Microplastic (MP) contamination in terrestrial animal products poses an emerging threat to human and animal health, yet the extent of this contamination on farms is unclear. Current MP detection methods in animal feed require MP extraction from samples for quantification and characterization, a time-consuming process that varies based on the matrix composition. To address this limitation, handheld near-infrared spectroscopy (NIRS) was evaluated as a direct method to detect MP in corn silage (CS), a common cattle feed in northern Italy. Twelve CS batches from various farms were spiked with low-density polyethylene MP at concentrations ranging from 0% to 2.0% (w/w), yielding 240 split samples. Calibration models were developed using two strategies: individual batch calibrations and batch-independent calibrations combining all samples. Partial least squares regression was applied, with approximately 75% of samples used for calibration and 25% for external validation. Individual batch calibration showed variable performance (R-2 P = 0.81-0.98), with most models achieving sufficient accuracy for quality control purposes (RPD>3.0). The batch-independent calibration exhibited excellent performance (R-2 P = 0.97, RPD=6.3) when spectra were averaged at each concentration level. These findings demonstrate that handheld NIRS can effectively monitor MP contamination directly within individual batches for quality control and, through batch averaging, enable larger-scale regional assessments of feed.

The blackberry poses a threat as an invasive plant in various regions worldwide, where it aggressively competes with native species and risks delicate ecosystems. Livestock grazing has emerged as a potential strategy to mitigate its spread. This study investigated the effects of seasonal variations and altitude on the chemical composition and in vitro degradability of blackberry leaves. The leaves accessible to goats were collected in the Northwestern Italian Alps across all seasons at three altitudes (low: 450 m, medium: 700 m, high: 1000 m). The findings indicated that blackberry leaves can serve as a cost-effective, high-protein, and high-fiber feed for ruminants in these regions. However, the goats exhibited a limited capacity for fiber degradation. Furthermore, the nutritional value of these leaves was significantly influenced by the season, altitude, and their interaction. Spring leaves had the highest protein content (241.9 g/kg dry matter) and the best digestibility, with lower lignin levels (69 g/kg dry matter). At higher altitudes, lignin content decreased significantly during winter compared to the other seasons, resulting in a significant increase in fiber degradability. These insights offer crucial guidance for optimizing the utilization of the blackberry plant in goat feeding systems and underscores the necessity of considering both seasonal and altitudinal factors in grazing management practices.

This study examined the effects of microplastic (MP) contamination on rumen fermentation dynamics and concentrate degradability using an in vitro model with lamb rumen fluid. Three types of MPs-polyethylene terephthalate (PET), low-density polyethylene (LDPE), and polyamide (PA)-were tested at contamination levels of 0%, 0.6%, 1.2%, and 1.8% of dry matter. MP contamination significantly disrupted rumen fermentation dynamics, reduced feed degradability, increased gas production, accelerated fermentation rates, and shortened the lag time before gas production (p < 0.05). Additionally, MPs impaired microbial efficiency, increased ammonia-nitrogen (NH₃-N) levels, decreased rumen protozoa populations, and reduced concentrate degradability (p < 0.05). LDPE exhibited the most severe effects, causing the highest increases in gas production and NH₃-N levels (15% and 12%, respectively at LDPE highest dose) while decreasing microbial efficiency, protozoa count, and feed degradability (16.0%, 16.4%, and 4.5%, respectively at LDPE highest dose). The severity of MPs' impacts followed a significant linear trend, with higher concentrations leading to more pronounced negative effects. The findings highlight MPs as significant emerging pollutants that can adversely affect rumen function and animal nutrition.

Microplastics (MPs) have emerged as a significant environmental threat, infiltrating livestock systems. This study presents the first in vitro investigation of the effects of low-density polyethylene (LDPE) MP contamination on rumen fermentation dynamics and feed utilization in a simulated ruminal digestive system. Concentrate feed was incubated in buffered rumen fluid collected from lambs, supplemented with LDPE MPs at concentrations of 3.3 g/L and 6.6 g/L and compared to the concentrate incubated in the buffered rumen fluid without MP contamination. The results demonstrate that both levels of LDPE MPs significantly altered rumen fermentation dynamics by reducing asymptotic gas production by 11% and 15% and increasing the constant rate of gas production by 16% and 19% at low and high addition levels, respectively, compared to the control. However, the early-stage fermentation dynamics remained unaffected. Furthermore, both levels of LDPE MPs reduced rumen protozoal populations (20% and 23%) and ammonia-nitrogen levels by 11% at both of addition levels. Despite these disruptions, rumen pH remained unaffected. Increasing the addition level of LDPE from 3.3 to 6.6 g/L did not exacerbate the disruptions. The results of this study highlight the potential risks posed by LDPE MPs in ruminal nutrition. Further in vivo investigations are essential to validate these findings and assess their impact on animal performance.

Microplastic (MP) pollution is an emerging concern in ruminant production, as animals are exposed to MPs through air, water, and feeds. Ruminants play a key role in MP transmission to humans via animal products and contribute to MP return to agricultural soil through excreta. Identifying effective strategies to mitigate MP pollution in the ruminant sector is crucial. A promising yet understudied approach involves the potential ability of rumen microbiota to degrade MPs. This study investigated the in vitro ruminal degradation of three widely distributed MPs—low-density polyethylene (LDPE), polyethylene terephthalate (PET), and polyamide (PA)—over 24, 48, and 72 h. PET MP exhibited the highest degradation rates (24 h: 0.50 ± 0.070%; 48 h: 0.73 ± 0.057%; and 72 h: 0.96 ± 0.082%), followed by LDPE MP (24 h: 0.03 ± 0.020%; 48 h: 0.25 ± 0.053%; and 72 h: 0.56 ± 0.066%) and PA MP (24 h: 0.10 ± 0.045%; 48 h: 0.02 ± 0.015%; and 72 h: 0.14 ± 0.067%). These findings suggest that the ruminal environment could serve as a promising tool for LDPE, PET, and PA MPs degradation. Further research is needed to elucidate the mechanisms involved, potentially enhancing ruminants’ natural capacity to degrade MPs.

Ruminants play a crucial role in the food chain, but are also considered contributors of greenhouse gas (GHG) emissions . Essential oils (EOs) are emerging as natural feed additives in ruminants’ nutrition to enhance animal health, performance and reduce environmental footprint. Among EOs, lemongrass (Cymbopogon winterianus) and oregano (Origanum vulgare) EOs (LEO and OEO) have attracted attention as modulators of ruminal fermentations, but their role needs to be clarified. The experiment was designed using a randomised setup to assess the effects of LEO and OEO on in vitro ruminal fermentation and GHGs, using total mixed ration (TMR) as substrate (incubation time 24h). Experimental treatments included (doses as % of TMR on DM basis): 1) control only TMR (0% EOs) 2) 0.07% LEO 3) 0.07% OEO 4) 0.035% LEO + 0.035% OEO 5) 0.07% LEO + 0.07% OEO. Each treatment was repeated three times in two experimental runs. Only EO combinations reduced total gas (−9%, p=0.001). All EOs decreased CO2 emissions by −5 to −12% with no significant differences between treatments (p<0.001), although anti-methanogenic effects were not observed (p=0.192). Volatile fatty acids were slightly affected only by EOs blend at the highest dose, resulting in a reduction of propionate (−1.3%, p=0.02), an increase in acetate:propionate (+0.16%, p=0.04) and isovalerate (+0.7%, p=0.03). LEO reduced pH (−0.6%, p=0.004), while OEO increased oxidation capacity (+4.2%, p=0.004), but both parameters remained within physiological ranges. Canonical discriminant analysis confirmed distinct EOs effects, highlighting their potential as natural additives for improving ruminal fermentation and mitigating ruminant environmental footprint.

Climate change, feed shortages, and rising production costs highlight the need for alternative and sustainable forages for ruminants. This study aimed to evaluate the nutritional composition, in vitro ruminal fermentation, and methane emissions of Urtica dioica ecotypes originating from contrasting bioclimatic zones in Tunisia. Aerial parts of Urtica dioica were harvested at the early flowering stage from arid, semi-arid, and sub-humid regions. Samples were subjected to chemical composition in vitro ruminal fermentation to determine dry matter degradability (DMD), neutral detergent fiber degradability (NDFD), metabolizable energy (ME), and methane production. The results demonstrate that Urtica dioica is a promising protein-rich forage, with a stable crude protein content across ecotypes (18.58–20.97% of dry matter). In contrast, NDFD, DMD, ME, and methane emissions varied significantly according to origin. The arid ecotype, characterized by the highest fiber, ether extract, and polyphenol content, exhibited the lowest DMD (53% vs. 61% and 60%), NDFD (45% vs. 55% and 56%), and ME (7.2 vs. 8.6 and 9.0 MJ/kg dry matter) but produced the lowest methane emissions (38.8 vs. 53.2 and 74.2 mL CH4/kg DMD) compared with the semi-arid and sub-humid ecotypes. The semi-arid and sub-humid ecotypes had comparable DMD, NDFD, and ME values; however, methane emissions were higher in the sub-humid ecotype. Overall, the semi-arid ecotype provided the most favorable balance between nutritive quality and environmental sustainability. These findings highlight the critical role of ecological origin in determining the feeding value and greenhouse gas footprint of Urtica dioica, providing a scientific basis for its potential use as a sustainable forage in ruminant feeding systems.

The presence of microplastics in the forage and feedstuffs of domestic animals represents an imminent threat to the entire food chain that may reach humans since the particles could be transferred into the intestinal barriers and contaminate blood and animal products. Until now, there is no simple, rapid, sustainable, and reliable method to detect microplastics in animal feed. The objective of this study was to investigate the ability of near-infrared spectroscopy (NIRS) to detect microplastics in ruminant feeds. Two types of instruments were tested using four feeds (corn silage, mixed hay, rye grass silage, soybean meal) and a total mixed ration. Two types of crumbled contaminants, low-density polyethylene and polystyrene, were accurately mixed at ratios of 0, 1, 3, and 5 mg g-1. The pool of the five matrices examined by the benchmark instrument (714-3333 nm) yielded an accuracy of approximately 0.8 mg g-1 and a detection limit of about 1 mg g-1, however, the errors could be halved in separate calibrations. A short wavelength range (714-1070 nm) or a smart NIRS instrument proved an acceptable discrimination of the concentrations. Following these preliminary results, any validation on other samples with different and powerful NIRS tools is encouraged.

The alarming presence of micro plastics in the digestive system of ruminants highlights the urgent need for precise assessment methods to comprehend their effects specifically on rumen function, an integral aspect of overall animal health. This study aimed to validate the applicability of an in vitro gas box system, that mimics the rumen environment, for exploring the effects of introduction of varying levels of low-density polyethylene microplastics (ranging from 2 to 200 mg/30 mL of buffered rumen fluid) into the rumen under controlled laboratory conditions. The results successfully demonstrated the effectiveness of this technique in detecting the effects of low-density polyethylene micro plastics on the dynamic of gas produced by rumen fermentation including asymptotic gas production, the constant gas production rate, the average fermentation rate, the time to the onset of rumen gas production and the time to half-maximum gas production. Moreover, this system detected the effects of the low-density polyethylene microplastics on concentration of rumen ammonia nitrogen and the level of rumen protozoa. Lastly, the study highlighted the ability of the gas box system to discriminate not only the presence of low-density polyethylene microplastics, but also its dose-dependent effects across all these parameters.

Microplastics (MPs) raise environmental concerns. However, their effects on the ruminal–gastro-intestinal system have not yet been studied. This study aims to investigate the effects of polyethylene terephthalate (PET) MPs on the ability of the ruminal–gastro-intestinal system to degrade and digest mixed hay. Using a three-step in vitro ruminal–gastro-intestinal incubation system, PET MPs were introduced at concentrations of 0, 5, 10, and 15 g/L in ruminal and gastro-intestinal solutions. Ruminal fluid was collected from three 16-month-old Piedmontese bulls. The experiment was conducted on three mixed hays and was repeated three times, with triplicate incubations in each run. The results reveal that PET MPs reduced the degradability and digestibility of crude protein. Specifically, crude protein degradation was reduced by 9% at medium and 16% at high PET MP concentrations in the ruminal phase, while the crude protein digestibility of undegraded crude protein was reduced by 8% at the lowest PET MPs concentration in the gastro-intestinal tract. Additionally, PET MPs reduced the degradation of neutral detergent fiber at medium and high PET MP concentrations in the ruminal phase by 9% and 13%, respectively. These results highlight the risks of PET MPs contamination on ruminal–gastro-intestinal functions and underscore the urgent need to mitigate MPs contamination in the livestock sector.

This study aims to evaluate the efficacy of Texture Profile Analysis on homogenized cooked patties, referred to as TPAH, in accurately predicting patty texture and distinguishing between various patty types, similar to traditional TPA. Eight types of patties (96 samples), comprising one meat patty, one commercial pea protein-based patty, and six homemade pea protein-based patties, underwent analysis for hardness, cohesiveness, gumminess, chewiness, resilience, and springiness. All parameters measured by both methods exhibited similar variations, except for springiness. Homogenization maintained the ability to differentiate between different types of patties and generally reduced the load, albeit in a manner dependent on the type of product. For instance, the hardness decreased from 32.6 to 29.6N for the meat patty, from 18.7 to 10.0N for the homemade patties, and from 17.4 to 5.0N for the commercial patty. The meat patty exhibited a greater consistency with a 9.2% drop, while the homemade vegetable patties experienced a drop of 46.5%, and the commercial patty even more so with 71.3%. Canonical Discriminant Analysis applied to the two methods demonstrated the superior performance of TPAH compared to TPA. The TPAH method has proven to be valuable in predicting and comparing the texture of cooked patties.

Plastics and, in particular, microplastics (MPs) (< 5 mm) are emerging environmental pollutants responsible for interconnected risks to environmental, human, and animal health. The livestock sector is highly affected by these contaminants, with 50–60 % of the foreign bodies found in slaughtered domestic cattle being recognized as plastic-based materials. Additionally, microplastics were recently detected inside ruminant bodies and in their feces. MPs presence in ruminants could be explained by the intensive usage of plastic materials on farms, in particular to store feeds (i.e. to cover horizontal silos and to wrap hay bales). Although feed could be one of the main sources of plastics, especially of microplastics, a specific protocol to detect them in ruminant feeds is not actually present. Hence, the aim of this study was to optimize a specific protocol for the extraction, quantification, and identification of five microplastic polymers (high-density polyethylene, low-density polyethylene, polyamide fibers/particles, polyethylene terephthalate and polystyrene) from feeds typically used in ruminant diets (corn silage, hay, high protein feedstuff and total mixed ration). Several combinations of Fenton reactions and KOH digestion were tested. The final extraction protocol involved a KOH digestion (60 °C for 24 h), followed by two/three cycles of Fenton reactions. The extraction recoveries were of 100 % for high-density, low-density polyethylene, polyamide particles, and polystyrene and higher than 85 % for polyethylene terephthalate and polyamide fibers. Finally, the optimized protocol was successfully applied in the extraction of microplastics from real feed samples. All the feeds contained microplastics, particularly polyethylene, thus confirming the exposure of ruminants to MPs.

Ankom Daisy II incubator (Ankom Technology, Macedon NY, USA) has gained acceptance as an alternative to traditional in vitro procedures to measure feed degradability. It reduces labour requirements and increases the number of determinations that can be completed by a single operator. The apparatus allows simultaneous incubation of multiple feedstuffs in the same jar, weighed in single bags, and placed in a continuously rotating incubator at 39. 5$\circ$c with a buffered inoculum. This simple procedure shows some functional limitation that can be resolved to obtain more reliable results. In particular, the jars do not rotate smoothly, with slowdowns, stops, and restarts that increase the variability of the instrument itself. In this paper, some low-cost and easily implementable structural adjustments are proposed, modifying the two drive rollers, and using a new drive pulley. These modifications can ensure steady conditions which are necessary in scientific experiments and reduce the doubts of the variability in degradability results related to an inaccurate instrumentation functionality.

In vitro methods have been standardized and tested to correctly simulate the rumen environment and fermentation process. A few studies have verified that the feed degradability achieved as a result of stirring the samples is higher when the samples are incubated under continuous stirring than when they are only stirred twice daily. The objective of this study has been to verify the effect of the speed of stirring on feed degradability during In vitro incubation. For this purpose, the apparent and true dry matter degradability (ADMD and TDMD) of grass hay, pelleted alfalfa, corn silage, barley meal, straw, and a total mixed ration (TMR) were measured after 48 h of incubation in jars under different rotation speeds. The same types of feed were placed in the four jars of each instrument, and the rotation system of the machine was modified to ensure the simultaneous rotation of a pair of original jars (which sometimes stopped and/or rotated slowly and irregularly) together with a pair of modified jars under regular and continuous rotation. A rev counter data logger was mounted onto the jars, and the rotation speeds of the original and modified jars were measured and compared under different conditions (empty jars, jars with liquid, jars with rumen fluid, and sample bags). The modifications to the instruments stabilized the rotation of the jars, thereby making the stirring more regular during incubation. The degradability was partly influenced by the regular stirring, albeit with just one instrument, and for grass hay, barley meal, corn silage, and TMR. In short, it has been found that the regular stirring of sample bags is not essential to obtain reliable degradability measurement during incubation, although it is better to maintain a constant rotation to ensure a regular and standardized In vitro incubation process and therefore to allow reproducibility and comparisons of the results on feed degradability.

The objective of this study has been to verify whether a combination of the standard Texture Profile Analysis and the back extrusion, which we have named "TPAH" since the analysis was performed after homogenization, can be applied to products that are difficult to handle. The TPAH was applied to 180 samples, divided equally into 18 batches of home-made pea-based patties, commercially pea-based patties, and meat patties. Seven TPAH parameters were measured on both raw and cooked samples: adhesiveness, chewiness, cohesiveness, gumminess, hardness, springiness and resilience. The specific density of the raw and cooked samples as well as a few physico-chemical parameters were also measured. All TPAH parameters were able to clearly discriminate between home-made, commercial, and meat patties (P-value <.05 to 0.001). A Canonical Discriminant Analysis highlighted the effectiveness of TPAH on both raw patties (R-2 = 0.960, Wilks' Lamba test Pr < 0.0001) and cooked ones (R-2 = 0.955, Wilks' Lamba test Pr < 0.0001). Even when the Canonical Discriminant Analysis was narrowed to cooked plant-based patties, the method proved to be efficient (R-2 = 0.809, Wilks' Lamba test Pr < 0.0001). The protein content was significantly related to all the TPAH parameters, except for adhesiveness. The TPAH method could be useful in research related to the substitution of meat patties with plant-based ones.

A pasture-based swine management (PBSM) trial was conducted in Piemonte (N-W Italy) to study the performances and the carcass yield of 16 hybrid pigs (8 castrated males and 8 females; average initial weight: 90 kg). Animals were allowed to forage pea, clover, beet and alfalfa pastures for 170 days in a crop-pasture rotation on different paddocks. A concentrate was fed to supply 50% of estimated energy requirements. Forage dry matter intake (DMI) ranged from 0.32 kg/day (alfalfa) to 2.85 kg/day (pea), depending on the period and forage type. Pigs were weighted every 30 days and at slaughtering; average daily gain (ADG) was 0.29 kg. The stocking rate (SR) ranged from 109 kg/ha LW (clover) to 2347 kg/ha LW (pea). Data collected at slaughtering (average final weight: 141 kg) were: hot carcass weight and yield, lean and fat cuts weight, backfat thickness, pH45 and pH24. The statistical analysis (ANOVA of SPSS) did not show differences between males and females. Results showed that PBSM should be especially appealing to limited-resource farmers due to low inputs needed; pasture can be used to replace 50% of the nutritional needs, helping to save on grain costs, without affecting carcass characteristics.

Digestibility trials need a viable rumen fluid as inoculum to degrade feeds. The variability of rumen fluid depends on the animal's diet, while its viability is greatly influenced by the sampling and handling procedures. In this article, we present a replicable protocol for sampling the rumen fluid from slaughtered animals for in vitro digestibility trials. A detailed list of the tools and a step-by-step standardized procedure for the collection, storage and the transportation of the rumen fluid from the slaughterhouse to the laboratory is presented. We also describe a digestibility trial for establishing the maximum storage time of rumen fluid from sampling to its use. The results show that the rumen fluid, collected and maintained according to the proposed protocol, can be stored and used from 30 to 300 min from sampling without significantly compromising the fermentative activity of the microbial population.

Rumen fluid is the most widely used inoculum for in vitro feed digestibility trials. The digestate from animal manure is widely studied but there are no data on its use as an alternative inoculum; its use would be greatly beneficial thanks to its availability, easiness in sampling and possibility to store it for long times. In this study we perform a preliminary test on the potential efficacy of the digestate as inoculum for in vitro digestibility of feeds using rumen fluid as control. The parameter used to assess the efficacy of the digestate was the Neutral Detergent Fiber Digestibility of nine Total Mixed Rations for dairy cows classed into three groups according to their Neutral Detergent Fiber amount (low; medium; high). Four incubation times (48 h, 60 h, 72 h and 96 h) were tested; the data were compared with those measured with the rumen fluid after 48 h of incubation. The results showed that no significant differences were observed among the four incubation times. The digestibility using digestate as inoculum was lower than rumen fluid with low fiber diets at 48 h of incubation. For medium fiber diets, the digestibility values were similar with only one exception; for high fiber diets no differences were observed between rumen fluid and digestate at all incubation times. According to these results, digestate proved to be an efficient substitute of the rumen fluid with high or medium fiber diets, with low fiber diets incubation time need to be of 60h to have similar values to rumen fluid. Further trials with digestates of different origin and chemical and microbiological composition are needed to confirm its efficacy to determine the in vitro digestibility of a wider range of feeds.

The quality of a forage influences the production of animals, and it can be defined in many ways. Laboratory analyses are important tools because they can be used to indicate the quality of the forages, and they represent a relatively quick way of defining their nutritive values. However, specific quality indexes are necessary to evaluate and rank forages. The quality of conventional forages is predicted by different indexes, according to whether they are legumes or grasses. However, no indications are given about what formulae should be used for unusual forages. In the present study, laboratory analyses have been conducted on three unusual crops belonging to three different botanical families (amaranth, borage, and camelina) at four growth stages, and conventional quality indexes have been calculated and applied to establish their quality. The obtained results have shown that the nutritive value of the unusual forages modified during the growth, although they always maintained a high quality. Hence, the Relative Feed Value of unusual forages can be measured using the ADF content or digestibility value. The Relative Forage Quality, calculated with the legume formula, seems more appropriate for the considered unusual forages as it was able to reveal any changes that took place during maturity.