Rumen Ammonia Nitrogen Concentration Research Articles

Investigating the effect of supplementing different levels of Isochrysis galbana on in vitro rumen fermentation parameters.

This study aimed to investigate the effect of supplementing Isochrysis galbana (I. galbana) at levels of 0 (control), 1, 2, 3, 4, and 5 (g/100 g DM) of the diet on the gas production kinetics, methane production, rumen fermentation parameters, and relative microbial population in vitro. Supplementation of I. galbana at high level (5g/100 g DM) caused a significant decrease in total gas production (p < 0.05). High supplementation rates (4 and 5g/100 g DM) decreased CH4 production relative to the control by 18.4% and 23.2%, respectively. Although rumen ammonia nitrogen (N-NH3) and total volatile fatty acids (VFA) concentrations were affected by dietary treatments, but the VFA profile did not changed. The relative proportion of protozoa and methanogenic archaea as well as Anaerovibrio lipolytica, Prevotella spp., Ruminococcus flavefaciens, and Fibrobacter succinogenes were decreased significantly as a result of microalgae supplementation. However, the relative abundance of Ruminococcus albus, Butyrivibrio fibrisolvens and Selenomonas ruminantium were significantly increased (p < 0.05), related to the control group. As well, the pH was not affected by dietary treatments. It was concluded that I. galbana reduced in vitro CH4 production and methanogenic archaea that its worth to be investigated further in in vivo studies.

The response of rumen pH, fermentation parameters and rumen bacteria to feeds of different concentrate to roughage ratios in buffalos

This experiment was conducted to study the regularity influence in apparent digestibility, rumen fermentation parameters, and relative bacterial abundance in buffaloes with different concentrate to roughage ratios. Three adult female barren buffaloes with permanent rumen fistulas were fed five diets with concentrate to roughage ratios of 20:80, 35:65, 50:50, 65:35, and 80:20 according to an incomplete Latin square design of 3×5, respectively. The pre-feeding period of each period was 12 d. From day 13 to 15 of the experiment, the feed intake of each buffalo was accurately recorded and all feces were collected. Samples of diet and feces were collected for nutrient analysis. Rumen fluid was collected to determine rumen fermentation parameters, and rumen bacteria were analyzed by 16S rRNA sequencing. After 2 hours of feeding in the morning on the 15th day of the experiment, rumen bacteria were analyzed. The daily gain and DMI (G/kgW0.75) reached the highest at the concentrate to roughage ratio of 50:50, and the apparent digestibility of ADF NDF NDICP ADICP reached the highest at the concentrate to roughage ratio of 35:65. The weight loss of the experimental animals when the concentrate to roughage was 80:20. Rumen pH decreased with the increase of concentrate level, starch content and NFC content. The rumen ammonia nitrogen concentration increased with the increase in the concentrate to roughage ratio and protein content. The concentration of total volatile fatty acids (mmol/L) in the rumen decreased with the increase of NDF but increased with the increase of NFC and CP, and the acetic acid proportion increased with the increase of NDF. There were differences in the relative abundance of rumen bacterial microbiota with the different concentrate to roughage ratios. Moreover, the relative abundance of each bacterial microbiota changed regularly with the change of concentrate to roughage ratio. The relative abundance of Bacteroidetes, Firmicutes, and other rumen core microbiota varied linearly or nonlinearly with the change of concentrate to roughage ratio. This suggests that the relative abundance of the ratio of rumen microbiota can be used to specify or measure rumen health and subacute rumen acidosis/rumen acidosis.

Exogenous fibrolytic enzymes promoted energy and nitrogen utilization and decreased CH4 emission per unit dry matter intake of tan sheep grazed a typical steppe by enhancing nutrient digestibility on China loess plateau.

Exogenous fibrolytic enzyme (EFE) products in ruminant nutrition may be an important alternative to meet the increased demands for animal products in the future with reduced environmental impacts. This study aimed to evaluate the dose-response of EFE supplementation on the nutrient digestibility, nitrogen and energy utilization, and methane (CH4) emissions of Tan sheep grazed in summer and winter. A total of 20 Tan wether sheep with an initial body weight of 23.17 ± 0.24 kg were used in a randomized complete block design and categorized into two groups. Animals fed orally with 1 g of EFE (10,000 U/g) mixed with 30 mL of water using a drencher constituted the EFE group. For experimental accuracy, the control (CON) group was orally administered with 30 mL of normal saline daily before grazing. The following results were obtained: EFE in the diet increased dry matter intake (DMI) (P < 0.05), average daily gain (ADG) (P < 0.05), and digestibility (P < 0.05) compared with CON in summer and winter. DMI increased but ADG and digestibility decreased in winter compared with those in summer. Sheep fed with the EFE diet increased the concentrations of rumen ammonia nitrogen (P < 0.05) and total volatile fatty acids (P > 0.05), but reduced pH (P > 0.05), compared with CON in summer and winter. EFE increased nitrogen (N) intake, digestible N, retained N, and retained N/digestible N (P < 0.05) but reduced fecal N/N intake, urinary N/N intake, and excretion N/N intake in summer and winter (P < 0.05), compared with CON. Retained N/N intake was reduced and excretion N/N intake increased in winter relative to those in summer. In winter, gross energy (GE), manure E/GE, CH4 emissions, CH4/DMI, and CH4/GE increased but digestion energy and metabolic energy decreased compared with those in summer. Sheep fed with the EFE diet had a greater GE intake than those fed with the CON diet (P < 0.05) but had lesser CH4/DMI and CH4E/GE (P < 0.05) than those fed with the CON diet in both summer and winter. In conclusion, EFE supplementation increased DMI, apparent digestibility, and N deposition rate. These effects were beneficial for animal production. The CH4 emission per unit DMI of grazing Tan sheep was lesser and conducive for augmenting the environmental benefits.

Feed utilization efficiency and ruminal metabolites in beef cattle fed with cassava pulp fermented yeast waste replacement soybean meal

The purpose of this study was to see how substituting cassava pulp fermented yeast waste (CSYW) for soybean meal (SBM) in a concentrate affected feed intake, digestibility, and rumen fermentation in Thai native beef cattle. In this study, four male Thai native beef cattle with an average age of 15.0 ± 25.0 months and body weights of 140 ± 5.0 kg were used. The experimental design was a 4 × 4 Latin squared design, with dietary treatments of CSYW replacing SBM at 0, 33, 67, and 100% in the concentrate mixture. It was discovered that the presence of CSYW had no negative impact on feed intake, nutritional intake, or apparent digestibility (p > 0.05). CSYW had no significant effects on ruminal pH or temperature (p > 0.05). When the amount of CSYW in the diet increased, the rumen ammonia–nitrogen concentration increased (p < 0.05). Blood urea nitrogen was not affected by CSYW (p > 0.05). The total bacterial population increased when the diet's CSYW amount was increased (p < 0.05). Feeding CSYW to beef cattle had no influence on total volatile fatty acid, acetic acid (C2), or butyric acid (C4) proportions (p > 0.05). The concentration of propionic acid (C3) and the C2:C3 ratio increased when the amount of CSYW in the diet was increased (p < 0.05). In conclusion, CSYW can completely replace SBM in a concentrate diet for beef cattle with no adverse effects on feed utilization or rumen fermentation while the total bacterial population and C3 concentration increase.

Effects of trace minerals supply from rumen sustained release boluses on milk yields and components, rumen fermentation and the rumen bacteria in lactating yaks (Bos grunniens)

The experiment was conducted to evaluate trace mineral supplies of iron (Fe), copper (Cu), manganese (Mn), zinc (Zn), cobalt (Co), iodine (I) and selenium (Se) using rumen sustained release boluses on milk yield and milk components, rumen fermentation and the rumen bacteria in lactating yaks. Sixteen multiparous lactating yaks, blocked by parity, liveweight, and milk yield, were randomly assigned to two groups: CON (control group), a high forage diet with no supplemental iron Fe, Cu, Mn, Zn, Co, I and Se; MIN (dietary supplementation of inorganic trace minerals), the CON diet was fed and one rumen sustained release boluses providing inorganic Fe, Cu, Mn, Zn, Co, I and Se were given. The milk yield and lactoferrin concentration were greater (P < 0.01) in the MIN group than those in the CON group. The MIN group had a higher yield of milk protein (P = 0.02) and lactose (P < 0.01) and a lower milk fat content (P = 0.04) than those in the CON group. Relative to the CON group, MIN group had higher (P < 0.05) milk content of Ca, P, Mg, Cu, Mn and Fe. The rumen ammonia nitrogen (NH3-N) concentration (P = 0.02) and valerate proportion (P = 0.01) were higher and acetate proportion were lower (P = 0.03) in the MIN group than those in the CON group. The relative abundances of Planctomycetes tended to be higher and the Lentisphaerae, Candidatus_Melainabacteria Erysipelotrichaceae_UCG-004 and Tenericutes_bacterium tended to be lower in MIN group. Operational taxonomic units (OTU) unique to the CON and MIN belonged mainly to the phylum Bacteroidetes and Firmicutes, respectively. The relative abundance of Candidatus_Saccharimonas, Erysipelotrichaceae_UCG-004, Ruminococcaceae_UCG-014 and Ruminococcaceae_NK4A214_group correlated positively with concentration of milk fat and acetate. Relative abundance of Succiniclasticum and Acinetobacter positively correlated with concentration of lactoferrin, milk yield, milk protein yield and milk lactose yield. Overall, these results suggest that trace mineral supply from rumen sustained release boluses has influenced milk yield, milk components and rumen microbiota of lactating yaks, which provides new insights in understanding the trace mineral metabolism, and shed lights on the trace mineral application of yaks and other ruminants lived at Qinghai-Tibetan Plateau.

PSXII-24 Effects of feeding levels on digestibility, rumen fermentation and blood metabolites of growing Korean native goats (Capra hircus coreanae)

Abstract The objective of this study was to investigate the effects of feeding levels on nutrient digestibility, rumen fermentation and blood metabolites of growing Korean native goats. Five growing bucks (19.5±1.4 kg) with an average age of 5 months were randomly allocated to one of five feeding levels [maintenance (M), 1.1 x M, 1.2 x M, 1.4 x M, and 1.6 x M]. The experimental design was 5 × 5 Latin square design and all animals were housed individual pens (1.2 m × 0.9 m) for an adaption period of 2 weeks and collection period for 1 weeks. Rumen samples were collected before morning feeding using oral stomach tube. Nutrient digestibility increased linearly in goat as feeding level increased (P &amp;lt; 0.01), but body weight did not differ among feeding levels. Rumen pH and ammonia nitrogen concentration showed no significantly differences among feeding levels. The total and individual volatile fatty acids concentration increased linearly (P &amp;lt; 0.01) and quadratically (P &amp;lt; 0.05) with increased feeding levels. Blood metabolites did not differ among feeding levels. The fecal energy loss was not influenced by feeding levels, but digestible energy was increased linearly (P &amp;lt; 0.01) and quadratically (P &amp;lt; 0.05) with increased feeding levels. The metabolizable energy requirement was estimated using quadratic line model and ranged from 154 to 163 kcal per metabolic body weight based on average daily gain and ME intake. These results suggest that higher feeding levels of growing goat increases digestibility and nutrient utilization efficiency in the rumen. These results serve as a basis for the establishment of goat feeding programs at the farm scale in the Republic of Korea.

Partial replacement of corn silage with whole-plant soybean and black oat silages for dairy cows

This study aimed to evaluate the effects of partially replacing corn silage (CS) with whole-plant soybean silage (SS) or black oat silage (OS) on nutrient intake and digestibility, in vitro neutral detergent fiber degradability of silages, feeding behavior, rumen fermentation, and performance of dairy cows. Twenty-four lactating Holstein cows (6 of which were rumen-cannulated) with 32.5 ± 4.92 kg/d milk yield, 150 ± 84.8 days in milk, and 644 ± 79.0 kg of body weight were used in a 3 × 3 Latin square design to evaluate the following treatments: (1) corn silage diet (CSD): using corn silage as the only forage source in the diet [48% dietary dry matter (DM)]; (2) whole-plant soybean silage diet (SSD): SS replacing 16% of corn silage from CSD; and (3) black oat silage diet (OSD): OS replacing 16% of corn silage from CSD. The inclusion of OS and SS decreased intakes of DM, organic matter, and crude protein. Corn silage had the greatest in vivo effective degradability of DM, and SS had the least effective degradability of neutral detergent fiber. The OSD treatment decreased milk and protein yields, whereas SSD increased rumen ammonia nitrogen concentration compared with the other diets. Cows fed OSD exhibited a greater preference for feed with small particles (<4 mm) compared with those fed SSD. Cows fed treatments containing either SS or OS at the expense of CS had increased rumination and chewing activities. Although replacing CS with OS and SS reduced feed intake, SS had no effect on productive performance of dairy cows.

Effects of rumen-protected methionine and lysine supplementation on milk yields and components, rumen fermentation, and the rumen microbiome in lactating yaks (Bos grunniens)

The objectives of this study were to investigate the effects of supplementing rumen-protected methionine (RPM) or lysine (RPL) alone or in combination with RPM and RPL (RPML) on milk yield and milk components, rumen fermentation characteristics, and the rumen microbiome in lactating yaks. Thirty-two multiparous lactating yaks with parity (2.13 ± 1.08 lactations), body weight (169 ± 15.0 kg), and milk yield (1.02 ± 0.13 kg/d) were blocked by milk yield and randomly assigned into one of the four treatments: control (CON; basal diet without adding rumen-protected amino acid) and the basal diet supplemented with RPM (50.0 g/d), RPL (66.7 g/d), or RPML (12.5 g/d RPM and 50.0 g/d RPL). The basal diet consisted of 600 g/kg rye hay and 400 g/kg corn-based concentrate. The dry matter intake, lactoferrin concentration, and lactose yield were greater (P < 0.05) in the RPM and RPML groups than those in the CON and RPL groups. Compared to the other three groups, the RPM supplementation increased (P < 0.01) the milk and protein yield. The milk protein content in the RPM group was greater (P < 0.01) than that in the CON and RPML groups. The RPM group had a higher milk content of alanine (P < 0.01) and aspartic acid (P = 0.01) than that in the other three treatments. The RPM group had a lower (P < 0.01) rumen pH and a higher (P = 0.02) valerate proportion than those in the other three treatments, whereas the RPML group had a higher (P = 0.03) rumen ammonia nitrogen concentration than that in the other three treatments. The relative abundances of Proteobacteria (P = 0.01) and Prevotella_1 (P = 0.02) were increased in the RPM and RPML groups, respectively. Operational taxonomic units (OTU) unique to the yaks of RPL and RPML groups belonged mainly to the phylum Bacteroidetes, whereas the majority of OTUs unique to the yaks of the RPM group belonged mainly to the phylum Firmicutes. The relative abundances of Fibrobacter and Selenomonas_1 were positively correlated with milk yield and concentration of propionate, valerate, butyrate, and total volatile fatty acids. The relative abundances of Candidatus_Saccharimonas, Ruminococcaceae_UCG-014, Rikenellaceae_RC9_gut_group, and Erysipelotrichaceae_UCG-004 were positively correlated with the content of milk protein. These results suggest that supplementation of RPM and RPL can affect rumen microbial populations, which in turn affect rumen fermentation and thus, the metabolites available for milk synthesis.

Rumen characteristics and blood parameters of West African dwarf goats fed vetiver grass (Chrysopogon zizanoides. L. Roberty) ensiled with cassava peels at different ratio

Vetiver is a perennial grass of tropical origin, commonly used as edge row plants for the control of erosion. Being leafy and with a high tillering ability, it has not been properly integrated as forage for ruminants. Thus, an experiment was carried out to determine the effect of ensiling a four week re-growth of vetiver grass with cassava peels on rumen and blood metabolites of West African dwarf goats. Sixteen goats were used for the study. A completely randomized design was used with four animals per treatment. Vetiver grass was ensiled with cassava peels at ratio (A) 80:20, (B) 70:30, (C) 60:40 and (D) 50:50 were provided ad-libtum at 5% body weight. Rumen and blood samples were collected at the end of the experiment which lasted for 90 days. Results of the study showed rumen ammonia nitrogen (NH3-N) concentration of 7.25-7.93mg/100mL, and pH of 6.75-6.81. Variations among the treatments were within the acceptable range for rumen microbial activity. There was a uniformly low plasma urea (4.36-5.16mm/l). Glucose (85.36-89.04g/dL), total protein (6.42- 7.50g/dL), cholesterol (60.95-66.19g/dL), haemoglobin (10.9-12.7g/100ml), packed cell volume (30.0-31.0%) and white blood cell (10.25-10.67×103/ul) were within the range reported for healthy goats. Ensiled vetiver grass with cassava peels had no detrimental effects on the rumen and blood parameters of the experimental animals.

Effect of Feeding Oak (quercus Aegilops) Acorns on Nutrient Digestibility, Nitrogen Balance, Ruminal Fluid Characteristics And Some Blood Metabolites in Sheep And Goats

This study aimed to examine the response of sheep and goats to dietary effects of feeding different levels of oak (Quercus aegilops) acorns in terms of nutrient digestibility, nitrogen balance, rumen function and some serum metabolites. The study was conducted over 4 periods each of 15 days; in each period, rams and bucks were allocated to one of the dietary treatments (control, 5, 10 and 15% oak acorns). Rams and bucks exhibited different responses to the effects of dietary levels of oak acorns. The digestibility coefficient of DM was reduced in both rams and bucks upon feeding acorns, but this decline was significant (P≤0.05) only in rams fed 10 and 15% acorns as compared to rams fed control. Also, the rams and bucks showed numerical decrease in digestibility coefficients of OM, CP, CF, and NPN. The experimental treatments had no effects on nitrogen balance parameters. Bucks exhibited significantly (P≤0.05) higher concentrations of rumen ammonia-nitrogen before, 4 hours and 6 hours after morning feeding. The rumen pH value was significantly (P≤0.05) by the animal species only at the time before morning feeding. The serum metabolites were not affected by the level of acorns in the diet. The results of this study indicate that goats are superior in digesting diets containing oak acorns up to 15%.

Effects of replacing alfalfa hay with malt sprouts and corn stover on milk production and nitrogen partitioning in dairy cows

The aim of this investigation was to study the effect of replacing alfalfa hay with malt sprouts and corn stover on feed intake and apparent digestibility, rumen fermentation, milk production and composition, and N partitioning in dairy cows. Six multiparous Holstein dairy cows were used a replicated 3 × 3 Latin square design with each period lasting 27 d. The cows were assigned randomly to one of three treatment groups: (1) 0 g/kg malt sprouts and 0 g/kg corn stover (0MS), (2) 49.1 g/kg malt sprouts and 34.4 g/kg corn stover (5MS), and (3) 133 g/kg malt sprouts and 49.1 g/kg corn stover (13MS). The diets were isonitrogenous and contained identical corn silage and concentrate mixtures, but different proportions of corn stover and malt sprouts. The in situ effective degradability of dry matter, neutral detergent fiber and crude protein were higher in cows fed 13MS or 5MS diets than in those fed the 0MS diet. The respective intake and total-tract apparent digestibility of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber were greater for 13MS than for 5MS or 0MS. Cows fed the 13MS diet had greater milk production, energy-corrected milk, milk protein and lactose yields and percent milk protein than cows fed other diets, but fat yield, percentage of milk fat, lactose, somatic cell count, milk urea nitrogen concentration and feed efficiency were similar for the three treatments. Compared with the 0MS diet, cows fed 5MS or 13MS diets had higher rumen ammonia nitrogen and total volatile fatty acids concentration, PD to creatinine ratio. Moreover, the cows that consumed a MS diet had a higher rate of manure excretion. Thus, it appeared that the combination of malt sprouts and corn stover effectively replaced a portion of alfalfa hay in diets without affecting the performance of dairy cows.

Effect of essential and vegetable oil blend supplementation on animal performance, feed intake, rumen fermentation and rumen microbial populations of crossbred steers finished in a pasture system

Recent years have seen a general increase in consumer concern regarding the profile of additives in animal feed and food sources, prompting the industry to study essential oil blends that have been promoted to replace synthetic products. This study evaluated the effect of essential oil blends supplementation on animal performance, feed intake, rumen fermentation and rumen microbial populations in crossbred steers finished in a pasture system. A total of 40 steers (½ Bons Mara vs. ½ Nellore) with a mean age of 20 ± 2.0 months and a mean body weight of 416.9 ± 5.56 kg were distributed in a completely randomized design with five diets and eight replications per diet. The five experimental diets were: CONT – basal diet, and oil blend inclusion in dosages of 1500, 3000, 4500 or 6000 mg/animal/d. Animal performance was similar among diets. The forage intake, crude protein, neutral detergent fiber, ethereal extract, non-fibrous carbohydrates, and the digestibility of crude protein, neutral detergent fiber, and non-fibrous carbohydrates were greater when essential oil blends were fed to steers. There was an increase in the concentrations of rumen ammonia nitrogen, and propionic and isovaleric volatile fatty acids when essential oil blends were used. The microbiological population of the rumen was similar among the five diets. Our results suggest that the inclusion of doses above 1500 mg/animal/ is high for livestock grazing on temperate pasture, further studies are needed to identify a promising dose to replace antimicrobial additives.

Effects of Saccharomyces cerevisiae supplementation on growth performance, plasma metabolites and hormones, and rumen fermentation in Holstein calves during pre- and post-weaning periods.

This study aimed to evaluate the effects of supplementing Saccharomyces cerevisiae (SC) during the pre- and post-weaning periods on growth, metabolic and hormonal responses, and rumen fermentation in calves. Three-week-old Holstein calves were assigned to either control (n=12) or SC group (n=12), the latter of which received 2×109 cfu/day of SC. The experiment was conducted over a period of 7weeks around weaning. Daily gain (DG) in the SC group was higher (p<.05) than that in the control group. In the SC group, plasma glucose, insulin, and growth hormone (GH) concentrations were higher (p<.05) and concentrations of glucagon and insulin-like growth factor 1 (IGF-1) tended to be higher (p<.1) than in the control group. Proportion of rumen propionate and concentration of rumen ammonia nitrogen at 10weeks of age were greater (p<.05) in the SC group than that in the control group. Supplementation of SC around weaning may improve dietary nutrient and energy availability and increase plasma GH and IGF-1 concentrations. These changes observed in SC-supplemented calves could be closely related to the improvement of DG.

Specific enrichment of microbes and increased ruminal propionate production: the potential mechanism underlying the high energy efficiency of Holstein heifers fed steam-flaked corn

Corn grain has a high starch content and is used as main energy source in ruminant diets. Compared with finely ground corn (FGC), steam-flaked corn (SFC) could improve the milk yield of lactating dairy cows and the growth performance of feedlot cattle, but the detailed mechanisms underlying those finding are unknown. The rumen microbiome breaks down feedstuffs into energy substrates for the host animals, and contributes to feed efficiency. Therefore, the current study was conducted to investigate the ruminal bacterial community changes of heifers fed differently processed corn (SFC or FGC) using 16S rRNA sequencing technologies, and to uncover the detailed mechanisms underlying the high performance of ruminants fed the SFC diet. The results revealed that different processing methods changed the rumen characteristics and impacted the composition of the rumen bacteria. The SFC diet resulted in an increased average daily gain in heifers, an increased rumen propionate concentration and a decreased rumen ammonia nitrogen concentration. The relative abundance of the phylum Firmicutes and Proteobacteria were tended to increase or significantly increased in the heifers fed SFC diet compared with FGC diet. In addition, the relative abundance of amylolytic bacteria of the genera Succinivibrio, Roseburia and Blautia were elevated, and the cellulolytic bacteria (Ruminococcaceae_UCG-014 and Ruminococcaceae_UCG-013) were decreased by the steam flaking method. Spearman correlation analysis between the ruminal bacteria and the microbial metabolites showed that the rumen propionate concentration was positively correlated with genera Succinivibrio and Blautia abundance, but negatively correlated with genera Ruminococcaceae_UCG-014 abundance. Evident patterns of efficient improvement in rumen propionate and changes in rumen microbes to further improve feed conversion were identified. This observation uncovers the potential mechanisms underlying the increased efficiency of the SFC processing method for enhancing ruminant performance.

Effect of Spirulina (Spirulina platensis) Supplementation on Nutrient Intake, Digestibility and Rumen Fermentation Pattern in Barbari Goats

Present study was conducted to examine the effect of spirulina (Spirulina platensis) supplementation on nutrient intake, digestibility and rumen fermentation pattern in growing Barbari goats. Eighteen male Barbari goats were divided into three groups, G1 (Control), G2 and G3 (treatment) of six animals each in completely randomized design. All the animals were fed with complete pellet feed having Bengal gram straw and concentrate mixture in 60:40 ratio. In G1 no spirulina was supplemented while in G2 and G3 spirulina was supplemented at 0.25 and 0.50% of DM, respectively. Experimental feeding durations was 90 days. After 60 days of experimental feeding, a metabolism trial of six days collection period was conducted to determine nutrients balance. Rumen liquor samples were collected from each animal at the end of experimental feeding 4h post feeding. The digestibility (%) of dry matter, organic matter, ether extract and total carbohydrate was similar among groups. The digestibility (%) of different fibre fractions (neutral detergent fibre, acid detergent fibre, cellulose and hemi cellulose) was similar in groups. Animals of control and treatment groups were in positive nitrogen balance. Concentration of total volatile fatty acids (mmol/dL SRL) in rumen fluid was statistically similar in goats of G1 (20.75), G2 (24.93) and G3 (20.37). No significant difference in total volatile fatty acid fractions was observed between control and treatment groups. There was no significant difference (P>0.05) in total nitrogen and non-protein nitrogen between control and treatment groups. TCA-precipitable nitrogen showed no significant difference among groups. Ammonia nitrogen (mg/dL SRL) showed significant difference in between control and treatment groups, highest for G1 (29.16) and lowest for G3 (16.80). From present study, it can be concluded that supplementation of spirulina @ 0.25 and 0.50 of DMI had no effect on intake, digestibility of nutrients but reduced the rumen ammonia nitrogen concentration.

Effects of dietary protein levels and calcium salts of long-chain fatty acids on nitrogen mobilization, rumen microbiota and plasma fatty acid composition in Holstein bulls

The aim of this study was to investigate the impact of dietary crude protein (CP) levels and calcium salts of long-chain fatty acids (CSFA) on the nutrient intake and digestibility, nitrogen deposition, rumen fermentation characteristic and microbiota, plasma biochemical indexes and fatty acid composition in the Holstein bulls. Eight Holstein bulls was used in a 4 × 4 Latin Square design with 2 × 2 factorial diets, including two levels of CP (133 or 112 g/kg dry matter), and with or without 2.32 g/kg CSFA. The high CP level diets increased the CP intake and the CP apparent digestibility and the urinary nitrogen excretion (P = 0.001). Dietary supplementation with CSFA promoted the apparent digestibility of organic matter (P = 0.012). The diets of CSFA and high CP level raised the rumen ammonia nitrogen concentration (P = 0.009), and enhanced the isovalerate and valerate concentrations, respectively. The high CP diets improved the abundance of Butyrivibrio fibrisolvens (P = 0.037) and Megasphaera elsdenii (P = 0.023), while the CSFA reduced the abundance of methanogens (P = 0.047). High CP increased urea concentration (P = 0.008). Dietary supplementation with CSFA increased the cholesterol and the low-density lipoprotein cholesterol concentration in the plasma, and the proportion of C16:0, C18:1n9c and Δ9 desaturase C18, while it reduced the ratio of C21:1 and C22:0. The low CP diets reduced the protein waste and environmental pollution in the final stage of fattening Holstein bulls. Further study needs to be done to investigate the effect of CSFA on the CH4 emission in terms of microbial mechanism in the rumen.

Determining the optimal dose of virginiamycin for ruminal parameters and performance of Nellore cattle on pasture

There are no studies evaluating the virginiamycin (VM) doses under tropical conditions. So, the present study was conducted to evaluate the optimal dose of VM for growing Nellore bulls on tropical pasture. Two experiments were conducted. The first experiment, one hundred and two Nellore bulls (307 ± 25 kg body weight [BW]; 22 months) were used. Animal performance was evaluated using a randomized block design, with group as experimental unit (n = 8; 12 animals each). The second experiment, a double 4 × 4 Latin square, eight animals were used to evaluate the ruminal parameters. Four doses were evaluated: 0, 35, 55, and 75 mg VM per 100 kg BW. The average daily gain (P = 0.08) and carcass gain (P = 0.05) exhibited a trend of quadratic behavior. An increased dose of VM did not affect supplement intake (P = 0.64), rumen pH (P = 0.96), acetate: propionate ratio (P = 0.73), or the total concentration of volatile fatty acid (P = 0.63). The concentration of rumen ammonia nitrogen exhibited a quadratic effect (P = 0.01). A quadratic behavior was found for volatile fatty acid, except for propionate (P &lt; 0.01). In conclusion, the dose of 47 mg VM per 100 kg BW is recommend for growing Nellore bulls on tropical pasture.

Intermittent feeding of citrus essential oils as a potential strategy to decrease methane production by reducing microbial adaptation

The objective of the present study was to assess the effects of citrus essential oils (CEO) on growth and rumen fermentation of Hu sheep as well as to evaluate the effects of intermittent feeding of CEO to decrease methane production by reducing microbial adaptation in an in vitro batch culture system. Growth and rumen fermentation without CEO supplementation (W0_NE) and with supplementation with 0.8 mL CEO/L rumen volume from week 1 to week 3 (W1_EO, W2_EO, and W3_EO), as well as 2 additional weeks without CEO (W5_NE), were examined in 5 rumen-fistulated Hu sheep. Rumen fermentation and gas production of three substrates, corn meal (CM), Chinese wild rye hay (WH), and mixed feed (MF) of WH + concentrate (2:1, dry matter basis), and three doses of CEO (0, 0.8 and 1.6 mL/L) were tested in rumen fluid collected from W0_NE, W1_EO, W3_EO, and W5_NE in vitro. The results showed the CEO had no significant effects (P > 0.05) on body weight, average daily gain, dry matter intake and total-tract apparent digestibility. The CEO altered nitrogen metabolism and was characterized by reductions (P < 0.01) of the concentrations of blood urea nitrogen and rumen ammonia nitrogen. CEO decreased the concentrations of total and individual volatile fatty acids as well as the acetate to propionate ratio in vivo (P < 0.01). Anti-methanogenic effects of CEO were observed in W1_EO (P < 0.05) without additional CEO supplementation, but they were only observed in W3_EO and W5_NE with additional CEO supplementation. These results suggest that CEO introduce selective pressure on rumen microbes and induce methanogenesis adaptation in microbial communities. Intermittent feeding of CEO might be a potential strategy to decrease methane production by reducing the ability of microbes to adapt.

Effect of calcium lignosulfonate supplementation on metabolic profiles of confined lambs.

This study aimed to evaluate the effect of calcium lignosulfonate associated with whole cottonseed in high-concentrate diets for sheep. Eight Dorper crossbred sheep with an average live weight of 42.5 ± 1.70kg were assigned to two 4 × 4 Latin squares. The following experimental diets were evaluated: control diet (without calcium lignosulfonate) and diets with inclusion of 50, 100, and 150g of calcium lignosulfonate/kg fresh matter. Diets were composed of soybean meal, groundcorn, and whole cottonseed. Feed intake, digestibility, metabolic characteristics, and feeding behavior were evaluated. The intake of nutritional components did not show significant differences as a function of the lignosulfonate levels in the diet; however, the increase in calcium lignosulfonate levels linearly decreased the dry matter digestibility. Rumen ammonia nitrogen concentrations decreased linearly as the lignosulfonate levels in the diets were increased. There was no effect of lignosulfonate levels on blood parameters or feeding behavior of the animals. The use of lignosulfonate associated with cottonseed decreases the digestibility of dry matter and the concentration of rumen ammonia nitrogen, but does not change the intake of nutritional components, the blood parameters, or the feeding behavior of sheep.

Effect of diet synchrony on rumen fermentation, production performance, immunity status and endocrine in Chinese Holstein cows

In order to maximise utilisation of nutrients for ruminants, researchers directed the supply of nitrogen and organic matter synchronously to the rumen. In the current research, two experiments were conducted, one using the in situ nylon bag technique and the other using in vivo study. In Experiment 1, dynamic degradation rates of organic matter (OM) and nitrogen of each feedstuff were determined using the in situ nylon bag technique. Accordingly, three diets were formulated with the same chemical components, but differing in synchrony index (0.74, 0.85 and 0.97). Experiment 2 was subsequently carried out in vivo to evaluate the influence of diet synchrony on rumen fermentation, productive performance, immunity status and endocrine in Chinese Holstein cows. Rumen degradability of OM and neutral detergent fibre (NDF) and total tract digestibility of OM were linearly increased with the increase of synchrony index, respectively (P &amp;lt; 0.05). Total volatile fatty acids concentration of rumen fluid was increased linearly with the increase of synchrony index (P &amp;lt; 0.05). Meanwhile, rumen ammonia nitrogen concentration and blood urea nitrogen concentration were decreased in cows with the increase of synchrony index, (P &amp;lt; 0.05). Microbial crude protein production, the efficiency of microbial protein synthesis, and milk protein percentage, were linearly increased with the increase of synchrony index (P &amp;lt; 0.05). Serum concentrations of prostaglandin E2 and immunoreactive fibronectin-γ were linearly decreased with the increase of diet synchrony index (P &amp;lt; 0.05). The aforementioned results implicate that an increase of diet synchrony index could improve diet’s nitrogen utilisation, apparent digestibility of OM, and NDF. Additionally, it could promote rumen fermentation capacity, productive performance and immunity status in dairy cows.