The Influence of Highly Dispersed Metal Forms on Calcium and Phosphorus Metabolism in Polygastric Animals

Determining which forms of mineral feed additives can increase farm animal productivity is a key area of research. This study assessed the mineral composition of ruminal fluid and the effectiveness of calcium and phosphorus used by animals after the introduction of finely dispersed particles (FDP) of SiO2 (group I) and FeCo (group II) with a hydrodynamic radius of 109.6 ± 16.6 and 265 ± 25 nm, respectively. The deposition and use of calcium and phosphorus in the body of the experimental animals exceeded the control values. In group I, 30.8% more calcium was deposited (p ≥ 0.05), and in group II, the value was 30.3% (p ≥ 0.01). In the experimental groups, the calcium utilization rate was 27.3% higher in group I (p ≥ 0.05), and 28.2% higher in group II (p ≥ 0.01) compared to in the control. Phosphorus deposition was 34% higher (p ≤ 0.01) in experimental group I and 6% higher in experimental group II, compared with the control. Group I had a high utilization rate of phosphorus from the feed (with a 29% difference compared to the control). Comparison of the experimental groups revealed that the introduction of SiO2 FDP promoted an increase in the concentration of silicon, phosphorus, and calcium in the ruminal fluid. The introduction of FeCo FDP was accompanied by a decrease in the concentration of iron and cobalt in the ruminal fluid. Thus, the use of feed additive in finely dispersed form in the diet of animals was accompanied by an increase in the use of calcium and phosphorus by the animal’s body, which is advisable when intensifying milk and meat productivity. The obtained results require further research. Keywords: finely dispersed forms of microelements, ruminants, calcium and phosphorus exchange, feeding

Changes in the concentration of methane in the ecosystem in vitro against the background of Asteraceae family plants biomass

The assessment of Asteráceae Family Plants (rhizomes and roots of elecampane and wormwood) influence on the process of methane formation in the rumen ecosystem and metabolic processes was carried out. Studies (in vitro) were carried out using ANKOM Daisy II incubator (modifications D200 and D200I) according to a specialized method. Rumen contents were obtained from beef bulls with chronic rumen fistula. Gas analysis of air and volatile fatty acids samples was performed by gas chromatography. The results of the study showed that different dosages of phytobiotic preparations did not significantly affect the characteristics of fermentation in vitro. Phytobiotic preparations of elecampane and wormwood reduce the production of methane in the ruminal fluid, which may be associated with various active components or dosages of their administration.

Intake, ruminal fermentation parameters, and apparent total tract digestibility by beef steers consuming Pensacola bahiagrass hay treated with calcium oxide

To determine the effect of CaO treated Pensacola bahiagrass (Paspalum notatum) hay on intake, ruminal fermentation parameters, and apparent total tract digestibility of nutrients, 9 ruminally cannulated Angus-crossbred steers were used in a triplicated 3 × 3 Latin square design. Steers had ad libitum access to either: 1) untreated dry hay (DH; n = 8); 2) hay at 50% DM treated with 8.9% CaCO3 [dry matter (DM) basis; CC; n = 9]; or 3) hay at 50% DM treated with 5% CaO (DM basis; CO; n = 8). Water was added to reach 50% DM in the CC and CO diets. Ruminal fluid and blood samples were collected every 3 h for 24 h. Ruminal fluid was analyzed for pH, volatile fatty acids (VFA), and ammonia-nitrogen (NH3-N). Blood was analyzed for plasma urea nitrogen (PUN). Hay and fecal samples were collected for 4 d, 4 times daily for hay and twice daily for feces, to determine apparent total-tract digestibility of nutrients. The hay provided to steers during the digestibility period was analyzed for in vitro organic matter digestibility (IVOMD) for 48h. Data were analyzed as repeated measures for blood and ruminal fermentation parameters. Total DM intake was not affected (P ≥ 0.674) by treatment. A treatment effect (P < 0.001) was observed for average ruminal pH, where steers consuming CO had the greatest pH (P < 0.001). Ruminal concentration of NH3-N tended (P = 0.059) to be reduced in steers consuming CO. There was a treatment × time interaction (P = 0.023) on concentrations of PUN, where at 3 h DH and CO were lesser than CC (P ≤ 0.050) and at 21 h DH was lesser than CC (P = 0.020). Total VFA, acetate, propionate, butyrate, branched-chain VFA, and valerate concentrations were affected by treatment (P ≤ 0.035), where a reduction (P ≤ 0.034) occurred in steers consuming CO. No treatment differences were observed for total-tract digestibility of DM (P = 0.186), organic matter (P = 0.169), or crude protein (P = 0.152); however, steers consuming DH had greater neutral detergent fiber (P = 0.038) than CC and tended to be greater than CO (P = 0.082). The CO hay had greater (P = 0.005) IVOMD compared with DH and tended (P = 0.100) to be greater than CC. Bahiagrass hay treated with CaO may reduce ruminal fermentation, as indicated by decreased total VFA concentration without altering DM intake. The addition of CaO did not improve the digestibility of bahiagrass hay in vivo; however, in vitro results are contradictory and warrant further elucidation.

Analysis of pH and electrolytes in blood and ruminal fluid, including kidney function tests, in sheep undergoing long-term surgical procedures

Background The physiology of sheep as small ruminants is remarkably different from monogastric animals especially regarding the forestomach system. Using sheep for surgical procedures during scientific research thereby presents an exceptional setting for the anaesthetist. Long-term anaesthesia generally demands deprivation of food to reduce the risk of bloat in sheep. This might influence the energy and electrolyte balance. In horses and companion animals, close monitoring of mean arterial blood pressure, capnography and blood gas analysis are common procedures during long-term surgery. However, few data are available on reference ranges for blood gas in sheep and these cover only short periods of anaesthesia. To the authors’ knowledge, there is no study available that includes the monitoring of electrolytes and pH in ruminal fluid and kidney function tests in sheep undergoing long term anaesthesia. Thereby, the aim of the present study was to gather data on blood parameters, and data on ruminal fluid and kidney function during long-term anaesthesia in sheep. Data were obtained from eight sheep undergoing the invasive surgical procedure of left pneumonectomy and auto-transplantation or isolated left lung perfusion. After a 19-h fasting period, the animals were administered xylazine and ketamine and then intubated and maintained in general anaesthesia under artificial ventilation using isoflurane in oxygen. Blood samples were evaluated during 9 h of anaesthesia; ruminal fluid and kidney function tests were evaluated during 7 h of anaesthesia. Results Blood parameters such as electrolytes and partial pressure of carbon dioxide revealed few changes, yet blood glucose decreased and beta-hydroxybutyric acid increased significantly. All animals showed an elevated arterial pH and bicarbonate concentration despite artificial ventilation. In ruminal fluid, the pH significantly decreased and no significant changes in electrolytes occurred. Kidney function tests revealed no significant changes in any of the animals. However, fractional excretion of water and phosphate was slightly increased. One animal showed severe complications due to hypokalaemia. Conclusion Invasive surgery under long-term anaesthesia in sheep is possible without great imbalances of arterial pH and electrolytes. Nevertheless, potassium concentrations should be monitored carefully, as a deficiency can lead to life-threatening complications. The operated sheep tended not to develop metabolic acidosis and the mean kidney function could be maintained within the physiological range throughout anaesthesia. However, slight elevations in renal fractional water and phosphate excretion could suggest an early tubular reabsorption dysfunction. In ruminal fluid, acidification occurred, though no significant changes were observed in l- and d-lactate levels or in electrolyte concentrations. To our knowledge, the role of the rumen in storing fluids and balancing electrolytes in the blood has not yet been documented during anaesthesia. However, the importance of the rumen for fluid equilibrium in sheep indicates the necessity for routine monitoring and further research.

Prior Forage Type Influences Ruminal Responses to a Wheat Grain Challenge in Lactating Dairy Cows

To increase the dry matter and metabolisable energy intake of cows, dairy farmers often supplement pasture with concentrates and conserved fodder. Feeding large amounts of highly fermentable concentrates to cows can result in metabolic issues, such as ruminal acidosis, and thus safer but more efficient introduction strategies are desirable. We assessed the role that forages play in ruminal, behavioural and production responses to a wheat grain challenge in dairy cows with no previous wheat adaptation. Multiparous lactating Holstein dairy cows (n = 16) were fed a forage-only diet of either lucerne (Medicago sativa) hay, perennial ryegrass (Lolium perenne L.) hay or one of two cultivars of zero-grazing fresh perennial ryegrass herbage (Bealey or Base), for 3 weeks. The forage diet was then supplemented with crushed wheat grain at 8 kg dry matter/cow day−1, with no adaptation period. Wheat comprised between 32 and 43% of total dry matter intake. Cows fed hay maintained a higher mean ruminal fluid pH than those fed herbage, on both the forage-only diet (6.43 vs. 6.17) and the forage plus wheat diet (6.03 vs. 5.58). Following supplementation of wheat, cows fed herbage exhibited minimum ruminal fluid pH levels indicative of acute ruminal acidosis, at 5.15 and 5.06 for cultivars Bealey and Base, respectively. Furthermore, for both herbage cultivars, adding wheat resulted in a ruminal fluid pH under 6 for >20 h/day. The ruminal environment of cows fed lucerne hay remained most stable throughout the grain challenge, spending the least amount of time below pH 6.0 (9.0 h/day). Hay created a ruminal environment that was better able to cope with the accumulation of acid as wheat was digested. A combination of increased ruminating time and a slower rate of fermentation, due to higher neutral detergent fiber and lower metabolisable energy concentrations in the hays, is likely responsible for the higher ruminal fluid pH values. Forage plays a critical role in wheat introduction strategies; aggressive adaptation strategies could be implemented when a hay such as lucerne is used as the base forage.

PSVI-1 Evaluation of the synergistic effect of iron and an aqueous extract of oak bark on rumen microbiome of cattle

The search for new substances, alternatives to feed antibiotics in animal husbandry, is relevant in connection with the development of antibiotic resistance of pathogenic microorganisms. Substances of plant and mineral origin including nanoforms are of particular interest. The experiment studied the synergistic effect of iron (Fe; d = 80 nm) and an aqueous extract of oak bark (Ex; 1:10) on the microbiome of ruminal fluid of bulls (age 14 months, n = 5). Group I - control; Group II - Ex (0.6 ml / kg / lm); Group III - Fe (0.1 mg/kg/FM) with Ex in the same dosage. The collection of ruminal fluid was performed through a chronic ruminal fistula. Metagenomic analysis of cicatricial fluid was performed on a MiSeq device (Illumina, USA). Analysis of the data showed that the Bacteria domain is more influenced by Ex, there is a decrease by 27.0% (P ≤ 0.05), while in group III by 3.0% relative to the control. At the phylum level, Bacteroidetes and Firmicutes had the greatest importance, in group I their ratio was 39.3 and 54.7%, in group II - 37.7 and 56.4%, in group III - 46.1 and 47.0% of the total the number of bacteria. The use of Ex increases the amount of Bacilli by 14.7 and 13.4 (P ≤ 0.05) % relative to groups I and III. The introduction of the composition Ex and Fe increases Lachnospiraceae - 15.0% and Ruminococcaceae - 8.1% of the total number of microorganisms and reduces Streptococcus relative to other groups by 1.3 and 14.9% (P ≤ 0.05). Thus, the combined use of Ex and Fe affects the numerical value of microorganisms, as well as their ratio in the rumen through inhibition. At the same time, the data obtained require further research, including in vivo experiments. This research was performed with financial support from the RSF (20-16-00088).

Alfalfa Hay Supplementary Intake is Advancing Effect To Rumen Fermentation and Microbial Function of Gansu Alpine Fine Wool Sheep During Cold Season

Bodyweight loss and rumen microbial dysfunction of grazing sheep was a challenge for the sheep production industry during cold season, which were considered to correlated with under-roughage-feeding. The objective of our research was to assess the role of Alfalfa hay supplementary intake in roughage in ewes’ rumen fermentation and microbial function. 120 ewes were allocated randomly into 4 groups, and were fed with different level of alfalfa hay, respectively. Individual ewes’ bodyweight, blood biochemical indexes and rumen microbial characteristics were analyzed after the end of feeding trials. The results showed that alfalfa hay supplementary could significantly enhance sheep body weight, nitrogen components (Total-N, Soluble protein-N and Ammonia-N), blood biochemical indices (LDH, BUN and CHO) and ruminal volatile fatty acids (P < 0.05). Meantime, alfalfa hay supplementary increased the richness and diversity of ruminal fluid microbiota, and decreased ruminal fluid microbiota beta-diversity. The ruminal fluid microbiota of alfalfa hay supplementary feeding showed low immune pathway and high carbohydrate metabolism pathway. Overall, the study suggested that there was an increasing tendency of alfalfa-hay-supplementary group in 30% Yellow Maize Silage + 70% Alfalfa Hay roughage in body weight, ruminal fermentation and microbial function, which improved GS performance through developing hay supplementary system during cold season.

The effect of ruminal fluid pH on milk fatty acids composition in cattle

The present study aimed to evaluate the effects of ruminal fluid pH on the fatty acids (FA) profile of bovine milk. The experiment was performed on 250 Polish Holstein-Friesian cows reared in 11 commercial high-yielding dairy farms. Ruminal fluid samples were collected by rumenocentesis, and fat and FA concentrations in milk were analyzed by Fourier transform infrared spectroscopy. According to ruminal fluid pH, cows were categorized into three pH groups: high pH (pH > 5.8), moderate pH (pH 5.8–5.6), and low pH (pH < 5.6). Milk produced by low-rumen pH cows had a decreased fat content as compared to milk from moderate- and high-rumen pH cows (P ≤ 0.05). Moreover, milk from low-rumen pH cows was characterized by the lowest level of short-chain FA (SCFA; P ≤ 0.05), and consequently, the highest medium-chain FA to SCFA ratio (P ≤ 0.01). The regression analysis showed that these traits explained a small proportion of rumen pH variance, which makes them unreliable indicators of subacute ruminal acidosis (SARA) in dairy cows. However, despite the extensive variability in milk fat composition observed in this study, the effect of ruminal pH on SCFA in all the analyzed herds showed the same trend. Future research aimed to identify SARA biomarkers should therefore be conducted using techniques that allow detection of more individual FA in milk, including SCFA.

Ruminal and Fecal Bacteriome of Dairy Calves Fed Different Levels and Sources of NDF

A starter concentrate containing different levels and sources of NDF can modify the gastrointestinal bacteriome. This study evaluated 18 Holstein calves housed in un-bedded suspended individual cages, fed one of three treatments: 22NDF: a conventional starter containing 22% NDF (n = 7); 31NDF: a starter with 31% NDF, replacing part of the corn by soybean hull (n = 6); and 22Hay: diet 22NDF plus coast-cross hay ad libitum (n = 5). All animals received 4 L of milk replacer daily, weaned at 8th week of age, and housed in wood shelters until week 10. To evaluate the bacteriome, the bacterial community of ruminal fluid and fecal samples was determined by sequencing V3 and V4 region amplicons of the 16S rRNA gene. Bacterial diversity in rumen was not affected by diet or age. The phyla Firmicutes and Bacteroidota, and Prevotella’ genus were the most abundant in ruminal fluid and fecal samples. In feces, the α-diversity indices were higher for 22Hay. All indices were significantly affected by age. We believe that the ruminal bacteriome was affected by basal diet components, but not affected by NDF levels or sources. The supply of hay was effective in modifying the fecal bacteriome of dairy calves due to hind gut fermentation.