Rumination Efficiency Research Articles

Dynamics of Fermentation Parameters and Bacterial Community in Rumen of Calves During Dietary Protein Oscillation

Dietary crude protein concentration oscillation can improve the nitrogen utilization efficiency of ruminants. However, little is known about the dynamic changes in microbiota and fermentation in the rumen of calves during the oscillation period. In this study, six calves were fed an oscillating diet at 2-day intervals, including a high-protein diet (HP) and a low-protein diet (LP). The rumen fermentation parameters, plasma urea-N concentration, and rumen bacterial diversity were characterized throughout the oscillation period. The concentrations of volatile fatty acids, NH3-N, and plasma urea-N in rumen changed significantly with an oscillating diet. The abundance of Prevotella_1, Selenomonadales, Succiniclasticum, Clostridiales, Ruminococcaceae, Lachnospiraceae, and Rikenellaceae_RC9_gut_group showed significant changes with diet. Prevotella_1 was positively correlated, and Lachnospiraceae_AC2044_group and Saccharofermentans were negatively correlated with NH3-N. The abundance of Amino Acid Metabolism, Metabolism of Other Amino Acids, and Glycan Biosynthesis and Metabolism pathways, annotated by bacterial functional genes, decreased when the diet changed from HP to LP. The abundance of the Carbohydrate Metabolism pathway increased after the two dietary changes. In conclusion, the plasma urea-N concentration was not as sensitive and quick to adapt to diet changes as the rumen fermentation parameters. Rumen bacteria were responsible for increasing the nitrogen utilization efficiency of calves fed an oscillating diet.

Exploring the Spatial Variation in the Microbiota and Bile Acid Metabolism of the Compound Stomach in Intensively Farmed Yaks

Yaks are one of the important livestock on the Qinghai–Tibet Plateau, providing abundant dairy and meat products for the local people. The formation of these dairy and meat products mainly relies on the microbiota in their gastrointestinal tract, which digests and metabolizes plant feed. The yak’s gastrointestinal microbiota is closely related to the health and production performance of the host, but the molecular mechanisms of diet-induced effects in intensively farmed yaks remain to be elucidated. In this study, 40 chyme samples were collected from the four stomach chambers of 10 intensively farmed yaks, and the bacterial diversity and bile acid changes in the rumen (SFRM), reticulum (SFRC), omasum (SFOM), and abomasum (SFAM) were systematically analyzed using 16S rRNA sequencing and bile acid metabolism. Our results showed that the gastrointestinal microbiota mainly distributes in the four-chambered stomach, with the highest microbial diversity in the reticulum. There is a highly negative correlation among the microbiota in the four chambers. The dominant bacterial phyla, Bacteroidota and Firmicutes, were identified, with Rikenellaceae_RC9_gut_group being the dominant genus, which potentially helps maintain short-chain fatty acid levels in the stomach. In contrast, the microbiome within the four stomach chambers synergistically and selectively altered the content and diversity of bile acid metabolites in response to intensive feeding. The results of this study provide new insights into the microbiota and bile acid metabolism functions in the rumen, reticulum, omasum, and abomasum of yaks. This can help uncover the role of gastrointestinal microbiota in yak growth and metabolic regulation, while also providing references for improving the production efficiency and health of ruminants.

Effect of replacing Tifton 85 hay with Moringa hay (Moringa oleifera L.) on the nutrient metabolism, metabolic profile, and water balance of sheep.

This study aimed to evaluate the effect of replacing Tifton 85 hay (TH) with Moringa hay (MH) on the intake, apparent digestibility, ingestive behaviour, rumen parameters, serum attributes, nitrogen balance, water balance, and urinary attributes of sheep. Thus, 5 rams, ½ Dorper + ½ Santa Inês, that were 12 ± 4 months of age with an initial body weight of 32.8 ± 2.6kg were distributed in metabolic cages in a Latin square design. The experiment lasted 85 days and was divided into five 17-day periods. The animals received rations with increasing replacement (0, 100, 200, 300, or 400g/kg of dry matter in the total diet) of TH for MH. The forage: concentrate ratio of the diets was 40:60. Replacing TH with MH reduced (P < 0.05) the intake of organic matter, crude protein, neutral detergent fibre (NDFap), and total digestible nutrients by sheep. The apparent digestibility of NDFap and the feeding and rumination efficiencies of NDFap were reduced (P < 0.05) when MH replaced TH in the animals' diet. This replacement did not influence (P > 0.05) serum urea, total protein, creatinine, or aspartate aminotransferase in sheep. Replacing TH with MH decreased water intake and excretion (P < 0.05). In addition, nitrogen excretion via urine, urinary creatinine, and nitrogen absorption decreased (P < 0.05) when TH was replaced with MH. However, there was an increase in the sheep's nitrogen retention and urine pH. We recommend replacing 30% TH with MH in the diet of lambs because it does not compromise nutrient metabolism.

Seven hundred and ninety-seven metagenome-assembled genomes from the goat rumen during early life

The rumen microbiome plays an important role in providing energy and protein to the host. Manipulation of rumen microbiome during early life may have a long-term beneficial effect on the health, growth performance, and feed efficiency of ruminants. To better understand the profiles and functional potentials of rumen microbiome in young ruminants, metagenomic binning was performed to investigate the rumen microbiome of goat kids from one to 84 days of age. A total of 797 metagenome-assembled genomes (MAGs) were recovered from the rumen of 42 Laiwu black goat kids. Our findings provide fundamental knowledge of the rumen microbiome during early life based on metagenomic binning, which may provide insights into effective strategies to achieve long-term beneficial effects on animal health and production.

Influence of Feed and Feeding Strategies on Rumen Microbiome: A Review

The presence of complex microorganisms in the rumen of ruminants are able to process the lignocellulose from low quality feed and fodder into volatile fatty acids, convert non-protein nitrogen into microbial protein and synthesize B vitamins, thus, ruminants are able to produce food of animal origin without competition for feed with non-ruminants and man. On the other hand, they contribute 14 per cent of anthropogenic methane, released annually into the atmosphere. Manipulating the rumen microbiome is considered as an important approach to reduce environmental impact, while increasing production efficiency in ruminants. A systematic literature search was undertaken and relevant research and review articles were downloaded, classified and salient points extracted to prepare the narrative review on “Influence of Feed and Feeding strategies on Rumen microbiome”. The microbial community in the rumen is the most diverse composed of bacteria, archaea, protozoa, fungi and uncharacterized virome. Differences in ruminal microbial community compositions are predominantly attributable to diet. Dietary manipulation offers a viable solution to alter the rumen microbiome so that the present-day challenges faced by the ruminant livestock industry is addressed.

Effects of yeast and exogenous fibrolytic enzyme additives on lamb performance and feed efficiency.

Yeast and fibrolytic enzymes serve as additives incorporated into the nutrition of ruminants to regulate rumen fermentation and increase the digestibility of fiber, thereby enhancing the efficiency of rumen fermentation. Two experiments were conducted to assess the impact of five diets: a control diet without additives, diets with yeast (Saccharomyces cerevisiae) or exogenous fibrolytic enzymes (EFE), and diets with a blend of 0.7yeast + 0.3EFE or 0.7EFE + 0.3Yeast (based on recommended levels in g/kg of total DM). In the first experiment, 40 five-month-old Santa Ines lambs (mean weight 25.0 ± 1.3kg) were distributed in a completely randomized design (5 treatments and 8 lambs) for 81 days to evaluate performance, ingestive behaviour, and serum metabolites. In the second experiment, 25 Santa Ines male lambs weighing 25.7 ± 4.1kg were housed in metabolic cages, in a randomized design with 5 treatments and 5 lambs, evaluating digestibility, nitrogen balance, and rumen pH. EFE supplementation increased intakes of dry matter (DM), total digestible nutrients (TDN), and apNDF (mean of 38.1, 5.26, and 27%, respectively) compared to yeast or the 0.7yeast-0.3EFE blend. Feed conversion was most efficient (mean of 27.1%) in lambs fed Yeast, 0.7EFE + 0.3yeast, and the control diet. Lambs fed 0.7yeast + 0.3EFE spent less time eating (mean of 16.5%) and more time idling (mean of 10.75%), whereas EFE-fed lambs spent more time eating (mean of 19.73%), and 0.7EFE + 0.3yeast-fed lambs spent more time ruminating (mean of 20.14%). Control group lambs chewed and ruminated less (means of 24.64 and 17.21%, respectively) compared to other treatments. Lambs on the 0.7yeast + 0.3EFE blend had higher eating and rumination efficiency rates for DM and apNDF (mean of 19.11 and 17.95%, respectively) compared to other additive treatments or individual additives. They also exhibited lower (means 7.59g/d) urinary N excretion, with improved N retention (mean 3185g/d) compared to the control group. There were significant effects on serum albumin and cholesterol concentrations, with the 0.7yeast + 0.3EFE blend showing higher albumin (mean 4.08g/dL) levels, while diets without additives and yeast-EFE blends had higher cholesterol (mean of 62.51g/dL) concentrations. Including Saccharomyces cerevisiae yeast along with 0.7 yeast + 0.3 EFE blend is recommended when feeding similar lamb diets to those used herein because it improves the efficiency of intake, rumination of DM and NDF, and nitrogen utilization without affecting the lamb performance.

Assessing the efficacy of date-pits holocellulose as a novel additive candidate for ruminant feeding.

Holocellulose (HC) fraction extracted from date-pits was evaluated as a novel feed additive for ruminant feeding. This study was performed to investigate the effectiveness of the HC additive on rumen fermentation, methane (CH4) production, and diet degradability over 24h of in vitro incubation. Three independent incubation trials were conducted over three consecutive weeks, employing the same in vitro methodology to assess four treatment doses in a completely randomized design. The experimental diet incorporated four increasing doses of HC, containing HC at 0 (HC0), 10 (HC10), 20 (HC20), and 30 (HC30) g/kg dry matter (DM). In vitro gas production (GP) and CH4 production, volatile fatty acids (VFAs) concentration, protozoa accounts, degraded organic matter (DOM), metabolizable and net energy (ME and NE), and hydrogen (H2) estimates were measured. No significant differences in ruminal pH were observed as the HC doses gradually increased. All incremental doses of HC additive over 24h resulted in a linear increase in GP (P < 0.001), DOM (P < 0.001), total VFAs (P = 0.011), and propionate (P < 0.001) concentrations, as well as estimated energy (ME and NE) (P < 0.05) and microbial protein (P = 0.017) values. However, the inclusion of increasing doses of HC in the diet displayed linear reductions in the net CH4 production (ml/kg DOM; P = 0.002), protozoa abundance (P = 0.027); acetate (P = 0.029), and butyrate (P < 0.001) concentrations, the acetate-to-propionate ratio (P < 0.001), and the estimated net H2 production concentration (P = 0.049). Thus, the use of date-pits HC additive generated positive ruminal fermentability, including increased total VFAs and a reduction in the acetate-to-propionate ratio, leading to decreased CH4 output over 24h of in vitro incubation. Hence, HC could be considered a potent feed additive (at up to 30g/kg DM), demonstrating promising CH4-mitigating competency and thereby enhancing energy-use efficiency in ruminants.

Characterization of the ruminal microbiota in sheep and goats fed different levels of tannin-rich Sericea lespedeza hay.

Understanding ruminal microbiota and diet-host breed interactions under forage feeding conditions is essential for optimizing rumen fermentation and improving feed efficiency in small ruminants. This study aimed to investigate the effects of different ratios of condensed tannin-rich Sericea lespedeza (SL; Lespedeza cuneata) in the diets on changes and interactions of ruminal microbiota and host species (i.e., sheep and goats). Katahdin sheep (n = 12) and Alpine goats (n = 12) at approximately 10 to 12 mo of age were blocked by body weight (BW = 30.3 and 25.5kg, respectively) and randomly assigned to one of the 3 treatments. Diets contained 75% coarsely ground forage and 25% concentrate. The forages were 1) 100% alfalfa hay (AL), 2) 100% SL, and 3) 50% AL + 50% SL (ASL). In the present study, the diversity and composition of ruminal microbiota differed between sheep and goats fed similar diets. Based on the taxonomic analysis, there was a distinct clustering pattern (P < 0.05) for sheep by diets, but such a pattern was not observed for goats (P > 0.1). The most predominant phyla were Firmicutes, Bacteroidetes, Ascomycota, and methanogen species of Methanobrevibactor sp. in the rumen of sheep and goats, regardless of diets. The Bacteroidetes and Ascomycota were enriched in sheep fed AL and ASL. In contrast, these microbial phyla were enhanced in goats fed tannin-rich SL diets, with the diet-by-host species interaction (P < 0.02) for the Bacteroidetes phylum. Sheep rumen fluid samples showed a higher degree of variability in microbial community composition compared to goat rumen fluid samples. The relative proportion of the Aspergillus fungi population was reduced to 90.7% in the SL group compared with the AL group, regardless of host species. The antimicrobial activity of tannins and greater sensitivities of selected microbiota species to these tannin compounds during SL feeding in sheep and goats perhaps caused this difference. The results from this study suggest that differences in the microbiota were associated with differences in diets and host species. Therefore, this study provides a better understanding of ruminal microbiota and diet-host species interactions under various tannin-rich diets, which could advance consolidative information on rumen microbiome community diversity changes and may improve sheep and goat production.

Soybean Oil, Linoleic Acid Source, in Lamb Diets: Intake, Digestibility, Performance, Ingestive Behaviour, and Blood Metabolites.

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.

Effect of mushroom crop residue on growth performance, carcass traits, nutrient digestibility, nitrogen balance, ingestive behavior, ruminal and blood parameters of lambs

Using agricultural wastes as substrates of mushroom cultivation can minimize environmental pollution and provide a high-quality substrate that might be used for animal feeding after cultivation, which is beneficial for ruminants. Three experiments were conducted to evaluate the nutritional value of cultivated mushroom residue in lamb diets. Seven inoculation times (0, 5, 10, 15, 20, 25, and 30 days of cultivation) of mushroom substrates by Pleurotus ostreatus were evaluated in a completely randomized design with five replications to characterize the mushroom crop substrate. Within 30 days of cultivation, the mushroom crop residue (MCR) was sun-dried and tested on the lambs’ diet. The first experiment involved 40 uncastrated crossbred lambs (Santa Ines × Dorper), with a mean body weight (BW) of 27.8 ± 2.37 kg (mean ± SD), which were randomly assigned to five groups of six lambs each. They received five levels of MCR replacing Tifton-85 hay: 0, 25, 50, 75, and 100 % on dry matter basis (DM) to evaluate performance, carcass traits, ingestive behavior, and blood parameters. In the second experiment, 25 lambs (40.0 ± 3.0 kg BW) were distributed in metabolic cages in a completely randomized design with the same five treatments of experiment 1 (MRC replacing Tifton-85 hay) and six replications to determine nutrient digestibility and nitrogen balance. To evaluate ruminal parameters, a third experiment was conducted with five Santa Ines × Dorper crossbreed rumen-cannulated sheep weighing 42.0 ± 4.0 kg, which were distributed in a 5 × 5 Latin square. After 30 days of cultivation of the fungus Pleurotus ostreatus, there was a reduction in the MCR contents of DM, ether extract (EE), and non-fiber carbohydrates (NFC). In contrast, ash, crude protein (CP), neutral detergent fiber expressed exclusive of residual ash (aNDF), acid detergent fiber (ADF), and in vitro DM digestibility coefficient (IVDMD) increased (P ≤ 0.05) over the cultivation time. The intake of DM, CP, aNDF and NFC quadratically increased (P ≤ 0.05) with the addition of dehydrated MCR in the lambs’ diet. The effective consumed CP composition and the digestibility coefficient of DM, CP, and aNDF decreased linearly (P ≤ 0.05) due dehydrated MCR addition in the lambs’ diet. The time spent eating and idling, and the rumination efficiency rates (g DM and NDF/h) increased linearly (P ≤ 0.05) with the replacement of Tifton-85 hay by the dehydrated MCR. The time spent on rumination and chewing, the nº of boli chewed, and the DM intake efficiency rate reduced linearly (P ≤ 0.05). There was a linear (P ≤ 0.05) increase in N-intake, N-fecal, and N-retention and linear reduction (P ≤ 0.05) in N-urinary excretion and rumen protozoa count due to the inclusion of MCR in the lambs’ diet. Growth performance, carcass traits, rumen pH, ammonia nitrogen (NH3-N), and blood parameters were not changed by the replacement of hay with MCR. Dehydrated mushroom crop residue inclusion at 75 % of total DM replacing Tifton-85 hay in lambs’ diet is recommended because it improves rumination efficiency, and N-retention without any negative effect on rumen pH, blood metabolites, and carcass traits.

Genital route in experimental infection, a promising approach to study genital leptospirosis in ruminants

Infection by Leptospira sp., mainly strains from the Sejroe serogroup, impairs the reproductive efficiency of ruminants leading to economic losses. Although the majority of experimental studies use the intraperitoneal route of leptospiral infection, it has been suggested that natural infection occurs frequently by sexual transmission. Thus, we assessed the genital route of infection to study genital leptospirosis in the sheep model. A strain of L. borgpetersenii serogroup Sejroe, serovar Hardjobovis was inoculated in 18 ewes, divided into three groups for inoculation: intraperitoneal (n=6; Gip), cervical superficial (genital) (n=6; Ggen) and conjunctival (n=6; Gconj). Monthly, for 90 days, blood samples were collected for serology (MAT) and PCR was performed on urine, cervical-vaginal mucus, and uterine fragments. All ewes were successfully infected, independently of the infection route. Gip and Ggen did not differ throughout the experiment, either on seroconversion or on PCR positivity on urine or genital samples. In contrast, Gconj presented fewer seroreactive animals (P<0.05) and fewer PCR-pos on genital samples than the other groups. The results obtained demonstrated that, although all groups presented both urinary and genital infections, the genital route was more efficient and did not differ from the traditional intraperitoneal. It indicates that genital via, besides being a naturally occurring transmission via, represents a promising and interesting route regarding future studies related to genital leptospirosis in ruminants, and its use should be encouraged.

Nutrient digestibility, characteristics of rumen fermentation, and microbial protein synthesis from Pesisir cattle diet containing non-fiber carbohydrate to rumen degradable protein ratio and sulfur supplement.

To achieve optimal feed efficiency in ruminants, especially Pesisir cattle, it is necessary to maintain a harmonious equilibrium between energy and protein levels within the rumen. Sulfur supplementation can potentially escalate the energy-protein balance in the rumen. The aim of this study was to explore the formulation of ruminant diets by synchronizing rumen degradable protein (RDP) and non-fiber carbohydrate (NFC) while adding sulfur minerals at different levels. Nutrient digestibility, NH3 concentration, volatile fatty acids (VFA) production, microbial protein synthesis (MPS), and methane gas production were assessed. We employed a randomized block design with a 2 × 2 × 3 factorial arrangement and examined diverse incubation periods of 6, 24, and 48 h. Treatment consisted of RDP (60% and 65%), NFC (35% and 40%), and sulfur (0%, 0.15%, and 0.3%) levels. In this study, the Tilley and Terry in vitro technique, which used Pesisir cattle's rumen fluid, was employed to assess the digestibility of dry matter, organic matter, acid detergent fiber, neutral detergent fiber, and RDP-Rumen undegradable protein. In addition, it measures various rumen fluid attributes, including pH, NH3, VFA, MPS, and methane gas production. Treatment with a coordinated combination of 65% RDP and 40% NFC combined with 0.15% sulfur supplement yielded significantly improved digestibility and notably reduced methane gas production (p < 0.05). The enhancement in digestibility and reduction in methane gas emissions can be attributed to the interaction of RDP, NFC, and sulfur. Feed digestibility was increased in the 65% RDP treatment with 40% NFC and 0.15% sulfur, along with a decrease in methane gas production.

Flavonoids from citrus peel display potential synergistic effects on inhibiting rumen methanogenesis and ammoniagenesis: a microbiome perspective.

Flavonoids have been recognized as potential phytochemicals to reduce enteric methane (CH4) production and improve rumen nitrogen efficiency in ruminants. We evaluated whether naringin, hesperidin, their combination, or a mixed citrus flavonoid extract (CFE) as additives can inhibit methanogenesis and ammoniagenesis in dairy cows using an in vitro rumen batch refermentation system. The rumen inocula from dairy cows were incubated in batch cultures with five groups: no addition (CON), hesperidin (20 g/kg DM), naringin (20 g/kg DM), hesperidin + naringin (10 g/kg DM of hesperidin + 10 g/kg DM of naringin), and CFE (20 g/kg DM). The combination of naringin plus hesperidin and CFE achieved greater reductions in CH4 and ammonia production compared to either naringin or hesperidin alone. Microbiome analysis revealed that the decrease in CH4 emissions may have been caused by both the direct inhibitory impact of citrus flavonoids on Methanobrevibacter and a simultaneous decrease in protozoa Isotricha abundance. The relatively lower proportion of Entodinium in naringin plus hesperidin or CFE was responsible for the lower ammonia concentration. These results suggest that citrus flavonoids possess potential synergistic effects on mitigating ruminal CH4 emissions by cows and improving nitrogen utilization.

Whole-plant sesame silage in substitution of whole-plant corn silage in diets of feedlot lambs

ABSTRACT The study evaluated the replacement of whole-corn plant silage (WCPS) by whole-sesame plant silage (WSPS) in diets for finishing lambs. Forty castrated crossbred Santa Inês lambs with an average initial body weight of 21.8 ± 1.97 kg were randomly assigned to four replacement levels: 0, 333, 670 and 1000 g kg−1 DM. The intake of neutral detergent fibre (NDF) decreased linearly while ether extract intake increased linearly. The digestibility of NDF decreased linearly while crude protein digestibility decreased quadratically with the lowest value (690 g kg−1) found at the level of 333 g kg−1. Digestibility and intake of the other nutrients, such as the performance did not display differences. The time spent per chewed bolus decreased quadratically, reaching the minimum value of 39 sec/bolus at the level of 370 g kg−1. The feeding efficiency of NDF decreased quadratically with the lowest efficiency of 77 g/h at the level of 600 g kg−1. Rumination efficiency (RE) of DM increased linearly while RENDF reduced quadratically, reaching the lowest value of 36 g/h at the level of 370 g kg−1. Carcass traits were not affected by the diets. Thus, WSPS can be used up to 400 g kg−1 DM in diets for finishing lambs.

Cactus species and tree forage hay in the diet of dairy goats.

The purpose of this study was to evaluate the influence of the association of Opuntia stricta (OS) or Nopalea cochenillifera (NC) with Moringa hay (MY) or Leucaena hay (LY) on nutrient intake, ingestive behavior, serum biochemistry, and milk production and composition of dairy goat. Eight multiparous Saanen goats were used, with an average of 68 ± 8 days in milk and 48.5 ± 6kg of initial weight, fed with the following treatment diets: OS + MY; OS + LY; NC + MY, and NC + LY. The treatments were distributed in a double Latin square, in a 2 × 2 factorial scheme (two varieties of cactus and two of hay). Goats fed with NC had higher (P < 0.05) intakes of dry matter, crude protein, neutral detergent fiber (NDF), and non-fibrous carbohydrates. There was no influence (P > 0.05) on milk production, but goats fed with OS produced milk with higher (P < 0.05) fat content and presented higher (P < 0.05) feed efficiency. There was no effect (P > 0.05) of the hay type on the nutrient intake and milk production and composition of goats, but the animals fed with MY had higher (P < 0.05) serum cholesterol levels and greater efficiency of NDF rumination. Goats fed with OS showed greater feeding and rumination efficiency. Our results indicated that both cactus species could be successfully included in the diet of low yielding dairy goats fed 18.4% concentrate.

Predicting feed efficiency of Angus steers using the gastrointestinal microbiome

Microbial composition of the gastrointestinal tracts is an important factor affecting the variation in feed efficiency in ruminants. Several studies have investigated the composition of the ruminal and fecal microbiotas, as well as their impacts on feed efficiency and digestion. In addition, next-generation DNA sequencing techniques have allowed us to gain a better understanding of such microbiomes. In this study, the beef cattle microbiome data were analyzed using both a multivariate and a univariate approach and the results were compared. Moreover, a statistical procedure to classify calves in two groups with extreme Residual Feed Intake (RFI) values, using their microbiota profile, was developed. Both fecal and ruminal samples were collected from 63 Angus steers at two different time points for evaluation of their microbiomes: at the beginning and at the end of the feedlot. An additional fecal sample was collected at weaning. A total of 149 and 119 bacterial families (BFs) were retrieved from the ruminal and fecal samples, respectively. A Canonical Discriminant Analysis (CDA) was used to investigate whether BFs were able to distinguish between rumen and fecal samples. A sub-sample of 28 steers was divided in two groups based on their feed efficiency status: positive or negative for RFI. Fecal samples collected at weaning were used to assign the positive and negative RFI animals to their corresponding groups using both Stepwise Discriminant Analysis and CDA. Results revealed that CDA was able to distinguish between rumen and fecal samples. Peptostreptococcaceae was the family most associated with the fecal samples, whereas Prevotellaceae the most associated with the ruminal samples. The CDA using 19 BFs selected from the stepwise was able to correctly assign all animals to the proper RFI groups (negative or positive). Rhizobiaceae was the family most associated with negative RFI, whereas Comamonadacea was the family most linked with positive RFI. The results from this study showed that the multivariate approach can be used to improve microbiome data analysis, as well as to predict feed efficiency in beef cattle using information derived from the fecal microbiome.

Forage cactus as an additive in corn without the cob silages of feedlot sheep diets.

This study aimed to assess the impact of adding forage cactus as an additive to the production of corn silage without the cob on the performance of feedlot sheep and subsequent silage losses. The experimental design was completely randomized, consisting of three treatments: corn silage without cob; 0% = 100% corn plant without the cob; 10% = 90% corn plant without cob + 10% forage cactus; 20% = 80% corn plant without cob + 20% forage cactus. Significant effects were observed for dry matter intake (P = 0.0201), organic matter (P = 0.0152), ether extract (P = 0.0001), non-fiber carbohydrates (P = 0.0007). Notably, nutrient digestibility showed significant differences in organic matter (P = 0.0187), ether extract (P = 0.0095), neutral detergent fiber (P = 0.0005), non-fiber carbohydrates (P = 0.0001), and metabolizable energy (P = 0.0001). Performance variables, including total weight gain (P = 0.0148), average daily weight gain (P = 0.0148), feeding efficiency, and rumination efficiency of dry matter (P = 0.0113), also exhibited significant effects. Consequently, it is recommended to include 20% forage cactus in corn silage, which, based on natural matter, helps meet animals' water needs through feed. This inclusion is especially vital in semi-arid regions and aids in reducing silage losses during post-opening silo disposal.

Effect of detoxified castor bean meal inclusion in sugarcane ensilage on intake, digestibility, water balance, ruminal parameters, serum biochemistry, and ingestive behavior of sheep

This study aimed to evaluate the effect of including detoxified castor bean meal (DCM) in sugarcane ensilage (SCE) on nutrient metabolism, water balance, ruminal parameters and serum biochemistry of sheep. We used five intact male Santa Inês sheep, with 31.02 ± 2.71 kg, housed in metabolic cages receiving treatment diets with 0 (control), 5, 10, 15, and 20 % as fed DCM in SCE. The animals were evaluated for 85 days, divided into five experimental periods. The intake of dry matter (DM), crude protein (CP), neutral detergent insoluble fibre (NDF) and non-fibrous carbohydrates (NFC) increased (P<0.05), while the apparent digestibility of DM, CP, and NDF decreased (P<0.05) with the inclusion of DCM in the SCE. Ruminal ammonia nitrogen decreased (P<0.05) while serum glucose and magnesium increased (P<0.05) with DCM inclusion in the SCE. Including DCM in the SCE did not influence (P>0.05) water balance. The intake and rumination efficiencies increased (P<0.05) with the inclusion of DCM in the SCE. We recommend the inclusion of up to 20 % DCM in the SCE for use in the diet of sheep.

Effects of different additives on cattle feed intake and performance - a systematic review and meta-analysis.

In the last few years, there has been a growing interest in the use of natural feed additives in animal feed. These can be used as replacements for antibiotics, to alter rumen fermentation and increase feed efficiency in ruminants. Therefore, the objective of this study is to evaluate the effects of adding different feed additives in the diet of beef and dairy cattle on their performance, dry matter intake (DMI) and feed efficiency, through a systematic review followed by meta-analysis. The systematic review suggested 43 peer-reviewed publications, according to the pre-established criteria. In beef cattle, the ionophore antibiotics reduced the DMI, improved the feed efficiency without interfering in the average daily gain (ADG). Non-ionophore antibiotics and propolis extract increased the ADG. In dairy cattle, the ionophores, yeast-based additives, and enzyme additives increased the feed efficiency, DMI, and daily milk production (MY), respectively. Essential oil supplementation in beef and dairy cattle had no effect on the feed intake and animal performance. The systematic review and meta-analysis allowed us to conclude that different feed additives have different effects on cattle performance, however, our results suggest that there are a few gaps regarding their effects on animal performance.

Comparative analysis of functional diversity of rumen microbiome in bison and beef heifers.

Ruminants play a key role in the conversion of cellulolytic plant material into high-quality meat and milk protein for humans. The rumen microbiome is the driver of this conversion, yet there is little information on how gene expression within the microbiome impacts the efficiency of this conversion process. The current study investigates gene expression in the rumen microbiome of beef heifers and bison and how transplantation of ruminal contents from bison to heifers alters gene expression. Understanding interactions between the host and the rumen microbiome is the key to developing informed approaches to rumen programming that will enhance production efficiency in ruminants.