Forage Type Research Articles

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 < 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 < 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 impact 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 (SoyCorn); 2) CM and corn silage (CanCorn) and 3) CM and cool-season grass silage (CanGrass). 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 16h-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., SoyCorn versus CanCorn, and the effect of forage in cows fed CM, i.e., CanCorn versus CanGrass. 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 like 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.

Insights into the effects of saline forage on the meat quality of Tibetan sheep by metabolome and multivariate analysis

This work aimed to investigate how two different types of forage (saline and alkaline) impact the meat quality and muscle metabolism of Tibetan sheep. An integrative multi-omics analysis of meat quality and different metabolites was performed using untargeted and targeted metabolomics approaches. The research results indicated that GG grass (saline and alkaline forage) possessed superior characteristics in terms of apparent quality and secondary metabolite content compared with HG grass (Non saline alkali forage), regardless of the targeted metabolites or non-targeted ones. Simultaneously, under stress conditions, the carbohydrates-rich salt-alkali grass play a significant role in slowing down the decline in pH, increasing the unsaturated fatty acid content and reducing the thawing loss in Tibetan sheep. This study provides an understanding of the impact of different salt-alkali grass on the quality of Tibetan sheep meat, while providing a scientific basis for the future development of salt-alkali livestock industry.

Synergistic negative effects between a fungicide and high temperatures on homing behaviours in honeybees.

Interactions between environmental stressors may contribute to ongoing pollinator declines, but have not been extensively studied. Here, we examined the interaction between the agricultural fungicide Pristine (active ingredients: 25.2% boscalid, 12.8% pyraclostrobin) and high temperatures on critical honeybee behaviours. We have previously shown that consumption of field-realistic levels of this fungicide shortens worker lifespan in the field and impairs associative learning performance in a laboratory-based assay. We hypothesized that Pristine would also impair homing and foraging behaviours in the field, and that an interaction with hot weather would exacerbate this effect. Both field-relevant Pristine exposure and higher air temperatures reduced the probability of successful return on their own. Together, the two factors synergistically reduced the probability of return and increased the time required for bees to return to the hive. Pristine did not affect the masses of pollen or volumes of nectar or water brought back to the hive by foragers, and it did not affect the ratio of forager types in a colony. However, Pristine-fed bees brought more concentrated nectar back to the hive. As both agrochemical usage and heat waves increase, additive and synergistic negative effects may pose major threats to pollinators and sustainable agriculture.

Forage type and additive effects on fermentation quality and biorefinery performance of silages

AbstractThe concept of a green biorefinery has recently gained interest and can be defined as a process where green biomass is processed to a variety of products. Most green biorefineries rely on fresh green biomass as the feedstock, but using a stable ensiled biomass could provide benefits. We evaluated the effects of silage additive treatments on silage fermentation quality and performance in a laboratory scale liquid–solid separation to simulate the first step of a green biorefinery. In Experiment 1, red clover and fresh and wilted grass were ensiled without additive or treated with a lactic acid bacteria inoculant or a formic acid based additive. In Experiment 2, grass or red clover were treated with a fibrolytic enzyme, formic acid or a combination of them, and a control without additive was also included. Silage fermentation quality was improved by additive use. Biomass dry matter concentration was negatively related to liquid yield, but effects of additive treatments on the biorefinery performance were minor and inconsistent between different forages. Optimizing agronomic and feedstock conservation management plays an important role for the success and sustainability of the biorefinery process. Good silage management practices with minimal losses during storage should be targeted, but no clear patterns in biorefinery outputs were observed in the current study when different types of additives were used in grass and clover silage production.

168 Evaluate the digestibility effects of alfalfa-bermudagrass mixtures on beef cattle in the Deep South

Abstract In the Deep South, one of the hardest times of year for cattle producers is the summer due to extreme temperatures and low-quality perennial forages. Incorporating a high-quality crop like alfalfa (Medicago sativa) into forage mixtures could be economically advantageous; however, there is not much alfalfa produced in the Deep South. Therefore, our objective was to evaluate the effects of forage type on in vivo digestibility and nutrient balance in beef cattle systems. There was also an interest in differing conserved forage types, so we analyzed digestion dynamics influenced by various conserved forage types. Three treatments including bermudagrass (Cynodon dactylon) hay, alfalfa baleage, and alfalfa-bermudagrass baleage were supplied to four fistulated steers (average 412.34 kg +/- 41.25 kg) 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 total fecal excretion, feed intake, feed refusal, total urine output, and rumen fluid dynamics. Data were analyzed using R Core Team (2023) and the GLIMMIX procedure of SAS version 9.4 (SAS Inst., Cary, NC). There were significant differences in dry matter digestibility (DMD) between diets (P &amp;lt; 0.0015). We found that alfalfa-bermudagrass baleage had a 9% (+/- 0.058, 95% C.I.) less DMD than bermudagrass hay (P &amp;lt; 0.0088) and alfalfa baleage had a 7% (+/- 0.058, 95% C.I.) greater DMD than bermudagrass hay (P &amp;lt; 0.025). Results indicate that alfalfa baleage provides the most nutrient use efficiency when comparing alfalfa-bermudagrass mixtures. There was no significant conserved forage effect potentially due to baleage quality and inadequate fermentation of the alfalfa-bermudagrass baleage. That said, there is still potential for beef cattle producers in the Deep South to diversify feeding strategies by using nutrient-rich forage additives like alfalfa and different conserved forage methods to increase digestibility, thus increasing returns in their operations.

74 Effect of grazing native warm season grasses on parasitism and growth in weaned Katahdin lambs

Abstract Parasitism in lambs during the post-weaning period has effects on growth, survival, and sheep enterprise profitability. Opportunities to minimize exposure to infective larvae during this period may reduce clinical effects and improve lamb performance. Native warm season grasses (NWSG) offer increased growth during summer months and taller plants that allow grazing at greater heights. The objective here was to evaluate NWSG as a forage for post-weaning development of lambs in spring lambing, forage-based systems. Over 2 yr, Katahdin lambs (Yr 1, n = 30; Yr 2, n = 31) were managed at a producer farm in the piedmont region of North Carolina. Beginning 2 wk post-weaning, lambs were randomly assigned to graze on either NWSG (Big Bluestem and Indiangrass) or cool season grass (CSG, Kentucky 31 Tall Fescue base) pasture. Lambs were continuously grazed for 70 d in Yr 1 and 55 d in Yr 2. Fecal egg count (FEC), FAMACHA score, and body weight (BW) were measured every two weeks. Lambs were dewormed at FAMACHA ≥ 3. Forage analysis was conducted at the start and end of the grazing period. Statistical analysis were performance using the PROC Mixed procedure of SAS. Lambs in each group were raised in similar litter sizes and sire and sex were evenly distributed between groups. Fecal egg count and growth estimated breeding values (EBV) were similar between NWSG and CSG groups. In Yr 1 and 2, no differences were observed in FEC between grazing groups (P &amp;gt; 0.05). However, FEC did increase in both groups throughout the grazing period (P &amp;lt; 0.05). In Yr 1, no differences were observed in total BW gain (P = 0.74). However, in Yr 2, lambs grazing CSG had greater total BW gain than the NWSG group (P &amp;lt; 0.05). In both years, there were no differences in the percentage of lambs requiring deworming (Yr 1, P = 0.36; Yr 2, P = 0.47) but lambs requiring treatment had greater FEC EBVs (P &amp;lt; 0.05). Nutrient quality of NWSG pasture was reduced compared with CSG pastures. Total digestible nutrients and crude protein were less in NWSG compared with CSG pastures (Yr 2: 61.5% vs. 63.9% and 8.9% vs. 13.6%, respectively) and neutral detergent fiber was greater (Yr 2: 74.1% vs. 65.2%, respectively) resulting in decreased nutrient availability for NWSG group. While NWSG may provide additional biomass for summer grazing, rapid maturity rates may limit nutrient availability for lambs resulting in decreased growth performance despite similar levels of parasitism. Lamb FEC EBV may have a role in parasite resistance and deworming requirements regardless of forage type. Thus, genetics must be considered along with grazing management as part of an integrated parasite management plan.

Fermentation characteristics of maize–forage legume mixtures ensiled in small-scale silos

This study was conducted to evaluate the ensiling characteristics of maize–forage legume mixtures in small-scale silos. Sole and intercrops forage materials were harvested 80 days after planting and ensiled in small-scale silos, that is: plastic bags, plastic drums, and small pits, for 60 days. After ensiling, samples were collected to examine the chemical composition, microbial community and fermentation quality. Mixed silages stored in the drum silos had significantly (p ≤ 0.05) higher DM content (35.69%) than that from pit and bag silos. The drum silos had significantly (p ≤ 0.05) higher crude protein concentration (20.57% DM) in sole legume silages than other silo types. Neutral detergent fibre concentration (39.76% DM) of sole forage silages was greatest in bag silos than in other silos. High in vitro dry matter digestibility and water-soluble carbohydrate values (58.15 and 12.19% DM respectively) for mixed silages were recorded in drum silos. Bag silos showed lower numbers of lactic acid bacteria and higher populations of enterobacteria (4.86 and 4.26 log10 CFU g−1 respectively) in sole forage silages than other silos. Mixed silages ensiled in drum silos produced significantly lower (p ≤ 0.05) pH (3.03) and ammonia nitrogen content (3.73% TN) compared to pit and bag silos. The study concluded that ensiling maize–forage legume mixtures in drum silos can have a positive effect on the nutritive value of ruminants’ feeds. Therefore, the recommended forage type for ensiling is mixed silages.

Environmental Management of Equine Asthma

Environmental practices related to the inhalation of airborne dust have been identified as the main cause of equine asthma (EA) and reasonably, they are truly relevant in its treatment and control, especially for horses with its severe form. Vast research regarding environmental recommendations has been conducted in recent years. However, no recent exhaustive reviews exist that gather all this new evidence. The aim of this review is to report and compare the most pertinent information concerning the environmental management of EA. The main findings highlight the importance of the type of forage used for feeding but also its method of production and possible contamination during manufacture and/or storage. Procedures to reduce this, such as soaking and steaming hay, improve its hygienic quality, although they also decrease forage’s nutritional value, making dietetic supplementation necessary. Regarding stabling, despite some conflicting results, avoiding straw as bedding and improving barn ventilation continue to be the common recommendations if turning to pasture is not feasible. Finally, owners’ compliance has been identified as the most critical point in correct environmental control. Educating owners about the genuine benefits of these measures should be a cornerstone of EA management.