Nutrient Disappearance Research Articles

Influence of forage-to-concentrate ratio on the effects of a radiata pine bark extract on methane production and fermentation using the rumen simulation technique.

Climate change and food safety standards have intensified research into plant-based compounds as alternatives to dietary supplements in animal feed. These compounds can reduce enteric methane (CH4) emissions and the formation of ruminal ammonia. This study investigated the effects of radiata pine bark extract (PBE) supplementation on CH4 production, ruminal fermentation parameters, and nutrient disappearance using the rumen simulation technique in diets with different forage-to-concentrate (F:C) ratios. The experimental design was a 22 factorial arrangement of two F:C ratios [70:30 (HF) vs 30:70 (HC)], without or with PBE (2% on a DM basis). Two consecutive incubations were conducted during 15days, with 10days of adaptation, followed by 5days of sampling. Use of PBE decreased ammonia nitrogen (NH3-N, P<0.001) and total volatile fatty acids (VFAs, P=0.019) concentrations, while it increased acetate (P<0.001) and propionate (P<0.001) proportions in both diets. However, CH4 yield [mg/g organic matter (OM) disappeared] tended to be reduced by 33.6% (P=0.088) only in the HF diet supplemented with PBE. The OM disappearance tended to increase (P=0.079) with PBE; hemicellulose disappearance increased in HF and decreased in HC diets (P<0.001), whereas protein disappearance decreased in HF and increased in HC diets (P<0.001). In conclusion, PBE supplementation reduced NH3-N and VFA concentrations in HF and HC diets, but CH4 yield (mg/g OM disappeared) was only reduced in the HF diet. Additionally, nutrient disappearance was dependent on the F:C ratio of the diet, without adverse effects on ruminal fermentation. Hence, the incorporation of radiata PBE into HF diets could serve as an environmentally friendly additive, potentially offering an alternative use for a forestry industry by-product, while beneficially modulating ruminal fermentation.

Use of an extruded microalgae and flaxseed blend product and its effects on ruminal fermentation and nutrient disappearance

Omega-3 fatty acid supplementation has been researched in both the dairy and beef cattle sectors since these fatty acids are considered essential to animal health. Naturally Better Omega-3 Technologies (Manhattan, Kansas) has developed a supplement consisting of an extruded blend of flaxseed and microalgae (FAB; greatOplus) that is fed to livestock to supplement α-linolenic acid (ALA). Our objective was to evaluate how ruminal microbes alter composition of the fatty acids in the FAB, and their post ruminal disappearance. Eleven steers fitted with ruminal and duodenal cannulas were housed in a facility equipped with the Insentec feed and water monitoring system (Hokofarm, Emmeloord the Netherlands). A cross over design was utilized and treatments included a control diet without ALA supplementation and a treatment diet with supplementation of the FAB at 10 % of the diet dry matter. Duodenal flow of total fatty acids (g) was greater (P=0.002) for cattle supplemented with FAB than for non-supplemented cattle. In particular, duodenal flow of ALA (g) was observed to be four times greater (6.3 g/d vs 1.6 g/d; P=0.001) for steers fed the FAB supplement compared to steers fed the control diet. The inconsistent amount of unsaturated fatty acids consumed compared to the apparent duodenal flow of unsaturated fatty acids, indicates that substantial biohydrogenation of the FAB occurred in the rumen. Supplementing steers with FAB increased the apparent duodenal flow of ALA however, substantial biohydrogenation of the ALA likely occurs and must be taken into consideration when feeding this FAB to increase ALA consumption in cattle.

Drying Methods for Black Soldier Fly (Hermetia illucens) Larvae as a Feed Ingredient for Pigs Affect In Vitro Nutrient Disappearance

The objective of the present research was to determine the nutrient utilization of full-fat black soldier fly larvae (Hermetia illucens; BSFL), which were processed by various drying methods, using in vitro procedures for pigs. Four sources of BSFL were prepared using various drying methods: (1) hot-air drying at 65 °C for 24 h; (2) microwave drying at 700 W for 5 min, three times; (3) freeze drying at −40 °C for 72 h; (4) infrared drying at medium infrared region (ranged from 2.0 to 6.0 μm) and at 95 °C for 12 min. In vitro ileal disappearance (IVID) of nutrients in the BSFL was measured using a procedure simulating the nutrient digestion and absorption in the stomach and small intestine of pigs. In vitro total tract disappearance (IVTTD) of nutrients in the BSFL was also measured using a procedure that simulated the total intestine of pigs. The contents of dry matter, ether extract, and crude protein in the dried-BSFL ranged from 94.6 to 96.8%, 49.2 to 52.8%, and 30.0 to 36.8%, respectively, on an as-is basis. Microwave drying resulted in a greater (p &lt; 0.05) IVID of dry matter in BSFL, compared with the freeze drying or infrared drying method, which caused the least IVID of dry matter. Hot air-dried BSFL, microwave-dried BSFL, and freeze-dried BSFL had a greater (p &lt; 0.05) IVID of crude protein and a greater (p &lt; 0.05) IVTTD of dry matter and organic matter, compared with infrared-dried BSFL. In conclusion, the hot-air drying, microwave drying, and freeze drying of full-fat black soldier fly larvae resulted in fairly comparable and relatively high nutrient digestibility based on the present in vitro study for pigs. However, the infrared drying method impaired nutrient utilization of full-fat black soldier fly larvae for pigs.

A New Strain of Saccharomyces cerevisiae in Diets of Lactating Holstein Cows Improved Feed Efficiency and Lactation Performance

Abstract This study compared the effects of feeding a new strain of Saccharomyces cerevisiae HSA2020 with a commercial strain on in vitro rumen fermentation and production performance of dairy cows. Permeate was used as a substrate for the laboratory production of the new strain of S. cerevisiae after the hydrolysis by β-galactosidase (5000 µ/mL at 37°C). Two experiments were conducted: in Experiment 1, the effects of three levels (1, 2 and 3 g/kg dry matter) of S. cerevisiae on in vitro ruminal fermentation kinetics were evaluated. In Experiment 2, for 60 days, sixty multiparous Holstein cows (639±24.8 kg BW, 3±1 parity, 7±1 days in milk, with a previous milk production of 23±2.0 kg/d) during the previous lactation, were randomly assigned to 3 treatments in a completely randomized design. Cows were fed without any additives (control treatment) or supplemented with 2 g/kg feed daily of laboratory produced (PY) or commercial (CY) S. cerevisiae. In Experiment 1, inclusion of PY and CY increased (P&lt;0.05) gas production, propionate, and nutrient disappearance, while decreased (P&lt;0.05) methane production and protozoal count. Moreover, in Experiment 2, PY followed by CY increased (P&lt;0.01) nutrient digestibility, and serum concentrations of total protein, albumin, and glucose (P&lt;0.05). Higher daily milk yield, and milk energy output were observed with PY and CY without affecting concentrations of milk components or milk fatty acid profile. Compared to control, increased feed efficiency was observed with PY and CY. Compared to PY, CY increased serum concentrations of urea-N and decreased triglycerides, while PY decreased serum aspartate transaminase and increased concentration of conjugated linoleic acids in milk. In early lactating cow diets, both strains of S. cerevisiae improved production performance at 2 g/kg, and minimal differences between strains were found.

In Vitro Evaluation of Chito-Oligosaccharides on Disappearance Rate of Nutrients, Rumen Fermentation Parameters, and Micro-Flora of Beef Cattle.

The study aimed to investigate the effect of dietary chitosan oligosaccharides (COS) meal levels on the nutrient disappearance rate, rumen fermentation, and microflora of beef cattle in vitro. A total of 24 fermentation tanks were randomly divided into four treatments containing 0% COS (CON), 0.02% COS, 0.04% COS, and 0.08% COS for an 8-day experiment period, with each treatment comprising six replicates. The disappear rates of DM, CP, EE, and total gas production were quadratically increased with increasing COS levels. The disappear rates of DM, CP, EE, and ADF were greatest, whereas the total gas production was lowest in the 0.08% COS group. The pH, NH3-N, MCP, the content of propionate, isobutyrate, butyrate, valerate, and the A/P were quadratically increased with increasing COS levels, while the A/P were linearly decreased. The pH, MCP, and the content of propionate, and butyrate were highest, whereas the NH3-N and the content of acetate, isobutyrate, valerate, and the A/P were lowest in the 0.08% COS group. Microbiomics analysis showed that the rumen microbial diversity was not altered between the CON and the 0.08% COS group. However, the relative abundance of Methanosphaera, Ruminococcus, Endomicrobium, and Eubacterium groups was increased, and the relative abundance of pathogenic bacteria Dorea and Escherichia-Shigella showed a decrease in the 0.08% COS group. Overall, the 0.08% COS was the most effective among the three addition levels, resulting in an increase in the disappearance rate of in vitro fermented nutrients and improvements in rumen fermentation indexes and microbial communities. This, in turn, led to the maintenance of rumen health.

PSI-13 Digestible and metabolizable energy concentrations in soybean meal, fermented soybean meal, and soy protein concentrate fed to nursery pigs

Abstract Accurate information of energy concentrations in protein supplements is critical in formulating diets for nursery pigs. Soybean products are widely used in nursery pig diets due to the high crude protein (CP) concentrations. The objective of the present study was to determine the digestible (DE) and metabolizable energy (ME) in soybean meal (SBM, 48.5% CP), 3 sources of fermented SBM (FSBM-A, FSBM-B, and FSBM-C; 52.6% CP, 55.1% CP, and 49.8% CP, respectively), and soy protein concentrate (SPC, 58.4% CP) fed to nursery pigs. Twelve barrows with an initial body weight of 8.7 kg (standard deviation = 0.5) were individually housed in metabolism crates. A replicated 6 × 4 incomplete Latin square design with 12 animals, 6 experimental diets, and 4 periods was employed. A basal diet contained 96.9% corn as the sole source of energy. The experimental diets were prepared by replacing the basal diet with SBM at 31%, FSBM-A at 27%, FSBM-B at 26%, FSBM-C at 29%, and SPC at 24%. Each period consisted of a 4-d adaptation period and a 4-d collection period. The marker-to-marker procedure was used for the quantitative collection of feces. Urine was collected for 96 h. The difference procedure was employed to calculate the DE and ME values of the soybean ingredients. Additionally, a 3-step in vitro assay was conducted to determine in vitro total tract disappearance of nutrients in the ingredients. The DE concentrations in FSBM-A (4,171 kcal/kg as-fed), FSBM-B (4,111 kcal/kg as-fed), FSBM-C (4,027 kcal/kg as-fed) and SPC (3,999 kcal/kg as-fed) were greater (P &amp;lt; 0.05) than that in SBM (3,724 kcal/kg as-fed). The ME concentrations in FSBM-A (3,883 kcal/kg as-fed) and FSBM-B (3,841 kcal/kg as-fed) were greater (P &amp;lt; 0.05) than that in SBM (3,528 kcal/kg as-fed) but did not differ from those in FSBM-C (3,728 kcal/kg as-fed) or SPC (3,767 kcal/kg as-fed). The DE:gross energy (GE) was greatest (P &amp;lt; 0.05) in FSBM-B but lowest (P &amp;lt; 0.05) in SBM with intermediate ratios for other 3 ingredients whereas the ME:GE and ME:DE were not different among the 5 ingredients. The in vitro total tract disappearance of dry matter and organic matter in SPC was less (P &amp;lt; 0.05) than that in other ingredients. In conclusion, fermented soybean meal and soy protein concentrate contain greater energy concentrations compared with soybean meal.

PSVI-5 Extruded blend of Nannochloropsis oculata microalgae and flaxseed and its effects on ruminal fermentation and nutrient digestion

Abstract Omega-3 fatty acids are essential nutrients for mammals, and are required for cellular growth and synthesis of numerous cellular signaling molecules. NBO3 Technologies, LLC (Manhattan, KS) has developed an omega-3 supplement consisting of an extruded blend of flaxseed and Nannochloropsis oculata microalgae (GreatOplus; GOP). Our objective was to evaluate effects of GOP on dry matter intake (DMI), water intake (WI), ruminal metabolism, and apparent total tract nutrient disappearance in cannulated Holstein steers (n = 11; initial body weight 586.4 ± 49.7 kg). Treatments consisted of backgrounding diets (40% roughage, 60% concentrate) containing 0% (CON) or 10% GOP (dry basis). Feed and water intake were recorded using an Insentec Roughage and Water monitoring system (Hokofarm Group; Emmeloord, The Netherlands). Steers were utilized in a cross-over design with two 19-d periods. Each period consisted of a 15-d adaptation phase and a 4-d collection phase. Ruminal contents, duodenal digesta, and feces were collected at 8-h intervals for 4 d starting at 1000 h on d 16. The sampling schedule was advanced by 2 h with each subsequent sampling day, thus generating a 24-h profile at 2-h intervals post-feeding over the 4-d sampling phase. Titanium dioxide (15 g) was dispensed directly into the rumen of each steer 15 min before feeding and to estimate apparent ruminal flow and fecal excretion of nutrients. There was a Treatment X Day interaction for DMI (P &amp;lt; 0.001); DMI was greater for steers fed GOP some of the days during the adaptation phase compared with steers fed the control diet, but intakes were similar during the collection phase. Ruminal fluid pH, ruminal ammonia concentration, and WI were not affected by treatment (P &amp;gt; 0.10). As expected, ruminal outflows of total fatty acids (195.6 vs 338.1 g/d for CON and GOP, respectively) and α-linolenic acid (ALA; 1.6 vs 6.3 g/d, respectively) were greater for steers fed GOP compared with steers fed CON (P &amp;lt; 0.05); however, ruminal disappearance (i.e., biohydrogenation) of ALA was extensive, with only 8% and 4.7% of ALA intake exiting the rumen for CON and GOP, respectively. Apparent total tract digestion of organic matter was not impacted by diet (P &amp;gt; 0.20; 78.1 and 76.8% for CON and GOP, respectively). Supplementing an extruded blend of flaxseed and microalgae can effectively increase the amount of α-linolenic acid available for absorption in the small intestine, but overall recovery of dietary α-linolenic acid is relatively low due to extensive biohydrogenation by microbes within the rumen.

Novel oxidising feed additives reduce in vitro methane emissions using the rumen simulation technique

Enteric methane (CH4) produced by ruminant livestock is a potent greenhouse gas and represents significant energy loss for the animal. The novel application of oxidising compounds as antimethanogenic agents with future potential to be included in ruminant feeds, was assessed across two separate experiments in this study. Low concentrations of oxidising agents, namely urea hydrogen peroxide (UHP) with and without potassium iodide (KI), and magnesium peroxide (MgO2), were investigated for their effects on CH4 production, total gas production (TGP), volatile fatty acid (VFA) profiles, and nutrient disappearance in vitro using the rumen simulation technique. In both experiments, the in vitro diet consisted of 50:50 grass silage:concentrate on a dry matter basis. Treatment concentrations were based on the amount of oxygen delivered and expressed in terms of fold concentration. In Experiment 1, four treatments were tested (Control, 1× UHP + KI, 1× UHP, and 0.5× UHP + KI), and six treatments were assessed in Experiment 2 (Control, 0.5× UHP + KI, 0.5× UHP, 0.25× UHP + KI, 0.25× UHP, and 0.12× MgO2). All treatments in this study had a reducing effect on CH4 parameters. A dose-dependent reduction of TGP and CH4 parameters was observed, where treatments delivering higher levels of oxygen resulted in greater CH4 suppression. 1× UHP + KI reduced TGP by 28 % (p = 0.611), CH4% by 64 % (p = 0.075) and CH4 mmol/g digestible organic matter by 71 % (p = 0.037). 0.12× MgO2 reduced CH4 volume by 25 % (p > 0.05) without affecting any other parameters. Acetate-to-propionate ratios were reduced by treatments in both experiments (p < 0.01). Molar proportions of acetate and butyrate were reduced, while propionate and valerate were increased in UHP treatments. High concentrations of UHP affected the degradation of neutral detergent fibre in the forage substrate. Future in vitro work should investigate alternative slow-release oxygen sources aimed at prolonging CH4 suppression.

107 Bacterial direct-fed microbial mixtures effects on beef cattle ruminal degradability kinetics

Abstract The effects of bacterial direct-fed microbial (DFM) mixtures on beef cattle ruminal degradability were evaluated. Six ruminally cannulated beef steers (BW = 520 ± 30 kg) were used in a replicated 3 × 3 Latin square design and offered a steam-flaked corn-based finishing diet to ad libitum intake during three, 28-d periods. Treatments were: 1) Control (no DFM, lactose carrier only); 2) Treat-A (L. animalis, P. freudenreichii; B. subtilis; and B. licheniformis), at 1:1:1:3 ratio, respectively; totaling 6 × 109 CFU (50 mg)/animal-daily minimum; and 3) Treat-B, the same DFM combination, but with doses at 1:1:3:1 ratio. Bacterial counts were approximately 30% greater than the minimum expected. Pre-dehydrated (55ºC for 72 h) diets and forage substrates were ground (2 mm) and placed into 10 × 20 cm (28 µm) nylon bags (8 and 5 g, as-is respectively). The diet-substrate included a mixture of (DM basis) steam-flaked corn (70%), alfalfa hay (10%), and wet corn gluten feed (20%). The forage-substrate was represented by ‘WW-B Dahl’ Old World bluestem (Bothriochloa bladhii). Substrate in-situ bags were placed within a nylon mesh (with weights) at the ruminal ventral sac, and reversely removed at 0, 2, 4, 8, 12, 20, 32, 48, 64, 72, and 96 h after feeding. Samples were removed, rinsed, and dehydrated for 72 h at 55oC. Residues were composited within period, steer, incubation-time, corrected for residual moisture and were used to fit a first-order kinetics model using the NLIN procedure of SAS (animal = experimental unit). Steers offered Treat-A tended to show an increase on the rate of degradation of NDF (P = 0.15) and ADF (P = 0.10) fractions; increased (P &amp;lt; 0.01) hemicellulose potentially degradable fraction (B); and increased (P = 0.02) the effective degradable fraction of NDF (tendency for ADF, P = 0.08) at pre-established rate of passages of 4, 5, and 6% of the diet-substrate compared with Control, while tending to have a reduced rate of degradation for the overall DM (P = 0.06) and OM (P = 0.08) fractions. When the in-situ bags containing the forage-substrate were incubated, steers offered Treat-A showed an increased (P &amp;lt; 0.01) lag time (T0) for hemicellulose compared with Control, while those offered Treat-B had a decreased (P = 0.02) hemicellulose potentially degradable fraction (B) compared with Control. The effective degradable fraction for hemicellulose at pre-established rate of passages of 4, 5, and 6% tended (P = 0.09) to numerically increase for steers offered Treat-A compared with Control. The combination of bacteria in Treat-A enhanced the ruminal degradation of high-quality fiber components, as indicated by the improvements observed within the more degradable fractions from ingredients used in the diet and the forage substrates. Further assessment is warranted to investigate post-ruminal nutrient disappearance.

Effects of yeast culture and oxalic acid supplementation on in vitro nutrient disappearance, rumen fermentation, and bacterial community composition.

Hemicellulose is an important polysaccharide in ruminant nutrition, but it has not been studied as thoroughly as cellulose. Further research is needed to explore supplements that can improve its digestibility and ruminal buffering effects. Our previous research demonstrated the efficacy of oxalic acid (OA) as an essential nutrient in yeast culture (YC) for improving rumen fermentation performance. Consequently, we conducted in vitro rumen digestion experiments to examine the effects of YC and OA on rumen fermentation and bacterial composition. Two diets containing different levels of hemicellulose were formulated: diet 1 with 10.3% and diet 2 with 17% hemicellulose. Three levels of YC (0.00, 0.625, and 1.25 g/kg) and three doses of OA (0.0, 0.4, and 0.8 g/kg, DM) were added into each diet with a 3 × 3 factorial design. A comprehensive assessment was conducted on a total of 18 experimental treatments at fermentation periods of 0, 6, 12, 24, and 48 h. In the first experiment (diet 1), the supplementation of YC, OA, and their interaction significantly increased in vitro DM disappearance (IVDMD) and NDF disappearance (IVNDFD; p < 0.001). In the second experiment (diet 2), the supplementation of OA and the interaction between YC and OA (p < 0.001) increased IVDMD and IVCPD, but had no significant effects on IVNDFD. The interactions of YC and OA significantly increased ammonia nitrogen (p < 0.001). The production of acetic acid, propionic acid, and total volatile fatty acids (TVFA), and pH levels were significantly higher in treatments supplemented with YC and OA (p < 0.001). YC and OA in both diets significantly altered the rumen bacterial community leading to increased Shannon and Simpson diversity indices (p < 0.001). In both diets, OA supplementation significantly increased the relative abundance of the phylum Bacteroidetes and Prevotella genus. The result also showed a positive correlation between the Prevotella and Selenomonas genera with IVDMD, IVNDFD, propionic acid, and TVFA production, suggesting that these dominant bacteria enhanced nutrient disappearance in the rumen. In conclusion, adding YC and OA resulted in modifications to the bacterial community's composition and diversity, and improved nutrient disappearance. These changes indicate improved rumen fermentation efficiency, which is promising for future in vivo studies.

Effects of heating soybeans on postruminal amino acid bioavailability, performance, and ruminal fermentation in lactating cows.

Soybeans can provide ruminally degradable protein, lipid, and metabolizable amino acid (AA) to lactating dairy cows; however, soy-based trypsin inhibitors can limit protein digestion in nonruminants. Eight ruminally cannulated lactating Holstein cows were used to evaluate the impacts of soy-based trypsin inhibitors on nutrient disappearance, lactation, and plasma AA bioavailability. Treatments were abomasal infusion of 0 or 400g/d casein or a crystalline AA analog of casein with unroasted or roasted soybeans fed at 10% dry matter (DM). Data were analyzed using the MIXED procedure of SAS. Measures of digestion were determined from fecal output determined with acid detergent insoluble ash and urine output determined from measures of urine creatinine. Neither soybean processing (P ≥ 0.20) nor the source of abomasal infusion (P ≥ 0.60) impacted nutrient digestibility. Ruminal ammonia, isobutyrate, and isovalerate were increased (P ≤ 0.01) among cattle consuming unroasted soybeans. Source of infusion did not affect (P ≥ 0.38) ruminal volatile fatty acids or nitrogen metabolism. Ruminal N metabolism was largely unaffected by soybean processing although microbial N efficiency was greater (P < 0.01) among cows fed unroasted soybeans. DM intake and energy-corrected milk were greater (P < 0.01) in cows fed roasted compared to unroasted soybeans. The proportion of fat, protein, lactose, and solids not fat (SNF) in milk did not differ between soybean processing or postruminal AA source, but fat, protein, lactose, and SNF yield was greater (P ≤ 0.01) when cows were fed roasted soybeans because milk yields were greater when cows were fed roasted vs. unroasted soybeans. As expected, infusion of casein or its crystalline AA analog increased plasma essential AA and milk urea nitrogen concentration. The rate of increase in essential AA concentration in plasma was 2.9× greater for casein than for crystalline AA. These data seem to indicate that soy-based trypsin inhibitors have no impacts on postruminal AA bioavailability when fed to cows and that metabolizable protein from casein is greater than from crystalline AA.

Appropriate particle size of rice straw promoted rumen fermentation and regulated bacterial microbiota in a rumen simulation technique system.

The purpose of this study is to reveal the effects of different particle sizes of rice straw on the rumen protozoa count, nutrient disappearance rate, rumen fermentation, and microbial community in a rumen simulation technique (RUSITEC) system. In this experiment, a single-factor random trial design was adopted. According to the different particle sizes of rice straw, there were three treatments with three replies in each treatment. Three kinds of goat total mixed ration (TMR), with the same nutrients were used to carry out a 10 days in vitro fermentation experiment using the rumen simulation system developed by Hunan Agricultural University, including 6 days the pretrial period and 4 days formal period. This study found that the organic matter disappearance rate, concentrations of total volatile fatty acids (VFAs), acetate, propionate, and iso-butyrate were greatest in the 4 mm group (p < 0.05). There were no significant differences in the alpha diversity, among the three groups (p > 0.05). The relative abundance of Treponema and Ruminococcus of the 2 mm group increased; the relative abundance of Butyrivibrio and Prevotella in samples increased in the 4 mm group. In addition, the results of correlation analysis showed that Prevotella and Ruminococcus was positively correlated with butyrate, ammonia-N, dOM and d ADF (p < 0.05) and negatively correlated with valerate (p < 0.05); Oscillospira was positively correlated with valerate (p < 0.01) and negatively correlated with propionate, butyrate, ammonia-N, dOM and dADF (p < 0.05). The present results imply that compared to the other groups, rice straw particle size of 4 mm may improve the disappearance rate of nutrients and promote the production of volatile fatty acids by regulating ruminal microorganisms.

Vegetable By-Products as Alternative and Sustainable Raw Materials for Ruminant Feeding: Nutritive Evaluation and Their Inclusion in a Novel Ration for Calf Fattening.

This research aimed to evaluate the nutritional composition, in vitro digestibility, and gas production kinetics of 15 vegetable by-products generated by the agri-food industry compared with corn silage as a reference raw material. Nutritional characterization and in vitro ruminal fermentation tests were performed to determine in vitro organic matter digestibility and digestible energy values, short-chain fatty acids, and the gas production profile. Results indicate that vegetable by-products were more degradable, more extensively fermented, and fermented at a faster rate than corn silage. Going one step further in the valorization of these by-products in animal feed, the second part of the research aimed to compare the novel ration designed for calf fattening with a conventional one. An artificial rumen unit was used to obtain nutrient disappearance, rumen fermentation parameters, and gas production of rumen digesta. Very slight differences were observed between both experimental rations, with their composition being the main difference. Most of the unitary vegetable by-products and all mixes, as real examples of by-product generation in the agri-food industry, have higher digestibility and a greater nutritional value than corn silage. These by-products showed the potential to be used in ruminant-ensiled rations and could replace part of the ingredients in conventional diets.

Shortening the adaptation of Nellore cattle to high-concentrate diets using only virginiamycin as sole feed additive negatively impacts ruminal fermentation and nutrient utilization.

Feedlot cattle are usually adapted to high-concentrate diets containing sodium monensin (MON) in more than 14 days. However, considering that the dry matter intake DMI is usually lower during adaptation when compared to the finishing period, the use of MON during adaptation may decrease even further the DMI, and virginiamycin (VM) may be an alternative. This study was designed to investigate the effects of shortening the adaptation length from 14 to 9 or 6 days on ruminal metabolism, feeding behavior, and nutrient digestibility of Nellore cattle fed high-concentrate diets containing only VM as the sole feed additive. The experimental design was a 5 × 5 Latin square, where each period lasted 21 days. Five 17 mo-old Nellore yearling bulls were used (415 ± 22 kg of body weight), which were assigned to five treatments: (1) MON (30 mg/kg) and adaptation for 14 days; (2) MON (30 mg/kg) + VM (25 mg/kg) and adaptation for 14 days; (3) VM (25 mg/kg) and adaptation for 14 days; (4) VM (25 mg/kg) and adaptation for 9 days, and (5) VM (25 mg/kg) and adaptation for 6 days. A quadratic effect for adaptation length when only VM was fed was observed for mean pH (P = 0.03), duration of pH below 5.2 (P = 0.01) and 6.2 (P = 0.01), where cattle consuming VM adapted for 9 days had higher mean pH and shorter period of pH below 5.2 and 6.2. Cattle that consumed only MON had a lower concentration of butyrate (P = 0.02) and a higher concentration of propionate (P = 0.04) when compared to those consuming VM and adapted for 14 days. As the adaptation length decreased for animals consuming only VM, the rumen degradability of dry matter (P < 0.01), neutral detergent fiber (P < 0.01), and starch (P < 0.01) decreased; however, protozoa numbers of Entodinium and total protozoa increased. It is not recommended to shorten the adaptation length of these animals to either 6 or 9 days without negatively impacting nutrient disappearance and ruminal fermentation patterns.

Evaluation of stirring time through a rumen simulation technique: Influences on rumen fermentation and bacterial community.

Rumen motility is a key element that influences ruminant nutrition, whereas little is known about the effects of rumen contraction duration on rumen fermentation and ruminal microbiome. We previously reported that proper rotation speed of a rumen simulation technique (RUSITEC) system enhanced rumen fermentation and microbial protein (MCP) production. In the present study, different contraction durations and intervals were simulated by setting different stirring times and intervals of the stirrers in a RUSITEC system. The objective of this trial was to evaluate the influences of stirring time on rumen fermentation characteristics, nutrient degradation, and ruminal bacterial microbiota in vitro. This experiment was performed in a 3 × 3 Latin square design, with each experimental period comprising 4 d for adjustment and 3 d for sample collection. Three stirring time treatments were set: the constant stir (CS), the intermittent stir 1 (each stir for 5 min with an interval of 2 min, IS1), and the intermittent stir 2 (each stir for 4 min with an interval of 3 min, IS2). The total volatile fatty acid (TVFA) concentration, valerate molar proportion, ammonia nitrogen level, MCP density, protozoa count, disappearance rates of dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber, emissions of total gas and methane, and the richness index Chao 1 for the bacterial community were higher (p < 0.05) in the IS1 when compared to those in the CS. The greatest TVFA, MCP, protozoa count, nutrient disappearance rates, gas productions, and bacterial richness indices of Ace and Chao 1 amongst all treatments were observed in the IS2. The relative abundance of the genus Treponema was enriched (p < 0.05) in CS, while the enrichment (p < 0.05) of Agathobacter ruminis and another two less known bacterial genera were identified in IS2. It could be concluded that the proper reduction in the stirring time might help to enhance the feed fermentation, MCP synthesis, gas production, and the relative abundances of specific bacterial taxa.

Supplementing Proteolytic Enzymes Increased the In Vitro Nutrient Effective Degradability and Fermentation Characteristics of Pineapple Waste Silage

Pineapple waste silage (PAS) is an abundant agro-industrial by-product characterized by its high fiber content posing a high potential feed value as roughage for ruminants. Studies on its supplementation with proteolytic enzyme (PE) will help extend its utilization as an alternative nutritive feed source for cattle nutrition. Thus, this study aimed to determine the in vitro nutrient degradability and fermentation characteristics of fiber-rich but low-protein PAS supplemented with different levels of PE. Seven treatments were evaluated in this study: PAS without PE and PAS1 to PAS6, which corresponds to incremental levels of PAS supplementation as follows: 0.1%, 0.2%, 0.3%, 1%, 2%, and 4%. The nutrient disappearance, nutrient effective degradability, and fermentation characteristics such as total gas production, ammonia-nitrogen, and pH values were evaluated in vitro. PAS without added PE showed a comparably good nutritive value (dry matter: 94.30%, neutral detergent fiber: 63.66%, acid detergent fiber: 34.78%) to that of commonly used corn silage in South Korea. With the supplementation of PE in PAS, the PE increased the effective degradability of different nutrients such as dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), organic matter (OM), and crude protein (CP). The effect of PE supplementation on the degradation of nutrients was consistent with improvements in in vitro rumen fermentation characteristics. Supplementing PAS with PE increased the total gas production and decreased the pH values, which are characteristics of heightened fiber degradation and fermentation. The ammonia-N concentration of the in vitro-incubated PAS was moderated by the addition of PE, which is likely due to the decrease in pH or in vitro acidosis and has shown a synergistic protease activity effect on nutrient degradation. Overall, supplementing PAS with PE increased the effective degradability of DM, NDF, ADF, OM, and CP, with the most dramatic effects observed in PAS3 and PAS6 (0.3% and 4%, respectively).

Effects of different heat processing methods of rapeseed on ruminal and post-ruminal nutrient disappearance

Due to improving the nutritive value of oilseeds and changing their digestion site in ruminants, processing, including heat treatment, seems necessary. The present research was conducted to evaluate the effect of applying heat processing such as roasting, microwaving and autoclaving on nutritive values; the amount and rate of degradability in rumen, and the disappearance of rapeseed nutrients in rumen, post-rumen and total tract. This evaluation was performed using mobile nylon bags techniques; three-step method of digestion and protein CNCPS fraction. A completely randomized design was used to investigate the effect of applying heat processing, and SAS software was used to analyze the data. The field Emission Scanning Electron Microscope was used to monitored the effect of heat treatment on surface of rapeseed. The application of heat processing in this research (roasting, microwaving and autoclaving) had no significant effect on the chemical composition of rapeseed. The results obtained from mobile nylon bags method and three-step digestion method showed that raw rapeseed has the highest disappearance of DM and CP in rumen and therefore has a significant difference with processed seeds (P&lt;0.05). Also, the disappearance of DM and CP of processed rapeseed in intestines was significantly higher than raw seed (P&lt;0.05), and this was higher than other processing for autoclaved rapeseed. According to the results obtained from CNCPS protein fractionation, applying heat processing altering protein fractionation (P&lt;0.05). Applying microwave processing has created cracks in the surface of the rapeseed wall, and this condition was not observed in the wall surface of other heated seeds. In general, it can be said that in addition to increasing the digestibility of rapeseed in the entire gastrointestinal tract, applying heat processing reduces its degradability in the rumen and has increased the disappearance of nutrients in the intestine, that it can be stated the digestion site is altered from rumen to intestine, which can prevent the loss of protein sources in ruminant feed.

Energy concentrations and nutrient digestibility of high-fiber ingredients for pigs based on in vitro and in vivo assays

The objective of the present study was to determine energy concentrations and nutrient digestibility of high-fiber ingredients for pigs using in vitro and in vivo assays. In experiment 1, in vitro ileal and total tract disappearance of nutrients in soybean hulls, corn gluten feed, wheat bran, rice bran, and cashew nut testa were determined. Two-step and 3-step in vitro procedures were used to simulate the digestion of nutrients in the gastrointestinal tract of pigs. The coefficient of in vitro ileal disappearance of dry matter (DM) in rice bran was the greatest (P < 0.05) among the test ingredients followed by wheat bran, corn gluten feed, cashew nut testa, and soybean hulls. The coefficient of in vitro total tract disappearance of DM and organic matter in rice bran was also the greatest (P < 0.05) among the test ingredients followed by wheat bran, cashew nut testa, corn gluten feed, and soybean hulls. In experiment 2, in vivo energy values and nutrient digestibility of the same ingredients used in experiment 1 were determined. Twelve barrows with an initial body weight of 57.5 kg (standard deviation = 5.7) were assigned to 6 experimental diets in a replicated 6 × 4 incomplete Latin square design. A basal diet consisted of 750 g/kg corn and 227 g/kg soybean meal (SBM) as the sole energy sources. Four experimental diets were prepared by replacing 400 g/kg of corn and SBM with soybean hulls, corn gluten feed, wheat bran, or rice bran. An additional diet was prepared by replacing 100 g/kg of corn and SBM with cashew nut testa. Each period consisted of a 4-day adaptation period and a 4-day collection period. On an as-fed basis, digestible energy and metabolizable energy concentrations in soybean hulls (2198 and 2242 kcal/kg), corn gluten feed (2317 and 2227 kcal/kg), and wheat bran (2751 and 2679 kcal/kg) were less (P < 0.05) than those in rice bran (3503 and 3459 kcal/kg), but those were greater (P < 0.05) than those in cashew nut testa (352 and 519 kcal/kg). The coefficient of apparent total tract digestibility of DM in wheat bran was greater (P < 0.05) than that in corn gluten feed and cashew nut testa. In conclusion, energy values and nutrient digestibility in rice bran were the greatest among the high-fiber ingredients, whereas cashew nut testa had the lowest values based on the present in vitro and in vivo experiments. In vitro procedures can be a potential alternative method for determining energy digestibility of ingredients for pigs.

PSXIII-B-1 Black Soldier fly Larvae Were More Digestible Than Adult Flies, and Nutrient Disappearance in Black Soldier fly Larvae can be Predicted Using Acid Detergent Fiber Based on in Vitro Assays for Pigs

Abstract The objectives were to evaluate the nutrient utilization of fish meal, black soldier fly (BSF, Hermetia illucens) larvae, and adult BSF meal and to develop equations for estimating in vitro nutrient disappearance of BSF larvae for pigs. Two-step and 3-step in vitro procedures were used to simulate the digestion and absorption of nutrients in the gastrointestinal tract of pigs. In Exp. 1, defatted BSF larva meal had less (P &amp;lt; 0.05) in vitro ileal disappearance (IVID) of dry matter (DM; 81.2% vs. 91.6% and 61.6%) and crude protein (CP; 81.8% vs. 92.2% and 67.2%) and in vitro total tract disappearance (IVTTD) of DM (82.6% vs. 93.6% and 65.7%) and organic matter (OM; 78.1% vs. 91.5% and 63.2%) than fish meal and greater (P &amp;lt; 0.05) values than adult BSF. In Exp. 2, CP concentrations in BSF larvae were negatively correlated with ether extract (r = −0.91) but positively correlated with acid detergent fiber (ADF; r = 0.98) and chitin (r = 0.95). Acid detergent fiber and chitin concentrations in BSF larvae were negatively correlated with IVID of DM (r = −0.98 and −0.88) and CP (r = −0.87 and −0.84) and IVTTD of DM (r = −1.00 and −0.94) and OM (r = −0.99 and −0.98). Equations for in vitro nutrient disappearance of BSF larvae using ADF (% DM) as an independent variable were developed: IVID of CP, % = −0.95×ADF + 95 (r2 = 0.75 and P = 0.058) and IVTTD of OM, % = −2.60×ADF + 115 (r2 = 0.98 and P &amp;lt; 0.01). In conclusion, in vitro nutrient utilization of defatted BSF larva meal was less compared with fish meal but was greater compared with adult flies and in vitro nutrient utilization of BSF larvae can be predicted using ADF as an independent variable.

Modulation of rumen bacterial community and feed utilization in camel and sheep using combined supplementation of live yeast and microalgae

The combination of live yeast and microalgae as feed supplementation could improve rumen fermentation and animal productivity. This study aimed to investigate the impact of a mixture of (YA) yeast (Saccharomyces cerevisiae) and microalgae (Spirulina platensis and Chlorella vulgaris) as feed supplementation on feed intake, rumen disappearance of barley straw, bacteria, and fermentation, blood parameters of camels and sheep. Three fistulated camels and three fistulated rams were fed a concentrates mixture and ad libitum barley straw as a basal diet alone or supplemented with YA mixture. The dietary supplementation improved the feed intake, rumen disappearance of barley straw nutrients, and the blood immunity parameters. The YA supplementation affected rumen fermentation as well as the composition and diversity of rumen bacteria; however, the response to the supplementation varied according to animal species. Principle Coordinate Analysis (PCoA) separated bacterial communities based on animal species and feeding treatment. Phylum Bacteroidetes and Firmicutes dominated the bacterial community; and the dominant genera were Prevotella, RC9_gut_group, Butyrivibrio, Ruminococcus, Saccharofermentans, Christensenellaceae_R-7_group, and Succiniclasticum. Our results suggest positive impacts of YA supplementation in rumen fermentation and animal performance.