Neutral Detergent Fiber Research Articles

Optimal fertilization of Marandu grass with gelatin industry sludge

This study determined optimal fertilization levels for Marandu grass (Urochloa brizantha cv. Marandu) as a forage using sludge from the gelatin industry. The experiment was performed in a greenhouse with five treatments: three rates of gelatin sludge application (0, 200, and 300 m3 ha-1), an organo-mineral (100 m3 ha-1 + mineral: 60 mg dm-3 N), and pure mineral fertilizer (100 mg dm-3 N) with six replicates. Plant and stem height, number of tillers, leaves, leaves/tiller, chlorophyll index, dry mass (leaves, roots, and residue), crude protein, neutral and acid detergent fiber, macronutrient, and micronutrient concentrations were measured. Plant and stem height, number of tillers, leaves, and biomass production increased linearly as gelatin sludge dosage increased. There was a linear increase in crude protein with reduction in neutral detergent fiber and acid detergent fiber with increasing gelatin sludge fertilization. Gelatin sludge dosage did not affect the contents of P, Mg, S, Cu, and Fe. Only Mn had a positive linear response to gelatin sludge with reduction at the highest rate. The 300 m3 ha-1 dosage of gelatin sludge increased biomass production and chlorophyll index. In contrast, the organo-mineral fertilizer promoted higher crude protein and lower neutral detergent fiber concentrations in grass. The gelatin sludge dosage of 300 m3 ha-1 improved the nutritive value of Marandu grass compared to mineral fertilizer. Gelatin sludge is a promising pasture amendment for growing Marandu grass as it recycles industrial animal waste for a more integrated livestock-cropping system.

EFFECT OF DIFFERENT PLANT DENSITY ON THE FORAGE YIELD AND SOME FORAGE QUALITY CHARACTERISTICS OF MORINGA (Moringa oleifera Lam.)

In sustainable animal husbandry, the use of highly adaptable shrub and tree species as alternative forage crops has gained importance in recent years. One of these plants is moringa (Moringa oleifera Lam.), which is considered one of the promising feed sources due to its high nutritional value. This research was carried out to determine the potential of Moringa as a forage crop for the Mediterranean climate during 2020 and 2021 growing season in the experimental areas of the Department of Field Crops, Faculty of Agriculture, University of Ege, Türkiye. The effects of four different plant densities (60x20 cm, 60x30 cm, 60x40 cm, 60x60 cm) on the some forage quality and digestibility traits were investigated. The Moringa cultivar "PKM-1" was used as plant material and plant height, stem diameter, dry matter, herbage yield, crude protein, crude ash, crude fat, neutral detergent fiber (NDF) and acid detergent fiber (ADF) were examined during two consecutive vegetation periods. In the study conducted in Mediterranean ecological conditions, the average values of the moringa plant for two years were obtained as Plant height 159.2-170.3 cm, total herbage yield 3.310-6.970 kg/da, crude protein ratio 17.12-18.15%, ADF ratio 35.31-37.85% and NDF ratio 45.66-49.71%. Increasing the planting density increased the herbage yield and the highest value was obtained from 60x20 cm planting density. In addition, 60x20 cm planting density is also suggested in terms of protein , ADF and NDF traits.

Performance Evaluation of Lambs Fed Tifton 85 Grass Hay and Concentrate Through LIPE® Marker

The research was carried out with the aim of evaluate increasing levels of concentrate supplementation on intake and performance of lambs fed Tifton 85 grass hay adopting LIPE® marker technique. Twenty-four weaned and castrated Santa Inês crossbreed lambs with initial body weight (BW) of 20.99 ± 3.62 kg were distributed in four treatments with Tifton 85 hay exclusive or associated with concentrate levels (0.0, 6.6, 13.3 and 20.0 g kg-1 BW d-1), in a completely randomized design with six animals per treatment. The experimental period lasted 98 days, with the first 14 days for animal adaptation to the new environmental conditions, handling and feeding. The diets were fed ad libitum twice a day. Lambs were weighted at each 14 days. Dry matter intake (DMI) was estimated by the technique of Isolated, Purified and Enriched Lignin (LIPE®) while neutral detergent fiber intake (NDFI) and crude protein intake (CPI) were obtained from the content of their fractions present in the diets. There was an increase in DMI and CPI and a similar response in NDFI with the increasing levels of concentrate. The daily liveweight gain per animal showed a linear response when the levels of concentrate were increased and the highest values wereobserved when 20.0 g kg-1 BW d-1 of concentrate was fed. The increasing levels of concentrate supplementation allowed greater daily and total body weight gains per lamb and there is a consistent relationship between nutrient intakes and performance in the treatments and the LIPE® marker proved to be an efficient technique to evaluate the DMI by lambs.

Use of bacteria solubilizing phosphate, limestone, and phosphate fertilization in tifton 85 pasture

Using inoculants can be an alternative to reduce chemical fertilizers and improve the production of cultivated pastures. The objective of this work was to evaluate the use of an inoculant containing bacteria of the genus Bacillus (Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus pumilus) in a pasture of the genus Cynodon cv. Tifton 85, with and without liming and phosphating. The experiment was carried out in Vista Alegre do Prata, RS, in an area of Tifton 85 established in 2012, organized in randomized blocks with a factorial scheme 2 (with and without inoculant) x 4 (control, liming, phosphating, liming + phosphating), with four repetitions. The parameters evaluated after 49 days were plant height, production of dry and fresh mass of the aerial part, nutrient content in the tissue, neutral detergent fiber (NDF), and acid detergent fiber (ADF). At 119 days, the height of the plants and the production of the dry and fresh mass of the aerial part were evaluated. The results demonstrated that phosphate fertilization and/or liming did not influence the efficiency of using Bacillus spp. The application of Bacillus spp. increased plant height and Tifton's fresh and dry mass in the first cut, but chemical corrections did not affect these parameters. The treatments did not impact forage quality (NDF and ADF). In the second cut, only the height of the plants was greater with the application of the inoculant, suggesting the need for reapplication. Therefore, the application of Bacillus spp. favors the development of Tifton 85, maintaining forage quality.

Nitrogen fertiliser application rate to temperate mid-season grass: Digestion, nitrogen balance and rumen microbiota in beef cattle, and rumen fermentation and methane production in vitro

Nitrogen (N) excretion by cattle, particularly urinary N, can have detrimental environmental impacts on air and water quality, and contributes to greenhouse gas emissions. The effects of increasing the application rate of inorganic N fertiliser from 15 (N15) to 80 (N80) kg/ha per cut to Lolium perenne dominant swards in summer, on intake, rumen fermentation, rumen microbial populations, apparent total-tract digestibility and N-balance in beef cattle, and in vitro fermentation and methane output, were studied. Sixteen suckler-bred Charolais steers, used in a randomised block design experiment, were offered fresh grass mechanically harvested 21-d after N fertiliser application. Similar grass was incubated in an eight-vessel in vitro RUSITEC system. Grass crude protein concentration was 50 g/kg dry matter (DM) higher for N80 compared to N15. There was no difference in grass DM intake between treatments. Rumen fermentation variables did not differ between treatments, except for the molar proportion of propionate, which was greater for N80 than N15. Gross microbial community structure in the rumen was not significantly altered by inorganic N fertiliser application rate. The relative abundance of individual genera Lachnospiraceae_NK3A320_group and Ruminococcaceae_NK4A214_group, and Acetitomaculum were significantly lower at the higher N application rate. Mean plasma urea concentration was greater for N80 compared to N15. In vivo digestibility of DM, organic matter, neutral detergent fibre and acid detergent fibre was unaffected by fertiliser N application rate. Nitrogen intake was 75 g/d greater, and urinary and faecal N excretion were 20 and 5 g/d greater, respectively, for N80 than N15. The quantity of N retained and N use efficiency was greater for N80 compared to N15. In vitro NH3 concentration was greater for N80 than N15, whereas other rumen fermentation variables, and in vitro methane and total gas output, did not differ between treatments. Reducing the inorganic N fertiliser rate applied to mid-season temperate grass reduced N excretion from beef cattle, which is environmentally beneficial, with no effect on in vitro methane production.

Reshaping the spatiotemporal patterns of temporal stability of forage nutrition quality in alpine grasslands of the Qinghai–Tibet Plateau: Spatial homogeneity, overall decline and localized increases

There is increasing evidence that forage nutrition quality is becoming more unstable over time due to climate change and/or human activities. However, there are limited numbers of studies at the regional scale exploring the spatiotemporal patterns and driving mechanisms of temporal stability of nutrition quality. Therefore, this study quantified the spatiotemporal patterns of temporal stability of forage nutrition quality in alpine grasslands of the Qinghai–Tibet Plateau under the singular or combined influences of climate change and human activities in 2000–2020. Temporal stability of forage nutrition quality displayed obvious spatiotemporal patterns, with human activities altering the impact of climate change on these spatiotemporal patterns. Under combined effects of climate change and human activities, spatial average values of temporal stability of crude protein (CP), ash (Ash), ether extract (EE), water-soluble carbohydrates (WSC), acid detergent fiber (ADF), and neutral detergent fiber (NDF) decreased by 13.54 %, 7.40 %, 9.02 %, 17.78 %, 9.20 %, and 7.28 % across the whole grasslands, respectively. However, 39.43 %, 45.72 %, 42.98 %, 37.82 %, 42.27 %, and 43.50 % areas showed increasing trends for the temporal stability of CP, Ash, EE, WSC, ADF and NDF, respectively. Climate change predominated 46.15 %, 44.46 %, 44.22 %, 47.32 %, 28.68 %, and 45.31 % of the relative change of temporal stability of CP, Ash, EE, WSC, ADF, and NDF, but human activities had higher influence for 53.82 %, 55.53 %, 55.77 %, 52.55 %, 71.30 %, and 54.68 % of grasslands, respectively. Therefore, the spatial patterns of temporal stability of forage nutrition quality were shifting towards homogeneity, with an overall decrease in temporal stability but localized increases in alpine grasslands of the Qinghai-Tibet Plateau. The effects of climate change and human activities on forage nutrition quality were not always synergistic. The trade-off between nutrition quality and its temporal stability did not always exist, but varied with geographic position.

Environmental contamination of arsenic: pathway analysis through water-soil-feed-livestock in Nadia District (India) and potential human health risk.

This study investigated arsenic (As) concentrations in diverse environmental components and their potential impact on the health risks faced by residents of the arsenic (As)-contaminated Nadia district in West Bengal, India. A random selection of 182 cattle and 255 goats from 40 livestock farmers in the district revealed that both animals and humans were naturally exposed to elevated arsenic levels through contaminated drinking water, foods, grasses, concentrate feeds, various fodder tree leaves, and other food/feed resources. The mean As concentration in roughages (483.18µg/kg DM) was significantly higher (p < 0.001) than in tree leaves (391.53µg/kg DM), and concentrate feed/ingredients (186.66µg/kg DM). Pond water exhibited higher arsenic levels (106.11µg/L) compared to shallow tube well water (47.96µg/L) and deep tube well water/tap water (10.64µg/L and 10.04µg/L, respectively). The mean arsenic concentration in soils DM of fodder fields, crop fields, and grassland was 10.25, 10.58, and 10.20mg/kg, respectively. It was observed that protein-rich feeds had lower levels of arsenic accumulation (p < 0.048), while fiber-rich feeds containing more cellulose, hemicellulose, and lignin had higher arsenic levels (p < 0.017). Goats consumed 73.46% more arsenic per kg body weight compared to dairy cows. Although chronic and sub-chronic arsenic exposure in the district did not typically manifest symptoms or visible signs in ruminant animals, concentrations in the hair and feces of both cattle and goats exceeded normal values. Cattle feces had significantly higher arsenic (410.43µg/kg DM) levels (p < 0.001) than goat feces (227.00µg/kg DM), and arsenic concentration in cattle hair (1917.74µg/kg DM) was also significantly greater (p < 0.001) than goat hair (1435.74µg/kg DM). Arsenic levels in milk samples from both species were below 10µg/kg. Liver (356.02µg/kg DM) and kidney (317.22µg/kg DM) contained significantly higher (p < 0.001) levels of arsenic compared to muscle (204.23µg/kg DM), and bone (161.98µg/kg DM) in local meat-type adult male goats. The skin accumulated the highest amount of arsenic (576.24µg/kg DM) among the non-edible parts of the goat carcass. The cumulative cancer risk value for adults was 4.96 × 10-3, exceeding the threshold value (1 × 10-6). This suggests a significant risk of cancer development for the population in arsenic-affected areas. Non-cancer risks (hazard indexes) were estimated at 11.01 for adults. Our observations revealed that the highest bioaccumulation of arsenic occurred in the hair of cows, and goats in the examined localities. The biotransformation factor (BTF) for hair was much higher compared to other excreted samples from both species. The calculated BTF followed the order: hair > feces > milk for cows and goats. Livestock farmers in Nadia district are advised to carefully select feed resources, prioritizing those high in crude protein and low in neutral detergent fiber, and they should provide drinking water from deep aquifers to ensure the safety of milk and meat for human consumption.

Dehydrated Brewery Residue (DBR) can reduce the cost of rabbit production in Brazil, but affects performance, blood nutrients, and carcass characteristics

The study aimed to determine the chemical composition, apparent digestibility of dry matter, energy, and nutrients of Dehydrated Brewery Residue (DBR) for New Zealand White rabbits, as well as evaluate performance, biochemical and immunological blood parameters, carcass characteristics, and meat quality. Two experiments were carried out: digestibility and performance, both in a completely randomized design. In the digestibility experiment, 20 animals of mixed sexes were used, from 45 to 60 days of age, which consumed reference feed (RF) or test feed (TF - 70% RF + 30% DBR). In the performance experiment, 50 mixed-sex animals were used from 31 to 70 days of age. For digestibility, bromatological analyses were made of total dry matter (DM), crude protein (CP), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF), ether extract (EE), mineral matter (MM), organic matter (OM), calcium (Ca), phosphorus (P), gross energy (GE), hemicellulose, cellulose and lignin from samples of feces, feed (RF and TF) and experimental feed (DBR). In terms of performance, the treatments were the basal feed (BF) + four TF, made up of increasing levels of DBR inclusion (10, 20, 30, and 40%). Overall, the apparent digestibility coefficient (ADC) of DM was 64.68 ±7.91%, while the ADC of GE and CP were 67.39 ±7.79% and 80.64 ±8.99%, respectively, resulting in digestible energy and digestible protein contents of 3,081 ±356 kcal/kg and 17.97 ±2.00%. There was a linear reduction (P&lt;0.05) in the final weight, daily weight gain, and daily feed intake, but there was a linear reduction in production costs (P&lt;0.05) for both the 31- to 50-day phase and the 31- to 70-day phase. Circulating levels of calcium (P=0.013) and phosphorus (P=0.019) responded in a linear decreasing pattern to the experimental feeds. The same response was observed for slaughter weight, hot and cold carcass weight, yield of skin, head, commercial cuts, and relative weight of edible organs, as well as meat quality, in which the loss of water on thawing (P=0.004) and shear force (P=0.005) indicated less juiciness and less tenderness in the meat. Levels of 10 to 40% DBR in feed for rabbits from 31 to 70 days of age mitigate production costs, but result in a worsening of performance and reduce circulating levels of calcium and phosphorus, reduce carcass weight, commercial cuts, and edible organs, as well as increasing water loss on thawing, and reducing meat tenderness.

Co-expression of endoglucanase and cellobiohydrolase from yak rumen in lactic acid bacteria and its preliminary application in whole-plant corn silage fermentation.

Endoglucanase (EG) and cellobiohydrolase (CBH) which produced by microorganisms, have been widely used in industrial applications. In order to construct recombinant bacteria that produce high activity EG and CBH, in this study, eg (endoglucanase) and cbh (cellobiohydrolase) were cloned from the rumen microbial genome of yak and subsequently expressed independently and co-expressed within Lactococcus lactis NZ9000 (L. lactis NZ9000). The recombinant strains L. lactis NZ9000/pMG36e-usp45-cbh (L. lactis-cbh), L. lactis NZ9000/pMG36e-usp45-eg (L. lactis-eg), and L. lactis NZ9000/pMG36e-usp45-eg-usp45-cbh (L. lactis-eg-cbh) were successfully constructed and demonstrated the ability to secrete EG, CBH, and EG-CBH. The sodium carboxymethyl cellulose activity of the recombinant enzyme EG was the highest, and the regenerated amorphous cellulose (RAC) was the specific substrate of the recombinant enzyme CBH, and EG-CBH. The optimum reaction temperature of the recombinant enzyme CBH was 60°C, while the recombinant enzymes EG and EG-CBH were tolerant to higher temperatures (80°C). The optimum reaction pH of EG, CBH, and EG-CBH was 6.0. Mn2+, Fe2+, Cu2+, and Co2+ could promote the activity of CBH. Similarly, Fe2+, Ba2+, and higher concentrations of Ca2+, Cu2+, and Co2+ could promote the activity of EG-CBH. The addition of engineered strains to whole-plant corn silage improved the nutritional quality of the feed, with the lowest pH, acid detergent fiber (ADF), and neutral detergent fiber (NDF) contents observed in silage from the L. lactis-eg group (p < 0.05), and the lowest ammonia nitrogen (NH3-N), and highest lactic acid (LA) and crude protein (CP) contents in silage from the L. lactis-eg + L. lactis-cbh group (p < 0.05), while the silage quality in the L. lactis-cbh group was not satisfactory. Consequently, the recombinant strains L. lactis-cbh, L. lactis-eg, and L. lactis-eg-cbh were successfully constructed, which could successfully expressed EG, CBH, and EG-CBH. L. lactis-eg promoted silage fermentation by degrading cellulose to produce sugar, enabling the secretory expression of EG, CBH, and EG-CBH for potential industrial applications in cellulose degradation.

Differential immunological responses in lamb rumen and colon to alfalfa hay and wheat straw in a concentrate-rich diet: insights into microbe-host interactions.

The impact of a concentrate-rich (CR) diet on the gut microbiome and epithelium homeostasis is well documented. However, it has not been systematically studied whether and how host-microbial interaction contributes to the immune homeostasis in the rumen and colon of lambs fed alfalfa hay and wheat straw, alone or combined, in a CR diet. In all, 63 lambs (initial body weight, 16.69 ± 1.50 kg) were randomly allotted to three dietary groups, each consisting of three pens with seven lambs per pen. Over 14 weeks, the lambs were fed diets as follows: 60% concentrate supplemented with either 40% wheat straw (WG), 20% alfalfa hay combined with 20% wheat straw (MG), or 40% alfalfa hay (AG). The present findings showed that lambs in the AG group had greater (P < 0.05) IgG and lower (P = 0.067) tumor necrosis factor-alpha concentrations relative to those in the MG and WG groups. The 16S rRNA analysis highlighted that various bacterial phyla and genera in the rumen and colon preferentially degrade fiber and starch derived from alfalfa hay and wheat straw. The weighted gene co-expression network analysis revealed that the bacterial genera from the Firmicutes are broadly associated with genes involved in various signaling pathways, underscoring the potential role of Firmicutes as key drivers of host-microbial interactions under the present feeding conditions. These findings shed light on the fact that the rumen and colon immune homeostasis is distinctively influenced by diets of alfalfa hay, wheat straw, or their combination in a CR diet. Further studies should examine the prolonged effects of replacing wheat straw with alfalfa hay in a concentrate-rich diet formulated to provide equivalent neutral detergent fiber levels. This could reveal how various forage fibers influence host-microbial interactions and gut health.IMPORTANCEIn contemporary feedlots, a growing trend is to feed animals a concentrate-rich (CR) diet that could disrupt the synchronized interplay between microbes and host metabolism, leading to altered metabolic functions. Wheat straw and alfalfa hay have different levels of protein and neutral detergent fiber, each with varying rates of digestion. It is unclear how including alfalfa hay and wheat straw, alone or combined in a CR diet, influences the host-microbial consortia and immune homeostasis. Herein, we showed that rumen and colon showed differential immune responses to the alfalfa hay, wheat straw, or both. Bacterial genera preferentially degrade fiber and starch derived from alfalfa hay, wheat straw, or both. Bacterial genera from Firmicutes phylum play a pivotal role in driving the host-microbial interactions, as indicated by their extensive association with genes across various signaling pathways.

Chemical characteristics of grass silage with the use of acidifier after opening the bag

The objective of this work was to evaluate the chemical characteristics of Miyagi grass silage (Megathyrsus maximus cv. Miyagi), with the addition of moisture sequestrants (ground corn grain - GCG, and dried distillers grain with solubles and high fiber, DDGS), and addition of inoculant (SiloSolveMC) and/or acid (Mold-Nil Liquid). The experimental design was completely randomized in a 3x3 factorial arrangement, with five replications: factor 01, the use of moisture scavengers (without additive, with the addition of GCG and/or DDGS), and factor 2, the use of bacterial inoculant (SiloSolveMC) and/or acid (Mold-Nil Liquid). For the chemical evaluation of the silage, the percentage of dry matter (DM), the insoluble fiber in neutral detergent (NDF), mineral matter contents (MM), and crude protein (CP). There were no interactions between moisture scavengers, bacterial inoculants, and/or acids. The use of moisture scavengers interfered with DM (P&lt;0.05), observing a value with GCG and DDGS use of 36.18% and 35.46%, respectively, higher than MGS (27,68%). For NDF values using GCG and DDGS, values of 51.39% and 65.47%, respectively, lower (P&lt;0.05) than MGS (70.72%) were observed. The use of microbial inoculant and acid did not alter (P&gt;0.05) the OM values, with an average value of 92%. As for CP, there was no interaction (P&gt;0.05) of moisture scavengers, microbial inoculant, and/or acid. It is recommended to include moisture-sequestering foods associated with MGS to obtain better DM, NDF, and CP values after opening the bag and the use of microbial inoculants and/or acids in the MGS did not influence these characteristics.

PSIV-28 Determination of the extent and rate of nutrient degradation of potato and other byproducts by rumen microorganisms in vitro

Abstract Byproducts in livestock diets have the potential to reduce the environmental impact of food production and the cost of animal feeding. The objective was to evaluate the extent and rate of nutrient degradability of potato and other byproducts by rumen microorganisms in vitro. Byproducts included barley malt sprouts, fries, dry peel, and hopper, which were supplied by Performix Nutrition Solutions (Nampa, ID). Two in vitro incubators (DAISYII, ANKOM Technology) each with four incubation jars were used to evaluate ruminal degradability of dry matter (DM) and neutral detergent fiber (NDF). Each jar contained 1,600 mL buffer solution (ANKOM Technology), 400 mL rumen contents (collected from two ruminally cannulated cows), 14 filter bags (F57, ANKOM Technology) with 0.5 g of ground byproduct, 14 filter bags with 0.5 g of ground corn (standard), and 14 blank bags. Each jar was purged with CO2 and filter bags were incubated at 39°C for 0, 3, 6, 9, 12, 24, and 48 h, then removed, rinsed, dried at 55˚C for 48 h, weighed, and analyzed for DM and NDF. Each byproduct was incubated in 3 jars on two different d (6 replicates). Degradation of DM was separated into fractions A (disappearance at 0 h), C (DM remaining after 48 h) and B (100%-A-C). Rate of degradation for fraction B was the slope of the natural logarithms of the DM disappearance. All byproducts were compared with standard corn grain as the control. Fraction A for DM was not different (P &amp;gt; 0.40) for barley malt sprouts (35.4%) and hopper (33.7%), and less (P &amp;lt; 0.05) for dry peel (27.8%) and fries (13.2%) when compared with corn grain (33.4%). Fraction B for DM was greater (P &amp;lt; 0.05) for fries (74.0%), not different (P = 0.44) for hopper (56.1%), and less (P &amp;lt; 0.05) for dry peel (43.6%) and sprouts (37.0%) when compared with corn grain (53.9%). Rate of DM degradation for fraction B was greater (P &amp;lt; 0.05) for fries (9.9%/h) and hopper (7.0%/h), and not different (P &amp;gt; 0.16) for dry peel (4.6%/h) and sprouts (3.0%/h) when compared with corn grain (3.8%/h). Fraction C for DM was greater (P &amp;lt; 0.05) for dry peel (28.6%) and sprouts (27.6%), and not different (P = 0.20) for fries (12.9%) and hopper (10.3%) when compared with corn grain (12.7%). The indigestible fraction of NDF after 48 h of incubation was greatest for dry peel (58.5%), intermediate for sprouts (40.1%) and hopper (36.7%), and least for fries (25.4%; P &amp;lt; 0.05). These results demonstrate that the extent and rate of ruminal DM degradability of various potato and other byproducts differ and may be more or less degradable in the rumen compared with corn grain.

PSXIII-22 Intake, digestibility, and ruminal parameters of Nellore cattle fed with amylolytic and fibrolytic enzymes in feedlot

Abstract This study was carried out to evaluate the use of dietary exogenous enzyme (ENZ) products with amylolytic and fibrolytic activity on nutrient intake, digestibility, and ruminal volatile fatty acids production (VFA) of Nellore cattle in feedlot. Rumen-cannulated Nellore steers [n = 10; body weight (BW) = 543 kg ± 28.6 BW] were distributed in a replicated Latin-square design (5 × 5) in individual pens. The treatments consisted of a negative control (CON; without ENZ); Amylase (AML; Amaize, Alltech, 0.5 g/kg of DM); Xylanase (FBL, Fibrozyme, Alltech, 0.9 g/kg of DM); Half dose (HD; AML 0.25 g/kg of diet DM and FBL 0.45 g/kg of diet DM); and Full dose (FD; AML 0.5 g/kg of diet DM and FBL 0.90 g/kg of diet DM; Table 1). The experimental period lasted 19 d (14 d of adaptation and 5 d of collection). Between d 15 and 18, total fecal collection was performed and on d 19 rumen fluid was collected at 0, 4, 8, 12, and 16 h post-feeding for ammonia, VFA, and pH determination. The data were analyzed as orthogonal contrasts using SAS: (C1) CON vs. ENZ, (C2) AML vs. FBL, (C3) HD vs. FD, and (C4) AML + FBL vs. HD + FD. There were no C1 differences for nutrient digestibility, total VFA, or ruminal pH (P &amp;gt; 0.10). However, a tendency effect in neutral detergent fiber (NDF) intake (P = 0.065) was observed, where animals fed ENZ had reduced values compared with animals kept in CON group. In the same way, ENZ reduced ther extract (EE) intake (P = 0.023), ruminal ammonia (P &amp;lt; 0.001), and isovalerate proportion (P = 0.080) as well as increased proportion of acetate (P &amp;lt; 0.001), valerate (P &amp;lt; 0.001) and acetate:propionate ratio (P = 0.030). No differences were observed in nutrient intake between AML and FBL (P &amp;gt; 0.10), but AML had greater organic matter (OM) digestibility (P = 0.097) and ruminal valerate (P = 0.039) and decreased butyrate proportion (P = 0.068). Animals that received FD had greater values of dry matter (DM; P = 0.009) and OM (P &amp;lt; 0.001) digestibility than HD. The enzyme combination resulted in greater DM (P = 0.026), OM (P = 0.062), crude protein (P = 0.018), EE (P = 0.063) and NDF (P = 0.040) intake and reduced OM digestibility (P = 0.008) compared with AML and FBL alone. The addition of exogenous enzymes in feedlot diets affected nutrient utilization and ruminal fermentation of Nellore cattle fed a feedlot finishing diet.

PSXI-24 Comparative analysis of the chemical composition and methane production from different total mixed fermentation (TMF) diets fed to Hanwoo cattle

Abstract Total mixed fermentation (TMF) feed is a mixture of forage, concentrate, and useful microorganisms utilized to enhance nutrient availability and livestock well-being. Recognized for its potential benefits, TMF has been noted to decrease acetate production while increasing propionate production in the rumen. However, a comprehensive understanding of its composition and potential impact on methane production remains lacking. Thus, this study investigated the chemical composition and in vitro methane production associated with different TMF diets designed for different Hanwoo cattle groups. A comparative analysis of 26 TMF diets, including 3 designed for calves, 7 for growing, 6 for early fattening, 6 for late fattening, and 4 for breeding, was conducted to examine their chemical composition. The TMF samples were submitted to Cumberland Valley Analysis Service (CVAS) for chemical analysis. Principal component analysis (PCA) was employed to visualize the TMF according to the Hanwoo feed-type groups and the chemical compositions to estimate the optimal parameters among different TMFs. An in vitro gas production trial was conducted to determine the effects of different TMFs on methane production. Gas samples were collected at 12 and 24 h of incubation and methane (CH4) concentration was measured using a gas chromatograph. All data were analyzed using the SAS 9.4, with P &amp;lt; 0.05 being considered significant. Analysis of the chemical composition of different TMFs, including crude protein, neutral detergent fiber, acid detergent fiber, ethanol-soluble CHO, and total digestible nutrients, showed no significant differences (P &amp;gt; 0.05) between the TMFs according to each Hanwoo category (calf, growing, early fattening, late fattening, and breeding). PCA revealed that digestibility-related parameters and fatty acid content were the main factors discriminating among the TMFs, with the TMFs for calves having the least fat content and those for the late fattening period having the greatest digestibility. Moreover, optimal TMFs were identified for each category of Hanwoo based on their chemical compositions. Among the TMFs tailored for each category of Hanwoo, TMF16, TMF23, TMF24, TMF25, and TMF26 were shown to have an optimal chemical composition for calves, growing, early fattening, late fattening, and breeding, respectively. A minimal reduction in CH4 production at 24 h incubation was observed in specific TMFs across different Hanwoo categories. Notably, TMF14 (7.21%) and TMF22 (8.52%) for calves, TMF05 (4.74%) for early fattening, TMF01 (3.76%) and TMF11 (3.76%) for late fattening exhibited reduced CH4 production. Additionally, CH4 production at 24 h incubation was significantly reduced (P &amp;lt; 0.05) by 23.06% and 10.90% in TMF15 and TMF26, respectively, both categorized for breeding TMF. Overall, while the chemical compositions of various TMFs did not significantly differ, TMF showed the potential to mitigate methane production in Hanwoo cattle.

PSIII-7 Effects of Saccharomyces cerevisiae fermentation product on total tract digestibility, ruminal fermentation, and plasma metabolome of beef steers fed a finishing diet

Abstract Saccharomyces cerevisiae fermentation product (SCFP) has been widely studied; however, its mode of action on high-concentrate diets has not been fully elucidated. This study evaluated the impact of SCFP on total tract digestibility, fecal excretions of N, P, Zn, and Cu, rumen fermentation, and plasma metabolome of finishing beef steers. Ruminally cannulated Holstein steers [n = 8; body weight (BW) = 580 ± 29.2 kg] were enrolled in a crossover design study with 25-d treatment periods and a 24-d washout period. Steers were fed ad libitum a finishing diet consisting of 20% corn silage and 80% concentrate (on DM basis). Steers were blocked based on initial BW and randomly assigned to two treatments in period 1 and switched to the other treatment in period 2. The treatments were CON (Control, basal diet only) and SCFP (basal diet top-dressed with 12 gּ steer-1ּ ּ d-1 SCFP, NaturSafe, Diamond V, Cedar Rapids, IA). Feed and fecal samples were collected during d 22 to 24 for determination of digestibility. Blood was collected before morning feeding on d 25. Plasma samples were analyzed for metabolome with liquid chromatography-mass spectrometry (LC-MS). Rumen fluid was collected via the rumen cannula at 0, 4, 8, and 12 h post-morning feeding on d 25 and analyzed for pH, volatile fatty acids (VFA), and NH3-N. Performance and ruminal fermentation characteristics data were analyzed using the GLIMMIX procedure of SAS 9.4. Metabolomic data analysis was conducted with Metaboanalyst 6.0. Supplementing steers with SCFP reduced DMI (10.6 vs. 11.4 kg/d, P = 0.05) without affecting (P &amp;gt; 0.05) average daily gain, feed efficiency, and digestibility of organic matter, crude protein, and neutral detergent fiber. Treatment did not affect (P &amp;gt; 0.10) fecal excretions of N, P, Cu, and Zn. Feeding SCFP increased ruminal pH (6.29 vs. 6.01, P = 0.01), numerically reduced concentrations of NH3-N (5.01 vs 6.25 mM, P = 0.16), and total VFA (96.8 vs. 102.5 mM, P = 0.15). SCFP also reduced the ruminal molar proportion of butyrate (11.2 vs. 12.8 molar %, P = 0.01) and tended to increase those of isobutyrate (1.03 vs. 0.90, molar %, P = 0.06) and isovalerate (2.62 vs. 2.29, molar %, P = 0.10). Supplementation of SCFP enriched (P ≤ 0.05) purine metabolism, amino sugar and nucleotide sugar metabolism, and lysine degradation pathways in the plasma. Additionally, tryptophan metabolism and pyrimidine metabolism pathways tended to be enriched (0.05 &amp;lt; P ≤ 0.10) by SCFP. Our findings indicate that feeding SCFP improved the ruminal pH of finishing cattle, which may be beneficial for preventing subacute ruminal acidosis in feedlot cattle. Additionally, SCFP enriched several important plasma nitrogen metabolism pathways, potentially associated with microbial nitrogen metabolism in the rumen, warranting further research.

PSXI-5 Transforming retailer’s food waste into silage for sustainable animal nutrition

Abstract Food waste (FW) represents a major environmental and socio-economic problem. In Canada, about 11.2 million metric tons of avoidable food waste is produced yearly. An alternative to reduce this impact would be preserving a greater proportion of this, for livestock feed. Therefore, the objective of this study was to use discarded fruits, vegetables, and bakery products from retailers (FW), ensile them, and assess their nutritional value and contribution to a sustainable livestock feed supply. For this, two treatments for reducing the moisture content of FW were evaluated: Sun-dried (SD), and Passive-dried (PD), were compared with Control (C), using laboratory mini-silos over 60 d of ensiling. Although dry matter (DM) increased by 1-5% for PD and SD, respectively, up to 41.9% of bread products were required to produce a targeted silage DM of 38%. Silage aerobic stability was assessed during 20 d exposure to air. Chemical analyses (pH, volatile fatty acids, lactic acid, ammonia) were assessed in pre-fermentation (d 0), and post-fermentation (d 60). Nutritional quality was evaluated according to AOAC standard methods. Statistical analyses employed mixed models for nutritional and fermentation data, with drying treatments (C, PD, SD) as fixed effects. All mature silages were greater in crude protein (15.2 to 15.7%), crude fat (6.0 to 6.3%), sodium (0.48 to 0.52 %), sugars (WSC; 0.95 to 1.53 %), and less in neutral detergent fiber (6.2 to 7.6%) as compared with traditional silages used as livestock feed. Fermentation parameters showed that lactic acid content was greater than acetic acid, and pH decreased from a maximum of 5.26 at d 0 to a minimum of 3.85 at d 60. Mycophenolic acid was the only mycotoxin above the limit of detection in d 0 silage, with all mycotoxins below reference concentrations at d 60. Plate counts of molds and yeasts declined (P &amp;lt; 0.001) by 5 to 7 log colony-forming units (CFU) over 60 d of fermentation and were not detected in mature silage. Silage showed aerobic stability after 20 d of aerobic exposure (pH 3.86 ± 0.027). In conclusion, ensiling FW could be a viable way of converting low-value waste products into good-quality feed. However, approaches other than SD and PD are required for increasing silage DM as insufficient bread products may be available for this purpose in all batches of FW. Further study of palatability along with digestibility testing will be needed for a scaling-up process.

PSI-26 Effects of particle size and enzyme supplementation on the energy value of field peas fed to growing pigs

Abstract An experiment was conducted to determine if particle size and enzyme supplementation affects the digestible energy (DE), metabolizable energy (ME), and net energy (NE) contents in field peas fed to growing pigs. Male weaned pigs [n = 30; TN70 × TN Tempo; body weight (BW) = 16.5 ± 0.4 kg] were assigned to 1 of 5 dietary treatments: 4 consisting of 50% peas and a corn-soybean meal basal diet. The experiment was carried out as a completely randomized design with treatments arranged in a 2 × 2 factorial design, based on two particle sizes (500μm, 700μm) and two levels of carbohydrase supplementation (0 g/mt, 1,000 g/mt) to give 6 replicates per treatment. Diets were formulated to meet or exceed NRC (2012) requirements. The study was carried out in 3 consecutive periods, each consisting of 15 d; the first 10 d were for adaptation, followed by 5 d of total fecal and urine collection (marker to marker procedure) to calculate DE and ME of diets. The energy content of peas was determined using the difference method. Data were analyzed using the MIXED procedure of SAS. The model included the particle size, enzyme supplementation, and their interaction as a fixed effect. The period was included as a random effect. Least squares means for each treatment were adjusted using Tukey post-hoc test. Dry matter (DM), acid detergent fiber, neutral detergent fiber, gross energy, starch, ash, crude protein, and ether extract contents were analyzed to allow for the prediction of NE content of peas. There were no interactions between particle size and enzyme supplementation on dietary energy values. Also, no main effects of particle size and enzyme supplementation were observed. The average DE, ME, and predicted NE contents for peas were determined to be 3,848, 3,735, and 2,691 kcal/kg DM, respectively. In conclusion, enzyme supplementation and particle size did not influence the DE, ME, and NE contents of the peas.

PSXIII-5 Behavior and blood urea nitrogen in cattle grazing meadow bromegrass and supplemented with condensed and hydrolizable tannins

Abstract The nutritional value of grasslands declines as the season progresses, negatively impacting cattle nutrition. Protein supplementation may reverse this trend, although high rates of ruminal proteolysis reduce the efficiency of N utilization. Tannins decrease protein degradability in the rumen, although they are also plant defenses with potential to influence animal behavior. The objective of this study was to determine in protein-supplemented cows grazing meadow bromegrass (MB) the influence of tannins on blood urea nitrogen (BUN), and on behavioral levels of activity. Twenty-four Black Angus cow [body weight (BW) = 614 ± 20 kg]-calf (BW = 244 ± 4 Kg) pairs were allotted to six 9-acre paddocks (4 pairs/paddock); animals in the Control (Ctrl; n = 3) and Tannin treatments (TT; n = 3) grazed meadow bromegrass (MB) and had a supplement of dried distillers grains with solubles (DDGS; (1 kgּ cow-1ּ d-1), with the addition of a mix of condensed (2/3): hydrolizable tannins(1/3; SilvaTeam) at 0.4% of the diet for TT. Grazing occurred from July to September 2023 with four experimental periods of 15 d each, the first being the adaptation period (no tannins; Baseline). Data were analyzed as a mixed-effects model with repeated measures and paddock as the experimental unit. Cows were fitted with accelerometers on their left back leg to determine activity, and blood samples were collected from all animals at the end of each period to estimate BUN. Representative samples of grass and supplement were collected from each period and paddock and analyzed for CP and fiber content. Herbage availability (DM basis) in each paddock was assessed before and post-grazing during each period using a rising plate meter and calibration curves. neutral detergent fiber (NDF) (62.9 to 65.1 ± 0.5%) and and acid detergent fiber (ADF) (38.7 to 43.9 ± 0.3%) increased, whereas CP (6.8 to 3.9 ± 0.1%) declined from Period 1 to 4 (P &amp;lt; 0.05). Initial biomass was 5,272 ± 211 Kg/ha and it declined after grazing (Period 4) to 2,319 ± 94 Kg/ha (P &amp;lt; 0.05) with no differences between treatments (P &amp;gt; 0.05). No differences between treatments were observed on motion index, number of steps taken per day, and the proportional percentage of time cows spent standing (9,379 ± 740, 2,611 ± 300, and 54.9 ± 0.02%, respectively; P &amp;gt; 0.05), suggesting that cows in TT did not invest extra time in searching activities or resting relative to Ctrl. It was only detected a greater percentage of transitions from lying to standing in TT than in Ctrl (7 to 3.4 ± 0.003%; P &amp;lt; 0.001). Values for BUN did not differ between treatments (P &amp;gt; 0.05), although they declined from Baseline to Period 4 by 28 % (8.2 to 5.9 ± 0.2mg/dL) in TT and by 2.6 % (5.75 to 5.6 ± 0.01 mg/dL) in Ctrl (P &amp;lt; 0.05). These results suggest that the addition of low levels of tannins to a protein supplement in cows grazing a low-quality grass diet reduces ruminal proteolysis without adversely influencing biomass removal or animals’ levels of activity.

PSXI-23 Development of sub-models to estimate protein requirements and supply of lactating dairy cows using machine learning algorithms

Abstract The objectives of this study were to develop sub-models for predicting protein requirements and supply, encompassing 1) net protein for maintenance (NPm), 2) lactation (NPl), 3) rumen undegradable protein (RUP), and 4) duodenal microbial nitrogen (MicN) from the feed protein. The dataset used in this study was constructed by integrating in vivo experimental data collected from open databases (the National Animal Nutrition Program) and articles (Journal of Dairy Science), which includes a total of 1,779 observations from 436 publications. In the development of the model, animal information and feed chemical components were used as candidate variables, and two types of machine learning algorithms, Random Forest Regression (RFR) and Support Vector Regression (SVR) were employed. After testing, the following predictors were selected for predicting: 1) NPm: body weight (BW) and dry matter intake (DMI), 2) NPl: BW, DMI, days in milk (DIM), and dietary organic matter (OM) and crude protein (CP) contents, 3) RUP: DIM, DMI, dietary DM content, and CP fraction intake (B and C), and 4) MicN: DIM, DMI, DM, dietary neutral detergent fiber (NDF) content, CP fraction intake (A, B, and C). The selected models were assessed using a cross-validation method with the following statistical metrics including the coefficient of determination (R2), root-mean-square error of prediction (RMSEP), residual analyses, and concordance correlation coefficient (CCC). For the RUP and MicN models, they were compared with the NASEM (2021) model. In predicting NPm, both SVR and RFR algorithms demonstrated increased precision (R2 = 0.965 vs. 0.969) and accuracy (RMSEP = 9.7 vs. 9.2 g/d); however, during residual analysis, the RFR model showed a statistically significant slope bias (P &amp;lt; 0.05). In the NPl prediction, the RFR algorithm showed slightly greater performance compared with SVR (R2 = 0.864 vs. 0.814 and RMSEP = 86.7 vs. 98.5 g/d). However, similar to the NPm prediction, the RFR model displayed a statistically significant slope bias (P &amp;lt; 0.05). In the supply model, the RFR model exhibited the greatest precision and accuracy in predicting RUP (R2 = 0.60, RMSEP = 0.326 kg/d, and CCC = 0.71) without any biases. This model achieved a 2.37-fold increase in R2 and a decrease of 0.111 kg/d in RMSEP compared with the NASEM model. As for MicN prediction, the SVR model performed the best (R2 = 0.76, RMSEP = 42.4 g/d, and CCC = 0.86) without biases. This model attained a 19-times improvement in R2 and a reduction of 38.7 g/d in RMSEP when compared with the NASEM model. In conclusion, the models developed using machine learning algorithms can be helpful for accurately and precisely predicting protein requirements and supply based on animal information and the chemical composition of feed.

PSV-26 Effect of addition of Ascophyllum nodosum and Asparagopsis taxiformis, alone or in combination, to an herbage-based diet on in vitro fermentation in continuous culture

Abstract This study investigated the effect of individual or simultaneous addition of two macroalgae species on in vitro fermentation in continuous culture. Four single-flow continuous culture fermentors were fed an orchardgrass herbage-based (orchardgrass; Dactylis glomerata L.) basal diet and randomly assigned one of four treatments: 1) control (CON), no macroalgae addition; 2) Ascophyllum nodosum dosed at 2.5% dry matter (DM; ASC); 3) Asparagopsis taxiformis dosed at 0.5% DM (ATX); and 4) A. nodosum (2.5% DM) + A. taxiformis (0.5% DM) dosed simultaneously (AS+AT). Four experimental periods were conducted in a randomized block design with 7 d of treatment adaptation and 3 d of sample collection. Fermentors were fed 82 g of DM per day in 4 equal feedings. In the last 3 d of each experimental period, daily samples of total effluent were taken for analyses of ammonia N and volatile fatty acids (VFA). Effluent was composited by fermentor and analyzed for DM, ash, neutral and acid detergent fiber, and crude protein. Purine concentrations of effluent and bacterial isolates were determined to estimate partitioning of N flow into feed, bacterial, and ammonia N fractions. Methane (CH4) emissions were measured in each fermentor every 15 min using a Fourier transform infrared gas analyzer, and pH was recorded every 2 min. Data were analyzed using the MIXED procedure of SAS v 9.4 with pre-planned contrasts comparing each individual macroalgae to CON (CON vs. ASC and CON vs. ATX) and comparing A. taxiformis with and without simultaneous addition of A. nodosum (ATX vs. AS+AT). Significance was declared at P ≤ 0.05 and tendencies at 0.05 &amp;lt; P ≤ 0.10. Nutrient digestibilities, CH4 emissions, pH, and N metabolism variables were not affected (P &amp;gt; 0.10) in ASC compared with CON, but total VFA concentration increased (P &amp;lt; 0.05) by 10%. Contrarily, the ATX diet tended (P = 0.61) to have reduced true organic matter digestibility, reduced (P &amp;lt; 0.05) total VFA concentration by 11%, and reduced (P &amp;lt; 0.05) CH4 production by 99.9% versus CON. Simultaneous the combination of microalgae (AS+AT) did not further reduce (P &amp;gt; 0.10) nutrient digestibility or total VFA concentration compared with ATX, and did not change (P &amp;gt; 0.10) the degree of CH4 inhibition. However, A. nodosum did not mitigate (P &amp;gt; 0.10) any of the negative effects on fermentation associated with A. taxiformis, as nutrient digestibilities and N metabolism variables in AS+AT were also not different (P &amp;gt; 0.10) from ATX. While the macroalgae species, A. nodosum and A. taxiformis, led to different fermentation patterns when added individually to continuous culture fermentors, no negative or positive interactions were observed from their simultaneous addition.