Organic Matter Digestibility Research Articles

Effect of combination of essential oils on in vitro methane production, volatile fatty acid fractions and feed digestibility with goat rumen flora

Different combination of garlic oil (GO from Allium sativum L.), clove oil (CO from Eugenia spp.) and peppermint oil (P from Mentha piperita L.) as GO+PO (1:1), GO+CO (1:1), CO+PO (1:1) and GO+PO+CO (1:1:1) was evaluated in in vitro gas production test for their effect on total gas production, methane production, dry matter organic matter digestibility and volatile fatty acid fractions. The addition level was low (D1) at 0.25 g/L, medium (D2) at 0.5 g/L, and high (D3) at 1.0 g/L of fermentation medium. Concentrate mixture and bengal gram straw (Cicer arietinum L.) in 40:60 ratio was incubated with incubation medium containing goat rumen liquor for 24 h at 39°C in glass syringes. Three goats fed with concentrate pellet and Bengal gram straw served as donor of the rumen liquor. In vitro fluid pH varied between 6.50 to 6.59. Total gas production (mL/g DM) in control group was 154.07, at lower dose level (0.25 g/L) there was increase in gas production which significantly decreased at highest dose level. There was significant (P<0.05) decrease in the methane production (mL/g DM and mL/g DDM) on GO and PO supplementation together. At low dose level (D1, 0.25g/L) there was no statistically (P>0.05) significant difference in in vitro dry matter and organic matter digestibility with the addition of different EO combinations evaluated as compared to control except PO+ CLO (1:1). At dose level (D2 and D3) GO+PO combination led to a moderate decrease in the in IVDMD and IVOMD along with decrease in in vitro methane production. Fraction of propionic acid was higher on addition of garlic and peppermint oil together. There was relative decrease in the methanogens population with bacteria as housekeeping gene as expressed by RT-PCR amplification with GO+PO addition. Present study concluded that among the EOs combinations in vitro tested, garlic and peppermint oil combination (GO+PO) has better potential in reducing in vitro methane production with lower effect on in vitro digestibility.

Effects of the level and source of dietary physically effective fiber on feed intake, nutrient utilization, heat energy, ruminal fermentation, and milk production by Alpine goats

Thirty-two primiparous and 31 multiparous Alpine goats were used to determine influences of diets varying in level and source of forage on performance in early to mid-lactation for 16 wk. Diets consisted of 40%, 50%, 60%, and 70% forage (designated as 40F, 50F, 60F, and 70F, respectively) with 60F and 70F containing coarsely ground grass hay (primarily orchardgrass) and 40F and 50F containing cottonseed hulls, alfalfa pellets, and coarsely ground wheat hay. Diets contained 15.9% to 16.3% crude protein and 37.8%, 42.1%, 53.5%, and 55.4% neutral detergent fiber (NDF) with 10.0%, 15.8%, 50.1%, and 55.5% particle retention on a 19-mm sieve, and 26.1%, 29.6%, 38.3%, and 40.0% physically effective NDF (peNDF) for 40F, 50F, 60F, and 70F, respectively. Dry matter intake (2.71, 2.75, 1.96, and 1.95 kg/d) and milk yield (2.82, 2.71, 2.23, and 2.10 kg/d for 40F, 50F, 60F, and 70F, respectively) were lower (P < 0.05) for the two diets highest in forage. Digestion of organic matter was similar among diets (P > 0.05), but digestibility of NDF was greater (P < 0.05) for 60F and 70F (57.5%, 58.4%, 68.9%, and 72.2% for 40F, 50F, 60F, and 70F, respectively). Diet affected (P < 0.05) milk fat (3.16%, 3.37%, 2.93%, and 2.97%) and protein concentrations (2.62%, 2.69%, 2.58%, and 2.52% for 40F, 50F, 60F, and 70F, respectively). Milk energy yield was greater (P < 0.05) for the two diets lowest in forage (7.51, 7.45, 5.68, and 5.34 MJ/d), although yield relative to dry matter intake was not affected (P > 0.05) by diet and was lower (P < 0.05) for primiparous vs. multiparous goats (2.71 and 3.09 MJ/kg). Ruminal pH and acetate proportion were greater for 60F and 70F than for the other diets and the proportion of butyrate was lower for the two diets highest in fiber. The mean lengths of time spent ruminating, eating, standing, and lying were not affected (P > 0.05) by diet or parity, but many interactions involving diet, period, hour, and parity were significant (P < 0.05). In conclusion, lactational performance of Alpine goats in early to mid-lactation will be constrained with diets high in forage of moderate quality, peNDF content, and large particle size, which appeared related to limited feed intake.

144 Utilizing invasive pigweed (Amaranthus Spinosus) as a novel methane mitigation strategy in beef cattle feed: A sustainable approach

Abstract By 2050, the US beef industry must produce an extra 40 million tons of beef to satisfy the global demand, while reducing methane (CH4) emissions. This surplus of cattle will be provided mostly by cow-calf operations, which rely primarily on grazing. Those pastures are often infested with weeds such as pigweed (Amaranthus spinosus), one of the most invasive in the US, known for its increased polyphenols concentration. Despite the known effect of polyphenols on CH4 reduction, few studies have explored pigweed as a feed additive. Our objective was to evaluate the effect of in vitro addition of pigweed on ruminal fermentation, digestibility, and CH4 production. We collected ruminal fluid from three American Aberdeen steers (374 ± 21 kg) receiving a backgrounding diet (80:20% corn silage:cotton gin trash, as fed). We incubated (24 h, 39°C) diet (0.7 g) plus the inclusion of 0, 2.5, 5, or 10% (of diet DM) of roots, stems, leaves, seeds, or the whole pigweed plant (WHO). Volatile fatty acids (VFA), CH4 (mmol g-1 organic matter), ammonia, pH, gas, in vitro dry matter, and organic matter digestibility (IVDMD and IVOMD) were determined. Using the MIXED procedure of SAS, data were analyzed as a randomized complete block design with a 5 × 4 factorial arrangement of treatments with plant part (n = 5) and inclusion level (n = 4) as fixed main factors. Incubation and bottle within incubation were random effects. Polynomial orthogonal contrasts were used to determine linear, quadratic, and cubic effects of inclusion level. Plant × level interactions were detected in acetate, propionate, and butyric molar proportion, total VFA, CH4 production, and IVDMD (P &amp;lt; 0.01). Increasing levels of stems increased acetate concentration (P = 0.03), while those from WHO led to a linear reduction of acetate (P &amp;lt; 0.01). The inclusion of 2.5% of leaves, seeds, and WHO increased propionate concentration (P = 0.05), but greater levels decreased it (P &amp;lt; 0.01). Increasing levels of all parts decreased acetate:propionate proportion (P &amp;lt; 0.001). Increasing levels of WHO resulted in a linear reduction of CH4 production (P &amp;lt; 0.05), while increasing inclusion of roots and stems increased CH4 production (P &amp;lt; 0.01). Quadratic reductions in CH4 production were observed after increasing the addition of leaves, seeds, and WHO (P &amp;lt; 0.001). Increasing levels of leaves and roots decreased ammonia concentration (P &amp;lt; 0.01) while stems increased it (P = 0.01). Except for stems and roots, there was a linear decrease in IVDMD with increasing levels of all parts (P &amp;lt; 0.001). The inclusion of low levels of seeds, leaves, and WHO promoted ruminal changes leading to a reduction of CH4 production without significantly compromising the digestibility.

91 Mealworm and black soldier fly larvae as protein supplements for beef steers consuming forage

Abstract The global population is projected to increase, indicating there will be greater demand for animal protein to meet the associated food needs. This demand will place additional pressure on livestock systems to increase output while also minimizing natural resource inputs. Insect protein has emerged as a potential environmentally sustainable alternative to conventional protein feeds, such as soybean meal. Further, insect protein does not compete in the human food market as the products of conventional oil crops often do. Mealworm larvae (MWL) has been studied in poultry and swine as an alternative protein feed; however, there is not currently research evaluating MWL for cattle. Black soldier fly larvae (BSFL) has also received attention for its potential use in livestock feed due to its scalability and nutritional value, but research in cattle is limited. The objective of this study was to evaluate the effects of whole dried MWL and defatted BSFL as protein supplements for cattle consuming forage. These procedures were approved by IACUC at Texas State University (#7726). Five ruminally cannulated steers were utilized in a 5×5 Latin square experiment to determine how MWL and BSFL supplementation affect forage utilization. Steers consuming low-quality forage (4.2% crude protein) were provided one of five treatments each period: 1) control with no supplement (CON), 2) soybean meal (CONV), 3) BSFL, 4) MWL, and a 5) 50% BSFL and 50% MWL by-weight (MIX). Supplements were provided at 100 mg N/kg BW. Periods included 8-d for treatment adaptation, 5-d for intake and digestion measurements, and 1-d for ruminal fermentation measures. Dry matter (DM), organic matter (OM), CP, neutral detergent fiber (NDF), and acid detergent fiber (ADF) were determined for diet, ort, and feces. Protein supplementation stimulated forage OM intake (P ≤ 0.01) relative to CON. There was a significant difference in FOMI (P ≤ 0.01) between BSFL and CONV. Steers receiving CONV treatment consumed 4.71 kg FOMI/d, which was significantly greater (P ≤ 0.01) than those receiving BSFL (4.30 kg/d). There were not differences in FOMI between other treatment groups. Total digestible OM intake (TDOMI) was stimulated by protein supplementation (P ≤ 0.01) from 1.94 kg/d for CON to an average of 3.24 kg/d across protein supplements. Organic matter digestibility (OMD) and neutral detergent fiber digestibility (NDFD) were not affected by treatment (P ≥ 0.37), for an average OMD of 66.5% and NDFD of 62.7%. There was also not a treatment effect (P = 0.96) on total volatile fatty acid (VFA) concentrations, although there were some shifts in molar proportions of individual VFAs across treatments. These data indicate that MWL may be more efficacious than BSFL in stimulating forage utilization in beef cattle, but both are viable protein supplements.

Chicory root powder included as a prebiotic in different cereal-based diets for dogs: Influences on gut health, metabolic and immunological status

The present experiment was conducted to study the influence of chicory root powder as a prebiotic on gut health, metabolic, and immunological status of dogs fed with different cereal-based diets. Sixteen Labrador dogs, fed either a wheat (WT) or sorghum (SG) based diet, each without (C) or with (P) supplemental chicory root powder at 10 g/kg diet, were divided into four equal groups namely WT-C, WT-P, SG-C and SG-P. The digestibility of DM, OM, and total carbohydrates was significantly (p < 0.05) higher with the SG-C diet than with the other diets. Faecal ammonia was reduced (p = 0.002) in the WT-P group; however, there were no differences (p > 0.05) observed in the faecal pH and contents of lactate, acetate, propionate and total short chain fatty acids (SCFAs). The faecal lactobacilli population was higher (p = 0.001) in both the prebiotic-supplemented groups with a similar trend (p = 0.079) for bifidobacteria. Coliform counts were reduced (p = 0.002) in prebiotic-supplemented diets irrespective of cereals. There were significant (p < 0.05) variations in haemoglobin and haematocrit values among the dietary groups. The delayed-type hypersensitivity response to intradermal phytohemagglutinin (PHA-P) was higher (p<0.001) in both the prebiotic-supplemented groups; a similar trend was evident in the humoral immune response measured as antibody response to sheep erythrocytes. The peripheral lymphocyte subpopulations of CD4+ and CD8+ varied with prebiotic supplementation of the sorghum-based diet. Overall, the findings implies that tailoring the dietary composition to include specific cereals may optimize the beneficial effects of prebiotics in supporting canine health.

Total Replacement of Soybean Meal with Sundried Soymilk Residue in the Total Mixed Ration has a Negative Impact on Intake, Digestibility, and Milk Production in Dairy Goats.

This study aimed to evaluate whether total replacement of soybean meal (SBM) with sundried soymilk residue (SSR) in a total mixed ration (TMR) affects intake, digestibility, milk production, and blood metabolites in dairy goats. A total of 12 healthy Saanen dairy goats (40.12 ± 5.80 kg of BW) in midlactation (31.23 ± 10.12 days) were used in a randomized complete design (n = 4 goats/group). Dietary treatments were based on a TMR as follows: control TMR without SSR (CON) or SBM-based TMR with 50% or 100% of SSR replacing SBM (SSR-50 and SSR-100, respectively). All goats had ad libitum access to feed and clean water throughout the experiment. The dry matter (DM) intake decreased (p < 0.05) with the increasing replacement ratio of SBM and was lowest in the SSR-100 group. Similarly, organic matter (OM) digestibility was lowest (p < 0.05) in the SSR-100 group. However, the digestibility of DM, CP, NDF, and ADF did not change (p > 0.05) by dietary treatments. Compared with CON, the milk yield decreased significantly (p < 0.05) with increasing replacement ratio of SBM. In contrast, milk composition such as total solids, solids-not-fat, milk fat, lactose, protein, and pH were not influenced (p > 0.05) by feeding dietary SSR. Compared with other treatments, blood glucose concentration was lower (p < 0.05) in the SSR-100 group. In contrast, packed cell volume, glucose, and plasma urea nitrogen concentrations did not differ (p > 0.05). The results indicated that SSR could replace SBM in a TMR at less than 50%. Thus, the present study provides support for further investigation to enhance the utilization of soybean waste as an alternative protein source in the TMR for dairy goats and potentially other ruminants.

145 The effect of a plant secondary metabolite blend on energy metabolism and nutrient balance of beef cattle consuming low-quality warm season grass hay

Abstract Plant secondary metabolites (PSM) such as condensed tannins, hydrolysable tannins, saponins and essential oils purportedly impact rumen fermentation at low inclusion rates in beef cattle diets. Twelve steers (347 ± 23 kg BW) of British and continental influence were allocated to 1 of 4 replicated 3 x 3 Latin squares. Latin squares each had 14 d periods (10 d adaptation and 4 d for sample collection). All cattle were fed ground warm-season hay (89.5% DM, 92.8% OM, 65.9% NDF, 43.6% ADF, 6.70% CP) at 1.5% of BW (DM-basis) and supplemented with soybean meal at 0.18% of BW (DM-basis) once daily. Treatments consisted of a blend of tannins, saponins and essential oils provided at 0% (Control), 0.1% (Low) and 0.3% (High) of hay offering. Treatments were mixed with daily soybean meal allotment and provided before feeding of hay. Urine and feces were completely collected from d 11 through 14 at 0730 h and daily amounts of urine and feces produced were measured gravimetrically. Measures of gaseous exchange were determined via indirect calorimetry on d 13 and 14. Open-circuit respiration calorimeters (91.4 × 91.4 × 191.2 cm) were used to collect respired gas and ruminal methane production. Total oxygen consumption and production of carbon dioxide and methane were calculated from the difference in concentration of oxygen, carbon dioxide, and methane from air exhausted from each calorimeter and concentration of oxygen, carbon dioxide, and methane in ambient air and multiplied by amounts of air flowing from each calorimeter standardized for temperature, pressure, and humidity. Data were analyzed for a Latin square using the MIXED procedure of SAS with fixed effect of treatment, period and square and random effect of steer. Linear and quadratic contrast coefficients were assigned using PROC IML for uneven spacing of treatments. Significance was declared when P ≤ 0.05. Per experimental design, forage N and OM intake did not differ (P ≥ 0.77). Apparent total tract digestion of OM, NDF and ADF did not differ (P ≥ 0.66) among treatments. Fecal nitrogen excretion, and the percentage of N excreted in feces increased linearly (P = 0.01). N balance tended (P = 0.08) to decrease linearly with increasing PSM supplemented. Methane (L/kg DMI) was not affected (P = 0.28) by treatments. Methane, GE, DE, and ME (mcal/kg DMI) was unaffected (P = 0.19) by treatment. Under the conditions of this experiment, a blend of PSM had little effect on rumen fermentation or energy metabolism in beef steers.

79 Dietary buffer comparison and tannins supplementation modulating subacute ruminal acidosis and fermentation in beef cattle

Abstract As the demand of nutrients by the population will continue to grow over the years, efficient practices are required in the food chain to satisfy the demand. This practice involves the intensification of production systems. Moreover, intensification can potentially harm the animal or environment if the resources are used to the limit. The latter, product of pushing to the limit the ruminal environment. Dietary buffers and tannins offer a key role addressing issues related to intensification. This study aimed to evaluate the effects of two dietary buffers and tannins. Ruminal fermentation parameters, in vitro methane production, ruminal pH, in vitro organic matter digestibility were measured. Eight ruminally cannulated steers were used in a duplicated 4 x 4 Latin square design. Steers were fed with a basal diet comprised of 35.5% corn silage, 18.7% protein supplement, 21.5% corn grain, 22% bermuda hay, 1% mineral supplement (DM basis). Four treatments were used: BICARB (Basal diet + 1.2% DM Sodium Bicarbonate), BRIC-050 (Basal diet + 1.2% DM BRIC), BRIC-150 (Basal diet + 1.2% DM BRIC + 0.15 % DM Tannins), TAN (Basal diet + 0.15% DM Tannins). Steers were housed in individual pens and received every morning a TMR and water ad libitum. The experiment consisted of 4 periods with 16 days total, composed by 3 d of covariates, 7 d of treatment adaptation, 1 d of 50% feed restriction, 1 d SARA challenge, 4 d of recovery, and 20 d of washout between periods. Two in vitro batch culture were performed in every period at the last day of covariates and last day of recovery, collecting ruminal fluid from each animal. Treatments with BICARB promoted a higher pH than TAN during the adaptation at 4 h after feeding (P = 0.01). Moreover, BRIC-150 showed similar results with a tendency to increase (P = 0.07) when compared with TAN. During the feed restriction BRIC-150 showed a greater pH (P = 0.01) when compared with TAN. While, for BICARB and BRIC-050 pH tended to be greater (P = 0.06) than TAN. During the SARA challenge and the recovery, treatments with buffer tended to have greater pH (P &amp;lt; 0.1). A significant reduction ammonia nitrogen was observed for BICARB and TAN compared with BRIC-050 and BRIC-150 (P &amp;lt; 0.01). Overall, the three buffers tested showed similar results in terms of maintaining a greater pH than treatment without buffer.

149 Using respiratory gas flux and backward dietary energy partitioning to estimate energy intake by beef cattle fed a high concentrate diet

Abstract Twelve Charolais steers (BW = 498 ± 47.4 kg) were used in a 73-d feeding experiment. Our objective was to determine if CH4 and CO2 emissions, and O2 consumption could be used as biomarkers to estimate energy intake in growing beef cattle when integrated with backward dietary energy partitioning calculations when fed a high concentrate diet. Steers were housed in a pen equipped with individual feed bunks with access to an automated head chamber system (AHCS; GreenFeed, C-Lock, Inc., Rapid City, SD). Steers were randomly assigned to 1 of 3 treatments according to DMI as multiple of maintenance, which are 1.1 (1.1 M, n = 4), 1.4 (1.4 M, n = 4), and 1.8 (1.8 M, n = 4). The diet fed was 35% chopped sorghum hay (CP = 6.39% of DM; in vitro OM digestibility = 57.77%) and 65% concentrate (CP = 19.10% of DM; in vitro OM digestibility = 91.84%). The concentrate consisted of 41.75% flaked corn, 8.5% cottonseed meal, 13% distillers’ grain and 1.75% limestone. Steers were supplemented daily with 0.85 kg of alfalfa pellets (Medicago sativa; CP= 16.55%; in vitro OM digestibility = 87.01%) that were fed through the AHCS as bait. Methane tended (P = 0.09) and CO2 emissions and O2 consumption (P &amp;lt; 0.01) increased with the increasing feeding rates. Measured gross energy (GE; 21.9, 24.8, 29.5 Mcal/d, respectively), digestible energy (DE; 19.7, 22.0, 25.8 Mcal/d, respectively), and metabolizable energy (ME; 17.2, 19.2, 22.7 Mcal/d, respectively) intake levels increased with the increases in energy retention and heat production. The predicted values for GE (17.4, 23.6, 28.2 Mcal/d), DE (15.1, 20.8, 24.4 Mcal/d), and ME (12.6, 17.9, 21.3 Mcal/d) intake rates increased with the increase from 1.1 M to 1.8 M. Comparison of measured and predicted GE, DE, and ME intake rates agreed closely (r = 0.95, 0.93, 0.92 Pearson correlation, respectively). This experiment shows that together with multiple short-term breath measurements from an AHCS, BW, and an estimate of average daily gain, GE, DE, and ME intakes by cattle consuming a high concentrate diet can be predicted.

In vitroruminal fermentation, core nutrient, fatty acids and mineral matter of pennyroyal (Mentha pulegium L.) herbage at different phenological stages.

In ruminants, fibrous feedstuffs must be included in the ration to ensure normal rumen physiology and to prevent the occurrence of rumen-related metabolic diseases. In addition to being a source of fibrous feedstuffs, they contain energy depending on the level of digestion and protein, minerals, fatty acids, minerals, and secondary compounds. This study aimed to determine the nutrient matter, fatty acid, mineral and in vitro rumen fermentation values of the pennyroyal (Mentha pulegium L.) plant. The pennyroyal plant samples were collected at different phenological stages (vegetative, full flowering, and seed bulking) from the natural meadow. The samples were analysed for core nutrients, condensed tannins, minerals, fatty acids, and in vitro ruminal fermentation parameters. The calcium (Ca) and iron (Fe) contents and in vitro ruminal fermentation parameters (total gas production and methane production, organic matter digestion (OMd), and the ammonia-nitrogen) decreased with increasing phenological stage (p < 0.05). The percentages of linoleic, α-linolenic, ω-3, ω-6 and polyunsaturated fatty (PUFA) acids of the pennyroyal plant linearly increased with the phenological stages (p < 0.05). However, butyric acid (BA) concentration in the in vitro ruminal fermentation fluid in the full flowering stage was lower than that of other stages (p < 0.05). Pennyroyal plant is a functional plant in terms of high values of ether extract (EE), α-linolenic acid, linoleic acid, ∑ω-3 fatty acids, Ca, Fe and Zn contents. For this plant to be used as animal feed, the stage when it has the highest values for Ca, Mg, S and Zn minerals and in vitro OMd were vegetative and full flowering. The stage with good potential as animal feed for ∑ω-3 and ∑ω-6 fatty acids and core nutrients (CP and EE) is the seed bulking stage.

Management strategies to improve the nitrogen use efficiency in grasslands and the protein quality in grass silages: Lessons from a practical study on dairy farms in Flanders

AbstractBackgroundGrasslands are the primary source of forage for ruminants. Legal restrictions on nitrogen fertilization force farmers to optimize nitrogen use efficiency (NUE) of grassland and protein quality in grass silage.MethodsThe present study included grassland data from 10 dairy farms in Flanders. For each grassland field, the presence of clover was determined based on the seed mixture composition. Soil and manure were sampled before the first application and analyzed to determine plant available N content. The annual NUE was calculated for each field possible (n = 28). Prewilted grass samples were taken just before ensiling (n = 65) and grass silage samples (n = 41) were collected from the same fields.ResultsClover fields demonstrated improved NUE due to a lower nitrogen input from fertilizers compared to pure grassland fields (75 vs. 265 kg ha−1). The protein quality of the grass silage was positively correlated with the organic matter digestibility, sugar content, and dry matter content of the prewilted grass. Conversely, crude ash content had a negative effect.ConclusionsThese findings underscore the importance and potential of clover and the practical feasibility of optimizing grassland management to improve both NUE in grasslands and protein quality of the silage.

Effects of supplemental bacteriophage on the gut microbiota and nutrient digestibility of ileal-cannulated pigs.

This study measured the potential changes of the microbiota in the gastrointestinal tract and energy and nutrient digestibility by supplemental bacteriophages in pigs. Twelve castrated male pigs (initial mean body weight = 29.5 ± 2.3 kg) were surgically cannulated using T-cannula. The animals were housed individually in pens equipped with a feeder and a nipple waterer. The pigs were allotted to 1 of 3 experimental diets in a quadruplicated 3 × 2 Latin square design with 3 experimental diets, 2 periods, and 12 pigs resulting in 8 replicates per diet. The 3 diets were a control mainly based on corn and soybean meal with no antibiotics or bacteriophages, a diet containing 0.1% antibiotics, and a diet containing 0.2% bacteriophages. On day 5 of the experimental period, feces were collected and on days 6 and 7, ileal digesta were collected. Genomic DNA for bacteria were extracted from the ileal digesta and feces and the V4 region of the 16S rRNA gene was amplified. The ileal and fecal digestibility of energy, dry matter, organic matter, crude protein, and fiber was unaffected by dietary antibiotics or bacteriophages. At the phylum level, the supplemental antibiotic or bacteriophage tended to result in a higher proportion of Firmicutes (p = 0.059) and a lower proportion of Bacteroidetes (p = 0.099) in the ileal digesta samples compared with the control group with no difference between the antibiotic and bacteriophage groups. At the genus level, the supplemental antibiotic or bacteriophage tended to result in a higher proportion of Lactobacillus (p = 0.062) and a lower proportion of Bacteroides (p = 0.074) and Streptococcus (p = 0.088) in the ileal digesta compared with the control group with no difference between the antibiotic and bacteriophage groups. In the feces, supplemental antibiotics or bacteriophages reduced the proportion of Bifidobacterium compared with the control group (p = 0.029) with no difference between the antibiotic and bacteriophage groups. Overall, supplemental antibiotics and bacteriophages showed positive effect on the microbiota of in the ileal digesta without largely affecting energy or nutrient digestibility, with no differences between the antibiotic and bacteriophage groups in growing pigs.

Time-varying microplastic contributions of a large urban and industrial area to river sediments

The quantification of microplastic (MP) pollution in rivers is often constrained by a lack of historical data on a multi-decadal scale, which hinders the evaluation of public policies. In this study, MP contents and trends were analyzed in dated sediment cores sampled upstream and downstream of a large metropolis, in environmental deposits that exhibited consistent sedimentation patterns from the 1980s to 2021. After a thorough sedimentological analysis, MPs were quantified in samples by micro Fourier Transform InfraRed spectroscopy (μFTIR imaging) and a density separation and organic matter digestion procedure. Microplastics recorded in the upstream core are relatively ubiquitous all along the dated sequence. The results also confirmed a sever increase of microplastics levels in the downstream core, by one order of magnitude, and an increase of polymer types. Polypropylene, polyethylene, and polystyrene represent ubiquitous contamination and were predominant at the two stations, whereas polyvinyl chloride and polytetrafluoroethylene were suspected to be abundant at the downstream station, but were not detected at the upstream station. Their presence could be linked to local contamination from specific industrial sources that manufactured and utilized these polymers. Surprisingly, in the downstream station sediment has recorded a relative improvement in polymers associated with industrial sources since the 2000s and, to a lesser extent, for ubiquitous ones since the 2010s. This trend of mitigation diverges from that of global assessments, that assume uncontrolled MP pollution, and suggest that European Union wastewater policy and regulation on industrial discharges have positively influenced water quality, and certainly also on MPs. However, the accumulation of microplastics remains high in recent deposits and raises the emerging concern of the long-term management of these reservoirs.

Feeding live or inactive yeast to primiparous Jersey cows: nutrient digestibility, rumen fermentation, and milk fatty acid profile

ABSTRACT The aim of this study was to evaluate the effects of live yeast (LY) or inactive yeast (IY) on intake and apparent total-tract digestibility of nutrients, ruminal fermentation, milk yield and composition, milk fatty acid profile, N utilisation, and microbial protein synthesis of primiparous Jersey cows. Twelve primiparous Jersey cows were employed, with an average body weight of 403 kg, a lactation period of 100 days, and average daily milk output of 14.7 kg. The experimental diets were: 1 – CON (no additives); 2 – LY (inclusion of 40 g/day of live yeast); 3 – IY (inclusion of 40 g/day of inactivated yeast wall). Cows fed LY exhibited the greatest DM intake. Cows’ intake IY had the greatest digestibility of DM, OM, and NDF. Feeding IY reduced ruminal concentrations of acetate, isobutyrate, and branched-chain fatty acids. Cows fed either LY or IY increased the production of milk and FCM. Cows under the LY treatment had greater milk fat content. Cows fed LY had the greatest N intake. Yeast treatments also increased the absorbable purine estimation. Supplementing primiparous dairy cows with yeast products, especially live yeast, improved dry matter intake by positively influencing digestibility, particularly for starch and NDF.

Effect of Rosemary (Rosmarinus officinalis L.) Powder Supplementation on Silage Fermentation Characteristics, Silage Quality, and In Vitro Digestibility in Corn Silage

The purpose of this study was to investigate how the addition of rosemary to corn silage affected the quality, fermentation, and in vitro digestion of organic matter. In the study, unaltered silage group constituted the control group, while silages prepared by adding 0.5, 1 and 2% rosemary constituted the experimental groups. After 60 days of ensiling, the pH of the opened silages was determined to be in the range of 3.67-3.72. As the amount of rosemary in the silages increased, the levels of ammonia nitrogen (NH3-N/TN) decreased. Compared to the control group, increases in in-vitro organic matter digestion (IVOMD) and metabolizable energy (ME) values were observed in the experimental groups due to the addition of rosemary. In comparison to the control group, the methane gas (CH4) rate of silages was reduced in the other groups. Meanwhile, the group receiving 2% addition of rosemary had the highest values of acetic acid (AA) and lactic acid (LA) among the supplemented silage groups. But, propionic acid (PA) and butyric acid (BA) were not detected in any of the silage groups. Consequently, it was determined that 1% and 2% of rosemary added to corn silage can enhance the quality of the silage.

EFFECT OF REPLACING TREATED AND UNTREATED CORN IMPURITIES WITH UREA INSTEAD OF WHEAT BRAN ON PRODUCTIVE PERFORMANCE OF AWASSI LAMBS

The study was conducted to study the effect of replacing different levels of treated and untreated corn impurities with urea instead of wheat bran on productive performance of Awassi lambs. Wheat bran were replaced by five levels of treated and untreated corn impurities as: 44:0%, 32:11%, 20:22%, 10:32% and 0:39% bran: impurities in a 2×5 factorial experiment. Concentrated fed at 3% of live body weight as dry matter basis, while alfalfa hay was offered ad libitum. Forty Awassi lambs were used, with an initial weight of 27.45 ± 2.16 kg and 4-5 months old. All lambs were fed individually feeding for 70 days, preceded by 14 days as adaptation period. Results showed a non-significant superiority in dry matter and nutrients intake by increasing corn impurities and a highly significant increased (p&lt;0.01) in ether extract and ash intake (g/day), with superiority of digestibility (P&lt;0.05) of organic matter% (OM) and crude protein% (CP), feed efficiency, daily gain (g/ day) and total weight gain (kg) for feeding 30% of corn impurities treated with urea (T9). In conclusion, it is possible to use corn impurities instead of wheat bran, preferably treated with urea to increase crude protein content, degraded crude fibers and improved nutritional values.

Long-Term Effects of Pre-Weaning Individual or Pair Housing of Dairy Heifer Calves on Subsequent Growth and Feed Efficiency.

Our objective in this exploratory study was to evaluate the long-term impacts of pre-weaning social isolation vs. contact on subsequent growth and feed efficiency of Holstein heifers. As pre-weaned calves, 41 heifers were housed individually (n = 15 heifers) or in pairs (n = 13 pairs; 26 heifers). At 18 months of age, heifers were blocked by body weight and randomly assigned to one of three pens within a block (six to eight heifers per pen; six pens total), with original pairs maintained. Body weight (BW), hip height and width, and chest girth were measured at the start and end of the study. Each pen was given 3 days of access to a GreenFeed greenhouse gas emissions monitor to assess potential physiological differences between treatments in enteric methane emissions or behavioral differences in propensity to approach a novel object. During the 9-week study, heifers were fed a common diet containing 62.3% male-sterile corn silage, 36.0% haylage, 0.7% urea, and 1.0% mineral (DM basis). To calculate daily feed intake, as-fed weights and refusals were recorded for individual heifers using Calan gates. Feed samples were collected daily, composited by week, and dried to calculate dry matter intake (DMI). Feed refusal and fecal samples were collected on 3 consecutive days at 3 timepoints, composited by heifer, dried, and analyzed to calculate neutral detergent fiber (NDF), organic matter (OM), and DM digestibility. Feed efficiency was calculated as feed conversion efficiency (FCE; DMI/average daily gain [ADG]) and residual feed intake (RFI; observed DMI-predicted DMI). Paired and individually housed heifers did not differ in DMI, ADG, FCE, or RFI. Although no differences were found in initial or final hip height, hip width, or chest girth, heifers which had been pair-housed maintained a greater BW than individually housed heifers during the trial. Methane production, intensity, and yield were similar between treatments. Pre-weaning paired or individual housing did not impact the number of visits or latency to approach the GreenFeed; approximately 50% of heifers in each treatment visited the GreenFeed within 8 h of exposure. Digestibility of OM, DM, and NDF were also similar between housing treatments. In conclusion, pre-weaning pair housing had no adverse effects on growth, feed efficiency, or methane emissions at 18 to 20 months of age.

Effects of saturated fatty acids with lysophospholipids on production and nutrient digestibility in lactating cows

The objective of the experiment was to determine the effects of supplemental saturated fatty acid (SFA) sources, lysophospholipids (LPL), and their interaction on production and nutrient digestibility in lactating dairy cows. The experiment was conducted with 48 cows in a randomized complete block design. Cows were blocked (total 12 blocks) by parity and days in milk and randomly assigned to 4 dietary treatments in each block (2 × 2 factorial arrangement), i.e., 2 sources of fat supplements, C16:0 (palmitic acid, PA)- or C18:0 (stearic acid, SA)-enriched fat, with or without LPL. The experiment was conducted for 6 wk to measure daily dry matter intake and milk yield and weekly milk composition. During the last week of the experiment, spot fecal and urine samples were collected to determine total-tract nutrient digestibility. Milk samples in the last week were also collected to analyze for milk fatty acid (FA) profile. All data were analyzed using the mixed procedure of SAS where block was used as a random effect and FA, LPL, and the interaction of FA by LPL were used as fixed effects. Week and interactions of week by FA or LPL were included for production measures. Different sources of SFA did not affect dry matter intake and milk yield. However, PA increased (39.7 vs. 36.8 kg) energy-corrected milk compared with SA due to increased milk fat yield. No effect of LPL on production measures was observed. Total-tract digestibilities of dry matter, organic matter, crude protein, and total FA were not different between PA and SA, but PA increased (41.4 vs. 38.8%) neutral detergent fiber digestibility compared with SA. Supplementation of LPL increased (64.7 vs. 60.5%) total FA digestibility, especially 18-carbon FA (74.1 vs. 68.2%). An interaction of SFA by LPL was found for 16-carbon FA digestibility. The PA diet increased the concentration of 16-carbon FA in milk fat and SA increased the concentration of preformed FA (≥18 carbons). Supplementation of LPL decreased the concentration of trans-10 C18:1. No difference in N utilization and excretion among treatments was observed. In conclusion, PA was more effective in improving milk fat yield of lactating cows compared with SA. Supplementation of LPL increased digestibility of total FA, especially 18-carbon FA but did not affect production.

Timing of High-Energy Supplementation to Early-Season-Pasture-Forage Fed Continuous Culture

A continuous culture study was conducted duplicating the daily meal pattern of pasture-grazed cattle and evaluating the time of two supplements differing in their composition (one complex: SUPP A and one simplistic: SUPP B) on their effects on nutrient digestion and metabolism of ruminal microorganisms. SUPP A contained ingredients containing substantial amounts of both structural and non-structural carbohydrates (NSC), fat, and protein, all having fractions with differing rates of availability. SUPP B’s predominate organic matter ingredients were only corn grain and soybean meal and contained approximately 3% less crude protein than SUPP A. All treatments were fed forage at five distinct times, mimicking forage intake on pasture, with supplements being fed at either a morning (AM) or evening (PM) feeding. The treatments were a) SUPP A fed AM, b) SUPP B fed AM, c) SUPP A fed PM, and d) Supp B fed PM. The results showed that dry matter, organic matter, and NSC digestibility’s were unaffected by supplement type or time of feeding. Supplement A showed greater fiber digestion than SUPP B, regardless of time of supplementation. The PM feeding decreased the digestion of both neutral detergent fiber and acid detergent fiber in SUPP B with no effect on fiber digestion in SUPP A. Culture pH remained more stable over the 24-hour day with SUPP B feeding than it did with SUPP A feeding while average pH was not affected by supplement or time of feeding. Total volatile fatty acid flow was unaffected by treatment, as were flows of acetic and propionic acids. Butyric acid flow decreased significantly on both supplements with the PM feeding. As expected, there were fewer total branch chain volatile fatty acids generated with SUPP B. Microbial growth measured in g microbial N flow/day increased for both supplements at the PM feeding. Flow of by-pass feed nitrogen was unaffected by supplement but was lower with PM feeding. Microbial efficiency was increased as a result of the PM feedings. The timing of a large amount of supplementation relative to the timing of daily forage meals can alter the effects seen in continuous culture work and may translate to effects in-vivo systems as well.

Comparison of forages’ digestion levels for different in vitro digestion techniques in horses

Forages are widely used in horse diets. Different in vitro techniques are being tried to determine the fermentation levels of forages in the horse digestive tract. This study aimed to evaluate the digestion levels of four dry forages commonly used in horse nutrition: alfalfa herbage, meadow hay, wheat straw, and Italian ryegrass. In vitro total digestion (TDT), in vitro Sunvold-large intestine digestion (SDT) and in vitro Menke-large intestine digestion (MDT) techniques were compared. The study determined in vitro true dry matter digestion (T-DMD), in vitro true organic matter digestion (T-OMD) and in vitro true neutral detergent fibre digestion (T-NDFD). Additionally, concentrations of straight short-chain fatty acids (SCFAs; acetic acid - AA, propionic acid , butyric acid, and valeric acid ) and branched short-chain fatty acids (BSCFA) were assessed. The highest in vitro T-DMD, T-OMD and T-NDFD values were determined by the in vitro TDT for the four forages (p<0.05). In vitro T-DMD and T-OMD values of alfalfa herbage were higher than those of Italian ryegrass, meadow hay and wheat straw in the in vitro TDT (p<0.001). In addition, in vitro T-DMD and T-OMD values of alfalfa herbage in the in vitro SDT were higher than those of meadow hay and wheat straw (p<0.001). In the in vitro TDT, the molarity of AA, total SCFA and BSCFA in the digestion fluid of alfalfa herbage was higher than those of other forages (p<0.05). The in vitro total enzymatic+fermentative digestion technique for horse forages revealed higher values than the in vitro fermentative digestion techniques. In general, the higher the non-structural carbohydrate and crude protein contents in the forage, the higher the results of the in vitro TDT compared to the other techniques.