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Simple Summary: The trace mineral nutrition of ruminants has been widely studied; however, most of the research has focused on the requirements of mature cattle, and the requirements of trace minerals for calves prior to weaning are poorly understood. This study investigated how two levels of trace mineral supplements provided to beef calves before weaning affect their performance and mineral status. Apart from Cu, which is often a limited trace mineral in many regions, the supplementation of trace minerals above the NASEM (2016) recommendations did not improve the mineral status of beef calves. In this 2-year study, approximately 84 days prior to weaning, 24 calves/year (Angus × Hereford) were randomly assigned to one of two treatments: trace mineral (Cu, Se, and Zn) supplementation following NASEM (2016) recommendations (Control) or trace mineral supplementation above NASEM (2016) recommendations (Super). Calves were individually fed, and trace minerals were provided in 0.5 kg of dry distiller's grains three times weekly. Body weight (BW), blood, and liver samples were collected on d 0 and at weaning (d 84). Additional BW and blood samples were collected post-weaning on d 85, 87, 88, 91, 95, and 99 during the preconditioning phase. Initial liver concentrations of Se, Cu, and Zn were similar between treatments (p ≥ 0.69). At weaning, a year effect (p < 0.001) and a tendency for treatment × year effect (p = 0.09) were observed for Cu liver concentration. In year 2, but not in year 1, calves assigned to the Super treatment tended to have greater liver Cu concentration than calves assigned to the Control treatment. Except for Cu, a notoriously limited trace mineral in multiple geographical locations, the supplementation of trace minerals above the NASEM (2016) recommendations did not improve the mineral status of calves in this environment. [ABSTRACT FROM AUTHOR]

(1) Background: This study explores the correlation between volatile fatty acid (VFA) concentrations and methanogenesis in ruminants, focusing on how the nutritional composition of their diets affects these processes. (2) Methods: We developed predictive models using multiple linear regression, artificial neural networks, and k-nearest neighbor algorithms. The models are based on data extracted from 31 research papers and 16 ruminal in vitro fermentation tests to predict VFA concentrations from nutrient intake. Methane production estimates were derived by converting and clustering these predicted VFA values into molar ratios. (3) Results: This study found that acetate concentrations correlate significantly with neutral detergent fiber intake. Conversely, propionate and butyrate concentrations are highly dependent on dry matter intake. There was a notable correlation between methane production and the concentrations of acetate and butyrate. Increases in neutral detergent fiber intake were associated with higher levels of acetate, butyrate, and methane production. Among the three methods, the k-nearest neighbor algorithm performed best in terms of statistical fitting. (4) Conclusions: It is vital to determine the optimal intake levels of neutral detergent fiber to minimize methane emissions and reduce energy loss in ruminants. The predictive accuracy of VFA and methane models can be enhanced through experimental data collected from diverse environmental conditions, which will aid in determining optimal VFA and methane levels. [ABSTRACT FROM AUTHOR]

Urochloa spp. are the most important grasses for ruminants in Brazil and contain secondary metabolites, mainly saponins. Urochloa brizantha extracts (ethanolic EE and hydroalcoholic HE with 3.62 and 5.38 mg protodioscin mL−1, respectively) were developed to verify their potential as additives for ruminant nutrition. The in vitro gas production technique was used to evaluate ten treatments in a completely randomized factorial arrangement (2 × 4 + 2), where the main effects were two extracts (EE and HE); four levels (50, 100, 150, and 200 mL of the extract kg−1 of DM), plus two controls (one positive with 25 ppm of monensin and another with no additives). The extracts EXT (EE and HE) produced a higher proportion of acetate (C2) and lower propionate (C3) than CTL, reflected in a 31% higher C2:C3 ratio. However, there was no significant difference (p > 0.05) between the treatments for methane production parameters. Archaea and Ruminococcus' relative gene expressions were higher in EE than in HE; however, the protozoa opposite occurred, HE was higher than EE. Fibrobacter succinogenes were 33% lower in EXT than in CTL. The addition of these extracts in a sheep diet increased the production of SCFA and decreased Fibrobacter succinogenes without altering the methane and archaeal population. [ABSTRACT FROM AUTHOR]

The biotransformation of poultry (PSW) and swine (SSW) slaughterhouse waste might provide protein feedstuffs, ensuring efficient ruminant systems while safeguarding the environment. The present study aimed to evaluate the potential of PSW and SSW as alternative protein feed for ruminant animals. A total of 24 lambs [25.4 ± 3.13 kg of body weight (BW), mean ± SD] were randomly allocated to one of three groups (n = 8): a control diet formulated with typical protein ingredients (CTRL) and two diets formulated with PSW or SSW meal as a protein source. Dietary inclusion of PSW or SSW did not alter (p = 0.05) dry matter intake or final BW. However, animals fed SSW showed the highest average daily gain (ADG, p = 0.04). In addition, substituting PSW and SSW improved the feed conversation ratio (FCR, p = 0.05). There were no diet effects (p = 0.05) on N intake, while fecal N excretion increased (p = 0.03) with SSW feeding. Compared to CTRL and PSW, ingestion of SSW decreased (p = 0.001) and retained N. The digestibility of crude protein and organic matter remained unchanged (p = 0.05). Additionally, there were no differences (p = 0.05) in potential microbial protein synthesis based on either protein content (SPMp) or energy content (SPMe). Similarly, potential metabolizable protein by protein (PMp) and potential metabolizable energy by protein (PMe) were not affected (p = 0.05). Overall, both PSW and SSW positively influenced the growth performance of ewe lambs. However, further studies are warranted to explore the impact of PWS or SSW feeding on rumen function, nitrogen pollution, and protein escaping the rumen into the intestine in ruminants.

Simple Summary: Enhancing the energy density of lamb diets is a proven method to improve their productivity. While using carbohydrates for this purpose may seem intuitive, it can lead to undesirable shifts in ruminal metabolism, potentially triggering metabolic diseases. Hence, substituting carbohydrates with lipids is favored. Nevertheless, lipids, though effective, can also disrupt ruminal fermentation parameters. Among these lipids, soybean oil stands out for its positive impact on both beef and dairy cattle, leading to improved performance. In our study, we sought to assess the effects of soybean oil supplementation on performance, digestibility, feeding behaviour, and blood metabolites of feedlot lambs. Our findings indicate that the inclusion of soybean oil resulted in a linear reduction in nutrient intake, consequently lowering the average daily gain of the lambs. Additionally, soybean oil supplementation induced selective feeding behaviour among the lambs. Based on our observations, we recommend incorporating soybean oil into lamb diets at a maximum inclusion rate of 41 g/kg DM to optimize production parameters. The strategy implemented to adapt lambs to increasing levels of high-fat diet mitigated the detrimental effects of lipids on the rumen, with high-density energy intake being the constraining factor on performance. The objective of the current study was to evaluate the effects of soybean oil inclusion in diets on feeding behaviour, digestibility, performance, and blood metabolites of feedlot lambs. Forty non-castrated Santa Inês lambs with a mean age of 5 months and initial body weight of 34.88 ± 3.19 kg were used in a 40-day feeding trial. The lambs were distributed in five experimental diets with the inclusion of increasing soybean oil (SO) levels: 0, 30, 60, 90, and 120 g/kg DM. The SO inclusion promoted a linear reduction in DM intake (p < 0.001), crude protein (CP, p < 0.001), non-fibrous carbohydrates (NFC, p < 0.001), and total digestible nutrients (TDN, p = 0.004). There was an increasing quadratic effect on the intake of ether extract (EE; p = 0.002) and decreasing for neutral detergent fiber (p = 0.005). The soybean oil inclusion promoted the greater apparent digestibility of CP (p = 0.016), EE (p = 0.005), NDFom (p < 0.001), and TDN (p < 0.001); on the other hand, the apparent digestibility of NFC (p = 0.005) was decreased. The average daily gain decreased (p < 0.001) with SO inclusion. The SO inclusion increased feeding time (p = 0.004), reduced the efficiency of DM rumination (p = 0.001), and reduced the concentration of blood N-ureic (p < 0.001). Considering the productive parameters, SO can be included in diets and it is recommended that we include SO of up to 41 g/kg DM in diets for fattening lambs as the ideal maximum level. The strategy implemented to adapt lambs to increasing levels of high-fat diet mitigated the detrimental effects of lipids on the rumen, with high-density energy intake being the constraining factor on performance. [ABSTRACT FROM AUTHOR]

Background and Aim: Ginger (Zingiber officinale) has great potential as a growth promoter and immunostimulant in ruminant nutrition. This study assessed the impact of ginger powder supplementation on Ossimi rams' rumen fermentation, biochemical parameters, and antioxidant levels. Materials and Methods: Fifteen Ossimi rams, aged 10 ± 1.3 months and weighing 30 ± 1.5 kg. Rams were randomly divided into three experimental groups: The control group (G1) received standard feed, while ginger powder (5 g and 7 g/kg body weight [BW] for G2 and G3, respectively) mixed in water was administered to groups G2 and G3 before their standard feed. Results: The control group recorded higher dry matter (DM) intake values (p < 0.05) than the ginger-treated groups. The ginger-treated groups showed superiority (p < 0.05) in weight gain and feed conversion compared to the control group. The digestion coefficients of DM, crude protein, and crude fiber were significantly (p < 0.05) increased by a high dose (7 g/Kg BW) of ginger supplementation, whereas organic matter, ether extract, and nitrogen-free extract digestibility remained unchanged. Compared to the control group, the rams given 5 g of ginger had significantly less (p < 0.05) total protein and globulin in their serum, but the rams given 7 g of ginger had significantly more (p < 0.05) of these proteins. In the ginger groups, these levels were significantly (p < 0.01) lower than those in the control group for serum creatinine, uric acid, urea, total lipids, triglycerides, total cholesterol, glucose, serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyl transferase. Rams given ginger had significant growth hormone, insulin-like growth factor-1, total superoxide dismutase, GSH-Px, TAC, immunoglobulin (Ig) A, and IgG enhancement (p < 0.01), and a decrease (p < 0.01) in malondialdehyde concentration compared to the control group. Significant increases in total short-chain volatile fatty acids, acetic, propionic, and isovaleric acids (p < 0.05), and significant decreases in NH3N and protozoa (p < 0.01). Conclusion: Ginger powder (5 g and 7 g) can improve growth, immune responses, antioxidant status, and ruminal parameters in rams. Further study is needed to evaluate the effect of ginger on different types of animals (cow, buffalo, and goat) to develop new feed additives. [ABSTRACT FROM AUTHOR]

The biotransformation of poultry (PSW) and swine (SSW) slaughterhouse waste might provide protein feedstuffs, ensuring efficient ruminant systems while safeguarding the environment. The present study aimed to evaluate the potential of PSW and SSW as alternative protein feed for ruminant animals. A total of 24 lambs [25.4 ± 3.13 kg of body weight (BW), mean ± SD] were randomly allocated to one of three groups (n = 8): a control diet formulated with typical protein ingredients (CTRL) and two diets formulated with PSW or SSW meal as a protein source. Dietary inclusion of PSW or SSW did not alter (p = 0.05) dry matter intake or final BW. However, animals fed SSW showed the highest average daily gain (ADG, p = 0.04). In addition, substituting PSW and SSW improved the feed conversation ratio (FCR, p = 0.05). There were no diet effects (p = 0.05) on N intake, while fecal N excretion increased (p = 0.03) with SSW feeding. Compared to CTRL and PSW, ingestion of SSW decreased (p = 0.001) and retained N. The digestibility of crude protein and organic matter remained unchanged (p = 0.05). Additionally, there were no differences (p = 0.05) in potential microbial protein synthesis based on either protein content (SPMp) or energy content (SPMe). Similarly, potential metabolizable protein by protein (PMp) and potential metabolizable energy by protein (PMe) were not affected (p = 0.05). Overall, both PSW and SSW positively influenced the growth performance of ewe lambs. However, further studies are warranted to explore the impact of PWS or SSW feeding on rumen function, nitrogen pollution, and protein escaping the rumen into the intestine in ruminants. [ABSTRACT FROM AUTHOR]

Simple Summary: Environmental factors like climate, diet, and farming methods significantly affect microbial activity and composition. Understanding these adjustments is crucial for improving ruminant nutrition and production. This review summarizes research on rumen microbiota and molecular methods for microbial identification in ruminant rumen fluid. Analyzing rumen microbiology in various ruminants is challenging due to environmental and nutritional influences on microbial interactions. Key genera include Entodinium spp. and Aspergillus spp. for protozoa and fungi, respectively, with Fibrobacter spp. prevalent among bacteria. Major techniques involve DNA extraction, amplification, and sequencing. In conclusion, this review highlights the knowledge in the literature about rumen microorganisms and the associated molecular approaches. Variations in environments, including climate, diet, and agricultural practices, significantly impact the composition and microbial activity. A profound understanding of these adaptations allows for the improvement of nutrition and ruminant production. Therefore, this review aims to compile data from the literature on the rumen microbiota and molecular techniques for identifying the different types of microorganisms from the rumen fluid of ruminants. Analyzing the literature on rumen microbiology in different ruminants is complex due to microbial interactions, influenced by the environment and nutrition of these animals. In addition, it is worth noting that the genera of protozoa and fungi most evident in the studies used in this review on the microbiology of rumen fluid were Entodinium spp. and Aspergillus spp., respectively, and Fibrobacter spp. for bacteria. About the techniques used, it can be seen that DNA extraction, amplification, and sequencing were the most cited in the studies evaluated. Therefore, this review describes what is present in the literature and provides an overview of the main microbial agents in the rumen and the molecular techniques used. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of giant cactus harvest time and the inclusion of pigeon pea hay in improving the ensiling process and the nutritional composition of cactus silage. In total, 40 polyvinyl chloride-PVC mini-silos (10 × 40 cm) were used. Mini-silos were distributed in a 2 × 5 factorial scheme, referent to 2 harvest times (18 and 24 months) and 5 levels (0, 10%, 20%, 30%, and 40%) of pigeon pea hay inclusion in a randomized design. Effluent losses (p < 0.001) showed a negative linear effect as the inclusion of pigeon pea hay increased. Gas losses (p < 0.001), dry matter (DM) recovery (p < 0.001), and pH (p < 0.001) revealed the interactive effects between the pigeon pea hay inclusion and the harvest time. The DM content was higher in the giant cactus harvested at 24 months. The difference in nutritional composition promoted by the harvest time did not affect the silage quality. The gradual inclusion of pigeon pea hay improved the fermentative and bromatological characteristics of giant cactus silage. It is important to highlight that the inclusion of pigeon pea hay contributed to the increase in pH without affecting the necessary acidity for ideal conservation. [ABSTRACT FROM AUTHOR]

Abstract Concentrated supplementation of ewes is a strategy to increase productivity. The objective was to evaluate the effects of supplementation in the diet of ewes before, during and in the final third of pregnancy and lactation on, the performance and production and composition of colostrum and milk. Forty animals were distributed in a completely randomized design, into the following treatments: CONT = control treatment with mineral salt supplementation only, SSREPRO = supplementation started 20 days before the estrus synchronization (ES) protocol, SSPREG = suplementação a partir da confirmação da gestação (60 days after ES), and SEPREG = supplementation in the third end of pregnancy (90 days after ES). Supplementation adoption changed (P < 0.05) the intake of organic matter, crude protein, neutral detergent fiber, the percentage of total digestible nutrients, and digestibility of dry matter, acid detergent fiber, non-fiber carbohydrates, and ether extract with their respective intake, in addition to colostrum and milk production and composition and animal performance. No difference (P > 0.05) was observed for organic matter, crude protein, and neutral detergent fiber digestibility and total digestible nutrient intake. Thus, supplementation in the final third of pregnancy may result in heavier lambs at weaning, reduction in slaughter time.

Simple Summary: Buffalo breeding in Italy has significantly increased in the new century because of mozzarella cheese, but also because of a growing interest in meat production. The nutritional factors that significantly affect animal performance are the forage/concentrate ratio, diet energy and protein content, supplementations (i.e., vitamins, minerals, additives), and the feeding system used. Since antibiotics were banned for auxinic purposes (Reg. 1831/2003/EC), the interest in the potential ability of feed additives to enhance nutrient utilization and animal performance by acting on rumen metabolism has increased. Among such additives, yeast cultures of Saccharomyces cerevisiae (SC) have found great interest for application in ruminant nutrition. Therefore, the growth performances of buffalo calves that were fed diets characterized by different forage/concentrate ratio, with or without Saccharomyces cerevisiae supplementation, were evaluated in this study. The aim of the present trial was to evaluate the growth performance of buffalo calves fed on diets characterized by different forage/concentrate ratios, with or without Saccharomyces cerevisiae supplementation (CBS 493.94, Yea-Sacc®). Twenty-four male buffalo calves (mean age of 145.1 ± 16.1 days; mean weight of 108.0 ± 18.7 kg) were assigned randomly to 4 groups, homogeneous in age, that were fed four different diets: diet 1, F:C ratio 50:50; diet 2, F:C ratio 30:70; diet 3, F:C ratio 50:50 + Yea-Sacc®; and diet 4, F:C ratio 30:70 + Yea-Sacc®. Buffalo calves were individually weighted before the start of the experiment and the data were used as a covariate, being taken monthly until the end of the trial. Dry matter intake (DMI), daily weight gain (DWG) and feed conversion ratio (FCR) were calculated. The differences in diets composition significantly (p < 0.01) affected all these parameters. In particular, the animals fed diet 1 and diet 3 showed higher values of DWG (0.91 and 0.88 g/d vs. 0.68 and 0.66 for group 2 and 4) and DMI (5.8 and 5.3 kg/d, respectively) compared to the other groups (4.3 and 4.4 kg/d for group 2 and 4), as well as a higher final body weight (370.5 and 334.1 kg for group 1 and 3 vs. 272.8 and 273.1 kg of group 2 and 4, respectively). Indeed, the supplementation with Yea-Sacc® at the dosage of 1 × 10E8 did not affect buffaloes' growth performance. [ABSTRACT FROM AUTHOR]

Simple Summary: The present meta-analysis was conducted to investigate the use of saponin extracts as dietary supplements for ruminants, based on in vivo studies. This study aimed to highlight the benefits of saponin extracts and their impact on ruminant health and production. A total of 26 articles, comprising 66 studies, were included in the database. The meta-analysis was designed to elucidate the effects of saponin extracts from different sources on production performance, milk yield, digestibility, rumen fermentation, nitrogen utilization, and blood metabolites. The results revealed that increased saponin supplementation linearly decreased milk production and altered rumen fermentation profiles without affecting digestibility rates, particularly influencing volatile fatty acid production and protozoa population. However, the efficacy and safety of different levels of saponin extracts vary, and further research is required to optimize its use for enhancing ruminant productivity, mitigating environmental impacts, and exploring the specific effects of saponin extracts on ruminant health. It can be concluded that the utilization of saponin extracts in ruminant diets is complex, and a comprehensive understanding of the optimal application of various saponin extracts across different ruminant physiological conditions is necessary. The present meta-analysis aimed to determine the underlying effects of different saponins extracted from different sources on the production performance, milk yield, digestibility, rumen fermentation, blood metabolites, and nitrogen utilization of ruminants. A total of 26 papers comprising 66 in vivo studies (148 data points of dietary treatments) were evaluated in the present study. The databases were statistically analyzed using the mixed model procedure of SAS, where experiments considered random effects and tannin-related factors were treated as fixed effects. Statistical procedures were then continued in comparing different sources of saponin extract through Mixed Model analysis, where experiments were also random factors and sources of saponin extract were fixed factors. The evidence revealed in the present meta-analysis that saponin supplementation of up to 40 g/kg DM appears to have no detrimental impact on feed intake across ruminant types, suggesting that it does not significantly affect diet palatability. However, the results indicated that there are species-specific responses to saponin supplementation, particularly in relation to palatability and nutrient absorption efficiency, with larger ruminants being better able to tolerate the bitterness induced by saponin extracts. Furthermore, the study found that saponin extracts can influence nutrient digestibility and rumen fermentation dynamics, with different effects observed in large and small ruminants. While some saponin extracts can enhance average daily weight gain and milk yield, others can have adverse effects, highlighting the importance of considering both saponin sources and animal physiological condition when developing nutritional strategies. Additionally, optimization of ruminant production by utilizing saponin extracts is necessary to avoid negative health implications, such as increased blood creatinine levels. Different saponin extracts utilization in ruminant nutrition and environmental management, have a distinct understanding associated to their various bioactive properties. However, among the saponin sources, saponin extracted from Quilaja saponaria is more likely to improve large ruminant production performance while maintaining ruminant health and metabolism, but negatively affect small ruminants. Further research is needed to unravel the intricate effects of different saponin sources on ruminant health and productivity, emphasizing the importance of tailored dietary strategies that consider the unique physiological and metabolic characteristics of the target livestock. [ABSTRACT FROM AUTHOR]

The concentration of linoleic and a-linolenic fatty acids (FA) in grasses can be increased through agronomic techniques; however, there is little information in this regard for tropical grasses. Therefore, the objective of the study was to evaluate the effect of N fertilization and regrowth age management on the FA profile of three tropical grasses. To do this, three plots of 100 m2 each were used for the species: Urochloa decumbens (Stapf) R.D. Webster, U. humidicola (Rendle) Morrone & Zuloaga, and Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs. The study was conducted during dry and rainy seasons. In each period, they were divided into two subplots and only one of them was fertilized. Grass sampling was carried out on days 20, 25, and 30 after fertilization. Five samples were taken from each subplot and an agronomic evaluation was made before each cut. The chemical composition and lipid profile were then determined. An ANOVA of a randomized complete block design with split plot arrangement was performed. The concentration of linoleic and a-linolenic acid was higher in M. maximus during drought (48.5 g 100 g-1 FA) and in U. humidicola during the rainy season (55.1 g 100 g-1 FA). This proportion was higher on day 20 (50.5 g 100 g-1 FA) compared to that recorded on days 25 and 30 (50.1 and 45.7 g 100 g-1 FA, respectively). The fertilized grasses had a higher concentration of linoleic and a-linolenic acid compared to the unfertilized ones (53.4 vs. 44.3 g 100 g-1 FA). It is concluded that fertilization with 50-20-00 (N-P-K) increases the proportion of linoleic and a-linolenic acids in grasses; however, such concentration decreases with increasing plant maturity. [ABSTRACT FROM AUTHOR]

Inositol is a bioactive factor that is widely found in nature; however, there are few studies on its use in ruminant nutrition. This study investigated the effects of different inositol doses and fermentation times on rumen fermentation and microbial diversity, as well as the levels of rumen and blood metabolites in sheep. Rumen fermentation parameters, microbial diversity, and metabolites after different inositol doses were determined in vitro. According to the in vitro results, six small-tailed Han sheep fitted with permanent rumen fistulas were used in a 3 x 3 Latin square feeding experiment where inositol was injected into the rumen twice a day and rumen fluid and blood samples were collected. The in vitro results showed that inositol could increase in vitro dry matter digestibility, in vitro crude protein digestibility, NH3-N, acetic acid, propionic acid, and rumen microbial diversity and affect rumen metabolic pathways (p < 0.05). The feeding experiment results showed that inositol increased the blood concentration of high-density lipoprotein and IgG, IgM, and IL-4 levels. The rumen microbial composition was significantly affected (p < 0.05). Differential metabolites in the rumen were mainly involved in ABC transporters, biotin metabolism, and phenylalanine metabolism, whereas those in the blood were mainly involved in arginine biosynthesis and glutathione and tyrosine metabolism. In conclusion, inositol improves rumen function, affects rumen microorganisms and rumen and blood metabolites and may reduce inflammation, improving animal health. [ABSTRACT FROM AUTHOR]

Simple Summary: The fatty acid composition of milk fat plays a crucial role in determining the nutritional quality of milk because particular fatty acids can have positive or negative influences on human health. Production of milk with a lower content of saturated fatty acids, and a higher content of unsaturated fatty acids, particularly n-3 fatty acids, is preferable due to their beneficial effects on health. Additionally, a higher level of rumenic and vaccenic acid in milk is desirable, as these fatty acids are believed to impart health-related properties. Manipulating animal nutrition proves most effective in achieving the desired milk fatty acid composition, with the inclusion of unconventional feed ingredients like oilseed processing byproducts being a successful strategy for modifying milk fatty acid profiles. This review provides a comprehensive overview of the existing 41 research studies regarding the incorporation of hemp, pumpkin, sunflower, camelina, and linseed byproducts into the nutrition of dairy cows, sheep, and goats, and their influence on milk production traits and milk fatty acid composition. This review concludes that, overall, the selected oilseed byproducts exhibit promising potential to improve the fatty acid profile of milk, with no adverse effects on milk production and composition. Milk contains more than 400 different fatty acids, some of which play a positive role in promoting human health. The profile of fatty acids in milk can be enhanced by providing animals with plant-based resources that possess feeding characteristics adequate for favorable changes in the fatty acid composition and increasing healthy fatty acids in milk. This review summarizes the available 41 research studies on the utilization of oilseed industry byproducts rich in linoleic acid (hemp, pumpkin, sunflower) and alpha-linolenic acid (camelina and linseed) in dairy cow, sheep, and goat nutrition; their impact on milk production characteristics; and potential to improve fatty acid composition of milk through the diet. This review illustrates that incorporating byproducts into the diet for dairy ruminants generally does not have any adverse effects on both milk production and composition. A similar trend of improvement in milk fatty acid profile was observed when ruminants were fed diets supplemented with camelina, linseed, and sunflower byproducts, while no significant changes were noted with pumpkin byproducts. Hempseed byproducts showed potential for use as an alternative ingredient in dairy ruminant diets. Nevertheless, more in-depth research investigating the inclusion of selected byproducts is required before valid conclusions can be drawn regarding their value. [ABSTRACT FROM AUTHOR]

A novel liquid chromatographic method for the measurement of essential oils within animal feed additives was developed and applied. The simple and effective extraction protocol described yielded analyte recoveries more than 90% for cinnamaldehyde, eugenol, carvacrol, capsaicin, and dihydrocapsaicin for the feed additives tested. These five analytes were separated with a peak resolution of more than 1 on a C-18 reversed phase column yielding between 500 000–2 000 000 theoretical plates per meter. UV absorption detection at 210 nm provided limits of detection of approximately 1 µg of analyte per gram of solution for all analytes. Limits of quantitation were approximately 4 µg of analyte per gram of solution. Results indicated that while capsaicin and dihydrocapsaicin were present at conserved levels within feed additives tested (0.2 and 0.05%, respectively), the content of cinnamaldehyde, eugenol, and carvacrol varied considerably. The new method will find use within the emerging field of targeted nutrition for increasing gains for ruminants and poultry. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of prepartum supplementation levels on the productive and nutritional performance and metabolic responses of Nellore cows in a grazing system. Forty-four pregnant Nellore cows multiparous with an initial mean gestation time of 230 days, average initial body weight (BW) of 541 ± 19 kg, and body condition score (BCS) of 5.5 ± 1.7 were used and distributed in a completely randomized design, with four treatments and 11 cows per treatment. The treatments evaluated consisted of four supplementation levels in the prepartum period with a duration of 60 days, according to the following scheme: 0.0 (Control = CON); 0.5 (LOW); 1.0 (Medium = MED) and; 1.5 (High = HIG) kg per animal day-1 of supplement. The supplement was composed of wheat meal and urea, and formulated to contain 22% of crude protein (CP). A positive linear effect (P < 0.05) was observed on the intake of CP and CP:digested organic matter (DOM) ratio as supplementation levels were increased. In addition, a quadratic effect (P < 0.05) was detected on the intake of neutral detergent fiber corrected for ash and protein (apNDF), digested neutral detergent fiber, and DOM with increasing supplementation levels in the prepartum period, in which MED cows had higher intakes compared to CON, LOW, and HIG cows. Prepartum supplementation levels did not affect (P > 0.10) the average daily gain in the prepartum or postpartum periods and, BCS of the dams, and BW of calves at birth or 45 days of age. In the prepartum period, supplementation levels did not affect (P > 0.10) the blood concentrations of total proteins, albumin, globulins, glucose, cholesterol, triglycerides, non-esterified fatty acids, and beta-hydroxybutyrate in the experimental cows. In conclusion, the provision of 1.0 kg of supplement per animal per day during the last 60 days of pregnancy improves prepartum nutritional performance and postpartum milk production of grazing beef cows.

Bioconversion of plant material with white-rot fungi has demonstrated improvements in in vitro digestibility, however, effects on rumen fermentation parameters and methane (CH4) production, when included as a dietary ingredient, are not clear. The aim of this study was to assess changes in rumen fermentation parameters and in vitro CH4 production by dietary inclusion of ryegrass-fescue hay biodegraded with P. ostreatus (H-PO) during 14 days of solid fermentation. The experiment used 2 diets with contrasting acid detergent fibre (aADFom) content which were added with 0, 3 and 6% H-PO. Substrates were incubated 3 times with sampling at 24 h. Results were analysed by ANOVA, and compared with Tukey’s test and polynomial contrasts. Inclusion of H-PO at concentrations of 3 and 6% resulted in increased in vitro dry matter (DM) disappearance (IVDMD) by 10 and 12% respectively, whereas high concentrations of aADFom reduced IVDMD by 10% as compared to low aADFom. Methane production (mg/g DM incubated) and yield (mg/g DM degraded) were reduced by increasing aADFom and P. ostreatus biodegraded hay concentrations in the diets (p

Urochloa spp. are the most important grasses for ruminants in Brazil and contain secondary metabolites, mainly saponins. Urochloa brizantha extracts (ethanolic EE and hydroalcoholic HE with 3.62 and 5.38 mg protodioscin mL−1, respectively) were developed to verify their potential as additives for ruminant nutrition. The in vitro gas production technique was used to evaluate ten treatments in a completely randomized factorial arrangement (2 × 4 + 2), where the main effects were two extracts (EE and HE); four levels (50, 100, 150, and 200 mL of the extract kg−1 of DM), plus two controls (one positive with 25 ppm of monensin and another with no additives). The extracts EXT (EE and HE) produced a higher proportion of acetate (C2) and lower propionate (C3) than CTL, reflected in a 31% higher C2:C3 ratio. However, there was no significant difference (p > 0.05) between the treatments for methane production parameters. Archaea and Ruminococcus’ relative gene expressions were higher in EE than in HE; however, the protozoa opposite occurred, HE was higher than EE. Fibrobacter succinogenes were 33% lower in EXT than in CTL. The addition of these extracts in a sheep diet increased the production of SCFA and decreased Fibrobacter succinogenes without altering the methane and archaeal population.

In today's food industry, fortifying food products with several nutrients is a priority, and animal nutrition represents a key strategy for achieving this goal. Nevertheless, the scarcity and high costs of conventional feedstuffs lead to investigation of industrial by-products as alternative solutions in livestock nutrition. White grape pomace, a byproduct of the winery industry, is well-known for its rich resveratrol content. Nevertheless, in addition to this, it can present significant quantities of other nutrients and antioxidant compounds, which exert beneficial effects when incorporated into ruminants' nutrition. Our study revealed a remarkable concentration of the white grape pomace nutrients, with important minerals, particularly manganese (106.35 mg/kg). The fatty acids profile showed a high composition of polyunsaturated fatty acids (65.05 g/100 g FAME), with a great amount of omega 3 fatty acids (62.66 g/100 g FAME). Concerning the antioxidant compounds, white grape pomace exhibited a concentration of 12.49 mg/g GAE for total polyphenols and 3.27 mg/kg for total flavonoids. Also, our study highlighted its high antioxidant potential, especially assessed through the DPPH radical scavenging assay (74.26 mM eq. Trolox), ABTS radical scavenging assay (75.07 mM eq. Trolox), and total antioxidant capacity (286.26 mM eq. ascorbic acid). [ABSTRACT FROM AUTHOR]

The Gram-negative, strictly anaerobic bacterium Megasphaera elsdenii was first isolated from the rumen in 1953 and is common in the mammalian gastrointestinal tract. Its ability to use either lactate or glucose as its major energy sources for growth has been well documented, although it can also ferment amino acids into ammonia and branched-chain fatty acids, which are growth factors for other bacteria. The ruminal abundance of M. elsdenii usually increases in animals fed grain-based diets due to its ability to use lactate (the product of rapid ruminal sugar fermentation), especially at a low ruminal pH (<5.5). M. elsdenii has been proposed as a potential dietary probiotic to prevent ruminal acidosis in feedlot cattle and high-producing dairy cows. However, this bacterium has also been associated with milk fat depression (MFD) in dairy cows, although proving a causative role has remained elusive. This review summarizes the unique physiology of this intriguing bacterium and its functional role in the ruminal community as well as its role in the health and productivity of the host animal. In addition to its effects in the rumen, the ability of M. elsdenii to produce C2–C7 carboxylic acids—potential precursors for industrial fuel and chemical production—is examined. [ABSTRACT FROM AUTHOR]

Different agricultural crop wastes (ACW) such as mesocarps (peel) are annually produced after consuming their edible parts in the world without any scientific information about their nutritional potential. Therefore, a study was conducted to determine the ruminal-microbial fermentation pattern and nutritional potential of some crop mesocarps (peel) including different species of melons (Watermelon, Galia melon, Rockmelon, Til sabz, and Til atashi) as well as cucumber and eggplant using common and standard laboratory methods. The amount of crude protein (CP) varied from 7.19 to 19.1% of dry matter (DM) for Til sabz and cucumber mesocarps, respectively. The highest (34.1% of DM) and lowest (15.4%) content of neutral detergent fiber (NDF) were related to eggplant and Til sabz peels, respectively (p < 0.05). The content of non-fiber carbohydrates (NFC) varied from 38.7% for eggplant peel to 66.6% for Til sabz. All mesocarps had a low DM percentage (4.88% of DM for cucumber to 8.45 for eggplant). Rockmelon peel had the highest amount of calcium (5.25 g/kg DM) and magnesium (5.75 g/kg DM) compared with the other mesocarps (p < 0.05). The highest amounts of potassium (33.4 g/kg of DM), sodium (7.15 g/kg of DM), and zinc (21 mg/kg of DM) were observed in the peels of watermelon, Til atashi, and cucumber, respectively (p < 0.05). The potential of ruminal-microbial gas production also differed from 55.6 ml/200 mg of DM for eggplant to 63.1 ml for Til sabz peel. Except for cucumber (8.75 MJ/kg of DM) and eggplant (8.71 MJ), other mesocarps (different melon species) had almost similar metabolizable energy (ME, 9.06–9.50 MJ/kg of DM). Among the studied mesocarps, the lowest ruminal-microbial DM and organic matter (OM) digestibility was also observed in eggplant and cucumber (p < 0.05). Gallia melon had the highest acid-base buffering capacity (267 mEq×10− 3, p < 0.05). According to our findings, the mesocarps of melons showed a higher nutritional value than the cucumber and eggplant. In general, Til sabz exhibited a notable favorite and superior nutritional characteristic compared with the other mesocarps. [ABSTRACT FROM AUTHOR]

Bioconversion of plant material with white-rot fungi has demonstrated improvements in in vitro digestibility, however, effects on rumen fermentation parameters and methane (CH4) production, when included as a dietary ingredient, are not clear. The aim of this study was to assess changes in rumen fermentation parameters and in vitro CH4 production by dietary inclusion of ryegrass-fescue hay biodegraded with P. ostreatus (H-PO) during 14 days of solid fermentation. The experiment used 2 diets with contrasting acid detergent fibre (aADFom) content which were added with 0, 3 and 6% H-PO. Substrates were incubated 3 times with sampling at 24 h. Results were analysed by ANOVA, and compared with Tukey's test and polynomial contrasts. Inclusion of H-PO at concentrations of 3 and 6% resulted in increased in vitro dry matter (DM) disappearance (IVDMD) by 10 and 12% respectively, whereas high concentrations of aADFom reduced IVDMD by 10% as compared to low aADFom. Methane production (mg/g DM incubated) and yield (mg/g DM degraded) were reduced by increasing aADFom and P. ostreatus biodegraded hay concentrations in the diets (p < 0.001) whereas concentrations of total short-chain fatty acids were not affected by the inclusion of biodegraded hay (p = 0.080) or aADFom concentration (p = 0.076). Increasing concentrations of biodegraded hay resulted in increased acetate (p < 0.001), and reduced propionate proportions (p = 0.021) but did not affect butyrate (p = 0.233). In conclusion the use of biodegraded hay as a pre-treated ingredient improved the utilisation of low and high fibre diets by increasing the in vitro disappearance, and decreasing CH4 emissions, without increasing the propionate proportion. The use of hay biodegraded with P. ostreatus (H-PO) improves the digestibility of ruminant diets. The use of H-PO decreases methane, and increases acetate production in in vitro conditions. The use of H-PO as an ingredient in ruminant diets could improve the sustainability of livestock systems. [ABSTRACT FROM AUTHOR]

Simple Summary: Edible trees and shrubs have been evaluated to improve animal nutrition and mitigate the emission of greenhouse gasses from ruminants. In the present study, researchers visited some farmers and identified eight potentially edible Brazilian trees. Nutritional value and gas (and methane) production from these edible trees were evaluated. The leaves of Aroeira, Candeia, and Jatobá had limited nutritional value. Samples of Santa Bárbara trees, Mulberry, and Tithonia showed an improved nutritional value. Furthermore, Tithonia decreased methane emissions and is a potentially edible tree for multifunctional redesigned ruminant production systems. The present study aims to evaluate the nutritional value of different tree and shrub leaves in Brazilian ruminant production systems. Eight potentially edible trees and shrubs were identified from interviews with 30 ruminant producers: Aroeira (ARO; Lithraea molleoides), Black Mulberry (BMU; Morus nigra), Candeia (CAN; Eremanthus erythropappus), Jatobá (JAT; Hymenaea courbaril), Gliricídia (GLI; Gliricidia sepium), Santa Bárbara tree (SBT; Mélia azedarach), Tithonia (TIT; Tithonia diversifolia), and White Mulberry (WMU; Morus alba). Four leaf samples of each edible tree were sampled, and chemical analyses and in vitro assays were performed. Edible trees (except CAN and JAT) had lower neutral detergent fiber content than Mombasa grass. In addition, SBT, BMU, WMU, and TIT had lower fiber content than the other evaluated edible trees. Consequently, SBT, TIT, BMU, and WMU had improved dry matter degradation. Among the edible trees and shrubs, SMW and WMU increased the potential for gas production (a parameter). On the other hand, CAN decreased the estimated gas production 48 h after incubation. Furthermore, TIT decreased methane production up to 24 h after in vitro fermentation. Thus, except ARO, CAN, and JAT, the edible trees evaluated in the present study are potential feeds in moderate- to high-producing animals. Additionally, TIT fermentation reduces in vitro methane production. [ABSTRACT FROM AUTHOR]

Saponin possessed antiprotozoal activity; therefore, it is generally used to mitigate enteric methane (CH4) emission in ruminant nutrition. The objective of this study was to evaluate the effects of Aloe saponaria (AS) supplementation on rumen fermentation, CH4, and microbial diversity in an in vitro experiment over 48 h incubation. Five treatments were used: (1) no additives (CON), 1% and 2% dosage of heat-dried AS (HAS), and freeze-dried AS (FAS), and the experiments were performed three times. After the incubation, volatile fatty acids (VFAs), CH4 proportion in total gas, and microbial diversity were evaluated. Gas production was assessed at 3, 6, 9, 12, 24, 36, and 48 h incubation. FAS addition significantly increased gas production compared to CON except for 6 and 48 h, whereas HAS addition did not significantly affect the gas production at all observed time points. AS addition significantly increased total VFA and the absolute abundances of fungi and Ruminococcus albus regardless of drying method. There was no significant change in the CH4 proportion at 48 h, although the reduction in ciliate protozoa was detected in FAS-treated groups. In conclusion, FAS may be an effective feed additive to improve ruminal fermentation via enhancing feed utilization by rumen microbes. [ABSTRACT FROM AUTHOR]

Simple Summary: Protein in the diet is essential for the growth and health of ruminants and other animal species. Protein is also one of the most expensive components in animals' diets, and finding good protein sources can sometimes be challenging. Urea supplementation, as a non-protein nitrogen source, is often recommended for goats fed low-quality forages. In the rumen, microorganisms transform urea into microbial protein that can be assimilated by the animal. In this study, we investigated nitrogen utilization in goats fed low-quality hay supplemented with molasses blocks containing various levels of urea. The findings and discussion in this paper contribute to a better understanding of nitrogen utilization in goats using urea as a non-protein nitrogen source. The use of goats for meat production faces challenges from environmental and nutritional factors. Urea is an affordable non-protein nitrogen source commonly utilized in ruminant nutrition. The objective of this study was to investigate nitrogen utilization in goats fed low-quality hay supplemented with molasses blocks containing urea. Twenty Anglo-Nubian doelings were individually housed in metabolic cages and provided with chopped Buffelgrass (Cenchrus ciliaris) hay ad libitum. Goats were randomly assigned to four urea levels (0, 2, 4, and 6%; n = 5 per treatment) in molasses blocks for a duration of 30 days. A negative nitrogen balance (−2.458 g/day) was observed in doelings consuming blocks without urea, compared with a positive balance (0.895 g/d) for those consuming the 6% urea blocks. Block nitrogen intake significantly increased with urea level, but urea supplementation did not affect dry matter (DM) or neutral detergent fiber (NDFom) intake or digestibility. A minimum crude protein (CP) requirement of 8% for maintenance in doelings consuming low-quality forage with a urea-based supplement was determined through regression analysis between CP intake (% of DM) and N balance (r2 = 0.479; p < 0.002). The value of 8% of CP obtained in this study is similar to several previous studies reported in the literature, but in this case, the increments in CP came exclusively from urea. In this study, increasing the urea content of molasses blocks up to 6% significantly increased nitrogen intake, retention, and balance in goats. These results contribute to a better understanding of nitrogen utilization in goats fed low-quality hay with urea supplementation. [ABSTRACT FROM AUTHOR]

Our understanding of metabolic alterations triggered by heat stress is incomplete, which limits the designing of nutritional strategies to mitigate negative productive and health effects. Thus, this study aimed to explore the metabolic responses of heat-stressed dairy cows to dietary supplementation with vitamin D3/Ca and vitamin E/Se. Twelve multiparous Holstein cows were enrolled in a split-plot Latin square design with two distinct vitamin E/Se supplementation levels, either at a low (ESe−, n = 6, 11.1 IU/kg vitamin E and 0.55 mg/kg Se) or a high dose (ESe+, n = 6 223 IU/kg vitamin E and 1.8 mg/kg Se) as the main plot. Treatment subplots, arranged in a replicated 3 × 3 Latin square design, comprised heat challenge (Temperature Humidity Index, THI: 72.0–82.0) supplemented with different levels of vitamin D3/Ca: either low (HS/DCa−, 1 012 IU/kg and 0.73%, respectively) or high (HS/DCa+, 3 764 IU/kg and 0.97%, respectively), and a pair-fed control group in thermoneutrality (THI = 61.0–64.0) receiving the low dose of vitamin D3/Ca (TN). The liquid chromatography-mass spectrometry-based metabolome profile was determined in blood plasma and milk sampled at the beginning (day 0) and end (day 14) of each experimental period. The results were analyzed for the effect of (1) TN vs. HS/ESe−/DCa−, and (2) the vitamin E/Se and vitamin D3/Ca supplementation. No group or group × day effects were detected in the plasma metabolome (false discovery rate, FDR > 0.05), except for triglyceride 52:2 being higher (FDR = 0.03) on day 0 than 14. Taurine, creatinine and butyryl-carnitine showed group × day interactions in the milk metabolome (FDR ≤ 0.05) as creatinine (+22%) and butyryl-carnitine (+190%) were increased (P 0.05) in plasma and milk, except for milk alanine which was lower (−69%, FDR = 0.03) in the E/Se+ groups, compared with E/Se−. Our results indicated that HS triggered more prominent changes in the milk than in the plasma metabolome, with consistent results in milk suggesting increased muscle catabolism, as reflected by increased creatinine, alanine and citrulline levels. Supplementing with high levels of vitamin E/Se or vitamin D3/Ca or their combination did not appear to affect the metabolic remodeling triggered by HS.

The objective of the current study was to evaluate the effects of soybean oil inclusion in diets on feeding behaviour, digestibility, performance, and blood metabolites of feedlot lambs. Forty non-castrated Santa Inês lambs with a mean age of 5 months and initial body weight of 34.88 ± 3.19 kg were used in a 40-day feeding trial. The lambs were distributed in five experimental diets with the inclusion of increasing soybean oil (SO) levels: 0, 30, 60, 90, and 120 g/kg DM. The SO inclusion promoted a linear reduction in DM intake (p < 0.001), crude protein (CP, p < 0.001), non-fibrous carbohydrates (NFC, p < 0.001), and total digestible nutrients (TDN, p = 0.004). There was an increasing quadratic effect on the intake of ether extract (EE; p = 0.002) and decreasing for neutral detergent fiber (p = 0.005). The soybean oil inclusion promoted the greater apparent digestibility of CP (p = 0.016), EE (p = 0.005), NDFom (p < 0.001), and TDN (p < 0.001); on the other hand, the apparent digestibility of NFC (p = 0.005) was decreased. The average daily gain decreased (p < 0.001) with SO inclusion. The SO inclusion increased feeding time (p = 0.004), reduced the efficiency of DM rumination (p = 0.001), and reduced the concentration of blood N-ureic (p < 0.001). Considering the productive parameters, SO can be included in diets and it is recommended that we include SO of up to 41 g/kg DM in diets for fattening lambs as the ideal maximum level. The strategy implemented to adapt lambs to increasing levels of high-fat diet mitigated the detrimental effects of lipids on the rumen, with high-density energy intake being the constraining factor on performance.

The objective of this study was to evaluate the effects of giant cactus harvest time and the inclusion of pigeon pea hay in improving the ensiling process and the nutritional composition of cactus silage. In total, 40 polyvinyl chloride-PVC mini-silos (10 × 40 cm) were used. Mini-silos were distributed in a 2 × 5 factorial scheme, referent to 2 harvest times (18 and 24 months) and 5 levels (0, 10%, 20%, 30%, and 40%) of pigeon pea hay inclusion in a randomized design. Effluent losses (p < 0.001) showed a negative linear effect as the inclusion of pigeon pea hay increased. Gas losses (p < 0.001), dry matter (DM) recovery (p < 0.001), and pH (p < 0.001) revealed the interactive effects between the pigeon pea hay inclusion and the harvest time. The DM content was higher in the giant cactus harvested at 24 months. The difference in nutritional composition promoted by the harvest time did not affect the silage quality. The gradual inclusion of pigeon pea hay improved the fermentative and bromatological characteristics of giant cactus silage. It is important to highlight that the inclusion of pigeon pea hay contributed to the increase in pH without affecting the necessary acidity for ideal conservation.

Simple Summary: Pineapple (Ananas comosus L.) fruit is mainly consumed fresh or after its transformation into juice, jam, candy, beverages, ice cream, powder, or wine. During processing, many leftovers are produced and released into the environment, contributing to pollution. This current study investigated the possible utilization of pineapple leftovers from two varieties (Smooth Cayenne and Sugarloaf) cultivated in West Africa. They were characterized individually (crown, bud end, peel, core, and pomace) regarding chemical composition, in vitro fermentation characteristics, and estimated metabolizable energy. As a result, the lipids and lignin content were at low levels and they would not negatively affect nutrient utilization in ruminants. However, the low dry matter and high sugar content in pineapples highlight preservation issues in their by-products. The core and pomace of pineapples showed low structural carbohydrate content, high in vitro degradability, and high volatile fatty acid production. This study suggests that pineapple by-products can be used in ruminant nutrition; the crown, bud end, and peel can be used as fiber sources, while core and pomace can be used as energy sources. In West Africa, these by-products could help farmers to supplement ruminants' diet during dry seasons characterized by the scarcity of natural pasture which represent the main feedstuff for ruminant in this region. Pineapple fruit, which is cultivated in tropical and subtropical areas, is processed by the food industry, generating a large amount of waste. Using pineapple by-products in animal nutrition could reduce feeding costs and contribute to the containment of pollution. The chemical composition and the in vitro fermentation of five pineapple by-products (crown, bud end, peel, core, and pomace) from two West African pineapple varieties (Smooth Cayenne—SC and Sugarloaf—SL) were evaluated. Significant differences were observed between the varieties and by-products. The dry matter (DM) content was low and superimposable between varieties, averaging 17.7%. On a DM basis, pomace showed the highest protein content (SC 8.10% and SL 8.81%, p < 0.001), whereas the crown showed the highest (p < 0.001) NDF content (47.62% and 39.01% for SC and SL, respectively). Due the high sugar content, the core and pomace showed high in vitro organic matter degradability (SC: 85.09% and SL: 83.98%), estimated metabolizable energy (SC: 7.91 KJ/kg and SL: 7.66 KJ/kg), and volatile fatty acid production (96.86 mmol/g and 90.62 mmol/g). Based on chemical composition and in vitro digestibility results, this study suggests that pineapple by-products have the potential to be used in ruminants' diets, considering the crown, bud end, and peel as fiber sources and the core and pomace as substitutes or supplements to concentrate feedstuffs. Further research should be conducted on the storability of these by-products through in vivo trials evaluating animals' performances and the quality of their products. [ABSTRACT FROM AUTHOR]

Essential oils are bioactive compounds, originating from the secondary metabolism of plants, recognized for their ability to modify rumen fermentation, gut health, and to function as antioxidant molecules in small ruminants. Indeed, small ruminant-derived products, such as milk, dairy, and meat can benefit from the utilization of essential oils, that have demonstrated antimicrobial, antioxidant and anti-inflammatory affects, in the animals' diet. This review reports on the findings that demonstrates the possible role of essential oils in controlling greenhouse gas emissions from ruminants through the modulation of ruminal microbial populations, in sustaining animal health and welfare by affecting the gut microbiota, and in ameliorating animals' products through enhancement of their nutritional composition from a human diet perspective. However, the current review highlighting the inconclusive findings related to the use of essential oils in small ruminant nutrition, supports the need of further studies to better understand the administration of how essential oils and to explore their specific actions at the molecular level. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigates the impact of seasonality on enteric methane emissions in islands with pasture systems, focusing on the 2006 Intergovernmental Panel on Climate Change (IPCC) Tier 2 methodology, refined in 2019. Feed samples for Azorean bovine were collected throughout the year, and their nutritional value and digestibility were determined. Significant differences were found between winter and summer pastures, with autumn presenting better nutritional quality. The total volume of enteric methane produced in the Azores was 20,341 t of methane (CH4), with peak emissions reaching 5837 t CH4 during the summer. Breeding bulls, beef cows, and heifers produce the highest amount of methane per animal, while pregnant dairy cows had the highest CH4 emissions per year, due to the high number of dairy cows in the archipelago. The study suggests that pastures are better managed during the autumn, resulting in lower emissions of enteric methane into the atmosphere. Quantifying entericCH4 from grazing systems is a challenge for all regions of the world, especially when cattle feed mostly on pasture throughout the year, as pasture quality varies with the seasons. In this study, we examine the influence of seasonality on enteric methane emissions in the Azores, considering the most recent IPCC updates, to minimise errors in estimating enteric methane emissions in this region. For this purpose, samples of corn and grass silage, different types of concentrate, and pasture were collected throughout the year, and their nutritional value and digestibility were determined according to standard conventional methods. The estimation of methane production was conducted using the 2006 IPCC Tier 2 methodology, refined in 2019. The results revealed significant differences (p < 0.05) between the chemical composition of winter and summer pastures. However, it was in the autumn that these pastures presented the best nutritional quality. We estimated that the total volume of enteric methane produced in the Azores was 20,341 t CH4, with peak enteric methane emissions (5837 t CH4) reached during the summer. Breeding bulls, beef cows, and heifers are the categories that produce the highest amount of methane per animal. However, if we consider the total number of animals existing in the region, pregnant dairy cows are the category of cattle with the highest emissions of CH4. Thus, considering the current system of cattle production in the region, we can infer that the pastures are better managed during the autumn, which translates into lower emissions of enteric methane into the atmosphere during this season. [ABSTRACT FROM AUTHOR]

Simple Summary: Licury cake is a by-product used to replace conventional ingredients in ruminant diets to reduce production costs. Some studies in sheep and in beef and dairy cattle showed promising results with the inclusion of licury cake in the diets of feedlot ruminants. The main objective of this study was to evaluate the productive performance and metabolic behavior of dairy goats subjected to increasing inclusion levels of licury cake in the diet. Our main results showed that the inclusion of licury cake in the diet did not promote negative effects on the nutrient intake, digestibility, metabolism, and performance of feedlot lactating goats. We additionally observed that, through feeding behavior, the inclusion of licury cake promoted greater efficiency in the intake and rumination of fiber. Moreover, through the metabolism, we found that the inclusion of licury cake promoted higher recycling of nitrogen; however, more studies are needed to elucidate these facts. Our results showed that the inclusion of licury cake of up to 200 g kg−1 of dry matter in the diets of lactating goats can be recommended without affecting productive performance. The objective of this study was to determine the effects of licury cake (LC) inclusion in the diets of lactating goats on productive and metabolic performance. Twelve lactating goats, eight Saanen and four Anglo-Nubian, were distributed in a triplicate 4 × 4 Latin square design, with four treatments (0, 66.7, 133.3, and 200 g kg−1 of dry matter—DM). On the one hand, the LC inclusion increased neutral detergent fiber, indigestible neutral detergent fiber, and potentially digestible neutral detergent fiber (p < 0.001) intake. On the other hand, LC inclusion reduced ether extract and non-fibrous carbohydrate (p < 0.001) intake. There was a reduction in dry matter digestibility (p = 0.018) and an increase in neutral detergent fiber digestibility (p = 0.036). Feeding (p = 0.005) and rumination (p < 0.001) efficiencies increased with LC inclusion. The nitrogen balance was similar for all tested diets; however, we observed recycling metabolism. Based on the studied parameters, mainly milk production and composition, we recommend the LC inclusion of up to 200 g kg−1 DM in diets for lactating goats. [ABSTRACT FROM AUTHOR]

The aim of this study was to validate selected precision livestock farming (PLF) methods of nutrition and feeding management of high-yielding Holstein dairy cows. In a feeding trial with 36 dairy cows, the effect of replacing 0.1 kg of sodium bicarbonate in the control total mixed ration (TMR-C) with 1 kg of wheat straw in the experimental total mixed ration (TMR-S) on the physiological status of cows and the amount of milk produced (milk yield, MY) was investigated. Feed intake time (FT), as measured using tensometric feed troughs (TFT), was significantly longer with TMR-S (188 min) than with TMR-C (157 min). Differences between TMR-C and TMR-S were not significant for FT or rumination time (RT), as measured by a sensor in the collar (VSC). There was only a weak correlation between the two technologies (TFT vs. VSC) for FT (r = 0.27). Differences between TMR-C and TMR-S were not significant for values measured in rumen fluid (pH, acid and ammonia levels) nor for values measured by sensors in the milking parlour (MY, fat and protein percentage of milk). Milk analysis in the laboratory showed that the cows fed TMR-C had higher urea (26.6 vs. 22.7 mg/100 ml) and free fatty acid (0.87 vs. 0.33 mmol/100 g) levels in milk. Moderate correlations were between TMR intake and MY (r = 0.55); between MY and milk fat (r = -0.46); between milk fat and milk protein (r = 0.63); and between milk fat and milk protein measured by sensors and in the laboratory (r = 0.47 and r = 0.42, respectively). In view of the above results, further research and data validation for each technology are needed.

The gastrointestinal (GI) tract of ruminants contains diverse microbes that ferment various feeds ingested by animals to produce various fermentation products, such as volatile fatty acids. Fermentation products can affect animal performance, health, and well-being. Within the GI microbes, the ruminal microbes are highly diverse, greatly contribute to fermentation, and are the most important in ruminant nutrition. Although traditional cultivation methods provided knowledge of the metabolism of GI microbes, most of the GI microbes could not be cultured on standard culture media. By contrast, amplicon sequencing of 16S rRNA genes can be used to detect unculturable microbes. Using this approach, ruminant nutritionists and microbiologists have conducted a plethora of nutritional studies, many including dietary interventions, to improve fermentation efficiency and nutrient utilization, which has greatly expanded knowledge of the GI microbiota. This review addresses the GI content sampling method, 16S rRNA gene amplicon sequencing, and bioinformatics analysis and then discusses recent studies on the various factors, such as diet, breed, gender, animal performance, and heat stress, that influence the GI microbiota and thereby ruminant nutrition.

IntroductionThe study aimed to assess yeast-based additives' effects, as monensin alternatives, on rumen fermentation parameters, greenhouse gas emissions, and ruminal kinetics of ruminant diets using an in vitro system. Three experiments were conducted, each individually evaluating escalating levels of three yeast-based additives.MethodsThree experiments were designed: Experiment 1 evaluated prebiotic blend 1—yeast culture [Saccharomyces cerevisiae (Scer)], beta-glucans, fructooligosaccharides, galactooligosaccharides, and mannanoligosaccharides; Experiment 2 investigated prebiotic blend 2—beta-glucan fractions and mannanoligosaccharides from Scer; Experiment 3 examined yeast cells—hydrolyzed, inactivated, and spray-dried yeast (Scer) cells. Uniform experimental design and procedures were employed across the three experiments. Each experiment had six treatments: monensin (Rumensin®, 25 mg/kg DM) as positive control, and yeast additive levels (0, 533, 1,067, 1,600, and 2,133 mg/kg on DM basis) added to ruminant diets (60% corn silage and 40% concentrate). An in vitro gas production (GP) system with 50 AnkomRF bottles assessed total GP (at 24 and 48 hours), kinetics, fermentation profiles, methane (CH4), and carbon dioxide (CO2) concentrations. Comparison with monensin utilized Dunnett’s test (5%). Yeast additive levels were analyzed for linear and quadratic responses.ResultsIn Experiment 1, the 1,600 mg/kg yeast additive had lower concentrations of propionate, isobutyrate, valerate, and branched-chain volatile fatty acids (BCVFAs), and a higher acetate concentration and acetate-to-propionate ratio than monensin. In Experiment 2, the 1,600 mg/kg yeast additive led to lower total VFA and isovalerate concentrations than monensin. Additionally, compared to the 1,067 mg/kg yeast additive, monensin showed lower isovalerate concentration and higher NH3-N concentration. In Experiment 3, the 533 mg/kg yeast additive resulted in lower valerate and BCVFA concentrations, and higher CH4 and CO2 concentrations than monensin. Monensin had lower total VFA, butyrate, and acetate-to-propionate ratio, and higher propionate concentration compared to the 2,133 mg/kg yeast additive.DiscussionCollectively, these findings suggest yeast-based additives could be monensin alternatives, enhancing animal nutrient utilization efficiency and contributing to improved livestock sustainability.

Proanthocyanidins (PAs), flavonoid polymers involved in plant defense, are also beneficial to human health and ruminant nutrition. To date, there is little evidence for accumulation of PAs in maize (Zea mays), although maize makes anthocyanins and possesses the key enzyme of the PA pathway, anthocyanidin reductase (ANR). Here, we explore whether there is a functional PA biosynthesis pathway in maize using a combination of analytical chemistry and genetic approaches. The endogenous PA biosynthetic machinery in maize preferentially produces the unusual PA precursor (+)-epicatechin, as well as 4β-(S-cysteinyl)-catechin, as potential PA starter and extension units. Uncommon procyanidin dimers with (+)-epicatechin as starter unit are also found. Expression of soybean (Glycine max) anthocyanidin reductase 1 (ANR1) in maize seeds increases the levels of 4β-(S-cysteinyl)-epicatechin and procyanidin dimers mainly using (-)-epicatechin as starter units. Introducing a Sorghum bicolor transcription factor (SbTT2) specifically regulating PA biosynthesis into a maize inbred deficient in anthocyanin biosynthesis activates both anthocyanin and PA biosynthesis pathways, suggesting conservation of the PA regulatory machinery across species. Our data support the divergence of PA biosynthesis across plant species and offer perspectives for future agricultrural applications in maize. Maize has an unconventional proanthocyanidin (PA) biosynthetic pathway which produces rare stereoisomers of PA monomers and dimers, highlighting an opportunity for further improving the nutritional value of maize. [ABSTRACT FROM AUTHOR]

Contextualization: Nutritional supplementation for cattle fed with grass requires local alternatives that allow optimizing the productive performance and reducing maintenance costs of the animals. Knowledge gap: Cocoa husk supplementation can be a nutritionally and economically viable alternative for tropical farms, that is why this research pretends to answer the following questions: What will be the effect of cocoa husk supplementation on productivity and quality of bovine milk? and its implementation will make possible to reduce maintenance costs without affecting the production parameters and the quality of the final product? Purpose: evaluate the effect of a cocoa husk supplement on the production and quality of milk from crossbred cows fed with tropical grasses. Methodology: 10 Brown x Guzerat crossbred multiparous bovine females were used, in their second third of lactation, with an average age of 7 years and an middling weight of 450 ± 38 kg, which were distributed under a completely random design with two treatments: control and supplemented [the supplemented treatment was provided daily (2kg/animal/day) with five repetitions each day]. The supplement was composed of cocoa husk, wheat bran, ground corn grain, molasses, urea, dicalcium phosphate and mineralized salt, and it was offered daily, at milking time, after a 14-day adaptation period. Milk production was quantified daily and corrected to 4 % of fat, and milk composition was analysed every 15 days using an infrared spectrophotometer. The data obtained were subjected to an ANOVA with 5 % of significance, using the PROC MIXED software from SAS v. 9.4. The economic analysis was carried out through partial budgets. Results and conclusions: the nutritional supplementation increased [p < 0,05] milk production which was corrected to 4 % fat. There was an interaction between treatments and collection times [p < 0,05] on the concentration of fat, protein, non-fat solids, and milk density. The concentration of lactose and minerals increased with supplementation and collection time [p < 0,05]. The nutritional supplementation improved net income from milk sales by USD$ 0,63 per animal at day. In summary, nutritional supplementation based on cocoa husks improves production and quality of milk on crossbred cows fed with Brachiaria humidicola pasture, generating higher income for milk producers. [ABSTRACT FROM AUTHOR]

Sulfur (S) is one of the basic building elements; after calcium and phosphorus, it is the third most abundant mineral in the human body. Sulfur is also essential in animal nutrition. It has long been recognized that S represents an essential element for rumen microbes and is closely related to nitrogen metabolism. Sulfur is an important constituent of amino acids, enzymes, and vitamins in humans and animals. Sulfur is a component of various organic nutrients required by ruminants. It is crucial for producing certain enzymes, vitamins, hormones, and amino acids in the rumen, including cystine, methionine, and cystine. Sulfur amino acids, for instance, are found in collagen, the primary structural protein in mammalian tissues. Also, sulfur is not stored in the body. Therefore, it needs to be presented in animal diets in order to maintain the synthesis of these nutrients in the rumen. In ruminants, sulfur supplementation is essential for overall health, growth and production, amino acid balance, and wool quality. Despite this, excessive sulfur digestion may cause a toxic effect on animals and adversely affect animals' performance and health, even causing serious diseases such as polioencephalomalacia (PEM). High sulfur levels in diets can significantly reduce animal performance, decrease milk production and sometimes even result in death. This article will focus on current knowledge about the metabolism and role of sulfur in the ruminant, factors affecting the production of hydrogen sulfide in the rumen, and the potential mechanisms behind sulfur toxicity in cattle. Additionally, possible strategies for minimizing sulfur toxicity in cattle diets will be discussed. [ABSTRACT FROM AUTHOR]

Nutrition has a very significant impact on animal performance. Given the limited agricultural area of the Azores, the optimization of forage quality, quantity, and availability is key for the local livestock industry's ability to respond to the challenges of an increasingly globalized market. This work's goal was to evaluate the use of near-infrared spectroscopy to determine several chemical and biological parameters of pastures under the agroclimatic conditions of the Azores, and to compare its predicative ability when applied to dry homogeneous samples and to fresh inhomogeneous samples, so that we can assess the feasibility of using it to predict new samples on-site in the future. Infrared spectra of 400 fresh and dried grass samples were collected and associated with the corresponding reference values, determined through conventional methods. Mathematical models were created that established relationships between these readings and the values of the properties of interest. Predictive capacity proved especially good for crude protein, neutral detergent fiber, acid detergent fiber, ash, and dry matter, but insufficient for the biological parameters included in the study related to gas production. Near-infrared spectroscopy proved to be useable on-site as a quick, non-destructive, and cost-effective technique to monitor forage quality on a regular basis, enabling forage management and diet design optimizations. [ABSTRACT FROM AUTHOR]

The objective of this research was to evaluate the ruminal fermentation parameters and in vitro Greenhouse gas (GHG) production derived from the fermentation of a balanced sheep diet with the addition of vegetable oils (canola, corn, safflower, and sunflower) or glycerol at different proportions (0, 20, and 40 g/kg of dry matter, DM). The fermentations showed that the highest Gmax was obtained with the addition of 40 g/kg of sunflower oil and 20 g/kg of glycerol with values of 180.97 and 179.95 mL/g DM, respectively. The treatment with 40 g/kg DM of corn oil showed the lowest values in CH4 production (7.15 mL/g DM when compared to the control) and it seemed to be a potential feeding strategy for reducing GHG emissions without affecting gas production. However, the N-NH3 content for this treatment in both doses (1.90 and 1.88 mg/dL) indicated that some toxicity for the animal could be expected. [ABSTRACT FROM AUTHOR]

Using invasive plants as non-conventional forage in livestock production can contribute to meeting climate change targets and provide a competitive advantage in a global market. This study evaluated the nutritional potential of several non-conventional plants: Pennisetum setaceum, Ricinus communis, Arundo donax, Acacia melanoxylon, Opuntia ficus-indica, Agave americana, Pittosporum undulatum, and Hedychium gardnerianum. Chemical composition, in vitro digestibility, gas production, and energy estimates were determined. Opuntia showed the lowest DM value (6.65%), while the highest was found for Acacia (39.43%). Ricinus recorded the highest levels of CP (23.56% DM), RFV (273.86), and in vitro gas production at 24 h (43.49 mL/200 mg DM). The highest NDF (80.39% DM), HEM (39.03% DM), and CEL (36.81% DM) values were observed for Pennisetum. Agave produced the highest amount of gas from the start to the end of incubation (22.68 to 48.99 mL/200 mg DM), while Acacia produced the least (3.83 to 14.78 mL/200 mg DM). The highest ME (8.72 MJ/kg DM) and NEL (5.06 MJ/kg DM) estimates were obtained for Agave. Correlations between the chemical compositions and feed quality indices of the plants were observed, showing strong negative correlations between ADF and DMD, OMD, and DMI (r > 0.86, p < 0.01). We can conclude that all these non-conventional plants have potential as an alternative feed for ruminants when there are fodder shortages. [ABSTRACT FROM AUTHOR]

Livestock production is the main economic engine of the Azores. Given the role nutrition plays in animal performance and the context of limited Averages sharing the same letter are noagricultural area of the archipelago, optimising the quality and availability of the fodder used in feeds takes on an important role in increasing the competitiveness and viability of the industry. This work evaluated the potential of NIR spectroscopy to quantify several chemical and biological parameters used to assess silage quality in the specific agroclimatic context of the Azores. Reference values were determined for 400 grass silage and 400 corn silage samples. The corresponding NIR spectra were extracted, and mathematical models capable of correlating these readings with the various parameters were built. The best results were obtained for crude protein, neutral detergent fibre, acid detergent fibre, and crude ash for both fresh and dry samples. For the biological parameters concerning gas production, no satisfactory results were reached. It was concluded that it was feasible to build models capable of accurately predicting these important quality parameters, which demonstrates that NIRS is a viable technique that can be used in the Azores to perform a close and timely monitoring of forage quality and to facilitate the management and optimisation of diets. [ABSTRACT FROM AUTHOR]

With an increasing demand for high-quality, eco-friendly food products and growing concerns over ecological conservation, the development of ecology-based alternatives for ruminant production in China is urgently needed. This review discusses the capabilities for integrating grassland grazing into existing livestock farming systems to meet the contemporary human needs for high-quality foods and ecologically stable environments. Additionally, this review provides a critical analysis of the challenges and future directions associated with grassland-based ruminant farming systems. Integrating nutritional manipulation with grazing manipulation is critical for improving the productivity of grassland-based ecosystems and natural ecological functions. Biodiversity is the primary determinant of grassland ecosystem functions, while the composition and function of rumen microbiomes determine ruminant production performance. Future studies should focus on the following aspects: 1) how livestock grazing regulates grassland biodiversity and the mechanisms of grassland biodiversity maintenance, offering an important scientific basis for guiding grazing manipulation practices, including grazing intensity, livestock types, and grazing management practices; to 2) characterize the microbial ecology within the rumen of grazing ruminants to offer clarified instruction for the nutritional manipulation of grazing ruminants. Our recommendation includes creating a transdisciplinary system that integrates ecology, animal nutrition, and animal behavior to develop grassland-based ruminant farming systems sustainably, thereby achieving high-quality animal production and environmentally sustainable goals.

Simple Summary: Forage plants are important for ruminant nutrition, so identifying their quality and nutritional value is effective in describing animal nutrition. A ruminal microbe attaches itself or is within close proximity to the surfaces of particulate substrates (primarily the inner surfaces) to digest them. However, incubation in the rumen can result in significant changes in the number of attached microbes. Nonlinear models may provide more accurate and comprehensive descriptions of feed fermentability. Improving the model suitability and validating the model are enhanced with low iterations. However, particle swarm optimization is the novelty of this study since it has never been used to study the digestive process with the above models. The modeling process has a wide range of applications in animal nutrition. The purpose of this work is to determine whether particle swarm optimization (PSO) could be used to explain the fermentation curves of some legume forages. The model suited the fermentation data with minor statistical differences (R2 > 0.98). In addition, reducing the number of iterations enhanced this method's benefits. Only Models I and II could successfully fit the fermentability data (R2 > 0.98) in the vetch and white clover fermentation curve because the negative parameters (calculated in Models III and IV) were not biologically acceptable. Model IV could only fit the alfalfa fermentation curve, which had higher R values and demonstrated the model's dependability. In conclusion, it is advised to use PSO to match the fermentation curves. By examining the fermentation curves of feed materials, animal nutritionists can obtain a broader view of what ruminants require in terms of nutrition. [ABSTRACT FROM AUTHOR]

The paper presents the results of three different ways of storing the dried mass of hay: bulk, small bales and large roll bales, as well as the impact of three drying methods: natural in the field, artificial drying with cold air and drying with dehumidification (warm air). In the tested meadow in the first swath, the results of chemical analyses showed differences in the method of drying hay. Regarding the tested drying method, the content of dry matter (DM) had significant differences between the storage methods as well as all variants with pre-heated air drying, where the average value of DM was in the interval of 86.18-93.01%. The content of mineral substances for certain methods of preparation and drying ranged from 5.77% to 7.72% on average. The highest content of crude proteins was in all variants of artificial drying and it ranged from 98.6 to 165.7 g/kg DM and had a statistically significant difference. Both methods of artificial post-drying had a significant impact on the cellulose content (33.76% to 28.86%) compared to drying in the traditional way because postponing the mowing time increases the cellulose content. The drying method had a statistically high significant difference on the content of neutral detergent fibres (NDF) and acidic detergent fibres (ADF), while the method of storage had no major impact. Knowledge of changes in the quality of hay during the growing season is of particular importance form the aspect of ruminant nutrition and balanced rations. The amount and quality of obtained hay is significantly affected by the time of mowing, height of mowing, swath, fertilization, floristic composition and weather conditions during drying of the green mass. [ABSTRACT FROM AUTHOR]

Corn stover (CS) is an abundant lignocellulosic by-product of the grain industry. Ferulic acid esterase producing (FAE+)-lactobacilli can potentially improve ensiled forages' nutritive value through the hydrolysis of ferulic acid ester bonds present in cell walls during the fermentation process, but this has not been addressed in CS silage. In this study, we characterized 8 FAE+ lactobacilli regarding their FAE activity and inoculant aptitude: Lactobacillus (L.) johnsonii (CRL2237, CRL2238, CRL2240), L. plantarum (ETC182, CRL046, CRL2241), L. fermentum CRL1446 and L. brevis CRL2239. Next, 25% dry matter (DM) CS mini silos were prepared and either not inoculated (UN) or inoculated with each strain (105 CFU g fresh matter−1). Compared to UN, DM loss was significantly reduced in CRL046 and CRL2239, and organic matter increased in CRL2241-inoculated silages. Although the rest of the digestibility measures were not improved, in situ acid detergent fiber degradability (ADFD) was increased by the CRL2238 strain when compared to UN. Results in inoculated silages were not correlated with FAE activity quantification or growth/acidification studies in a CS-derived culture broth. This study demonstrates the potential of several FAE+ lactobacilli strains as CS inoculants and encourages further research. [ABSTRACT FROM AUTHOR]

Simple Summary: The Opuntia ficus-indica, and the Agave americana L., are invasive plants, widespread across various countries, that are used by farmers as an alternative water source for ruminants in the summer. The goal of this study is to assess their nutritive value and potential throughout the year, so that their use in diets can be optimized. Both plants are very rich in water, minerals, and energy, but low in crude protein and fibre. Although a decrease in digestibility is observed in the summer, both plants can be a viable feed supplement for ruminants in both the winter and the summer, providing a cheap and eco-sustainable alternative water source. Opuntia ficus-indica, and the Agave americana L., can be fed to ruminants when associated with dried fodder, or incorporated into high crude protein diets for ruminants. Using invasive plants in animal production can provide an economical and eco-sustainable competitive advantage in a globalized market. The Opuntia ficus-indica and the Agave americana L. are invasive plants historically used by Azorean farmers as an alternative ruminant water source in the summer. This study aims to better understand their properties and how they vary throughout the year, so their use to complement animal diets can be optimised. Six samples of each species were collected on the Terceira Island during 2 growth seasons: winter (January 2021) and summer (September 2021), and their chemical composition, in vitro digestibility, and gas production, were determined. Significant (p < 0.05) differences were found in all parameters between the summer and the winter, with larger variations in both fibre (NDF and ADF) and digestibility parameters found between the Opuntia and the Agave. Gas production was greater in the summer for Opuntia and in the winter for Agave. Even though the digestibility was lower in the summer, we found that both plants offer a viable ruminant feed complement in both seasons, providing a cheap and eco-sustainable alternative water source, that can be associated to dry forage and compound feeding stuff with a high crude protein content when designing ruminant diets. [ABSTRACT FROM AUTHOR]

The aim of this study was to validate selected precision livestock farming (PLF) methods of nutrition and feeding management of high-yielding Holstein dairy cows. In a feeding trial with 36 dairy cows, the effect of replacing 0.1 kg of sodium bicarbonate in the control total mixed ration (TMR-C) with 1 kg of wheat straw in the experimental total mixed ration (TMR-S) on the physiological status of cows and the amount of milk produced (milk yield, MY) was investigated. Feed intake time (FT), as measured using tensometric feed troughs (TFT), was significantly longer with TMR-S (188 min) than with TMR-C (157 min). Differences between TMR-C and TMR-S were not significant for FT or rumination time (RT), as measured by a sensor in the collar (VSC). There was only a weak correlation between the two technologies (TFT vs. VSC) for FT (r = 0.27). Differences between TMR-C and TMR-S were not significant for values measured in rumen fluid (pH, acid and ammonia levels) nor for values measured by sensors in the milking parlour (MY, fat and protein percentage of milk). Milk analysis in the laboratory showed that the cows fed TMR-C had higher urea (26.6 vs. 22.7 mg/100 ml) and free fatty acid (0.87 vs. 0.33 mmol/100 g) levels in milk. Moderate correlations were between TMR intake and MY (r = 0.55); between MY and milk fat (r = -0.46); between milk fat and milk protein (r = 0.63); and between milk fat and milk protein measured by sensors and in the laboratory (r = 0.47 and r = 0.42, respectively). In view of the above results, further research and data validation for each technology are needed. [ABSTRACT FROM AUTHOR]

Simple Summary: Molasses is extensively used in ruminant nutrition. Different studies have evaluated their effects on VFA production, but no data are available on the potential changes in rumen microbiota. The aim of this study was to assess the way in which the use of molasses could have modified VFA production and the rumen microbial community in vitro. The obtained results show the ability of molasses to impact the rumen microbiota, leading to increased proportions of some peculiar bacterial families and reduced amounts of others, thus resulting in different VFA production and composition. The aim of this study was to assess if molasses could modify VFA production and the rumen microbial community in vitro. Three beet (treatment Beet) and three cane (treatment Cane) molasses preparations were randomly selected from a variety of samples collected worldwide and incubated in vitro with rumen fluid along with a control sample (treatment CTR, in which no molasses was used). Flasks for VFA analysis were sampled at 0, 1, 2, 3, 4, 6, 8, and 24 h of each incubation. For microbiota analysis, samples from each fermentation flask after 12 and 24 h were subjected to microbial DNA extraction and V3–V4 16S rRNA gene sequencing on an Illumina MiSeq platform. Total net VFA production was higher in the beet and cane preparations than in the control (CTR) group at 24 h (33 mmol/L, 34 mmol/L, and 24.8 mmol/L, respectively), and the composition of VFAs was affected by the inclusion of molasses: acetic acid increased in the CTR group (73.5 mol%), while propionic acid increased in the beet and cane molasses (19.6 mol% and 18.6 mol%, respectively), and butyric acid increased, especially in the cane group (23.2 mol%). Molasses even influenced the composition of the rumen microbiota, and particularly the relative abundance of the most dominant family in the rumen, Prevotellaceae, which decreased compared to CTR (37.13%, 28.88%, and 49.6%, respectively). In contrast, Streptococcaceae (19.62% and 28.10% in molasses compared to 6.23% in CTR), Veillonellaceae (6.48% and 8.67% in molasses compared to 4.54% in CTR), and Fibrobacteraceae (0.90% and 0.88% in molasses compared to 0.62% in CTR) increased in the beet and cane groups compared to the CTR group. Another important finding is the lower proportion of Methanobacteriaceae following the addition of molasses compared to CTR (0.26%, 0.28%, and 0.43%, respectively). This study showed the impact of molasses in influencing VFA production and composition as a result of a modified rumen microbial composition. [ABSTRACT FROM AUTHOR]