synthesis and breakdown. No data was available on N status; protein nutrition on neat silage was probably due to net efflux of AA with mobilization before influx with feeding and subsequent insulin action for uptake. Estuarine aquatic plant spp., water hyacinth used in the Philippines and duckweed studies in Australia, and post-harvest treatment with chemical additives and anti-microbial agents to help control potential transfer of diseases. “Greens” as supplements has yet to be established for anti-microbial properties for animal health and welfare. In conclusion, alfalfa silage fed at standard 0.6 cm particle size and wilted led to dramatic changes with AA breakdown, dramatic changes in duodenal AA flows from escape and recapture into microbial cells. Also N status of animals was compromised by lack of adequate “stores”, mobilized, resulting in a net decrease in total plasma AA with insulin-dependent uptake to tissue.

Effects of chop lengths of ramie silage on ruminal fermentation, free amino acid content, and cellulase activity in goats

Twelve Liuyang black goats were selected and divided into three groups in a randomized design and they were provided one of the three treatment diets with different chop lengths of ramie silage [1 cm (RS1), 2 cm (RS2), and 3 cm (RS3)]. The length had no effect on pH or the content of acetic acid, butyric acid, and valeric acid. In contrast, NH<sub>3</sub>–N decreased (P = 0.024) and the ratio of acetate to propionate (P = 0.083) and total volatile fatty acid (TVFA) content (P = 0.087) tended to decrease, and the proportion of propionic acid tended to increase (P = 0.096) with an increase in the chop length of ramie. The increasing lengths of ramie silage decreased the content of total essential amino acids (AA) (P = 0.001), total non-essential AA (P = 0.003), and total AA (P = 0.001), and decreased the concentration of aspartic acid (P = 0.076) in the ruminal fluid. Ramie silage affected xylanase activity (P = 0.043), with greater activity in RS1 than in RS2 and RS3. The recommended chop length of ramie silage is 1 cm because of increasing TVFA, amino acid concentration, and xylanase activity in the ruminal fluid of goats.

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

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

Carbon fiber versus glass fiber reinforcements: A novel, true comparison in thermoplastics

AbstractCarbon fiber and glass fiber are two dominating reinforcements for polymer composites. Fiber‐reinforced thermoplastics are widely used in many applications. It has a higher growth rate than thermoset composites due to ease in processing and recyclability. Glass fiber has been on the market for 80 years and carbon fiber over 50 years. There are hundreds, if not thousands, of research paper to compare the performance of the two fibers and hybrid. All the studies are from commercially available products. In all those cases, these two fibers are non‐comparable. They have different fiber diameter, size and sizing content, chop length and chopping process. Taiwan Glass Industries, Corp. has cordially provided two experimental chopped strands that match the characteristics of chopped carbon fibers. The first one is for nylon reinforcement and the second one is for polypropylene. Now the glass fiber and carbon fiber have the same fiber diameter (7 microns), same size and sizing content (1%), and same chop length (6 mm). Most importantly, they are produced in identical way (off‐line chop). The only difference between two fibers is silane on glass surface. This is the first of this kind of study. It gives a true comparison of two fibers with identical characteristics. As expected, fiber diameter has the biggest influence in mechanical properties among all fiber characteristics. For nylon, the difference between 7 micron and 10 micron glass fiber is small in tensile and flexural strength. It has bigger difference in impact strength. For polypropylene reinforcement, the fiber diameter of standard polypropylene dispersion (PP) glass fiber is 13 microns; almost double that of carbon fiber. Seven‐micron PP glass actually outperforms PP carbon fiber in composite strengths.

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

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

Effects of Chopping Length and Additive on the Fermentation Quality and Aerobic Stability in Silage of Leymus chinensis

The objective of this experiment was to evaluate the effects of the chopping length and additive on the fermentation characteristics and aerobic stability in silage of Leymus chinensis. L. chinensis was chopped to 1–2 cm and 4–5 cm, and immediately ensiled with the three treatments, i.e., 2% sucrose (fresh weight basis; SU), 1 × 105 cfu/g Lactobacillus plantarum (LP) or 1 × 105 cfu/g LP plus 2% sucrose (SU+LP). Silage treated with distilled water served as the control. After silage processing for 30 and 90 d, the fermentation quality of L. chinensis silage was evaluated. The composition of the fermentation products and the pH value in the silage were determined at 1, 3, 5 and 7 d after opening the silo. The results showed that in L. chinensis silage there was a lower pH value, higher lactic acid content and better aerobic stability at the 1–2 cm length than those at the 4–5 cm (p &lt; 0.001). When the chopping length was 4–5 cm, the addition of either LP or SU+LP increased the content of lactic acid and acetic acid, and decreased the pH value and butyric acid content, compared to those of the control and SU treatment (p &lt; 0.001). Furthermore, combination treatment of SU+LP performed better than LP alone, and the aerobic stability time of L. chinensis silage at 4–5 cm without any additives was the worst. In conclusion, enhanced fermentation quality and aerobic stability can be obtained by processing L. chinensis silage with the shorter length. When the L. chinensis is cut longer, e.g., 4–5 cm in this study, LP or SU+LP could be used as an effective method to improve the fermentation quality and aerobic stability of L. chinensis silage.

Effect of diet-induced negative energy balance on the feeding behavior of dairy cows

The objective of this study was to determine how feeding behavior of dairy cows is altered in response to diet-induced negative energy balance, and if this response varies depending on dietary particle size distribution. Multiparous Holstein cows (n = 30; days in milk = 59 ± 5; parity = 2.8 ± 0.19), producing 44.6 ± 1.2 kg/d of milk, were fed (on a dry matter basis) a lactating diet [net energy of lactation (NEL) = 1.66 Mcal/kg; 68% forage, including 1.8% wheat straw] during a 2-wk baseline period. To induce negative energy balance, cows were then exposed for 3 wk to 1 of 2 diets formulated for a 20% reduction in energy available for milk (NEL = 1.58 Mcal/kg; 73% forage, including 17.2% wheat straw). These diets were identical, only varying in straw chop length: (1) long straw diet (LS): straw chopped with a 10.2-cm screen, or (2) short straw diet (SS): straw chopped with a 2.54-cm screen. Cows consumed 25.6 ± 0.26 kg/d during the baseline period. Dry matter intake decreased on the experimental diets; dry matter intake was greater for the SS diet as compared with the LS diet (23.1 vs. 22.5 kg/d; standard error = 0.47). During the baseline period, cow serum nonesterified fatty acids (NEFA) and blood β-hydroxybutyrate averaged 0.27 ± 0.02 and 0.71 ± 0.05 mmol/L, respectively. During the experimental period, NEFA and β-hydroxybutyrate averaged 0.34 and 1.04 mmol/L, respectively, with a peak of NEFA (0.63 ± 0.06 mmol/L) occurring 4 d after dietary change. During baseline, cows produced 42.3 ± 0.33 kg/d of milk; milk yield was decreased for both SS cows and LS cows during the experimental period (SS = 39.0, LS = 37.8 kg/d; standard error = 0.67). On the experimental diets, cows spent more time eating (266.8 vs. 221.8 min/d), had longer meal lengths (46.9 vs. 37.5 min/meal), and consumed fewer meals (7.1 vs. 7.7 meals/d) compared with the baseline period. Within the experimental period, LS cows spent more time eating per day than SS cows (LS = 281.3, SS = 252.2 min/d). During the baseline period cows sorted against long particles (>19 mm), did not sort medium particles (8 to 19 mm), and sorted for short (4 to 8 mm) and fine (<4 mm) particles. Cows did not change sorting of long particles on the SS diet, but increased sorting against these on the LS diet. On the SS diet cows did not change their sorting of short and fine particles. On the LS diet cows increased sorting for short and fine particles. In the baseline period, no association was detected between feed sorting and serum NEFA concentration. During the experimental period, greater NEFA concentration was associated with greater sorting in favor of short particles for both the LS and SS diets. Furthermore, greater NEFA concentration was associated with greater sorting against the longest particles for both the LS and SS diets. No associations of blood and meal variables were detected during the experimental period. Overall, cows altered their feed sorting behavior in response to experiencing a diet-induced period of negative energy balance and the severity of negative energy balance was associated with the extent of that change in feed sorting.

Nutrient content and fermentation characteristics of ensiled Italian ryegrass and winter cereal mixtures for dairy cows

The interest in new alternative forages in Europe has increased in recent years. The nutritional composition and fermentation characteristics during different stages of ensiling were studied with Italian ryegrass (Lolium multiflorum Lam.) and winter cereal mixtures. The trial was carried out on a large-scale farm Galgamenti Agricultural Limited Company, Tura, Hungary. Two different forage mixes were studied: Mixture A (three types of Italian ryegrass 40% + two types of triticale 20%+ two types of oats 20%+ wheat 15%+ barley 5%) and Mixture B (three types of Italian ryegrass 55% + two types of winter oats 45%). Experimental field was 30.600 m 2 by the treatments, respectively. The two different forage mixes were sown on 11th September 2017 (Mixture A: 75 kg seed/ha; Mixture B: 75 kg seed/ha) with depth of 2-5 cm. Plant protection treatment was not applied during the growing season. Cutting was carried out in heading stage of triticale by hand at 10 cm stubble height. The fresh Mixture A (dry matter 189 g/kg; crude protein: 161 g/kg DM; NDF: 485 g/kg DM) and the fresh Mixture B (dry matter 195 g/kg; crude protein: 159 g/kg DM; NDF: 519 g/kg DM) were wilted to 28-32% DM (24h) without any movement on the windrow. The wilted forage was picked up by hand and chopped by a forage harvester (John Deere 7300) on concrete surface with theoretical chop length of 9 mm (weight: 800 kg). Wilted and chopped material of 510 g were packed by hand into a glass jars (0.00072 m3 volume, n=5, total no. of minisilos = 15). Five laboratory silos per mixtures were opened on 7, 14 and 90 days after ensiling. Dry matter (DM), crude protein (CP), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), ether extract (EE), ash, and total sugar of all treatments were determined. Additionally, pH and the concentration of ammonia-N, volatile fatty acids were measured in the ensiled mixtures. At the end of 90 days of ensiling in both mixture silages, there were significant differences (p&amp;lt;0.05) in all nutrient contents except for ADF in Mixture A and CP, ash and CF in Mixture B which was not affected by fermentation duration. Ensiling caused a significant decrease in pH (p&amp;lt;0.05), due to the production of lactic acid and succeeded to achieve lactic acid type fermentation. Values for ammonia-N, ethanol and acetic acid, butyric acid were all low. These results indicated that the fermentation quality of Italian ryegrass and winter cereal silages underwent rapid fermentation and were well-preserved.

Feeding diets varying in forage proportion and particle length to lactating dairy cows: I. Effects on ruminal pH and fermentation, microbial protein synthesis, digestibility, and milk production

Physically effective neutral detergent fiber (peNDF) content of dairy cow diets was modified by varying the theoretical chop length of alfalfa silage and forage:concentrate (F:C) ratio, and effects on nutrient intakes, ruminal fermentation, site and extent of digestion, microbial protein synthesis, and milk production were evaluated. Estimates of dietary peNDF contents were compared with recommendations, and predictions of ruminal pH from peNDF and the recently developed physically adjusted neutral detergent fiber (paNDF) system were compared with observed pH. The experiment was designed as a triple 4 × 4 Latin square using 12 mid-lactating dairy cows with 4 intact, 4 ruminally cannulated, and 4 ruminally and duodenally cannulated cows. Site and extent of digestion and microbial protein synthesis were measured in a single 4 × 4 Latin square. Treatments were a 2 × 2 factorial arrangement; 2 forage particle lengths (FPL) of alfalfa silage (short and long) were combined with low (35:65) and high (60:40) F:C ratios [dry matter (DM) basis]. The peNDF contents were determined by multiplying the proportion (DM basis) of total mixed ration retained on 2 (8 and 19 mm; peNDF8.0) or 3 (1.18, 8, and 19 mm; peNDF1.18) sieves of the Penn State Particle Separator by the neutral detergent fiber content of the diet. The dietary peNDF contents ranged from 10.7 to 17.5% for peNDF8.0 or from 23.1 to 28.2% for peNDF1.18. Interactions between F:C ratio and FPL content were few. Increasing peNDF content of diets by increasing F:C ratio decreased DM intake, milk yield, and milk protein yield, whereas apparent total-tract DM digestibility and milk efficiency improved. Increasing F:C ratio improved ruminal pH status but decreased total volatile fatty acid concentration and microbial protein synthesis. Increasing peNDF content of diets via dietary FPL increased mean ruminal pH, but did not affect DM intake, total-tract digestibility, or milk production. The results indicate that feeding dairy cows a low F:C diet helps increase DM intake, milk production, and microbial protein synthesis, but may adversely affect feed digestibility and milk efficiency due to increased risk of subacute ruminal acidosis. Increased FPL improved ruminal pH status, but had minimal effects on feed intake, ruminal fermentation, nutrient digestibility, and milk production. The results indicate a trade-off between reducing the risk of subacute ruminal acidosis and maximizing ruminal fermentation, feed digestibility, and milk production of dairy cows. The paNDF model showed improvement in the predictability of ruminal pH over the peNDF model, but the accuracy of predictions varied depending upon the diet and ruminal fermentation variables considered in the equations.

Design and Parameter Optimization of Spiral-Dragon Type Straw Chopping Test Rig

In order to address the problems of large chop length, high energy consumption and poor chopping effect that were associated with a horizontal total mixed rations (TMR) mixer, a straw chopping device was designed; further, its structure and working principle were analyzed. In this study, wheat straw was chosen as the test object. The number of processing times, number of fixed blades, cutting speed, number of tooth plates and the inclined angle of the box were considered as the test factors. The standard straw length rate and average power were used as evaluation indices for conducting the orthogonal rotation combination experiment with five factors and five levels of quadratic regression. The experimental results denoted that the order of influencing factors on the standard straw length rate can be given as follows: the number of processing times, number of fixed blades, cutting speed, number of tooth plates and inclined angle of the box. The order of the influence of each factor on the average power can be given as follows: the cutting speed, number of fixed blades and number of tooth plates. Further, the optimum structural and working parameters of the device can be determined as follows: linear cutting speed of 17-20 m/min, box inclined angle of 70°-80°, 20-23 fixed blades, 5-6 processing times and 4-7 tooth plates. Under such a circumstance, the standard straw length rate reached up to 70.5%-77.4% and the average power was low at 5.8-7 kW. The results can be used as reference for designing a chopping device for a TMR mixer. Keywords: total mixed rations, straw, chopping device, parameter optimization DOI: 10.25165/j.ijabe.20201301.4927 Citation: Ma P B, Li L Q, Wen B Q, Xue Y H, Kan Z, Li J B. Design and parameter optimization of spiral-dragon type straw chopping test rig. Int J Agric & Biol Eng, 2020; 13(1): 47–56.

Design and parameter optimization of spiral-dragon type straw chopping test rig

In order to address the problems of large chop length, high energy consumption and poor chopping effect that were associated with a horizontal total mixed rations (TMR) mixer, a straw chopping device was designed; further, its structure and working principle were analyzed. In this study, wheat straw was chosen as the test object. The number of processing times, number of fixed blades, cutting speed, number of tooth plates and the inclined angle of the box were considered as the test factors. The standard straw length rate and average power were used as evaluation indices for conducting the orthogonal rotation combination experiment with five factors and five levels of quadratic regression. The experimental results denoted that the order of influencing factors on the standard straw length rate can be given as follows: the number of processing times, number of fixed blades, cutting speed, number of tooth plates and inclined angle of the box. The order of the influence of each factor on the average power can be given as follows: the cutting speed, number of fixed blades and number of tooth plates. Further, the optimum structural and working parameters of the device can be determined as follows: linear cutting speed of 17-20 m/min, box inclined angle of 70°-80°, 20-23 fixed blades, 5-6 processing times and 4-7 tooth plates. Under such a circumstance, the standard straw length rate reached up to 70.5%-77.4% and the average power was low at 5.8-7 kW. The results can be used as reference for designing a chopping device for a TMR mixer. Keywords: total mixed rations, straw, chopping device, parameter optimization DOI: 10.25165/j.ijabe.20201301.4927 Citation: Ma P B, Li L Q, Wen B Q, Xue Y H, Kan Z, Li J B. Design and parameter optimization of spiral-dragon type straw chopping test rig. Int J Agric & Biol Eng, 2020; 13(1): 47–56.

Development and Performance Evaluation of Power Driven Chopper

Maize and sorghum stalk considered among the most fodder materials in Ethiopia. Therefore the chop machine was adapted and evaluated. The research was conducted at Asella Agricultural Engineering Research Center (AAERC), Arsi Negelle and Zuway Dugda districts to evaluate the machine performance in terms of chopping efficiency, throughput capacity, cutting efficiency and fuel consumption at different speed of cutter shaft. The output of chopper was found to be remarkable achievement. The chopping efficiency was decreased from 97.28 to 92.43 % on maize stalk and 95 to 90.2 % on sorghum stalk as rpm increases from 1150 to 1850 respectively. Throughput capacity of chopper was increases from 8.13 to 12.6 kg/min on maize stalk and 10.26 to 14.5 kg/min on sorghum stalk as rpm increases from 1150 to 1850 respectively. The mean of chopping length and cutting efficiency of 3.5 cm and 96.64 % on maize and also 2.53 cm and 97.63 % on sorghum stalk respectively.

The Effect of Increased Pork Hot Carcass Weights and Varying Chop Thicknesses on Consumer Visual Appearance and Purchase Intent Ratings of Top Loin Chops

ObjectivesThe objective of this study was to evaluate the effect of increased pork hot carcass weights on consumer visual acceptability and purchase intent ratings of top loin chops cut to various thicknesses in a price labeled versus unlabeled retail display scenario.Materials and MethodsPigs in this study were intentionally raised to reach heavier hot carcass weights when compared to industry standards. Pork loins (N = 200) were collected from 4 different hot carcass weight groups: a light weight (LT; less than 111.8 kg), medium-light weight (MLT; 111.8 to 119.0 kg), medium-heavy weight (MHVY; 119.1 to 124.4), and a heavy weight (HVY; 124.4 and greater). Loins were fabricated into 4 pairs of chops of specified thicknesses (1.27, 1.91, 2.54, and 3.18 cm) at Day 7, 8, or 9 postmortem. For each chop loineye area, length and width were measured. One chop from each specified thickness was then randomly assigned to be packaged with a label containing package price and weight information. The other paired chop was packaged without a label. Consumers (N = 393; 8 per panel) from the Manhattan, KS, area assessed chops from each weight group × thickness combination in both labeled and unlabeled scenarios. Chops were assessed on a 0 to 100 continuous line scale for desirability and purchase intent. Consumers were also able to indicate “yes” or “no” if the chop was either desirable and if they would purchase the chop.ResultsAs hot carcass weight increased, there was an increase in loineye area and chop length, with chops from HVY carcasses having greater (P &lt; 0.05) loineye areas and lengths compared to all other weight treatments. For both appearance and purchase intent ratings, chops from HVY carcasses were given higher (P &lt; 0.05) ratings compared to LT chops. Additionally, consumers gave greater (P &lt; 0.05) appearance ratings to thicker cut chops. There was a hot carcass weight × chop thickness interaction (P &lt; 0.05) for the percentage of consumers that indicated the chop was desirable overall. Regardless of hot carcass weight treatment, chops with a thickness of 1.27 cm had the lowest (P &lt; 0.05) percentage of consumers indicate they were desirable overall. Within the LT and MLT weight treatments, chops with a thickness of 1.91 and 2.54 cm were similar (P &gt; 0.05) with the greatest (P &lt; 0.05) percentage of consumers who indicated they were desirable. Within the HVY weight treatment, chops with a thickness of 2.54 cm had the greatest (P &lt; 0.05) percentage of consumers who indicated they were desirable. A greater (P &lt; 0.05) percentage of consumers indicated “yes” they would purchase chops cut to a thickness of 2.54 cm compared to all other thicknesses. Additionally, there was a greater (P &lt; 0.05) percentage of consumers who indicated they would purchase chops that were unlabeled compared to chops labeled with weight and pricing information.ConclusionThese results indicate that carcass weight and chop thickness can affect consumer preference and purchasing decisions. Thus, both should be considered by retailers when marketing fresh pork top loin chops.

Effects of wheat straw chop length in high-straw dry cow diets on intake, health, and performance of dairy cows across the transition period

The study investigated the effect of chop length of wheat straw in a high-straw dry cow diet on the feeding behavior, health, and performance of Holstein dairy cows across the transition period. Forty cows were enrolled at dry off, approximately 45 d before expected calving, and assigned to 1 of 2 dietary treatments containing (on a dry matter basis) 36% corn silage, 35% dry cow pellet, and 29% wheat straw. Diets were formulated to target an energy consumption of 19 Mcal/d of net energy for lactation per cow. The diets differed in the chop length of wheat straw: (1) long straw chopped with a 10.16-cm screen (LDD; n = 20), or (2) short straw chopped with a 2.54-cm screen (SDD; n = 20). Dietary treatments were fed throughout the dry period. Feeding behavior, rumination time, and reticulorumen pH were monitored electronically, and feed samples were collected to determine feed sorting. Blood samples were taken weekly, and body condition scores and body weights were taken every 2 wk. Postcalving, all cows were fed the same lactating cow total mixed ration for 28 d; the same measurements were recorded with the addition of daily milk yield and twice weekly milk components. During the dry period, cows fed the SDD treatment consumed more dry matter (15.6 vs. 15.0 kg/d), had more consistent dry matter intake in the week leading up to calving, had a faster feeding rate, consumed 0.4 kg/meal more, and had 0.6 fewer meals per day. No differences were observed in rumination time or mean reticulorumen pH between treatments in both the dry and lactating period. Regardless of treatment during the dry period, cows sorted against the long particles (>19 mm) and in favor of the short particles (<8, >4 mm), but cows fed the LDD treatment sorted to a greater extent than cows fed the SDD treatment. Dietary treatment in the dry period did not influence feed sorting behavior postcalving. Cows fed the LDD treatment had a greater daily change (decline) in rumen pH in the first week postcalving and had a greater blood β-hydroxybutyrate concentration in the third week postcalving. Overall, the results from this study indicate that feeding shorter chopped wheat straw in a high-straw dry cow diet improved intake, reduced sorting during the dry period, and resulted in greater metabolic health and rumen stability in early lactation.

Comparison of feeding diets diluted with sorghum-sudangrass silage or low-quality grass on nutrient intake and digestibility and growth performance of Holstein dairy heifers

This study was carried out to evaluate the nutrient intakes and growth of dairy heifers offered an alfalfa silage-corn silage diet (CON; 14.3% crude protein, 61.1% total digestible nutrients, 47.9% neutral detergent fiber) compared with diets containing 1 of 2 types of sorghum-sudangrass (SS) silages: conventional or photoperiod sensitive. The objective of the study was to determine the potential to use SS to control dry matter (DM) and nutrient intakes and weight gain. Both diets were similar in nutrient composition, with approximately 13% crude protein, 60 to 61% total digestible nutrients, and 55% neutral detergent fiber. Seventy-two Holstein heifers (16-18 mo at study initiation) were blocked by initial body weight (light = 422 ± 12.8 kg; medium = 455 ± 14.8 kg; heavy = 489 ± 16.7 kg) with 3 pens assigned to each weight block (8 heifers/pen; 24 heifers/block). The 3 diets were randomly allocated to the pens within each block and offered for 12 wk. Heifers offered the CON diet had greater DM, protein, and energy intakes compared with those offered the SS silage-based diets due to the greater neutral detergent fiber concentration of the SS diets. With lower DM and nutrient intakes, average daily gain was in the recommended range (0.8-1 kg/d for Holstein heifers) for heifers offered the SS silage-based diets (mean of 0.92 kg/d for both SS diets vs. 1.11 kg/d for CON). Sorting behaviors for heifers offered both SS diets were more aggressive against long, medium, and short particles compared with those of heifers offered the CON diet; however, heifers sorted large particles from photoperiod-sensitive silage more aggressively than those from conventional silage. Based on this study, SS silage-based diets can control the DM and energy intakes for heifers and maintain optimum growth rates, with harvesting at a shorter chop length likely helping to alleviate sorting issues.

Effects of the Forage Type and Chop Length of Ramie Silage on the Composition of Ruminal Microbiota in Black Goats.

Simple SummaryThe aim of this study was to evaluate the effects of the forage type and chop length of ramie (Boehmeria nivea (L.) Gaud.) silage on ruminal microbiota in black goats. The ruminal pH and relative abundance of microorganisms in the rumen differed with the lengths of the ramie silage fed to the goats. These results could provide a basis for ramie silage application in goats.The aim of this study was to investigate the effects of the forage type and chop length of ramie (Boehmeria nivea (L.) Gaud.) silage on rumen fermentation and ruminal microbiota in black goats. Sixteen Liuyang black goats (22.35 ± 2.16 kg) were fed with the roughage of corn silage or ramie silage at chop lengths of 1, 2, or 3 cm. The Chao 1 index and the observed number of microbial species differed significantly between the corn and ramie silage groups (p < 0.05); however, Firmicutes (relative proportion: 34.99–56.68%), Bacteroidetes (27.41–47.73%), and Proteobacteria (1.44–3.92%) were the predominant phyla in both groups. The relative abundance of Verrucomicrobia (0.32–0.82%) was lowest for the 2 and 3 cm chop lengths (p < 0.05) and was negatively correlated with rumen pH and propionic acid concentration (p < 0.05), but positively correlated with the ratio of acetic acid to propionic acid (p < 0.05). The ramie silage fermentation quality was highest for the 1 cm chop length, suggesting that moderate chopping produces optimal quality silage.