Organic Matter Digestibility Research Articles

Dose-dependent effect of spent coffee grounds on intake, apparent digestibility, fermentation pattern, methane emissions, microbial protein supply and antioxidant status in Latxa sheep.

Spent coffee grounds (SCG), a by-product rich in polyphenols, can form part of enteric CH4 mitigation strategies while promoting the circular economy. This study aimed to evaluate the effect of 3 levels of SCG inclusion in the concentrate on enteric CH4 production, feed intake, apparent digestibility, ruminal fermentation pattern, microbial protein supply and gene expression of immune and antioxidant markers in peripheral blood of dry dairy ewes. In a replicated 4 × 4 Latin square design, 8 non-productive Latxa ewes were assigned to a concentrate that differed in the level of SCG: Control (0g/kg DM), SCG100 (100g/kg DM), SCG150 (150g/kg DM) and SCG200 (200g/kg DM). In each period, 14 days of adaptation were allowed, followed by 7 days in individual metabolic cages, and 3 days in respiratory chambers. To avoid a carry-over effect a minimum of 7 days were allotted between periods in which ewes consumed control concentrate and grass hay. Total organic matter intake (OMI) and CH4 emissions (g/d) presented a quadratic response (P=0.008 and P<0.001, respectively) to increasing levels of SCG in the feed. However, when CH4 emissions were corrected for OMI, a linear decrease was observed with increasing levels of SCG in the concentrate (P=0.009). This reduction in CH4 emissions (g/kg OMI) could be explained by the linear decrease (P=0.034) observed in apparent digestibility of organic matter (OM), particularly in crude protein (CP) and starch (P=0.002 and P=0.003, respectively), with increasing levels of SCG in the concentrate. No significant response was found on CH4 emissions corrected for digestible OM and on ruminal fermentation pattern. Regarding microbial protein supply, a linear increase in microbial protein supply efficiency (P=0.008) was observed with increasing levels of SCG in the concentrate. Moreover, SCG inclusion linearly reduced interleukin 10 (P=0.031), nuclear factor E2-related factor 2 (P=0.007), nuclear factor kappa β (P=0.014), superoxide dismutase 1 (P=0.015) gene expression and tended to linearly reduce those of tumor necrosis factor-α (P=0.074) and glutathione peroxidase 1 (P=0.082). In conclusion, inclusion of SCG up to 200g/kg in the concentrate did not modify ruminal fermentation pattern, but linearly reduced CH4 emissions per kg of OMI, due to a linear decrease in apparent digestibility of CP and starch. Moreover, linearly increased the efficiency of microbial supply and improved sheep's blood antioxidant-immune status.

Effect of Partial or Complete Replacement of Dietary Inorganic Trace Minerals Supplement with an Advanced Chelated Source on Nutrient Digestibility in Sheep

The delicate balance of trace mineral supplementation is critical for optimizing rumen function and overall ruminant health. This study evaluated the solubility of an advanced chelate technology-based supplement and assessed its impact on rumen degradability and apparent total tract digestibility (ATTD) when replacing inorganic sources. The solubility of the advanced trace minerals supplement (ACTM) was assessed at pH 5 and pH 2. In situ ruminal degradability of dry matter (DM), organic matter (OM), and fiber fractions was evaluated using two fistulated rams fed diets supplemented with either ACTM or inorganic trace minerals. ATTD was determined in 6 lambs fed diets supplemented with 100% ACTM, 50% ACTM, and 50% inorganic (50% ACTM), or 100% inorganic sources in a Latin square design. Results showed solubilities ranging from 6.75% to 11.81% at pH 5, increasing to 69.24% to 80.47% at pH 2. ACTM supplementation significantly enhanced the rumen degradability of neutral detergent fiber (NDF) and acid detergent fiber (ADF) at 6 h of incubation (p ≤ 0.05). The 100% ACTM treatment significantly decreased rumen pH (p = 0.051) and improved DM, OM, NDF, and ADF digestibility, as well as trace mineral absorbability compared to 100% inorganic (p ≤ 0.05). These findings highlight the potential of ACTM supplementation to enhance ruminal degradability, promote better trace mineral absorption, and improve the ATTD of nutrients compared to inorganic sources.

Metabolomics and proteomics insights into hepatic responses of weaned piglets to dietary Spirulina inclusion and lysozyme supplementation

BackgroundStudying the effect of dietary Spirulina and lysozyme supplementation on the metabolome and proteome of liver tissue contributes to understanding potential hepatic adaptations of piglets to these novel diets. This study aimed to understand the influence of including 10% Spirulina on the metabolome and proteome of piglet liver tissue. Three groups of 10 post-weaned piglets, housed in pairs, were fed for 28 days with one of three experimental diets: a cereal and soybean meal-based diet (Control), a base diet with 10% Spirulina (SP), and an SP diet supplemented with 0.01% lysozyme (SP + L). At the end of the trial, animals were sacrificed and liver tissue was collected. Metabolomics analysis (n = 10) was performed using NMR data analysed with PCA and PLS-DA. Proteomics analysis (n = 5) was conducted using a filter aided sample preparation (FASP) protocol and Tandem Mass Tag (TMT)-based quantitative approach with an Orbitrap mass spectrometer.ResultsGrowth performance showed an average daily gain reduction of 9.5% and a feed conversion ratio increase of 10.6% in groups fed Spirulina compared to the control group. Metabolomic analysis revealed no significant differences among the groups and identified 60 metabolites in the liver tissue. Proteomics analysis identified 2,560 proteins, with 132, 11, and 52 differentially expressed in the Control vs. SP, Control vs. SP + L and SP vs. SP + L comparisons, respectively. This study demonstrated that Spirulina enhances liver energy conversion efficiency, detoxification and cellular secretion. It improves hepatic metabolic efficiency through alterations in fatty acid oxidation (e.g., upregulation of enzymes like fatty acid synthase and increased acetyl-CoA levels), carbohydrate catabolism (e.g., increased glucose and glucose-6-phosphate), pyruvate metabolism (e.g., higher levels of pyruvate and phosphoenolpyruvate carboxykinase), and cellular defence mechanisms (e.g., upregulation of glutathione and metallothionein). Lysozyme supplementation mitigates some adverse effects of Spirulina, bringing physiological responses closer to control levels. This includes fewer differentially expressed proteins and improved dry matter, organic matter and energy digestibility. Lysozyme also enhances coenzyme availability, skeletal myofibril assembly, actin-mediated cell contraction, tissue regeneration and development through mesenchymal migration and nucleic acid synthesis pathways.ConclusionsWhile Spirulina inclusion had some adverse effects on growth performance, it also enhanced hepatic metabolic efficiency by improving fatty acid oxidation, carbohydrate catabolism and cellular defence mechanisms. The addition of lysozyme further improved these benefits by reducing some of the negative impacts on growth and enhancing nutrient digestibility, tissue regeneration, and overall metabolic balance. Together, Spirulina and lysozyme demonstrate potential as functional dietary components, but further optimization is needed to fully realize their benefits without compromising growth performance.

Growth Performance and Microbial Activity Positively Responded to Interactive Effect of Nitrogen and Phosphorus in Young Holstein Dairy Calves.

We hypothesized that nitrogen (N) and phosphorus (P), as two pivotal nutrients that contributed to the growth of growing animals, may have interactive effect on growth performance and microbial development in young calves. For this purpose, feeding two starter protein contents (20% [20CP] vs. 24% [24CP], DM basis) and two phosphorus supplementation levels (0.35% [0.35P] and 0.70% [0.7P], DM basis) was evaluated on growth performance, health indicators, digestibility of nutrients and microbial protein synthesis (MPS), the latter estimated from urinary purine derivatives (PDs). Forty-eight female Holstein calves (3 days of age) were assigned randomly to the following treatments: 20CP-0.35P, 20CP-0.7P, 24CP-0.35P and 24CP-0.7P (n = 12, each). Milk feeding schedule was identical among treatments until weaning (d 59), but study lasted until d 73. Feeding 24CP compared to 20CP diet tended to improve starter intake, increased average daily gain (ADG) during pre-weaning period (p < 0.05), and final body weight (p = 0.01). Higher P supplementation has marginal effect on starter intake but improved ADG (pre-weaning; p = 0.02) and microbial activity by greater MPS (p = 0.02) compared to 0.35P. The greatest starter intake, the most favourable general appearance score, the highest withers height, the highest hip height, the greatest organic matter and neutral detergent digestibility, and the greatest MPS were found when calves fed diets contained 24CP along with 0.7P in starter. Based on the current study results, N and P have separate effects on the growth performance of young calves; however, their positive interaction can be attributable to growth performance and microbial development, especially during the pre-weaning period.

Pregnancy affects maternal performance, feed intake, and digestion kinetics parameters in beef heifers.

This study aimed to quantify the effects of physiological status (PS) and potential interaction of this factor with days of pregnancy (DOP) on beef heifers' weight variation, intake, and digestion kinetics. Twelve rumen-cannulated zebu beef heifers (n = 7 pregnant; n = 5 non-pregnant) were used. Heifers were placed in individual pens and fed medium-quality corn silage plus a protein-based supplement. Heifers' body weight was assessed at the beginning and end of each collection period. The feed intake was measured daily. Target outcomes were evaluated at 107, 170, 208, 240, 267, and 286 days of pregnancy. The apparent total-tract digestibility was determined considering the fecal spot collection, during five days within each collection period. Omasal and ruminal digesta samples were collected at 107, 208, and 267 days of pregnancy for determination of partial digestibilities and diet component outflow. For these purposes, Co-EDTA and indigestible neutral detergent fiber (iNDF) were used as indicators. All data were analyzed using a mixed model framework, considering the PS and DOP as fixed effects and the animal as a random effect. Significant differences were declared when P ≤ 0.05. Pregnant heifers showed an increase in body reserves (+35kg) from 107 to 240 days of pregnancy, but experienced a decrease in shrunk body weight (-36kg) from 240 to 286 days of pregnancy. The intake of dry matter (DM), organic matter (OM), crude protein (CP), and ash- and protein-free neutral detergent fiber (apNDF) increased as pregnancy progressed (P < 0.04). The apparent total-tract digestibility of DM tended to be lower (P = 0.09), and the apparent total-tract digestibility of apNDF was reduced (P < 0.01) in pregnant heifers. The digestibility of CP was higher (P < 0.01) on days 267 and 286 in pregnant cows compared to non-pregnant heifers. The ruminal digestibility of OM tended to be lower (P = 0.09) in pregnant beef heifers, while the ruminal digestibility of apNDF was lower (P = 0.02) in pregnant heifers compared to non-pregnant ones. The ruminal pool of wet matter and DM was lower (P ≤ 0.01) in pregnant heifers at 267 days of pregnancy. In all periods, the outflow tended to be greater (P = 0.06) in pregnant heifers compared to non-pregnant heifers. Pregnant beef heifers exhibited a faster (P = 0.01) digesta passage rate during late gestation. In conclusion, late-gestating beef heifers are less efficient in extracting energy from feed compared to non-pregnant animals.

The Evaluation of Substituting Native Grass with Citronella Waste on the Digestibility of Dry Matter, Organic Matter, and Crude Protein in Ruminants Feeding

This study aims to determine the effect of substituting native grass with citronella waste on the digestibility of ruminants' dry matter, organic matter, and crude protein. A completely randomized design with 6 (six) treatments and 3 (three) replications is used in this research. The treatments were as follows: P1 = 50% native grass + 0% citronella waste + 50% concentrate; P2 = 40% native grass + 10% citronella waste + 50% concentrate; P3 = 30% native grass + 20% citronella waste + 50% concentrate; P4 = 20% native grass + 30% citronella waste + 50% concentrate; P5 = 10% native grass + 40% citronella waste + 50% concentrate; and P6 = 0% native grass + 50% citronella waste + 50% concentrate. The results showed that substituting native grass with citronella waste significantly affects (P&lt;0.01) the digestibility of dry matter, organic matter, and crude protein. The highest digestibility values were observed in the treatment using 100% native grass, with dry matter digestibility at 52.67%, organic matter at 56.58%, and crude protein at 67.55%. The study concludes that while native grass cannot be entirely replaced by citronella waste, it can substitute up to 50% of the complete feed when native grass availability is limited.

Animal behaviour and dietary preference of dairy cows grazing binary and diverse pastures under the leaf regrowth stage defoliation criterion

In New Zealand, intensively managed pasture-based dairy systems rely on binary pastures mostly comprised of Lolium perenne L. and Trifolium repens L.. More frequent and extreme climatic events have been negatively affecting the persistency and production of these pastures, which now present increased seasonality, with marked peaks and troughs of production throughout the year. Diversification of plant species offers a solution to deal with increased seasonality. However, little is known about animal behaviour and dietary preferences of dairy cows grazing diverse pastures. The present study aimed to assess the grazing preferences of dairy cows when unrestrictedly offered binary (L. perenne and T. repens; Bi) and diverse pastures (L. perenne, Bromus valdivianus Phil., Dactylis glomerata L. and T. repens; Mix) subjected to three different leaf regrowth stage (LS) defoliation criteria. Secondarily, the study aimed to determine the main plant-related drivers for any potential animal preference. The treatments were MixLp (defoliated at L. perenne LS), BiLp (defoliated every time MixLp was defoliated), MixBv (defoliated at B. valdivianus LS) and BiBv (defoliated every time MixBv was defoliated), MixDg (defoliated at D. glomerata LS) and BiDg (defoliated every time MixDg was defoliated). Dairy cattle were evaluated over five agricultural seasons. The response variables were grazing time and location, bite rate, animal behavioural activity, pre-grazing herbage mass, undisturbed sward height, lamina:stem ratio, crude protein, metabolisable energy, organic matter digestibility, non-structural carbohydrates, neutral detergent fibre and lignin. Where significant differences were found, binary pastures presented lower sward height and higher non-structural carbohydrate content in comparison to the diverse pastures under the same LS defoliation criteria. However, no significant differences were found in the percentage of time that cows spent grazing both pastures. Season was the greatest contributor to the proportion variation found in all response variables, with values ranging from 47.55 % up to 88.77 %. In winter and spring, cows modulated their grazing behaviour (proportional time spent grazing, ruminating, or idling), investing more time actively grazing pastures under L. perenne LS interval of defoliation (2.5–3.0 LS), the criterion which resulted in shorter grazing rotations. This study allowed us to understand the suitability of diverse pastures from an animal perspective, and highlighted that independent of the pasture type, the positive productive and nutritional effects of defoliation management based on the LS may also extend themselves to positive outcomes in animal preference, interpreted as the percentage of time dairy cows spend grazing rather than ruminating or idling across and within seasons.

Macroalgae and microalga blend in dogs' food: Effects on palatability, digestibility, and fecal metabolites and microbiota

The promotion of dogs' nutrition, health, and well-being are highly valued by pet owners, leading to an increasing interest in pet food with alternative, functional, and more sustainable supplements, such as algae. Few studies have assessed the supplementation of dog food with individual algae species, but no information exists on combined macro- and microalgae. This study evaluated the effects of dietary supplementation of a commercial algal blend, composed of two macroalgae (Ulva rigida and Fucus vesiculosus) and one microalga (Chlorella vulgaris) on palatability, intake, digestibility, metabolizable energy (ME), and fecal characteristics, metabolites, and microbiota of adult healthy Beagle dogs. Palatability was assessed by comparing a complete diet without (control) and with 1.5 % algae blend using twelve dogs. Then, six of these dogs were randomly selected for the digestibility trials. Following an initial trial to determine the control diet digestibility, a replicated Latin square was performed with three experimental periods of 10 days each, and three algal blend supplementation levels (0.5, 1.0, and 1.5 %). Dietary algal blend did not affect the first approach and first taste, but dogs preferred the control diet. Algal blend levels had no impact on intake, but organic matter, fiber, and energy digestibility increased with 1.5 % inclusion compared with 0.5 %. At the highest level, algae blend promoted fecal total short chain fatty acids and acetate while at lowest fecal propionate decreased and fecal production increased. Compared with the control diet, algal blend-supplemented diets promoted most nutrients and energy digestibility, diet ME content, and fecal quality, while reducing fecal butyrate. Fecal microbiota diversity and abundance were mostly unaffected by algae blend supplementation, with health-promoting genera Turicibacter and Blautia being the most abundant in all samples. Overall, results suggest algal blend as a promising alternative supplement for dog food, but further research is needed to unveil potential health-promoting effects.

Mathematical analysis of an anaerobic digestion model for biogas production from solid waste.

Municipal solid waste is one of the most significant sources of gas emissions. In a context of renewable energy production and greenhouse gas emission reduction, we focus on the amount of biogas produced by the anaerobic digestion of organic matter in a controlled landfill environment. We present a mathematical model describing this process from a microbiological and biochemical point of view, including the dynamics of the methane and carbon dioxide produced. A qualitative analysis of the dynamic system shows the existence of an infinite number of non-hyperbolic equilibria inducing an attractor that has been identified. Through numerical tests, we explore how the non-connectivity of the attractor resulting from the choice of growth functions can entirely transform the performance of the process, and highlight critical initial stock values that influence the amount of biogas produced.

Utilization of Nutrition and Performance of Local Male Goats Given Concentrate Containing Fermented Cow Rumen Content Waste

The aim of the research was to determine the effect of feeding concentrates containing fermented cow rumen waste on the consumption and digestibility of dry matter, organic matter, nitrogen, NDF and ADF of local male goats. This research was conducted for 5 months using 20 local male goats aged 8-10 months with an average body weight of 11.71 kg and CV 12%. This experimental research used a completely randomized design with 4 treatments and 5 replications. The treatment is as follows P0: Kume grass 70% + concentrate 30% (without fermented cow rumen contents); P10: kume grass 70% + concentrate 30% (concentrate contains fermented cow rumen contents); P20: kume grass 70% + concentrate 30% (concentrate contains 20% contents of fermented cow rumen); P30: kume grass 70% + concentrate 30% (concentrate contains 30% contents of fermented cow rumen). The results of the variance analysis showed that the treatment had no significant effect of p&gt;0.05 on the consumption and digestibility of dry matter, organic matter, nitrogen, NDF and ADF in local male goats. The conclusion of this research is that concentrate supplementation containing fermented cow rumen waste up to a level of 30% gives relatively the same effect between each treatment on the consumption and digestibility of dry matter, organic matter, nitrogen, NDF and ADF of local male goats.

Effects of supplementing rumen-protected rubber seed oil to dairy cattle on feed digestibility and milk production.

The aim of this study was to determine the effect of rumen-protected rubber seed oil supplementation on feed digestibility, milk yield, and milk composition in tropical dairy cows. Twelve crossbred Holstien-Friesian dairy cows (75% Holstein-Friesian, 25% Thai native breed) with a mean body weight (BW) of 460 ± 30 kg and 20 ± 5 days in milk were randomly assigned to 1 of 3 treatments according to a completely randomized design. The treatments were as follows: a basal diet without rumen-protected fat (RPF) (control) or supplementation of rumen-protected palm oil (RPPO) at 300 g/h/d and rumen-protected rubber seed oil (RPRSO) at 300 g/h/d. Each cow was fed a total mixed ration ad libitum. The nutrient intake was similar among treatments (p>0.05). Adding RPF did not affect nutrient digestibility, while organic matter digestibility increased in dairy cows receiving RPRSO (p<0.01). Blood urea nitrogen, total protein, or glucose did not alter among treatments (p>0.05), while triglycerides and cholesterol were increased when cows were fed RPPO (p<0.01). Adding RPF increases milk yield in cows (p<0.01). The supplementation of RPRSO increased milk fat (p=0.04). Milk fat yield was higher in RPPO and highest in RPRSO (p<0.01). The addition of RPF increased the oleic acid (OA, C18:1 cis-9) in milk (p=0.01). In addition, cows fed RPRSO increased linoleic acid (LA; C18:26 cis-9,12 + trans-9,12) and -linolenic acid (ALA; C18-33 cis-9,12,15) in milk (p<0.01). The addition of RPF increased milk unsaturated fatty acids (UFA) and monounsaturated fatty acids (MUFA) (P≤0.04). The PUFA in milk increased with RPRSO supplementation (p<0.01). Supplementation of RPRSO during early lactation can increase feed digestibility and the concentration of milk fat with PUFA (LA and ALA) in tropical dairy cows.

Implication of dietary barberry (Berberis Vulgaris) leaves inclusion on growth performance, nutrient digestibility, and carcass traits in ostriches

This study determined production performance, nutrient intake, digestibility, and carcass traits from ostrich chicks fed with barberry (Berberis Vulgaris) leaves (BVL) as a replacement for alfalfa hay (AH). For 150 days, 30 male ostrich (Struthio camelus) (9.10 ± 0.89 kg live weight, mean ± SD) were randomly grouped into five dietary BVL inclusion levels to replace AH: a control diet based on 100% AH (CTRL), and four groups with BVL as a substitute for AH at varying levels including 25% (BVL25), 50% (BVL50), 75% (BVL75), and 100% (BVL100). The average daily feed intakes (ADFI) were recorded and birds were weighed monthly. The nutrient intake and digestibility were measured for the following final 5 days of the trial. The ADFI was higher (p = 0.025) for BVL100 and BVL75 than for CTRL. Ostriches fed on BVL50 had the highest average daily gain (ADG, p = 0.025) and the lowest feed conversation ratio (FCR, p = 0.0001). Return per kg BW gain was also enhanced (p = 0.018) with BVL50 feeding. Dietary BVL levels did not affect the digestibility of OM (p = 0.257), CP (p = 0.260), EE (p = 0.610), CF (p = 0.427), and Ash (p = 0.461). Also, there were no changes in AME (p = 0.180) or AMEn (p = 0.670). The hot carcass weight (HCW, p = 0.331) and dressing BW (p = 0.237) were not affected. Overall, the results suggest that BVL can replace AH in ostrich diets without deleterious impact on performance, however, its partial substitution (for 50% AH of diet) has been associated with improved ADG, FCR, and reduced feeding costs.

Optimum Level of Lactobacillus plantarum Supplementation as Probiotic on In Vitro Digestibility and Rumen Fermentation Products in Thai Native Cattle

The objective of this study was to determine in vitro gas production kinetics, and rumen fermentation products of total mixed ration (TMR) supplemented with different level of Lactobacillus plantarum supplementation in Thai native cattle. The experiment design was Completely Randomized Design (CRD). The in vitro procedure was completed using 200 mg DM of TMR and four different concentration of L. plantarum; CON (without supplementation of L. plantarum), T1 (107 CFU / mL of L. plantarum supplementation), T2 (108 CFU / mL of L. plantarum supplementation), and T3 (109 CFU / mL of L. plantarum supplementation). The samples were prepared in three replications and incubated for 96 hours for gas production. Rumen fermentation products (pH, NH3, VFA) and digestibility experiment were done in four replications and incubated for 24 hours. In vitro gas production for 96 hours, gas production from insoluble fraction (b), and potential extent of gas production (|a|+b) were improved in the T1 and T2 groups (P &lt; 0.05). The in vitro dry matter and organic matter digestibility, and true digestibility were particularly enhanced in the T1 group compared to other treatments (P &lt;0.05). The pH and NH3 in this study were significantly affected (P&lt;0.05). The significant improvements on the in vitro rumen fermentation products and digestibility endorse L. plantarum supplementation at concentration of 107 CFU/mL as probiotic candidate.

Microwave Cooking of Some or All High Starch Ingredients of Cattle Feed Concentrate Improves Nutritional Value and In Vitro Bioavailability.

Microwaving has been used to qualitatively improve feed ingredients prior to including them in cattle feed. However, it is not known whether feed ingredients should be microwaved separately or in a mixture before being included in cattle feed concentrates. In the current study, the effects of the partial and full microwaving of high starch ingredients were investigated regarding their impact on the nutritional composition, physicochemical properties, and in vitro digestibility of feed concentrates. The cassava was microwave-irradiated before being mixed with other ingredients (MC, 35% of formulation). A microwave-cooked cassava-corn meal mixture (MCC, 45% of formulation) and a combination of all solid components (MSI, 96% of formulation) were also compared. A feed containing non-microwaved ingredients was formulated and served as the control (NM). Significantly altered proximate compositions and nutritive profiles were observed in all the microwaved components (p < 0.05). The observed modifications in pHs, water absorption capacities, thermal properties (differential scanning calorimetry), diffraction patterns (X-ray diffractometry), and microstructures (scanning electron microscopy) indicated enhanced enzymatic hydrolysis in vitro. A higher cellulase organic matter solubility and digestible organic matter were observed in the MCC and MSIs feeds relative to the control NM (p < 0.05). These findings indicate a combination of components could be added to feedstock before it is microwave processed to potentially include this pretreatment in the feed production process.

Assessing the dry matter intake and enteric methane emissions of pre-partum dairy cows offered grass clover or grass-only silage from two different silage systems

Over the winter period, the low grass growth and availability in pasture-based dairy systems results in animals being housed and predominantly fed a diet of grass silage. There is limited availability of methane (CH4) data evaluating the impact of forage type on dairy cows over the pre-partum period. The objective of the current experiment was to evaluate the impact of feeding grass clover (GC) silage and grass-only (GO) silage on the dry matter intake (DMI) and enteric CH4 emissions of dairy cows pre-partum. A complete randomised block design was utilised for the 6-week experiment over two winter periods: from December 2020 to January 2021 and from December 2021 to January 2022. In each year, 30 non-lactating pregnant dairy cows were randomly allocated to two treatments (n = 15). In both years, cows in the GC treatment were offered grass clover bale silage, while cows in the GO treatment were offered grass-only pit silage. The DMI and gaseous emissions of individual animals were monitored daily using Hokofarm RIC (roughage intake control) feed stations and the GreenFeed technology. GC silage consistently had greater (p&amp;lt; 0.05) organic matter (OM) digestibility and lower (p&amp;lt; 0.05) neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents when compared with GO silage. Cows in the GC treatment had significantly greater (p&amp;lt; 0.05) total DMI (TDMI) compared with cows in the GO treatment. The daily CH4 emissions (in grams per day) were not affected by treatment; however, cows in the GC treatment had reduced (p&amp;lt; 0.05) CH4 yield (in grams per kilogram TDMI). Offering dairy cows GC silage over the pre-partum period resulted in greater DMI with reduced CH4 yield when compared with cows offered GO silage.

Productive performance and milk composition of dairy ewes supplemented with corn silage (Zea mays L.), sunflower (Helianthus annuus) silage and their mixture.

The work reported in the Research Communication investigated in vitro rumen gas kinetics and fermentation profile as well as in vivo performance of lactating ewes fed corn silage (CS), sunflower silage (SFS) and their 50 : 50 mixture (CS-SFS). For the in vivo experiment, nine early-lactation Suffolk × Texel ewes were grouped in a replicated 3 × 3 Latin square design of three 21-d periods. Treatments were based on ad libitum CS, SFS, and CS-SFS supplemented with concentrate at 48 g/kg LW0.75. In vitro results showed that the CS had the highest dry matter degraded substrate and microbial crude protein production followed by CS-SFS. The in vivo data showed that animals fed on CS had higher digestibility of dry matter and organic matter than CS-SFS, while SFS were intermediate. Nitrogen (N) intake, fecal N excretion, and urine N excretion were similar between groups, however, milk N excretion was lower in SFS than CS. Milk yield was higher for CS and CS-SFS than SFS group, however, SFS-fed ewes had higher milk fat content than either CS or CS-SFS (all differences reported here were significant, P < 0.05 or better). Overall, CS-SFS could be used as dietary roughage for dairy ewes without deleterious effects on nutrient intake, N-balance and milk yield whilst potentially offering a more sustainable alternative to CS.

Effects of Chitosan-Based Additive on Rumen Fermentation and Microbial Community, Nutrients Digestibility and Lactation Performance in Goats.

Recently, the potential of using chitosan (CHI) as a feed additive to enhance ruminal fermentation and improve animal performance has gained increasing attention in ruminant nutrition. This study was undertaken to investigate the effect of dietary supplementation with increasing doses of CHI on rumen fermentation attributes and microbial composition, digestibility and milk performance in Dhofari goats. Twenty-four lactating goats (27 ± 1.8 kg of initial live body weight) were fed a control diet comprising of Rhodes grass hay plus a concentrate feed mixture. Goats were assigned to one of three experimental treatments (n = 8 per treatment) as: (1) control diet with no supplement (CTRL), (2) control diet with 0.300 g/day CHI (CHI0.3) and (3) control diet supplemented with 0.600 g/day CHI (CHI0.6) for a 45-day experimental period. Dietary supplementation with increasing doses of CHI decreased (p < 0.05) linearly ruminal pH (p = 0.023), total short chain fatty acids concentrations (p = 0.011), acetate (p = 0.013) and butyrate (p = 0.042) proportions, acetate to propionate ratio (p < 0.001), estimated methane (CH4) production (p < 0.001), ammonia nitrogen concentrations (p = 0.003) and protozoa abundance (p = 0.003). However, the ruminal propionate proportion augmented (p = 0.002) linearly with increasing doses of CHI in the diet. Increasing doses of CHI linearly increased the abundance of the ruminal propionate-producing bacteria, while diminished acetate and CH4-producing bacteria (p < 0.05). Serum total protein (p = 0.037) and glucose (p = 0.042) levels linearly increased as CHI doses increased in the diet. However, serum UREA levels decreased linearly (p = 0.002) by 21% with increasing CHI amounts in the diet. The digestibility of organic matter, crude protein and neutral detergent fibre increased linearly with the increasing CHI doses (p < 0.05). Neither linear nor quadratic responses (p > 0.05) were observed in daily milk yield and feed efficiency by supplementing the diet with CHI. In conclusion, supplementing the diet with CHI at a dose of 0.600 g/day as a feed additive for dairy goats reduced estimated CH4 generation and improved fibre and protein digestion, with no influence on feed intake, milk yield or composition.

Effects of Alanyl-Glutamine Dipeptide Supplementation on Growth Performance, Nutrient Digestibility, Digestive Enzyme Activity, Immunity, and Antioxidant Status in Growing Laying Hens.

Alanyl-glutamine (Aln-Gln), a highly soluble and stable Glutamine-dipeptide, is known to improve the performance of poultry birds. This study aimed to investigate the effect of Aln-Gln during the rearing period on growth performance, nutrient digestibility, digestive enzyme activity, immunity, antioxidant status and relative gene expression of Hy-Line brown hens. A total of 480 healthy day-old Hy-line brown chicks with similar body weights were randomly divided into four dietary groups (8 replicates/group and 15 birds/replicate). Groups A, B, C and D were fed diets containing 0%, 0.1%, 0.2% and 0.3% Aln-Gln, respectively, for 6 weeks. The body weight (BW) and average daily gain (ADG) were higher in hens fed test diets compared with the control (p < 0.05). The feed conversion ratio (FCR) was better in test groups as compared to the control group (p < 0.05). The ADFI showed no significant difference between the groups. Dietary treatments had no effect on dry matter (DM), organic matter (OM) and crude fiber (CF) digestibility. The Aln-Gln also improved gross energy (GE) and crude protein (CP) digestibility (p < 0.05). It has also increased IgG levels in groups C and D. IgM levels were similar to the control in B, C and D. The Aln-Gln increased IL-1 in B and C, IL-2 in C and D, and IL-6 in all test groups (p < 0.05). The supplementation of Aln-Gln had no effect on serum antioxidant indices like CAT, MDA, GSH-PX, GSH, and SOD in 42-day-old growing hens. Aln-Gln supplementation had no significant effect (p > 0.05) on the activity of amylase and lipase, however, a significant improvement (p < 0.05) in the activities of trypsin and chymotrypsin was observed in the test groups. Supplemented Aln-Gln levels in the birds' diets led to an increase in the expression of genes related to growth factors (IGF-1, IGFBP-5), immune markers (IL-1, IL-2, IL-6) and antioxidant status (GSH-Px1), as compared to control group. Aln-Gln supplementation in Hy-Line brown hens during their growing period improved growth, nutrient digestibility, immunity and digestive enzymes activity. These findings suggest that Aln-Gln is a promising dietary additive for enhancing poultry performance.

NUTRIENT CONTENT, IN VITRO GAS PRODUCTION AND POST INCUBATION PARAMETERS OF INDIGENOUS BROWSE FODDERS IN DIFFERENT AGRO-ECOLOGICAL ZONES OF NORTHWEST ETHIOPIA

&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;In Ethiopia indigenous browse species have the potential to serve as a sustainable supplement for poor quality feeds and enhance ruminant livestock production. &lt;strong&gt;Objective:&lt;/strong&gt; To analyze the nutrient content, in vitro gas production, and post incubation parameters of indigenous browse species in northwestern Ethiopia. &lt;strong&gt;Methodology: &lt;/strong&gt;Eight indigenous browse fodder trees were collected from each agroecological zone for this experiment. Leaf and pod samples of the fodder trees were collected, dried and ground for laboratory analysis. Analysis of variance was carried out for nutrient content, in vitro gas, and methane production of the samples within agroecological zones using standard analytical procedures. The statistical design used to analyze the data was Completely Randomized Design (CRD). &lt;strong&gt; Results:&lt;/strong&gt; The highest CP content was recorded from &lt;em&gt;Vernonia&lt;/em&gt;&lt;em&gt; amygdalina &lt;/em&gt;(223.4 g/kg DM)&lt;em&gt;,&lt;/em&gt; &lt;em&gt;Dodonaea viscosa &lt;/em&gt;(207.7 g/kg DM), and &lt;em&gt;Acacia abyssinica &lt;/em&gt;(216.0 g/kg DM) in the highland, midland and lowland agro-ecology respectively. In lowland area, NDF, ADF and ADL contents were highest for &lt;em&gt;Albezia amara&lt;/em&gt; leaves and lowest for &lt;em&gt;Acacia brevispica&lt;/em&gt; respectively. &lt;em&gt;V. amygdalina&lt;/em&gt;, &lt;em&gt;Stereospermum kunthianum&lt;/em&gt; and &lt;em&gt;Ficus vasta&lt;/em&gt; had the highest gas volume at 24-hour incubation time in high, mid and lowland, respectively. The estimated organic matter digestibility, metabolizable energy and short chain fatty acid at 24 hour of incubation was the highest for &lt;em&gt;V. amygdalina&lt;/em&gt;, &lt;em&gt;S kunthianum&lt;/em&gt; and &lt;em&gt;F. vasta&lt;/em&gt; in high, mid and lowland, respectively. &lt;em&gt;Ficus sycomorus&lt;/em&gt; and &lt;em&gt;Myrica salicifolia&lt;/em&gt; had the lowest methane production among the species in the low, mid and highland study areas, respectively. &lt;strong&gt;Implications: &lt;/strong&gt;The present study provides a valuable resource for selecting suitable feed options for livestock in different agroecological zones. High CP and digestible browse species like &lt;em&gt;V. amygdalina,&lt;/em&gt; &lt;em&gt;S. kunthianum&lt;/em&gt;, and &lt;em&gt;F. vasta&lt;/em&gt; could be prioritized for livestock feed. Low methane-producing species like &lt;em&gt;F. sycomorus&lt;/em&gt; and &lt;em&gt;M. salicifolia&lt;/em&gt; could be incorporated into diets to reduce enteric methane emissions. &lt;strong&gt;Conclusion&lt;/strong&gt;: Based on their nutrient composition and in vitro gas production potential, these feed resources are of better quality to supplement grazing livestock during the seasons of critical feed shortage as the main feed resources are either limited in availability or lower in nutrient composition and digestibility in the study areas.&lt;/p&gt;

EFFECT OF MAIZE (&lt;i&gt;ZEA MAYS&lt;/i&gt;) COB BASED TOTAL MIXED RATION IN GROWING CALVES

The present study was conducted to study the effect of maize (Zea mays) cob on replacing paddy straw in the Total Mixed Ration (TMR). Twelve cross bred calves of about 5 to 8 months of age with body weight ranging from 41 to 79 kg were divided into two groups of six each in completely randomized design. Five complete diets were prepared (TMR1 to TMR5) using maize cobs at the level of 0%, 25%, 50%, 75% and 100% replacement of paddy straw in the diets containing 12 % CP and 60 % TDN of 50:50 concentrate to roughage ratio. There was significant (P&lt;0.01) differences among the diets in OM, CF, NFE, TA, AIA, NDF, ADF, Lignin, Hemicellulose and Cellulose contents. In vitro rumen fermentation study showed significantly (P&lt;0.01) higher total gas (ml/200 mg/48 h), in vitro dry matter and organic matter degradability in maize cob based ration than paddy straw contained ration (51.17 vs 36.00; 62.87 vs 57.25; 64.80 vs 59.93). Paddy straw (100%) based diet as control ration and maize cob (100 % replacement of paddy straw) based diet as treatment ration fed to growing calves for sixty days in growth trial. A seven day digestion trial was conducted in the middle of the experiment. The digestibility (%) of DM, OM, CP, EE, CF and NFE were significantly (P&lt;0.01) higher in the maize cob based diet fed group than paddy straw based diet fed group. The average body weight gain (kg) and FCR (kg DMI/ kg gain) were significantly (P&lt;0.05) higher in maize cob fed animals (19.47; 6.10) than paddy straw fed animals (16.02; 7.34). The feed cost per unit of weight gain in calves fed paddy straw based diet was numerically higher (30.78 %) than calves fed on maize cob based ration. It could be concluded that maize cob based ration could replace paddy straw at 100 % level in total mixed ration without affecting feed intake and nutrient digestibility and may also improve the body weight gain and reduce feed cost in growing calves.