Effects of a source of ruminally degradable protein and monensin on starch digestion in steers fed a high-grain diet

A digestion trial was conducted to evaluate a source of readily degradable protein and the polyether ionophore monesin on the accumulation of peptides and starch digestion in steers fed a high concentrate diet. Four dietary treatments: (1) urea supplement (urea), (2) soybean meal supplement (SBM), (3) urea plus monensin (urea +), and (4) soybean meal plus monensin (SBM +) were compared in a Latin Square 4 x 4 experimental design using four crossbred steers (BW = 280 ± 34 kg). Feeding SBM (P .05). Monensin decreased apparent organic matter digestion in the rumen (P 10). Ruminal starch digestion, however, tended to be decreased by monensin (P =.18). Total tract digestibilities of OM, NDF, ADF and starch were not affected by source of supplemental N or monensin (P \u3e.10). Supplemental SBM increased the flow of undegraded feed-N (P .10). Microbial efficiency calculated as g bac N/kg OM digested in the rumen was not affected by treatments although a numerical increase (P =.15) was observed with monensin. Microbial efficiency calculated as 9 bac N/kg starch digested in the rumen was improved when steers were fed SBM (P .10). Monensin increased the molar proportions of ruminal propionate when steers were fed urea supplemented diets but not when fed SBM supplemented diets (protein by monensin interaction, P \u3c.001). Neither source of dietary N nor monensin influenced ruminal NH3-N concentrations;Results are interpreted to indicate that accumulation of peptides in rumen fluid did not increase starch digestion. This study found no evidence to support in vitro studies that have shown that non-structural carbohydrate fermenting bacteria benefit from peptides present in the medium

Effect of polyethylene glycol on in vitro gas production kinetics of Prosopis cineraria leaves at different growth stages

The aim of this experiment was to determine the effect of polyethylene glycol (PEG) on in vitro gas production (GP) kinetics of Prosopis cineraria leaves at different growth stages. The contents of total phenol (TPH), total tannin (TT) and condensed tannin (CT) were determined. Effects on in vitro organic matter digestibility (OMD), metabolisable energy (ME) and effective dry matter digestibility were assessed by PEG tannin bioassay. No significant differences (P>0.05) were observed for TPH content; however, the stage of flowering had the highest (P0.05) were observed between the growth stage and PEG addition for in vitro GP and its parameters. Addition of PEG increased (P<0.05) GP, OMD and ME in all stages. In conclusion, adding PEG to P. cineraria leaves can improve their nutritive value and could be considered as a potential feed for ruminants

Beneficial effects of plant extracts in ruminant nutrition: A review

Use of antibiotics in animal feeds was banned hence researches on alternative natural products that can modulate ruminal fermentation have been intensified. Plant extracts are considered as natural compounds that can replace antibiotics as safe and sustainable alternatives. Extracts contain some plant secondary metabolites (PSM) that are a natural resource and are largely unexploited in ‘conventional’ animal production systems. They are considered as a source of antinutritional factors and not as a source of exploitable performance-enhancing compounds. Recent and continuing changes to legislation controlling the use of animal feed additives have stimulated interest in bioactive PSM as alternative performance enhancers. Interest is largely on their manipulative role in digestive and absorptive processes of the hindgut. The aim of the present review is to discuss the use of plants and their extracts to manipulate the rumen microbial ecosystem to improve the efficiency of rumen metabolism. The bioavailability of PSM and their actions on peripheral metabolism will be considered with a view to improve animal performance. In order to fully exploit their bioactive properties for the benefit of animal performance, modes of action need to be understood

Influence of polyethylene glycol on in vitro gas production profiles and microbial protein synthesis of some shrub species

The aim was to determine effects of addition of polyethylene glycol (PEG) on in vitro gas production and microbial protein synthesis of the shrub species Acacia constricta, Acacia shaffneri, Calliandra eriophylla, Condalia lycioides, Cordia parvifolia, Larrea tridentata and Mimosa biuncifera, which are commonly consumed by grazing small ruminants in semiarid regions of Mexico despite the abundance of tannins in their foliage. Three individual samples (a minimum of 10 plants of each) of each shrub species were collected from different areas and prepared for chemical and secondary metabolite analysis. In vitro evaluations for each sample of each shrub species were completed in three incubation runs in different weeks using calibrated glass syringes in a 7 × 2 factorial design (i.e., 7 shrub species × 2 treatments with or without PEG). In vitro gas production after 24 and 96 h, partitioning factor (PF), metabolizable energy (ME) content, efficiency of microbial protein synthesis (EMPS), and volatile fatty acids (VFA) were determined. A shrub species × PEG interaction (P<0.05) only occurred for some VFA, such as C3, C4, C4i and C5i, concentrations. Relative to control, addition of PEG increased (P<0.05) the concentrations of individual VFA in A. shaffneri, C. lycioides and C. parvifolia. Interactions between shrub and PEG occurred (P<0.001) for all gas production parameters (i.e., b, k, IVGP24, IVGP48). The fractional rate of gas production and IVGP24 h were highest in A. constricta and lowest (P<0.001) in A. shaffneri. L. tridentata had the highest PF and C. lycioides the lowest. A. constricta had the highest ME content. Purine content and EMPS differed (shrubs × PEG; P<0.001) among shrubs. Microbial protein synthesis was highest in M. biuncifera and lowest in C. eriophylla, while total VFA were highest in C. eriophylla. Incorporation of PEG increased (P<0.001) in vitro fermentation parameters and ME content with L. tridentata and C. lycioides being the highest. PEG also promoted reductions in the EMPS and PF values. In vitro fermentation variables such as fractional rate of gas production, VFA concentrations and EMPS support the potential of A. constricta, C. parvifolia and M. biuncifera as protein and energy sources for small ruminants in semiarid regions of North Mexico. Increments in gas production in these shrub species confirmed the affinity of PEG to bind condensed tannins and reduce EMPS

Effect of adding Salix babylonica Extracts and Exogenous Enzymes to Basal Diets on the Meat Quality of Growing Suffolk Lambs

It was evaluated the effect of adding Salix babylonica L. extracts and exogenous enzymes in combination or individually on meat quality in growing Suffolk lambs. Animals were divided into 4 groups of 4 animals each in a completely randomized design (CRD). Treatments were: (i) Control: basal diet of concentrate (30%) mixture and corn silage roughage (70%); (ii) EZE (exogenous enzymes): basal diet plus 10 g of enzyme (Zado®); (iii) SB (Salix babylonica): basal diet plus 30 ml of S babylonica extracts, and (iv) EZESB (exogenous enzymes + Salix babylonica): basal diet plus 10 g enzyme and 30 ml of S. Babylonica extracts. Lambs were housed in individual cages for 60 days. Extracts were dosed orally while EZE was mixed with concentrate. At the end of the trial, lambs were slaughtered and Longissimus dorsi samples were analysed. Samples were analysed for CP, CF, ash and DM. Meat quality parameters included color, pH, carcass temperature and kidney fat. No significant differences for live weight, chemical composition, as well as hot carcass weight and cold, initial and final temperature and kideny fat. Meat lightness (variable L *) and pHf were improved (P<0.05) with EZESB treatment compared to the other three treatments, and the most optimal pHf four treatments being the most acidic. Lambs fed SB or EZE were not different from the control. In conclusion, a combined administration of EZESB to the basal diet improves meat quality by reducing the pH and increasing its lightness when compared to either EZE or SB, individually

Detection of sensitive and mutant ruminal bacteria isolates from sheep, cattle, and buffalo using 14 therapeutic antibiotics

Subtherapeutic antibiotic use in ruminant feeding to optimize rumen fermentation may lead to residues in meat and milk (6), as well as an increase in the inhibition of ruminal bacterial populations (7). For this reason, in 2006, the European Union banned the use of antibiotics as growth promoters in livestock feeding due to potential toxicities to host animals, potential rumen microbial adaptation, and risk of the presence of residues of these compounds in milk and meat, with potential effects on human health (8).In the present study, sensitive and mutant colonies of some ruminal bacterial species isolated from sheep, cattle, and buffalo were detected. We counted and considered “mutant colonies” the bacterial colonies grown in the clear inhibition zone in the Kirby–Bauer disk diffusion susceptibility test. Detected mutant colonies were higher in buffalo than in cattle and sheep. Duricef and metronidazole caused no mutations in any species. The others formed mutant colonies, where roxithromycin = polymyxin = chloramphenicol = gentamicin streptomycin = piperacillin > erythromycin > vancomycin = cefoperazone = cefotaxime > roxithromycin > polymyxin > chloramphenicol). The number of sensitive isolates of the different ruminant species for all the antibiotics was highest in buffalo, followed by cattle and then sheep (P < 0.05). We could conclude that subtherapeutic antibiotic use in ruminant feeding may lead to the formation of antibiotic-resistant mutant colonies, making their subtherapeutic effect nonexistent

Effects of Exogenous Enzymes and Salix babylonica L. Extract on Cellular Immune Response and its Correlation with Average Daily Weight Gain in Growing Lambs

The aim of this study was to determine the effects of exogenous enzyme (EZ) and Salix babylonica L. (SB) extract on cellular immune response, and its correlation with average daily weight gain (ADG). Twenty Suffolk lambs, 6-8 months of age and average live weight of 24±0.3 kg, were used in a trial which lasted 60 days. The lambs were distributed into 4 groups of 5 lambs each and housed in individual 1.5x1.5 m cages in a completely randomized design. The treatments were: (i) Control; lambs consuming basal diet (BD) only; (ii) EZ; lambs consuming BD plus 10g of EZ (ZADO®); (iii) SB; lambs consuming BD plus 30 mL of SB, and (iv) EZSB; lambs consuming BD plus 10g EZ and 30 mL of SB. Blood samples were collected on days 0, 15, 30, 45 and 60 and analysed for helper T lymphocytes, cytotoxic T limphocytes, granulocytes and monocytes by flow cytometry. Treatments had no effect on parameters measured, but day of sampling had linear and cubic effects on helper T lymphocytes, granulocytes and monocytes (P<0.01) and cubic effects on cytotoxic T lymphocytes (P<0.01). The results suggest that EZ and SB have immunosuppressant effects in the first 15 days, after this effect were immunosuppressive on cytotoxic T lymphocytes and granulocytes, for monocytes the effect was immunostimulant. No there were correlation between ADG and cellular immune response in this experiment

Effect of exogenous xylanase on rumen in vitro gas production and degradability of wheat straw

In Mongolia, the low and seasonal yield of native pastures causes a feed gap between the annual pasture provision and the requirements of grazing ruminants. Therefore, there is a growing need to improve the feeding value of locally available resources such as wheat straw for supplementary feeding. Wheat straw constitutes an important source of roughage for ruminants. It typically contain more than 70% neutral detergent fiber (NDF) on a dry matter (DM) basis, with less than 40% total digestive tract digestibility of the NDF, even under ideal feeding conditions (NRC 2001).The objective of this study was to determine effects of xylanase on in vitro gas production (GP) and in sacco degradability of wheat straw. Rumen fluid was obtained from three Mongolian native goats fitted with permanent rumen cannulas. The trial consisted of five doses (0, 0.5, 1.0, 1.5, 2.0 μL/g of substrate) of a commercial xylanase (Dyadic® xylanase PLUS, Dyadic International, Inc., Jupiter, FL, USA). For the in sacco degradability, different levels of xylanase enzyme were added directly onto 2 g of wheat straw in nylon bags and incubated in the rumen for 3, 6, 12, 24 and 48 h to estimate degradability of wheat straw. Total GP increased (P < 0.001) at all times of incubation at intermediate levels of xylanase. Methane production had a similar pattern at 3 and 12 h of incubation; increased linearly at 24 h of incubation, and was unaffected at 6 and 48 h of incubation. Rumen NH3-N concentration increased linearly at 3 h and the highest values were observed with intermediate enzyme levels. All ruminal volatile fatty acids increased linearly with intermediate levels of the fibrolytic enzyme. The in sacco rate of dry matter degradation decreased linearly (P = 0.020) with increasing enzymes. Intermediate levels of xylanase improved rumen kinetic fermentation and degradability. The outcome of this research indicated that the application of xylanase enzyme could improve in vitro GP fermentation of wheat straw

Effects of cellulase and xylanase enzymes mixed with increasing doses of Salix babylonica extract on in vitro rumen gas production kinetics of a mixture of corn silage with concentrate

Therefore, the objective of this study was to assess the effects of different doses of plant extracts when combined with exogenous fibrolytic enzymes on in vitro ruminal fermentation of a mixture of corn silage with concentrate.An in vitro gas production (GP) technique was used to investigate the effects of combining different doses of Salix babylonica extract (SB) with exogenous fibrolytic enzymes (EZ) based on xylanase (X) and cellulase (C), or their mixture (XC; 1:1 v/v) on in vitro fermentation characteristics of a total mixed ration of corn silage and concentrate mixture (50:50, w/w) as substrate. Four levels of SB (0, 0.6, 1.2 and 1.8 mL g–1 dry matter (DM)) and four supplemental styles of EZ (1 μL g–1 DM; control (no enzymes), X, C and XC (1:1, v/v) were used in a 4×4 factorial arrangement. In vitro GP (mL g–1 DM) were recorded at 2, 4, 6, 8, 10, 12, 24, 36, 48 and 72 h of incubation. After 72 h, the incubation process was stopped and supernatant pH was determined, and then filtered to determine dry matter degradability (DMD). Fermentation parameters, such as the 24 h gas yield (GY24), in vitro organic matter digestibility (OMD), metabolizable energy (ME), short chain fatty acid concentrations (SCFA), and microbial crude protein production (MCP) were also estimated. Results indicated that there was a SB´EZ interaction (P<0.0001) for the asymptotic gas production (b), the rate of gas production (c), GP from 6 to 72 h, GP2 (P=0.0095), and GP4 (P=0.02). The SB and different combination of enzymes supplementation influenced (P<0.001) in vitro GP parameters after 12 h of incubation; the highest doses of SB (i.e., 1.8 mL g–1 DM), in the absence of any EZ, quadratically increased (P<0.05) the initial delay before GP begins (L) and GP at different incubation times, with lowering b (quadratic effect, P<0.0001) and c (quadratic effect, P<0.0001; linear effect, P=0.0018). The GP was the lowest (P<0.05) when the highest SB level was combined with cellulose. There were SB´EZ interactions (P<0.001) for OMD, ME, the partitioning factor at 72 h of incubation (PF72), GY24, SCFA, MCP (P=0.0143), and pH (P=0.0008). The OMD, ME, GY24 and SCFA with supplementation of SB extract at 1.8 mL g–1 DM were higher (P<0.001) than the other treatments, however