Forage Type Research Articles

Isolation and Characterization of Lactic Acid Bacteria: A Strategy to Produce Inoculum for Forage Ensiling

Purpose: Sri Lankan dairy sector faces challenges due to seasonal variability and suboptimal quality of forage for dairy cattle feeding. While silage offers year-round availability of forage, concerns arise regarding potential quality degradation during forage ensiling. Microbial inoculants are utilized to expedite the ensiling and minimize quality deterioration. This study involves the isolation and characterization of lactic acid bacteria (LAB) from silage, with the aim of identifying potential candidates to be used as silage inoculants.Research Method: Lactobacillus were isolated from 10 silage samples of each forage type: sorghum, maize, and guinea grass. They were characterized using the 16S rRNA gene sequencing procedure. The anaerobic sugar fermentation ability of the isolated LAB was evaluated by inoculating them into sterilized sugar solutions, and measuring the titratable acidity (TA) and pH value over time.Findings: The isolates were identified to be non-motile, non-spore-forming and Gram-positive rods. Further, they tested negative for catalase, triple sugar iron, citrate, urease, indole, gelatine hydrolysis, motility, and oxidase tests. The LAB isolated from guinea grass, sorghum, and maize corresponded to Lactobacillus oris, Lactobacillus rhamnosus, and Lactobacillus plantarum, respectively. The TA in all inoculated solutions was higher compared to the control (0.55-0.66% vs. 0.48%), with L. plantarum showing the highest TA (0.66%) at 30 hours incubation. Additionally, all sugar solutions treated with LAB isolates exhibited a lower pH value at 30 hours compared to the control (4.70-5.07 vs. 5.75). Notably, L. plantarum demonstrated the most significant pH value reduction at 18 hours (5.85 vs. 6.29-6.64).Value: Lactobacillus oris, L. rhamnosus, and L. plantarum, isolated from guinea grass, sorghum, and maize silage, respectively, have the potential to be developed as inoculants for ensiling forage.

Phytochemical profile and in vitro evaluation of cassava (Manihot esculenta Crantz) foliage as ruminant feed with/without green banana flour

Cassava (Manihot esculenta Crantz) is a crucial crop in tropics and subtropics, primarily cultivated for its tuber. However, its foliage is rich in protein and can supply essential elements for ruminants. The objective of this study was to evaluate the phytochemical compounds by Gas chromatography-MS (GC-MS) and the main phenolic by High Pressure Liquid Chromatography (HPLC) present in cassava foliage, along with the fermentation pattern using a semi-automated gas production (GP) system. The in vitro evaluation was carried out for four diets formulated as follows: T1 (alfalfa: grass hay at ratio of 30: 70); T2 (alfalfa: grass hay: banana flour 30:60:10); T3 and T4 (replaced alfalfa in T1 and T2 with cassava foliage, respectively). The addition of green banana flour aimed to increase the diets’ energy. The GC-MS results indicated that cassava foliage showed a large number of valuable bioactive components, with the biflavonoid isoginkgetin representing the major component at 25.33% of total peak area percentage. The HPLC analysis declared that rutin, gallic acid, and ferulic acid were the main phenolic compounds presented in cassava foliage ethanolic extract. The accumulative gas after 24 h of incubation was significantly lower with cassava diets compared to alfalfa diets, being 119.3 versus 130.1 ml/g DM, respectively. The degradation of both organic matter and neutral detergent fiber was significantly higher with alfalfa compared to cassava diets, while there was no significant difference between alfalfa and cassava diets on final pH, ammonia concentration and protozoal count. Banana flour inclusion, regardless of the forage type, decreased the accumulative gas after 24 h of incubation with about 9% compared with no banana addition. The use of cassava foliage in ruminant diets considered a promising protein source with valuable bioactive components that could have a positive effect on animal health and production.

Maceration and fractionation technologies in a demonstration-scale green biorefinery: Proteins, sugars, and lipids extraction and energy efficiency

Different configurations of maceration and wet fractionation of green biomasses were assessed at a demonstration scale intending to extend the extraction of leaf protein concentrate. Two maceration methods, one-stage and a multistage maceration, were investigated on six distinct green forage types. The study aimed to enhance the extraction of leaf protein concentrate for use as a soybean replacement in monogastric feed, while also extracting simple sugars and lipids for potential further value creation. The use of multistage maceration scenarios promoted a more robust mechanical disintegration of the plant biomass, leading to higher extraction of the soluble compounds. The highest crude protein extraction efficiencies were seen in red clover (29 %) and festulolium (28 %). While grass fiber had higher lignocellulosic content than legume fiber, additional maceration and fractionation did not further break down cellulose, which remained predominantly in the fiber fraction across all biomasses. The higher energy requirements associated with more advanced processes are offset by the significant increase in protein yields.

Rumen-Degradable Starch Improves Rumen Fermentation, Function, and Growth Performance by Altering Bacteria and Its Metabolome in Sheep Fed Alfalfa Hay or Silage.

Alfalfa silage due to its high protein can lead to easier feeding management, but its high proportion of rumen-degradable protein can reduce rumen nitrogen utilization. Nevertheless, increasing dietary energy can enhance ruminal microbial protein synthesis. Thirty-two Suffolk female sheep were used in this study, with a 2 × 2 factorial arrangement of treatment. The four treatments were a combination of two forage types (alfalfa hay; AH vs. alfalfa silage; AS) and two rumen-degradable starch levels (low RDS; LR vs. high RDS; HR) with a 15 d adaptation and 60 d experimental period. The rumen content and rumen epithelium samples were collected after slaughter. Feeding AS increased the rumen isobutyrate, valerate, ammonia-N (NH3-N) concentration, urase activity, and papillae height (p < 0.05) and reduced the feed to gain (F:G), rumen bacterial protein (BCP), rumen lactic acid concentration, and papillae width (p < 0.05) of sheep. Increased RDS in the diet improved the daily matter intake, average daily gain, and rumen weight, reduced the F:G, and enhanced the rumen nitrogen capture rate by decreasing total amino acids and the NH3-N concentration to increase BCP, aquaporins 3 gene, and protein expression. The rumen microbiota also changed as the HR diet reduced the Chao index (p < 0.05). The metabolomics analysis showed that feeding AS upregulated the rumen tryptophan metabolism and steroid hormone biosynthesis, while the purine metabolism, linoleic acid metabolism, and amino acid biosynthesis were downregulated. Furthermore, increased RDS in the diet upregulated rumen lysine degradation and sphingolipid metabolism, while aromatic amino acid biosynthesis was downregulated. Additionally, the correlation analysis results showed that ADG was positively correlated with 5-aminopentanoic acid, and three microorganisms (unclassified_f__Selenomonadaceae, Quinella, Christensenellaceae_R-7_group) were positively correlated with the rumen isobutyrate, valerate, NH3-N concentration, urase activity, tryptophan metabolism, and steroid hormone biosynthesis and negatively correlated with linoleic acid metabolism and amino acid biosynthesis in sheep. In summary, increased RDS in the diet improved the growth performance and rumen N utilization and reduced bacterial diversity in sheep. The alfalfa silage diet only increased feed efficiency; it did not affect growth performance. Additionally, it decreased rumen nitrogen utilization, linoleic acid, and amino acid biosynthesis. Nevertheless, there were limited interactions between forage and RDS; increased RDS in the AS diet enhanced the nitrogen capture rate of rumen microorganisms for alfalfa silage, with only slight improvements in the purine metabolism, linoleic acid, and amino acid synthesis.

Nano-encapsulated Yucca extract as feed additives: Ruminal greenhouse gas emissions of three forages

AbstractReducing greenhouse gas (GHG) emissions from livestock is a crucial step towards mitigating the impact of climate change and improving environmental sustainability in agriculture. This study aimed to evaluate the effects of Yucca schidigera extract, chitosan, and chitosan nanoparticles as feed additives on in vitro GHG emissions and fermentation profiles in ruminal fluid from bulls. Total gas, CH4, CO, and H2S emissions (up to 48 h), rumen fermentation profiles, and CH4 conversion efficiency were measured using standard protocols. The experiments involved supplementing 0.25, 0.5, and 1 mL/g dry matter (DM) of additives in different forages (alfalfa hay, corn silage, and oats hay). The chemical composition of forage showed suitable levels of DM, ash, crude protein, acid detergent fiber, neutral detergent fiber, lignin, and metabolizable energy. The addition of these supplements increased asymptotic gas production across all forages while simultaneously reducing CH4, CO, and H2S emissions, though the extent of reduction varied depending on forage type. Moreover, the treatments improved fermentation profiles, including pH and dry matter digestibility, and significantly influenced CH4 conversion efficiency (CH4:ME, CH4:OM, and CH4:SCFA; P &lt; 0.05). These results underscore the potential of Y. schidigera extract, chitosan, and chitosan nanoparticles as effective strategies for mitigating GHG emissions from ruminants given these promising in vitro findings. Further in vivo studies are recommended to validate their efficacy under real-world conditions, which could pave the way for practical applications in the field.

Gender relations and women’s empowerment in small-scale irrigated forage production in Ethiopia

Small-scale cultivation and irrigation of planted forages can increase the availability of good-quality animal feed in smallholder farms. However, low adoption rates of improved forage technologies in most parts of sub-Saharan Africa have been observed and are partly attributed to limited understanding of gender dynamics in the context of production and utilization of planted forages. The introduction of small-scale cultivation and irrigation of planted forages is likely to interlink gender relations in the mixed crop–livestock farming system given the differences in contributions, benefits and challenges men and women farmers face. Efforts to transform livestock systems through improving adoption, scaling, and sustainability forage interventions can benefit from empirical evidence on gender relations in feed-related activities. We aim to highlight the linkage between gender relations and women’s empowerment in the production and utilization of feed resources smallholder settings. We used mixed methods, drawing on quantitative data obtained from a cross-sectional survey of 250 men and 250 women, and qualitative data obtained from eight focus group discussions in smallholder settings of the Amhara and Southern Nations, Nationalities, and People’s regions of Ethiopia, where small-scale irrigation was introduced to boost the production of cultivated forages by households. We used the Women’s Empowerment in Livestock Index tool to elicit data and analyze the empowerment of the sampled men and women. Women’s empowerment differed significantly with different dimensions of gender relations, types of forages grown, and small-scale irrigation practice. Moreover, women in households practicing small-scale irrigation of planted forages were significantly more empowered and most (80%) achieved the adequate threshold in “work balance”. The study findings point to the positive link between empowerment and the likely shifts in gender relations from the practice of small-scale production and irrigation of forages.

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.

PSXIII-2 Does choice of apparatus affect detergent fiber fractions across forage types?

Abstract Since the 1960s, detergent fiber fractions have had a fundamental role in animal nutrition. Not only was this system an improvement on measurement of cell wall material, it has also helped advance our understanding and prediction of forage intake and digestibility. The ANKOM fiber analyzer, introduced in the 1990s, streamlined the assay, and multiple technical improvements have been introduced that increased the level of automation in the procedure. To date, however, there has not been an evaluation of the influence the choice of apparatus has on the results. The objective of this study was to determine the effect of fiber analyzer apparatus on recovery of detergent fiber fractions of various forage species. The study was designed as a randomized complete block design with a two-factor factorial treatment structure. The first treatment factor was fiber analyzer (ANKOM 200, ANKOM 2000, or ANKOM Delta), and the second treatment factor was forage (n = 12). Forages were ground to pass through a 1-mm screen and sealed in F57 fiber bags. All bags were subjected to neutral detergent fiber (NDF) and acid detergent fiber (ADF) assays according to manufacturer instructions in their designated fiber analyzer. After the ADF assay, samples were subjected to the acid detergent lignin (ADL) assay using the ANKOM DaisyII incubator. Data were analyzed using the GLIMMIX procedure of SAS 9.4. Across forage species, NDF concentrations were less (P = 0.02) from the manual ANKOM 200 (61.4%) than from ANKOM Delta or ANKOM 2000 (63.3 and 63.1%, respectively). Across forages, ADF was greatest (P &amp;lt; 0.01) from ANKOM 2000 (37.8%), followed by ANKOM Delta (36.2%), and least from ANKOM 200 (34.8%). However, these differences did not carry through as there was no effect of fiber analyzer on ADL concentrations (P = 0.67). Results are interpreted to mean that, across forage species, choice of fiber analyzer may have an influence on detergent fiber concentrations. However, these differences are minimized in the automated systems relative to the older, more manual apparatus.

PSLBII-13 Bioinformatics of rumen fluid from steers fed alfalfa-bermudagrass mixtures in the Deep South

Abstract When harvesting high-quality, high-water content forages like legumes, there is often a greater percentage of nutritive loss due to the drying process. Alternative feeding strategies like baleage provide a way to mitigate these losses. However, there is not much adoption of baleage in the Deep South. Therefore, our objective was to assess the influence of conserved forage type on rumen metabolomes of beef cattle systems in the Deep South. Three treatments including bermudagrass (Cynodon dactylon) hay, alfalfa (Medicago sativa) baleage, and alfalfa-bermudagrass baleage were supplied to four fistulated steers with a calculated daily forage allowance based on intake, body weight, and feed refusals. Each diet was allocated to one of three periods in which all four animals received the same diet due to potential feed spoilage. Each period had a 21-d adaptation period followed by a 5-d collection period to analyze rumen fluid, total fecal weight, feed intake, feed refusal, and total urine. This study integrated 16S RNA sequencing and LC-MS-based metabolomics to evaluate rumen bacterial diversity and metabolome of beef steers. Sequencing data from the rumen fluid samples were then analyzed using QIIME2. Bermudagrass hay had a reduced alpha diversity compared with alfalfa baleage (Shannon: H = 5.19, P = 0.02). Additionally, we saw a change in beta diversity (P &amp;lt; 0.001), measured using the unweighted UniFrac distance, between conserved forage types and distinct clustering in the PCoA analysis. The most abundant taxa in all microbial communities were from the orders Lachnospirales, Bacteroidales, and Oscillospirales. Previous analysis in this study evidenced that baleage had an increased dry matter digestibility (DMD; P = 0.02). The increase in DMD was associated with the increase in diversity of the metabolome which could influence animal health and performance. Thus, baleage can serve as a beneficial conserved forage type that mitigates the losses of high-quality forages and diversifies the gut microbiome of ruminant animals.

What the hay: predicting equine voluntary forage intake using a meta-analysis approach

To properly formulate diets, the ability to accurately estimate feed intake is critical as the amount of feed consumed will influence the amount of nutrients delivered to the animal. Inaccurate intake estimates may lead to under- or over-feeding of nutrients to the animal. Individual differences in equine forage intake are well-known, but predictive equations based on animal and nutritional factors are not comprehensive. The objective of the present study was to consolidate the current body of knowledge in the published literature on voluntary forage DM intake (VFDMI) in equines and conduct a meta-analysis to identify driving factors, sources of heterogeneity, and develop predictive equations. Therefore, a systematic literature search was applied and identified 61 publications which met the inclusion criteria. From each study, the outcomes of interest (e.g., forage intake), diet composition (e.g., forage information, nutrient composition), and animal factors (e.g., sex, age, breed, BW, exercise level) were extracted. Forage intake was analyzed as two different outcome variables: (1) VFDMI in kg/d and (2) VFDMI in g/kg BW. Linear mixed model analysis treating study as a random effect was applied, using a backward−stepping approach to identifying potential driving variables for VFDMI (both units) where all terms have P < 0.1. The best fitting models for VFDMI included similar factors (also across kg/d and g/kg BW) such as forage quality (i.e., neutral detergent fiber or CP content), forage type (i.e., grass, legume, or mixed), the animals’ size category (i.e., horses vs ponies), and some management factors (i.e., pasture access). As anticipated, forage intake increased when higher quality forages were fed (i.e., lower neutral detergent fiber or higher CP), potentially due to improved digestibility. Additionally, VFDMI increased as BW increased but ponies increased their VFDMI more per every kg increase in BW compared to horses. Lastly, pasture access (i.e., grazing) may influence VFDMI such that pastured animals consume less than stalled animals, possibly due to the time it takes to graze forage. In conclusion, equations to predict equine VFDMI with high accuracy and precision (concordance correlation coefficient = 0.82 – 0.95; root mean squared error RMSE = 0.82–5.49) were developed which could be applied in practice by equine nutritionists or owners and managers. The results of this meta-analysis confirm that animal traits and forage quality have a significant impact on the VFDMI of equines and should be accounted for when formulating diets to ensure nutritional requirements are met.

Factors affecting nutrient losses in hay production

AbstractThe primary objective of haymaking is to dry forage adequately to inhibit the growth of undesirable microbes and halt residual plant enzymatic activity that causes nutrient losses. During the field and storage phases of haymaking, the environment, management practices, and other factors influence the extent of dry matter losses. This review discusses these factors and the strategies that have been developed to mitigate nutrient losses. A major emphasis was placed on hay microbiome dynamics, as it has been scarcely studied despite its importance on nutrient losses during storage and harvest, especially under humid conditions. The effects of cutting height, mower type, and swath manipulation on soil contamination were discussed. Also, the impact of environmental conditions and swath manipulation on wilting time was analysed for humid and arid conditions. Special attention was given to design improvements in harvesting equipment to reduce wilting time and field losses. Furthermore, we assessed the nutrient losses during storage caused by microbial and residual plant enzymatic activity resulting from excessive moisture at baling or re‐introduced moisture during storage. The spoilage extent during storage depends on bale moisture, size, density, shape, wrapping, forage type, and storage facilities. A Venn diagram analysis showed that each phase of haymaking process has a unique microbiome and that certain fungal and bacterial genera could be shared across more than one hay production phase. To take corrective actions, hay producers need to be aware of the increased susceptibility to nutrient losses associated with particular field and storage practices, environmental conditions, and forage types.

Effects of protein and forage source on performance and splanchnic and mammary net fluxes of nutrients in lactating dairy cows

This study was conducted to determine if the decreased MP supply predicted by the NRC (2001) when canola meal (CM) substitutes soybean meal (SBM) was supported by direct measurement of net portal absorption of AA or energy-yielding nutrients, plus the effect of the type of forage in CM-based rations. Nine Holstein cows with indwelling catheters in splanchnic blood vessels, 8 also with a ruminal cannula, were used to examine the effects of protein source in corn silage-based diets, comparing SBM versus CM, and forage source in CM-based diets, comparing corn versus grass silage. The cows were allocated to a triple 3 × 3 Latin square design with 21-d periods. The 3 experimental diets, formulated to be isoenergetic and isonitrogenous, were based on: (1) SBM and corn silage (SoCo); (2) CM and corn silage (CaCo) and (3) CM and cool-season grass silage (CaGr). Averages of intake, milk yield, and milk composition of the last 3 d of each period were used for statistical analyses. On d 21 of each period, 6 sets of arterial, portal, hepatic, and mammary blood samples and 2 ruminal fluid samples were collected. On d 12 of period 2, the protein sources were incubated in nylon bags to determine 16-h ruminal disappearance of DM and N and to obtain 16-h residues. Finally, 5 d after the completion of the Latin square design, the mobile bag technique was used to determine DM and N intestinal disappearance of the 16-h residues of SBM and CM. Pre-planned contrasts were used to compare the effect of the protein source in cows fed corn silage (i.e., SoCo vs. CaCo) and the effect of forage in cows fed CM (i.e., CaCo vs. CaGr). Data of the cow without a rumen canula could not be used because of health problem. In corn silage-based diets, substitution of SBM by CM tended to increase milk (6%) and milk fat (7%) yields. The 8% higher ruminal N disappearance and the 19% decreased MP supply from RUP predicted by NRC (2001) were not supported by the 25% decrease in ruminal ammonia concentration, similar net portal absorption of AA (except 22% higher for Met), and the 14% decrease in urea hepatic removal when CM substituted SBM. Ruminal incubation of CM in nylon bags does not appear suitable for adequate determination of the rumen by-pass of a protein source such as CM. Inclusion of grass silage rather than corn silage in CM-based diets tended to increase milk (6%) and increased milk lactose (8%) yields. Neither protein nor forage source resulted in variations of metabolism of energy-yielding nutrients that could explain observed increments in cow performance. The present study indicates no decreased AA availability when CM substitutes SBM. Therefore, substitution of SBM by CM in diets based on corn silage and CM in corn- or grass silage diets can be used successfully in high producing dairy cows.

Potential of teff as alternative crop for Mediterranean farming systems: Effect of genotype and mowing time on forage yield and quality

The introduction of alternative/innovative crops in the current Mediterranean cropping systems is a promising strategy to cope with climate change effects, which are threatening the food and feed security of that geographic area. Thanks to its large environmental adaptability and good nutritive value for humans (grains) and animals (biomass), teff is an excellent candidate to perform its role as alternative plant species for cereal/forage farming systems. However, the adoption of a “new” crop requires information about the adaptation to the target environment as well as details on the best management practices to apply. Very little knowledge is available regarding the performance of teff under Mediterranean climatic conditions. The aim of this study was to assess the effect of genotype and mowing time on the biomass yield (dry matter, DM) and proximate composition of teff (including the first regrowth). Grain yield potential was also evaluated. The study was carried out during two consecutive years in central Italy. Two different experiments were conducted in adjacent fields to gain information on both forage and grain potential of the crop. In both trials, six teff genotypes were used (namely T6, T7, T8, T11, T13 and T14). Plant height, forage yield and quality were assessed in different growth stages: flag leaf completely unrolled, booting, and heading. The regrowth of the first cut mowed at booting stage was also evaluated. Our study demonstrated that teff has potential as forage and grain crop under Mediterranean climatic conditions. Considering the total biomass production, teff genotypes yielded from 7 t DM ha−1 to 11 t DM ha−1. If used as feed source, the best harvesting time is heading (GS: 57) since it allows to maximize both biomass yield and crude protein (CP) content. The teff accessions which deserve to be deeply explored as forage types were T8 and T14 (5–6 t DM ha−1, with 150–160 g CP kg−1 DM), while T6, T7 and T13 were good grain producers (0.8–1.2 t ha−1).

Nutrient composition, fermentation characteristics and mass balance of press juice and press cake obtained from biorefining of grass‐clover and red clover silage

AbstractBiorefining is seen as a potential method to produce protein‐rich feed for monogastric farm animals from grassland, which does not compete with human nutrition. Therefore, a new biorefinery facility was constructed and tested in this experiment by using silages from grass clover mixture and red clover. After biorefining, press juice was stored for further use while press cake was re‐ensiled. Samples from silage, press juice, fresh press cake and re‐ensiled press cake were analysed for nutrient composition, fermentation parameters, amino acids (AA) and biogenic amines (BA) concentrations. Furthermore, digestibility of silage and re‐ensiled press cake was tested in wethers. We found that press juice contained about 205 g crude protein (CP), more than 180 g crude ash and more than 130 g volatile organic compounds (VOC, all values per kg dry matter [DM]). Furthermore, press juice had an unfavourable AA ratio for use as a monogastric feed (methionine and cysteine were reduced). Forage type hardly affected nutritive value of press juice. Re‐ensiling of press cake was successful as a sufficient decrease of pH and VOC concentration was observed. Press cake had 26–36 g/kg DM lower CP content and 0.77–1.12 MJ/kg DM lower metabolisable energy content than silage with greater differences in red clover than in grass clover mixture. Press juice can be used as feed in monogastric animals, but its use is limited due to its low CP content and unfavourable AA profile. Press cake could be an appropriate feed for ruminants, especially dry cows or heifers.

Milking system and diet forage type effect on milk quality of Italian Holstein-Friesian

Moving from conventional (CMS) to automatic (AMS) milking systems could affect milk quality. Moreover, the type and preservation methods of the forages used in the TMR, such as alfalfa hay (HTMR) or corn silage (STMR) have been demonstrated to modify milk composition. Thus, this study investigated the effect of implementing AMS and different diet forage types on the quality of Italian Holstein-Friesian bulk milk. Milk samples (n = 168) were collected monthly from 21 commercial farms in northern Italy during a period of 8 mo. Farms were categorized into 4 groups according to their milking system (CMS vs. AMS) and diet forage type (HTMR vs. STMR). Milk quality data were analyzed through the mixed procedure for repeated measurement of SAS with the milking system, diet forage type, and sampling day as fixed effects. Milking through the AMS led to lower milk fat, freezing point, and β-LG A; longer coagulation time; and higher K content, pH, and β-LG B than CMS. Cows fed STMR produced milk with greater fat, protein, casein, Mg content, titratable acidity, and β-LG A, but with reduced curd firming time, freezing point, and β-LG B than those fed HTMR. In conclusion, milk quality is not only altered by the diet's forage type and characteristics but also by the milking system.

Farm-specific estimates of forage variability result in larger optimal control limits for forage quality monitoring

Variation in forage composition decreases the accuracy of diets delivered to dairy cows. However, variability of forages can be managed using a renewal reward model (RRM) and genetic algorithm (GA) to optimize sampling and monitoring practices for farm conditions. Specifically, use of quality-control-charts to monitor forage composition can identify changes in composition for which adjustment in the formulated diet will result in a better match of the nutrients delivered to cows. The objectives of this study were 1) assess the use of a clustering algorithm to estimate the mean time the process is stable or in-control (d) (TStable) and the magnitude of the change in forage composition between stable periods (ΔForage) for corn silage and alfalfa-grass silage which are input parameters for the RRM; 2) compare optimized farm-specific sampling practices (number of samples (n), sampling interval (TSample) and control limits (ΔLimit) using previously proposed defaults and our estimates for the TStable and ΔForage input parameters; and 3) conduct a simulation study to compare the number of recommended diet changes costs of quality control under the proposed sampling and monitoring protocols. We estimated the TStable and ΔForage parameters for corn silage NDF and starch and alfalfa-grass silage NDF and CP using a k-means clustering approach applied to forage samples collected from 8 farms, 3x/week during a 16-week period. We compared 4 sampling and monitoring protocols that resulted from the 2 methods for estimating TStable and ΔForage (default values and our proposed method) and either optimizing only the control limit (Optim1) or optimizing the control limits, the number of samples, and the number of days between sampling (Optim2). We simulated the outcomes of implementing the optimized monitoring protocols using a quality control chart for corn silage and alfalfa-grass silage of each farm. Estimates of T^Stable and Δ^Forage from the k-means clustering analysis were, respectively, shorter and larger than previously proposed default values. In the simulated quality control monitoring, larger Δ^Forage estimates increased the optimized ΔLimit resulting in fewer detected shifts in composition of forages and a lower frequency of false alarms and a lower quality control cost ($/d). Recommended diet reformulation intervals from the simulated quality control analysis were specific for the type of forage and farm management practices. The median of the diet reformulation intervals for all farms using our optimal protocols was 14 d (Q1 = 8, Q3 = 26) for corn silage and 16 d (Q1 = 8, Q3 = 26) for alfalfa-grass silage.

Effect of nicotinic acid supplementation on digestion, metabolism, microbiome, and production in late-lactation Holstein cows

The purpose of this experiment was to determine if nicotinic acid (NA) effects on dairy cows and rumen microbial characteristics are forage type dependent (corn silage, CS; grass silage, GS). Four late lactation (days in milk = 225 +/- 12 d) Holstein cows were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. The main effects were a CS (66.10% CS) based diet or a GS (79.59%) based diet with or without 12 g/d NA. Each experimental period lasted for 28 d. Milk production and milk components, blood metabolites, apparent total-tract nutrient digestibilities, minutes rumen pH were below 5.8 as an indicator of ruminal acidosis, and body temperature changes were analyzed as indicators of heat stress. Nicotinic acid supplementation did not improve apparent total-tract nutrient digestibility. Feeding a GS-based diet improved NDF and hemicellulose digestibility. Feeding a CS-based diet increased the apparent total-tract digestibility of fat, and minutes rumen pH below 5.8 for a greater proportion of the time. The CS-based diet also improved milk yield, milk fat and protein yields, and energy-corrected milk yield; however, somatic cell count and BHB were also increased. Supplementing NA tended to decrease nonesterified fatty acids, especially when combined with GS where DMI was low. There was a trend for the total protozoa population to increase when GS and NA were fed but decreased when CS and NA were fed. Nicotinic acid tended to decrease rumen protozoal populations of Dasytricha, but increased populations of Ophryoscolex and Diplodiniinae with GS diets and decreased with CS diets. Entodiniinae were increased with CS but NA had no effect. Body temperature was increased when a CS-based diet was fed when compared with a GS-based diet. More research is needed to determine how NA can affect rumen microbial protein synthesis and what kind of diets will provide the optimum effect.

The carcass characteristics and quality of meat from lambs grazing perennial wheat with different companion legumes (clover, serradella, lucerne) or a mineral supplement

This study compared carcasses as well as the quality and mineral concentration of meat from lambs extensively grazing perennial wheat with clover (PW + C), serradella (PW + S), lucerne (PW + L), or a mineral salt supplement (PW + Min). A split-plot design was used, wherein 3 crossbred ewe lambs (n = 72 in total) (sub-plots) grazed each of 4 forage types (plots), that were replicated across 6 locations (blocks). The feeding study concluded after 96 d, when all the lambs were slaughtered. The left longissimus lumborum muscles (LL) were collected and wet aged for either 5 or 56 d post-mortem. Lambs grazing PW + Min were found to produce carcasses with lower dressing percentage values to those grazing the other forage types (P = 0.037). The LL of lambs grazing PW + L had the lowest crude protein values (P = 0.015). Forage type by ageing period interactions did not affect meat quality. The 56 d ageing period resulted in higher purge loss (P < 0.001) and TVB-N values (P < 0.001) and a decline in shear force (P < 0.001) compared to the 5 d ageing period. The other carcass and meat quality parameters were not affected by forage type; including hot carcass weight, pH decline parameters, eye muscle area, cooking loss, intramuscular fat, sarcomere length, colour stability, and concentrations of calcium, iron, magnesium, sodium, and zinc in the LL. These findings confirm that perennial cereal production systems, that include legume forages with contrasting protein, energy, and micronutrient profiles, can deliver comparable lamb carcasses and meat quality.

Short- and long-term effects of different forage types supplemented in preweaning dairy calves on performance and milk production into first lactation

We investigated the short- and long-term effects of different forage types supplemented in preweaning dairy calves on growth performance, blood metabolites, rumen fermentation, bacterial community, and milk production during first lactation. A total of 60 healthy 30-d-old female Holstein calves were blocked by birth date and body weight and randomly assigned to 1 of 3 groups (n = 20): normal milk and pelleted starter feeding (CON), supplemented with chopped oat hay (OAH; 75.0 g/d per calf [DM basis]), or alfalfa hay (ALF; 75.0 g/d per calf [DM basis]). The forage supplementation started when calves were 30 d old (d 1 of the experimental period) and ended when they were 73 d old (d 44 of the experimental period, when calves were weaned). Milk and feed intakes and fecal consistency scores were recorded daily. Growth performance, rumen fluid, and blood samples were collected biweekly. After weaning, all the calves were integrated with the same barn and diets. After calving, the milk production was recorded daily. During the experimental period, the OAH group had greater solid feed and total DM intakes and greater rumen pH than the CON group (P ≤ 0.04), but had lower forage intake and CP digestibility than the ALF group (P ≤ 0.04). The ALF group had higher rumen pH and blood BHB concentration (P ≤ 0.04), lower fecal score (P = 0.02), and greater ether extract digestibility (P = 0.02) than the CON group. The ALF and OAH groups had lower concentrations of ruminal total VFA (P = 0.01). Still, the ALF group had a greater proportion of acetate and a relative abundance of cellulose degradation-related bacteria (Lachnoclostridium_1 and Oribacterium) and a lower relative abundance of inflammation-related bacteria (Erysipelotrichaceae_UCG-009) in the rumen compared with CON. Interestingly, the average milk production from 6 to 200 DIM was greater in the ALF group (P < 0.01), even though no significant effects were found on the rumen fermentation parameters and blood metabolites at 200 DIM. Generally, alfalfa hay supplementation in preweaning dairy calves had positive effects in the short- and long-term for rumen development, health status, and future milk production.

227 Comparative analysis of rumen bacterial communities from bison heifers fed two forage-based diets of different quality

Abstract Bison have a demonstrated ability to thrive on low-quality forage, an attribute that distinguishes them from their domestic ruminant counterparts. This could be attributed to the capability of their rumen symbiotic microorganisms in extracting more nutrients out of plant biomass. To gain further insight into the role of the bison microbiome in this beneficial adaptation, the primary objective of this study was to determine the diversity and composition of ruminal bacteria in bison fed poor versus good quality forage-based diets. Ruminal content was collected by stomach tubing from 25 bison heifers fed good quality forage (GQG) during the summer (last week of June 2023) at the McGinley Ranch (Gordon, Nebraska, USA). The same individuals were then transitioned to low quality hay (PQG) in pen confinement for approximately 4 to 5 wk before resampling. Data generated from Illumina MiSeq (2×300) sequencing of PCR amplicons targeting the V1-V3 region of the 16S rRNA gene were analyzed using a combination of custom Perl scripts, and publicly available software (Mothur v.1.40, RDP classifier and NCBI Blast). Principal Coordinate Analysis (PCoA) showed a clear distinction in bacterial composition between the two types of forages (Figure 1). Further analysis of species-level operational taxonomic units (OTUs) was performed, and a total of 78,808 OTUs were identified across all samples. From the 20 most highly represented OTUs, the respective abundance of twelve OTUs showed significant differences between the two forage types (Kruskal-Wallis’s sum-rank test; P &amp;lt; 0.05). For example, OTUs SD_Bb-00014 (µGQG = 1.06% vs µPQG = 0.19%), and SD_Bb-00049 (µGQG = 0.98% vs µPQG = 0.08%) showed significant decreases in abundance when animals switched to PQG. Conversely, OTUs SD_Bb-00071 (µGQG = 0.2% vs µPQG = 2.71%), SD_Bb-00049 (µGQG = 0.68% vs µPQG = 1.67%) and OTUs SD_Bb-00148 (µGQG = 0.19% vs µPQG = 1.40%) exhibited a significant increase in abundance in response to the forage transition. Notably, only one of the assessed OTUs, SD_Bb-00071, showed high sequence identity to its closest valid relative, Fibrobacter succinogenes (98.41%). In contrast, most of the other highly represented OTUs were found to be very dissimilar to known species, suggesting that they might represent novel or currently uncharacterized bacterial species (Table 1). Together, these results demonstrate the significant impact of variations in nutritional value and forage quality on the composition of rumen bacterial communities in the North American bison. Poor forage quality appeared to favor bacterial species such as Fibrobacter succinogenes, known for its cellulolytic capabilities, presumably because of its greater efficiency in breaking down more resistant plant cell walls. Its ability and that of other abundant OTUs to efficiently convert plant fibers into assimilable nutrients is likely critical in allowing bison to perform better on poor-quality forage compared with domesticated ruminants.