Molar Proportion Of Propionic Acid Research Articles

Trace mineral source influences in vitro fermentation characteristics and trace mineral solubility.

Two experiments were conducted to determine: 1) the impact of strained rumen fluid (SRF) alone or SRF with particle-associated microorganisms (PAO) included and dilution on in vitro dry matter digestibility (DMD) and 2) the impact of trace mineral (TM) source on in vitro fermentation characteristics and TM solubility under simulated abomasal and intestinal conditions. In Experiment 1, three cannulated steers were adapted to a diet formulated to meet the nutrient requirements for lactating dairy cows. Strained RF was obtained by straining rumen content through 2 layers of cheesecloth. Half of the remaining digesta was washed with McDougall's buffer and filtered through 2 layers of cheesecloth to obtain PAO. Both SRF and PAO were filtered again through 8 layers of cheesecloth. Strained RF was mixed with either McDougall's buffer (SRF) or PAO (SRF+PAO) at a ratio of 1:2 or 1:4 and incubated at 39°C for 12h using the ground basal diet as the substrate. Digestibility of DM was greater in digestion tubes containing SRF and SRF+PAO at a 1:2 ratio. In Experiment 2, eight steers fitted with ruminal cannula were blocked by body weight and assigned to one of two treatment groups. Treatments consisted of 10mg Cu, 40mg Mn, and 60mg Zn/kg DM from either: 1) sulfate (STM) or 2) hydroxychloride (HTM) sources. Steers were housed in individual pens and fed the same diet as described in experiment 1. Dietary TM treatments were mixed with dried distillers grains and mixed in the diet, by hand, immediately after basal diet delivery. Dietary treatments were fed for 14 d. On day 15, SRF+PAO was collected from each steer (STM-RF and HTM-RF) and used in a series of in vitro crossover experiments. In vitro substrates (S) used were the ground diets consumed by the animals on each treatment (STM-S and HTM-S). Incubations containing HTM-S had greater (P < 0.01) total VFA concentration and propionic acid molar proportions, but lesser (P < 0.01) acetic acid molar proportions than STM-S. Rumen fluid from steers supplemented with HTM had a greater (P < 0.03) total VFA than STM-RF at 24h post incubation. After 12h post incubation, the molar proportion of propionic acid in HTM-RF was lesser (P = 0.04) than STM-RF. After simulated abomasal digestion, soluble Mn concentration in HTM-S was greater (P < 0.01) than STM-S. These data indicate that the source of trace minerals can influence in vitro rumen fermentation characteristics and Mn solubility under simulated abomasal conditions.

Repeated inoculation with rumen fluid accelerates the rumen bacterial transition with no benefit on production performance in postpartum Holstein dairy cows

BackgroundThe dairy cow’s postpartum period is characterized by dramatic physiological changes, therefore imposing severe challenges on the animal for maintaining health and milk output. The dynamics of the ruminal microbiota are also tremendous and may play a crucial role in lactation launch. We aim to investigate the potential benefits of early microbial intervention by fresh rumen microbiota transplantation (RMT) and sterile RMT in postpartum dairy cows. Twelve fistulated peak-lactation dairy cows were selected to be the donors for rumen fluid collection. Thirty postpartum cows were divided into 3 groups as the transplantation receptors respectively receiving 10 L fresh rumen fluid (FR), 10 L sterile rumen fluid (SR), or 10 L saline (CON) during 3 d after calving.ResultsProduction performance, plasma indices, plasma lipidome, ruminal microbiome, and liver transcriptome were recorded. After fresh and sterile RMT, we found that the molar proportion of propionic acid was increased on d 7 in the FR and SR groups and the bacterial composition was also significantly changed when compared with the CON group. A similarity analysis showed that the similarities between the CON group and FR or SR group on d 7 were 48.40% or 47.85%, whereas the similarities between microbiota on d 7 and 21 in the FR and SR groups were 68.34% or 66.85%. Dry matter intake and feed efficiency were not affected by treatments. Plasma β-hydroxybutyrate concentration in the FR group was decreased and significantly different lipids mainly included phosphatidylcholine and lysophosphatidylcholine containing polyunsaturated fatty acids. Hepatic transcriptomics analysis indicated acute-phase response pathways were upregulated in the SR group.ConclusionsOur study suggests that RMT can shorten the transition process of the ruminal microbiota of postpartum dairy cows with no benefit on dry matter intake or feed efficiency. Inoculation with rumen fluid may not be a useful approach to promote the recovery of postpartum dairy cows.Graphical

The Influence of Tannins, Saponins, and Direct Fed Microbials on In Vitro Rumen Fermentation Characteristics and Microbiota

In-vitro experiments were conducted to determine the impact of tannins, saponins, and DirectFed-Microbials (DFM) on rumen fermentation characteristics. Rumen fluid was collected 2h post feeding from three cannulated crossbred (Angus x Hereford) feedlot steers (450±12.2 kg), adjusted to finishing diet. Rumen fluid from all steers were filtered, combined, and mixed with buffer. Vaccine bottles containing ground finishing diet and appropriate treatments were incubated with rumen fluid mixture (39 ˚C). Treatments consisted of 1) Control; 2) Commercial Tannin (TCH); 3) Hydrolysable Tannin (HT); 4) saponin; 5) TCH+DFM; 6) HT+DFM; and 7) Saponin+DFM. At 12 h post incubation, HT+DFM and Saponin+DFM had lesser (P&lt;0.05) molar proportions of acetic acid when compared to all other treatments. Saponin+DFM had greater (P&lt;0.05) molar proportions of propionic acid and a lesser (P&lt;0.05) acetate: propionate ratio when compared to treatments not containing DFM. Dry matter digestibility and pH were greater (P&lt;0.05) for saponin, TCH+DFM, HT+DFM and saponin+DFM, whereas pH was greater in treatments containing DFM compared to the controls. Percent CO2 was lesser (P&lt;0.05) in saponin and THC+DFM in vitro vessels compared to controls. At 18 h post fermentation total VFA concentrations, molar proportions of butyric and valeric acid, and gas cap N2 percentage were greater (P&lt;0.05) in in vitro vessels containing HT+DFM compared to controls. The percentage of CO2 was lesser in in vitro vessels containing HT compared to control and in vitro vessels containing saponin, HT+DFM and Saponin+DFM. At 12 h, alpha and beta diversity of the microbial community between treatments differed (P&lt;0.05). Across all samplesat 18 h of fermentation the genera Sharpea and Dialister were present, however Saponin+DFM and TCH+DFM treatments demonstrated the greatest relative abundance. While Sharpea contribute to rumen biohydrogenation, the presence of genus Dialister indicates association with energy harvesting bacteria and suggests that the inclusion of several of these feed additives allowed shifts of certain bacteria to occur.

Conventional Feed-Grade or Slow-Release Coated Urea as Sources of Dietary Nitrogen for Fattening Lambs.

Twenty-two Assaf male lambs (29.2 ± 0.9 kg live weight and 89 ± 0.2 days of age), distributed in two experimental groups, were used to evaluate the use of either feed-grade conventional urea (Control diet; n = 11) or slow-release urea (SRU diet; n = 11) as sources of dietary nitrogen on animal performance, ruminal fermentation, blood acid-base status, plasmatic metabolic profile, and carcass and meat quality. Animals were housed individually and fed ad libitum. At the end of the fattening period (day 70), the animals were slaughtered to compare the fermentation patterns in ruminal digesta and to evaluate the carcass and meat characteristics. No statistically significant differences (p > 0.05) were observed between treatments in the dry matter intake, final live weight, average daily gain, and feed conversion rate. Regarding the ruminal fermentation parameters, the molar proportion of propionic acid was higher (p < 0.05) and that of butyric acid was lower (p < 0.05) with the SRU than with the Control diet. There were no significant differences (p > 0.05) between experimental treatments in the blood acid-base status and biochemical profile, except for the concentration of urea in plasma, which was significantly (p < 0. 05) greater in SRU than in Control lambs. No statistically significant differences were observed between treatments (p > 0.05) in the carcass and meat characteristics. In conclusion, the use of slow-release urea as a replacement for feed-grade conventional urea in the diet of Assaf fattening lambs, under the experimental conditions of this study, did not improve animal performance and increased the feeding costs.

PSV-12 The Influence of Trace Mineral Source on Rumen Trace Mineral Solubility and In-Vitro Fiber Digestion in Steers Fed a Lactating Dairy Diet

Abstract Eight individually fed fistulated steers (410 ± 10 kg) were used to investigate the impact of trace mineral source on rumen trace mineral solubility and in vitro fermentation characteristics. Steers were sorted by body weight, into two trace mineral (TM) treatment groups (n = 4/treatment). Treatments consisted of TM supplementation at 10 mg Cu, 40 mg Mn, and 60 mg Zn/kg DM from either sulfate TM (STM) or hydroxy TM (HTM) sources. Steers were fed a diet balanced to meet the nutrient requirements (TMR) for lactation dairy cow. Dietary TM treatments were mixed with dried distillers grains and top dressed daily. Rumen contents were collected at 0, 2, and 4 h post feeding on d 1 and 14 of the experiment. Rumen samples were centrifuged at 1,500 × g for 15 min. The supernatant and the digesta pellet were frozen, separately, at −20°C for TM analysis. On d 15 of the experiment, approximately 500 g (wet weight) of rumen contents were collected from each steer 2 hours post-feeding. Strained ruminal fluid (SRF) was obtained by squeezing the rumen contents through 2 layers of cheese cloth. The retained digesta (150 g wet weight) was washed with 2.2 L pre-warmed McDougall’s buffer to remove particle associated microorganism (PAO). The SRF and the PAO were then filtered through 8 layers of cheesecloth, separately, and mixed at a ratio of 1:2 (SRF:PAO). The SRF:PAO mixture for each steer was incubated with the TMR containing HTM and a separate incubation with the TMR containing STM for 0, 12, and 24 h (3 replicate in vitro tubes/animal/TMR treatment) at 39°C under anaerobic conditions. After each incubation time, samples were centrifuged at 1,500 x g. The supernatant was removed and frozen at -20°C for VFA analysis. The digesta pellet was dried at 60°C and DM, NDF, and ADF digestibility determined. Data were analyzed as a completely randomized block design with individual animal as the experimental unit. There was a treatment x day x sample type interaction for rumen Zn (P &amp;lt; 0.04) and Mn (P &amp;lt; 0.03) concentrations. Zinc and Mn concentrations were greater in digesta and lesser in supernatant in STM compared with HTM supplemented animals. Rumen distribution of Cu was not impacted by TM source. In vitro molar proportions isobutyric acid were greater (P &amp;lt; 0.01) in HTM compared with STM supplemented animals, while the molar proportion of propionic acid were greater (P &amp;lt; 0.01) in STM supplemented animals. Total VFA concentration, molar proportions of acetic and propionic acid, and DM, NDF, and ADF digestibility were not impacted by dietary trace mineral source or rumen fluid source. These data may indicate that the source of trace mineral can influence trace mineral solubility in the rumen.

Performance, Methane Emission, Nutrient Utilization, and the Nitrate Toxicity of Ruminants with Dietary Nitrate Addition: A Meta-analysis from In Vivo Trials

This study aims to evaluate the effects of dietary nitrate addition on performance, methane emission, nutrient utilization, and the nitrate toxicity of ruminants by using the meta-analysis methodology from in vivo trials. A total of 38 published papers and 139 studies were used. Parameters observed were feed intake, animal performance, enteric methane emission, and nitrate toxicity. Data were subjected to the mixed model methodology. Nitrate doses or forms were treated as fixed factors, while the different studies were treated as random factors. Results revealed that nitrate supplementation significantly decreased the milk protein content, milk fat content, dry matter intake, gross energy intake, the molar proportion of the propionic acid, methane production, and the metabolism of vitamin A in a linear pattern (p<0.05). Moreover, nitrate addition significantly increased nitrate intake, the molar proportion of the acetic acid, the ratio of acetic acid to propionic acid, hydrogen molecule production, microbial protein synthesis, and nitrite blood levels (p<0.05). However, treatments did not affect the milk yield, final body weight, nitrate retention, and blood methemoglobin. There was a significant interaction among the animal types and the nitrate (forms and doses) on the milk protein content, dry matter intake, rumen pH value, total volatile fatty acids, the molar proportion of propionic acid, NH3 concentration, H2 molecule, microbial protein synthesis, metabolism of vitamin A, and the blood methemoglobin. This concludes that nitrate supplementation is an alternative feed additive for mitigating the enteric methane in ruminants without any adverse effects on animals’ health or performance despite its impact on the feed consumption rate.

Nutrient digestibility, rumen parameters, and (cannabinoid) residues in sheep fed a pelleted diet containing green hemp (Cannabis sativa L.) biomass.

The feeding value for ruminants of green hemp biomass, from the low Δ9-tetrahydrocannabinol (Δ9-THC) variety of Cannabis sativa L., is unknown. Twelve Merino ewes were individually penned and randomly allocated on a stratified liveweight basis to one of two pelleted dietary treatments, control (0% hemp, n = 6) or hemp (42% green hemp biomass, n = 6) that delivered a diet meeting the nutrient requirements of the animals. The experimental period consisted of 17 d dietary and housing adaptation, followed by 7 d total urine and feces collection for determination of apparent nutrient digestibility. A ruminal fluid sample was collected on day 27 and assessed for pH, ammonia, volatile fatty acid (VFA), and cannabinoid concentrations. A blood sample from the jugular vein and incisional subcutaneous fat biopsy from an area around the base of the tail were collected on day 28 with additional fat biopsies taken 35 d and 140 d post-feeding to measure cannabinoids. The dry matter (DM), organic matter (OM), and crude protein (CP) digestibilities, along with total VFA concentration did not differ (P = 0.713) between the two diets; however, acid detergent fiber (ADF) and neutral detergent fiber (NDF) digestibilities (P < 0.001), water intake (P = 0.023), and fecal water output (P < 0.001) were significantly lower for the sheep-fed Hemp. Rumen pH did not vary (P = 0.256) between diets, but ruminal ammonia concentration was significantly lower (P = 0.024) for sheep consuming Hemp. Sheep-fed Hemp had significantly greater molar proportions of butyric (P = 0.039) and hexanoic (P = 0.012) acids and lower molar proportions of propionic acid (P = 0.003). There were no differences between diets for N intake (P = 0.175), fecal N output (P = 0.253), and N balance (P = 0.695), with all sheep in positive N balance; however, there was significantly lower (P = 0.001) urinary N output for sheep-fed Hemp. Cannabidiolic acid (CBDA) and tetrahydrocannabinolic acid (THCA) were detected in plasma of all sheep-fed Hemp. ∆9-tetrahydrocannabinol was present in the subcutaneous fat of four of the six sheep on the final day of being fed Hemp, and in all (six) sheep 35 d post-feeding and one sheep 140 d post-feeding Hemp. No cannabinoids were detected in the corresponding samples taken from the sheep-fed Control. Thus, despite green hemp biomass being nutritionally a suitable feed for ruminants, under current Food Standards in Australia, the presence of these cannabinoid residues restricts its use in ruminant diets.

PSIX-13 The Impact of Saccharomyces Cerevisiae Fermentation Product on in-Vitro Rumen Fermentation Characteristics, gas Production, and Ruminal Microbiome Composition

Abstract The objective of this experiment was to evaluate the effect of Saccharomyces cerevisiae products (NaturSafe) on in-vitro rumen fermentation characteristics and microbial diversity. Three crossbred feedlot steers fitted with rumen cannulae were adjusted to a moderately high-concentrate diet for 28-d. On d-29, 1 L of rumen fluid was collected from each steer and composited. A set of vaccine bottles (n=5/treatment/time + blanks and controls) containing 0.5 g of basal diet plus dietary treatments were filled with 30 ml of rumen fluid-McDougall’s buffer solution (1:1), sealed, and placed in a 39°C water bath. Treatments consisted of 1) Control (no added NaturSafe); 2) NaturSafe-dry (9 g/animal/day equivalent); 3) NaturSafe-dry (12 g/animal/day equivalent); 4) NaturSafe-liquid (14 g/animal/day equivalent); 5) NaturSafe-liquid (21 g/animal/day equivalent); and NaturSafe-liquid (28 g/animal/day equivalent). Samples were collected at 0, 6 and 12 h post-fermentation. No treatment effect on any fermentation parameters was found at 6 h. At 12-h post-incubation, dry matter digestibility (DMD) (P &amp;lt; 0.04) and molar proportions of propionic acid (P &amp;lt; 0.03) were greater for treatments containing NaturSafe compared with control. Molar proportions of acetic acid (P &amp;lt; 0.07), percent CH4 (P &amp;lt; 0.08), and NH3-N (P &amp;lt; 0.06) tended to be lesser and percent CO2 tended (P &amp;lt; 0.07) to be greater for NaturSafe treatments compared with controls. Microbiome 16S rRNA analysis results suggest that microbial communities differed (P &amp;lt; 0.05) between 6 and 12 h post-incubation. Incorporating NaturSafe into fermentation vessels revealed an inverse correlation with NaturSafe concentration and microbial diversity (P = 0.08) and that the overall microbial diversity was altered (P &amp;lt; 0.03) by NaturSafe concentration. The microbial community was not affected by additive type. These data suggest that NaturSafe alters fermentation characteristics and microbial community diversity toward improved rumen efficiency while reducing environmental impact.

Reduction of enteric methane production with palm oil: Responses in dry matter intake, rumen fermentation and apparent digestibility in sheep

The aim of the trial was to assess the effect of palm oil (PO; Elaeis guineensis Jacq.) in a basal ration of low-quality Pennisetum purpureum grass on DMI, enteric CH4 emissions, rumen fermentation and apparent digestibility in hair sheep. Eight non-castrated male Pelibuey sheep with an average live weight (LW) of 28 ± 1.1 kg housed in metabolic crates inside respiration chambers, were used in a replicated 4 × 4 Latin square design. Each period lasted 18 days (13 days for adaptation to handling and rations, and 5 days for measurements of response variables). A control (CON) ration and three PO levels were evaluated: 20, 40 and 60 g/kg as a percentage of dry matter (DM) in the ration. The basal ration had a 70:30 forage:concentrate ratio (DM basis). Individual DMI was measured daily. Measurement of apparent digestibilities of nutrients was carried out by total collection of feces. Samples of rumen liquor were taken postprandial from sheep, subsequently, the molar proportion of VFA was determined. Enteric CH4 production (L/d) was measured using head boxes. Average intakes of DM per day (855 g/d), DM/kgW0.75 (64 g/d), organic matter (OM; 809 g/d) and crude protein (CP; 106 g/d) were not affected by treatment (P > 0.05). Neutral detergent fiber (NDF) and crude fat (CF) intake were reduced linearly (P < 0.05) as the percentage of PO in the ration was increased. Apparent digestibilities of DM, OM and NDF were not affected by the inclusion of PO (P > 0.05). Molar proportion of propionic acid in the rumen increased linearly as the level of PO inclusion in the ration was augmented (P < 0.05). The acetic:propionic acid ratio decreased linearly (P < 0.01) from 2.02 for the control ration to 1.66 for the ration with 60 g/kg PO. Enteric CH4 emissions decreased with increasing levels of PO in the ration (P < 0.01). Energy loss (MJ/d) as CH4 was reduced (P < 0.01), as well as methane energy loss as a proportion of gross energy intake (Ym; P < 0.01) and CH4 emission per year (EF; P < 0.01). Results demonstrate that PO is a promising by-product for mitigating CH4 emissions in hair sheep fed low-quality tropical grasses, with reductions of up to 14.1 %, without negative effects on DMI, nutrient intake and ration digestibility.

Effects of ammonia-treated maize on growth performance of beef cattle

High-moisture cereal grains are often treated with ammonia to prevent spoilage and for perceived animal performance advantages, but there are few reports on the effects of ammonia treatment of cereal on cattle performance. This study was carried out on 101 Charolais cattle to quantify the effects of feeding ammonia-treated maize on the performance of intensively fattened beef cattle. Animals were assigned to 16 pens in two sheds and all animals in each pen were fed on the same diet for 176 d. The cereal in the diets was either ammonia-treated maize (ATM) or untreated maize diet (UTM), formulated to be approximately isoenergetic and isonitrogenous. Cattle fed ATM had a lower feed conversion ratio (FCR) (6.14 ± 0.39 vs 6.49 ± 0.41 kg DM/kg BW; p = 0.011) and tended to have a higher average daily liveweight gain (ADG) (1.60 ± 0.10 vs 1.54 ± 0.10 kg/d; p = 0.060). The pH of the ruminal fluid at slaughter was higher (p < 0.001) in animals that were fed the ATM diet (6.35 ± 0.69) compared to those fed the UTM diet (5.46 ± 0.33). No differences were found in the concentrations of NH3 or total VFA in ruminal fluid between the two groups. The molar proportion of butyric acid from all VFAs was lower in animals fed ATM than UTM (14.69 ± 3.55% and 18.04 ± 2.97% respectively; p = 0.012), and the molar proportion of propionic acid was higher in the ATM than the UTM groups (22.14 ± 1.54% and 19.54 ± 1.72% respectively; p < 0.001). The ratio of acetic acid to propionic acid was significantly lower in animals fed ATM compared to those fed UTM (ATM vs UTM: 2.64 ± 0.26 vs 2.97 ± 0.29; p = 0.0038). Faecal starch was lower in cattle fed ATM than untreated maize (UTM) (14.73 ± 5.65 vs 18.14 ± 4.27% DM; p < 0.001). The pH of faeces in the ATM group was higher than that in the UTM group (4.75 ± 0.19 vs 4.55 ± 0.19; p < 0.001). In conclusion, ammonia treatment of maize resulted in increased ADG and decreased FCR, with reduced faecal starch concentration, suggesting possible gains in efficiency of starch utilisation.

Effects of wood kraft pulp as a partial replacement for roughage on rumen fermentation and productivity in dairy cows.

In this study, we evaluated the partial replacement of roughage with wood kraft pulp (KP) on rumen fermentation and productivity of dairy cows. Eighteen cows were divided into control and KP groups. The KP group started adaptation to KP 3weeks before calving; after calving, they were fed a total mixed ration for 12 weeks, wherein 18% Timothy hay was replaced with KP. The dry matter intake, body weight, and milk yield and composition were similar in the control and KP groups. The average daily rumen pH was higher with KP feeding, and the average daily ruminal temperature remained lower at 16 days after calving (P < 0.05). The concentration of volatile fatty acids remained unaltered, the molar proportion of acetic acid decreased, and the molar proportion of propionic acid increased, indicating a low acetic acid:propionic acid ratio (P < 0.05). Lipopolysaccharide activity in the rumen fluid was higher in the KP group (P < 0.05); however, the rumen microbiota were unaffected. The digestibility of dry matter and neutral detergent fiber increased 12 weeks after calving, whereas excretion of urinary nitrogen decreased (P < 0.05). Partial replacement of roughage with KP did not suppress rumen fermentation and maintained postpartum productivity.

Kinetics on propionic acid catalytic esterification with N-butanol over SBA-15 (santa barbara amorphous-15 material) catalyst

A batch reactor was used to investigate kinetic behaviour of propionic acid withN-butanol over acidic ion-exchange resign SBA-15. The kinetic studies were performed for temperatures ranges 358oK to 388oK then feed varies 1–5 the molar proportions of propionic acid to N-butanol. The response rate was discovered to rise with rising temperature. However, propionic acid equilibrium conversions slightly change the entire reaction temperature suggesting this reaction's impact is negligible. It’s been discovered that propionic acid conversion improves with feed molar ratios rising from 1 to 5. Based on the outcomes of binary adsorption studies, relative sorption between two interacting species is determined. Water > n-butyl propionate > propionic acid > n-butanol follows the severity of adsorption strengths. The kinetic information was associated Langmuir Hinshelwood Haugan Watson modelsto assess kinetic variables for each model, respectively. The LHHW has produced the highest outcomes among these researched models.

Effects of an artificial hay aroma and compound feed formulation on feed intake pattern, rumen function and milk production in lactating dairy cows

The Kempen system is a dairy feeding system in which diet is provided in the form of a compound feed (CF) and hay offered ad libitum. Ad libitum access to CF and hay allows cows in this system to achieve a high DM intake (DMI). Out of physiological concerns, the voluntary hay intake could be increased and the consumption pattern of CF could be manipulated to maintain proper rumen functioning and health. This study investigated the effects of an artificial hay aroma and CF formulation on feed intake pattern, rumen function and milk production in mid- to late-lactating dairy cows. Twenty Holstein–Friesian cows were assigned to four treatments in a 4 × 4 Latin square design. Diet consisted of CF and grass hay (GH), fed separately, and both offered ad libitum, although CF supply was restricted in maximum meal size and speed of supply by an electronic system. Treatments were the combination of two CF formulations – high in starch (CHS) and fibre (CHF); and two GH – untreated (UGH) and the same hay treated with an artificial aroma (TGH). Meal criteria were determined using three-population Gaussian–Gaussian–Weibull density functions. No GH × CF interaction effects on feed intake pattern characteristics were found. Total DMI and CF intake, but not GH intake, were greater (P < 0.01) in TGH treatment, and feed intake was not affected by type of CF. Total visits to feeders per day, visits to the GH feeder, visits to the CF feeder and CF eating time (all P < 0.01) were significantly greater in cows fed with TGH. Meal frequency, meal size and meal duration were unaffected by treatments. Cows fed CHF had a greater milk fat (P = 0.02), milk urea content (P < 0.01) and a greater milk fat yield (P < 0.01). Cows fed TGH had a greater milk lactose content and lactose yield (P < 0.05), and milk urea content (P < 0.01). Cows fed TGH had smaller molar proportions of acetic acid and greater molar proportions of propionic acid compared with UGH. In conclusion, treatment of GH with an artificial aroma increased CF intake and total DMI, but did not affect hay intake. Additionally, GH treatment increased the frequency of visits to both feeders, and affected rumen volatile fatty acid profile. Type of CF did not affect meal patterns, ruminal pH, nor fermentation profiles.

Inoculation of corn silage with Lactobacillus plantarum and Bacillus subtilis associated with amylolytic enzyme supply at feeding. 1. Feed intake, apparent digestibility, and microbial protein synthesis in wethers

The current study aimed to investigate the effects of corn silage inoculation and dietary supplementation with amylolytic enzymes, and their interactions, on feed intake, apparent digestibility, and microbial protein synthesis in wethers. Whole-crop corn forage was ensiled either with water (untreated) or with Lactobacillus plantarum MA 18/5U at 1 × 105 cfu/g fresh forage combined with Bacillus subtilis AT553098 at 1 × 105 cfu/g fresh forage (inoculated). Eight ruminally cannulated Dorper × Santa Inês crossbred wethers were used in a double 4 × 4 Latin square design. Wethers were assigned to one of four diets, as follows: 1) untreated corn silage with no amylolytic enzyme supply (US-NE); 2) untreated corn silage with amylolytic enzyme supply (US-WE); 3) inoculated corn silage with no amylolytic enzyme supply (IS-NE); and 4) inoculated corn silage with amylolytic enzyme supply (IS-WE). α-Amylase (602 dextrinizing units/kg of dry matter (DM)) was supplied to the wethers at total mixed ration delivery. Dietary supplementation with amylolytic enzyme increased (P = 0.045) DM and starch (P = 0.014) intake in wethers fed the US diet (+245 and +136 g/d, respectively), but not in those fed the IS diet. Inoculation of corn silage (P = 0.026) improved organic matter (OM), crude protein (CP), neutral detergent fiber (aNDFom), and gross energy (GE) digestibility by 5.3%, 11.5%, 25.8%, and 7.1%, respectively. Likewise, enzyme supply increased (P = 0.042) the apparent digestibility of DM, OM, CP, aNDFom, and GE by 5.1%, 4.7%, 9.4%, 20.7%, and 6.2%, respectively. Enzyme supply increased the molar proportion of propionic acid (P = 0.002; 24.1 vs. 19.6 mM / 100 mM) in wethers fed the US diet, but not in those fed the IS diet. Enzyme supply decreased microbial N synthesis (P = 0.025; 6.33 vs. 8.05 g/d) when the wethers were fed the IS diet, but not the US diet. In conclusion, despite the improved OM digestibility, dietary supplementation with amylolytic enzyme yielded inconsistent results with respect to feed intake and microbial protein synthesis in wethers fed diets differing in the use of silage inoculant.

Potential of Samanea saman pod meal for enteric methane mitigation in crossbred heifers fed low-quality tropical grass

Pods of Samanea saman have been reported to be effective in mitigating methane (CH4) emissions in ruminants. The aim of this study was to evaluate the effect of inclusion of S. saman pod meal in the ration on feed intake, apparent digestibility, rumen fermentation, rumen degradation, protozoa population, and enteric CH4 emissions in crossbred heifers fed low-quality tropical grass. Four crossbred heifers (Bos taurus × B. indicus) with an average live weight (LW) of 261.5 ± 1.29 kg were used in a 4 × 4 Latin square design with four periods of 23 days (17 days for adaptation and 6 days for measurements of response variables). Levels of inclusion of S. saman ground pods in the ration were 0, 10, 20 and 30% of dry matter (DM). Enteric CH4 emissions were measured using open-circuit respiration chambers. Additionally, rumen degradation of the different components of S. saman pods was assessed. Incorporation of S. saman levels had no effect on dry matter intake (DMI) (P > .05), apparent digestibility of dry matter (DM) and organic matter (OM) (P > .05) nor protozoal count (P > .05). It was found that molar proportion of propionic acid in rumen liquid was increased (P < .05), while that of acetic acid and acetic:propionic ratio was linearly decreased (P < .01) when heifers were supplemented with S. saman. Additionally, emissions of enteric CH4 showed a linear reduction as the inclusion of S. saman in the ration was increased (P = .007). A reduction of 50.9% in L CH4/day and 56.9% in L CH4/kg DM intake was observed at the highest inclusion level of S. saman compared to the control diet (P < .05). Potential degradation of DM of pods of S. saman was 79.6%. It is concluded that, the inclusion of S. saman pods in the ration has the capacity to reduce energy losses in the form of methane emissions in heifers fed low-quality tropical grass.

Ruminal digestibility, microbial count, volatile fatty acids and gas kinetics of alternative forage sources for arid and semi-arid areas as in vitro

Atriplex (Atriplex patula) and plantago (Plantago lanceolata) species are commonly found in grasslands which have arid and semi-arid climatic conditions. The aim of the study was to make comparison of atriplex, plantago and alfalfa (Medicago sativa) herbages in terms of nutrient matter content, gas kinetics, methane production, estimated digestion parameters, ammonia-N, volatile fatty acids (VFAs), total bacteria count and numbers of protozoa. In vitro gas production was carried out for up to 96 h by using the in vitro digestion technique. The molar total VFAs, metabolic energy (ME), net energy lactation (NEL), and organic matter digestibility (OMD) levels, count of total bacteria, number of total ciliate and number of Dasytricha sp., Diplodiniinae and Entodiniinae did not show significant differences between alfalfa and the alternative forages (p >.05). In vitro methane production of atriplex herbage was higher than that of plantago herbage (p <.01). The ruminal ammonia-N concentration of plantago herbage was lower than those of atriplex and alfalfa herbages (p <.001). The individual molar proportions of propionic acid of alfalfa herbage were higher than those of the other forages (p <.001). The results of the present experiment confirmed that A. patula and P. lanceolata, which are appropriate for the flora of the Mediterranean region, can be used as alternative good quality forage plants to alfalfa hay for grazing animals.

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This investigation was conducted to study the effect of protected kapok (Ceiba pentandra) seed oil supplementation upon the in vitro relative proportion of linoleic acid and ruminal fermentation parameters using rumen fluid of Etawah crossbred goat and elephant grass (Pennisetum purpureum) as &nbsp;feed. Research materials used were elephant grass (EG), kapok seed oil (KSO), lactating Etawah crossbred goat (ECG) rumen fluid, potassiumhydroxide (KOH) and calciumchloride(CaCl2). There were two treatment factors, namely KSO supplementation as factor I (S) and protection as factor II (P). The first factor consists of four levels, namely 5% (S1), 10% (S2), 15% (S3) and without KSO supplementation (S0), while the second factor consists of 5 levels, namely: 0% (P0), 25%(P1), 50% (P2), 75% (P3) and100% (P4), thus there were 15 combinations of treatment and one control (S0P0). Measured variables consisting of: in vitro neutral detergent fiber&nbsp; digestibility (IVNDFD), the molar proportion of acetic acid, propionic acid, butyric acid, acetic acid: propionic acid (A/P) ratio, the relative proportion of linoleic acid, stearic acid and ruminal lipid iodine number (IN). The results showed that 5% of unprotected KSO supplementation increased the molar proportion of propionic acid from 21.30% in the EG without supplementation becomes to 23.67% (P &lt;0.05) without any negative effect on IVNDFD. Supplementation of protected KSO at &nbsp;10 and 75% protection level &nbsp;increased (P &lt;0.05) the molar proportion of propionic &nbsp;acid significantly (35.49%) with A / P ratio: 1.68 without significant IVNDFD variation. Increasing levels of KSO supplementation (up to 15%) increased the relative proportion of ruminal linoleic acid, followed by increasing in iodine number. The combination between KSO supplementation and protection &nbsp;increased the ruminal linoleic acid relative proportion and lipid iodine number, were 47.14% and 51.09, respectively. The KSO supplementation at the level of 10% with 75% protection level can resulted in the same proportion of linoleic acid to 15% KSO supplementation with 75% protection level (45.39 and 46.50 and 97%, respectively) with higher IVNDFD (P&lt;0.05), namely 50.97 vs. 45.44%). &nbsp; Key words: Kapok seed oil, protection, linoleic acid, ruminal fermentability, elephant grass, Etawah crossbred goat, in vitro, linoleic&nbsp; acid.

Effects of niacin supplementation (40 weeks) and two dietary levels of concentrate on performance, blood and fatty acid profiles of dairy cattle

The present study was conducted to investigate the effects of 24 g niacin (nicotinic acid (NA)) supplementation over 40 weeks with two forage-to-concentrate ratios (60% concentrate vs. 30% in the total diet) on performance variables of energy metabolism such as plasma concentrations of non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHB), glucose and nicotinamide (NAM), and the fatty acid profile in rumen fluid. In a 2 x 2 factorial design, 64 German Holstein cows were divided postpartum into four dietary groups: i) 60% concentrate supplemented with 24 g NA (Group 60 + NA); ii) 60% concentrate without NA (Group 60−); iii) 30% concentrate with 24 g NA (Group 30 + NA) and iv) 30% concentrate without NA (Group 30−). The experiment started on the day of calving and continued for 40 weeks. Niacin supplementation did not affect milk yield or composition. The plasma niacin content increased in the supplemented groups, especially Group 30 + NA. Niacin supplementation led to decreased plasma glucose concentrations. The interaction of concentrate x niacin enhanced the molar proportion of propionic acid in rumen fluid in Group 60 + NA. Total short-chain fatty acid (SCFA) concentrations were increased by level of concentrate, niacin supplementation and the interaction, concentrate x niacin. Plasma levels of NEFA and BHB remained unaffected. In sum, concentrate level, niacin supplementation and the interaction of concentrate x niacin increased plasma NAM concentration, whereas plasma glucose concentration was decreased by niacin supplementation. Keywords: Milk performance, nicotinic acid, plasma metabolites, rumen fluid composition

Effects of Supplementation of Mulberry (&lt;i&gt;Morus alba&lt;/i&gt;) Foliage and Urea-rice Bran as Fermentable Energy and Protein Sources in Sheep Fed Urea-treated Rice Straw Based Diet

A digestibility study was conducted to evaluate the effects of supplementing mulberry foliage and urea rice-bran as a source of fermentable energy and protein to 12 sheep fed diets based on urea-treated rice straw (TRS). The three dietary treatments were: T1, TRS with mulberry; T2, TRS with 50% mulberry replaced with rice bran and urea; and T3, TRS with rice bran and urea. The study was arranged in a completely randomized design with four replications for each treatment. The sheep were fed one of the three diets and the supplements were offered at 1.2% of the body weight (BW) and the TRS was provided ad libitum. There were no differences (p>0.05) among the three treatment groups with respect to dry matter (DM) intake (76.8±4.2 g/kg BW0.75) and DM, organic matter (OM), and crude protein (CP) digestibility (55.3±1.22; 69.9±0.85; 46.3±1.65% respectively for DM, OM, and CP). The digestibility of fiber (neutral detergent fiber [NDF] and acid detergent fiber) was significantly lower (p<0.05) for T3 (46.2 and 46.6 respectively) compared to T1 (55.8 and 53.7 respectively) and T2 (54.1 and 52.8 respectively). Nitrogen (N) intake by sheep on diet T3 was significantly (p<0.05) higher than sheep fed diet T1. However, N balance did not differ among the three diets (3.0±0.32 g/d). In contrast, the rumen ammonia (NH3-N) concentrations in sheep fed T2 and T3 were significantly (p<0.05) higher than in sheep fed T1. The NH3-N concentrations for all three diets were above the critical value required for optimum rumen microbial growth and synthesis. Total volatile fatty acid concentrations were highest (p<0.05) in T1 (120.3 mM), whilst the molar proportion of propionic acid was highest in T3 (36.9%). However, the microbial N supply in sheep fed T1 and T3 was similar but was significantly (p<0.05) higher than for sheep fed T2. It was concluded that mulberry foliage is a potential supplement of fermentable energy and protein for sheep fed TRS based diet. The suggested level of supplementation is 1.2% of BW or 32% of the total diet since it resulted in similar effects on the intake of DM, OM, and NDF, digestibility of DM, OM, and CP, N utilization and microbial supply when compared to rice bran and urea supplementation.

Effects of feeding crude glycerin on performance and ruminal kinetics of lactating Holstein cows fed corn silage- or cottonseed hull-based, low-fiber diets

The objective was to determine whether crude glycerin could partially replace concentrate ingredients in corn silage- or cottonseed hull-based diets formulated to support minimal milk fat production without reducing milk production. Multiparous, lactating Holstein cows (n=24; 116±13d in milk) were assigned to dietary treatments arranged in a 2×3 factorial design; namely, 2 dietary roughage sources (cottonseed hulls or corn silage) and 3 dietary concentrations of glycerin [0, 5, or 10% on a dry matter (DM) basis]. Four different cows received each dietary treatment in each of 3 periods such that each diet was evaluated using 12 cows. Crude glycerin, produced using soybean oil, contained 12% water, 5% oil, 6.8% sodium chloride, and 0.4% methanol. Glycerin partially replaced ground corn, corn gluten feed, and citrus pulp. Diets of minimum fiber concentrations were fed to lactating dairy cows and resulted in low concentrations of milk fat (averaging 3.12% for cows fed diets without glycerin). The effects of glycerin on cow performance and ruminal measurements were the same for both dietary roughage sources with the exception of feed efficiency. Replacing concentrate with crude glycerin at 5% of dietary DM increased DM intake without increasing milk yield. Concentration and yield of milk fat were reduced when glycerin was fed at 10% of dietary DM. This was accompanied by a 30% reduction in apparent total-tract digestion of dietary neutral detergent fiber. Crude glycerin affected the microbial population in the rumen as evidenced by increased molar proportions of propionic, butyric, and valeric acids and decreased molar proportions of acetic acid. Efficiency of N utilization was improved as evidenced by lower concentrations of blood urea nitrogen and ruminal ammonia-N. Cows fed cottonseed hull-based diets consumed 5.3kg/d more DM but produced only 1.7kg/d more milk, resulting in reduced efficiency. Increased production of ruminal microbial protein, molar proportion of propionic acid, and passage of ruminal fluid resulted from feeding the cottonseed hull- versus corn silage-based diets, although apparent digestibilities of DM and neutral detergent fiber were reduced. Replacing 5 and 10% of concentrate ingredients with crude glycerin improved efficiency of 4% fat-corrected milk production when corn silage-based diets were fed but decreased it when cottonseed hull-based diets were fed.