Evaluating the effects of direct-fed microbial supplementation on the performance, milk quality and fatty acid of mid-lactating dairy cows.

BACKGROUND: The objective of the experiment was to investigate the effect of a mixture of direct-fed microbial (DFM) on feed intake, nutrient digestibility, milk yield and composition, milk fatty acid and blood parameter in crossbred mid-lactating cows. METHODS: Twenty-four crossbred Holstein cows (body weight = 650±15 kg; days in milk = 100±20; daily milk yield = 25±3 kg) were used in a completely randomized design with three treatments: (1) CON, without DFM; (2) LS, inoculation with Lactobacillus fermentum (4.5 × 108 CFU/day) plus Saccharomyces cerevisiae (1.4×1010 CFU/day); and (3) LSM, inoculation with LS plus Megasphaera elsdenii (4.5 × 108 CFU/day). All animals received the same ration with 45.7% forage and 54.3% concentrate. RESULTS: Results showed that the highest feed intake was observed in treatments LS and LSM (p = 0.02). Compared with the CON, milk production, 4% fat-corrected milk, energy-corrected milk, fat (kg/day), protein (kg/day) and lactose (kg/day), FE and percent of fat were increased (p<0.05) by LSM, but unaffected by LS. Also, compared with the CON, both LS and LSM increased antioxidant activity (p<0.05). The concentration of C18:2c n-6 increased significantly in treatment LSM compared with the CON (p = 0.003). The concentration of C20:0 increased significantly in treatment LS compared with the CON (p = 0.004). The highest concentrations of insulin, glucose, triglyceride and cholesterol were observed by LSM (p<0.05). Compared with the CON, both LS and LSM increased blood monocyte, neutrophil, eosinophil and basophil (p<0.05), and blood lymphocyte was increased (p = 0.02) only by LSM. CONCLUSIONS: The results of the research showed that the use of DFMs had no effect on the digestibility, microbial load and the major part of fatty acids in milk. However, it improved feed intake, milk yield and antioxidant activity of milk and also increased the milk concentration of C18:2 n-6.

Effect of dietary Conocarpus erectus leaves and branches on milk yield, quality, antioxidant activity and fatty acid profile, and blood parameters of Najdi dairy goats.

To investigate the effect of Conocarpus erectus tree leaves and branches as a partial replacement of forage on milk yield and components, blood and rumen parameters of goats, 16 Najdi goats were used in a completely randomized design with 2 treatments (CON, without C. erectus; CE, contains C. erectus). The basic ratio consisted of 60% concentrate and 40% forage. In treatment CE, 22.5% of the forage (alfalfa hay and wheat straw) was replaced with C. erectus leaves and branches. The lowest amount of dry matter intake and digestibility were observed in the treatment CE (P < 0.05). The amount of milk production significantly increased (P = 0.01) in the treatment CE. The total count did not differ between treatments, but the highest amount of Lactobacillus spp. (P = 0.01) and the lowest amount of mold (P = 0.01) were observed in the treatment CE. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity decreased on days 15 (P = 0.02) and 31 (P = 0.01) of the experiment in treatment CE. The highest amount of short-, medium-, and long-chain fatty acids and also conjugated fatty acids were observed in the treatment CE (P < 0.05). Also, the concentration of fatty acids C16:0 and C18:0 was lower in the treatment CE (P < 0.05). The lowest amount of triglycerides, blood urea nitrogen, cholesterol, low-density lipoprotein, high-density lipoproteins, serum glutamic pyruvic transaminase, and serum glutamic oxaloacetic transaminase were observed in the treatment CE (P < 0.05). Ruminal pH and ammonia-N concentration were not affected by experimental treatment (P > 0.05). According to the results, the use of C. erectus leads to improved milk production and fatty acid profile, antioxidant activity, and microbial load.

Effect of microbial feed additives on growth performance, microbial protein synthesis, and rumen microbial population in growing lambs.

Arabi lambs (n =28; body weight = 24 ± 3.7 kg; average age = 120 ± 8 days) were used to investigate the effect of microbial additives on growth performance, microbial protein synthesis and rumen microbial population of fattening lamb based on completely randomized design. Four treatments were studied: (1) control (without additive; CON); (2) Lactobacillus fermentum and L. plantarum (FP); (3) Saccharomyces cerevisiae (SC) plus FP (SCFP); and (4) Megasphaera elsdenii plus SCFP (MSCFP). Lambs were inoculated before morning feeding (daily oral dosed) with a 50 mL microbial suspension as follows: FP, 50 mL bacterial suspension containing 4.5 × 108 colony-forming unit per day (cfu/d) of L. plantarum and L. fermentum (in ratio 50:50); SCFP, 50 mL microbial suspension containing 4.5 × 108 cfu/d FP and 1.4 × 1010 cfu/d SC; MSCFP, 50 mL microbial suspension containing 4.5 × 108 cfu/d Me, 4.5 × 108 cfu/d FP and 1.4 × 1010 cfu/d SC. Feed intake and body weight of lambs were not affected by microbial additives. Average daily gain and feed efficiency were increased on day 0 to 21. The highest concentration of uric acid, total excreted purine derivatives (PD), microbial N, microbial CP, and metabolizable protein were in MSCFP lambs. The ruminal population of Ruminococcus albus and Ruminococcus flavefaciens was higher in MSCFP and SCFP than CON and FP lambs. The highest and the lowest abundance of M. elsdenii and methanogen respectively was observed in lambs fed on microbial additives. The tendency to improve growth performance vs. CON may be due to improvements in microbial protein synthesis and microbial populations, especially fiber-degrading bacteria. The decrease in the population of methanogens as a result of the use of microbial additives is another positive result.

The effect of biofloc produced from a fish farming system on nutrients digestibility, rumen fermentation, feeding behavior, and blood parameters of Najdi goats.

The aim of this study was to evaluate the effect of biofloc produced from a fish pond on digestibility, rumen fermentation, rumination activity, and blood parameters of Najdi goats. At the first, 200 common carp fish (1.00 g) in two water tanks were used for producing biofloc. Then, 12 goats (average body weight of 32.00 ± 1.50 kg aging eight months) were assigned through a completely randomized design to two treatments (six replicates) and fed for one month. The treatments were comprised of a control diet and a trial diet containing 1.50% biofloc. At the end of the experiment, digestibility of nutrients, rumen fermentation, blood metabolites, and rumination activity were measured. The results showed that the digestibility of dry matter (DM), crude protein, neutral detergent fiber (NDF), and acid detergent fiber (ADF) significantly increased in goats fed with 1.50% biofloc. Also, the rumen protozoa population, plasma glucose, average time of eating, rumination, and chewing per NDF and ADF intakes, total rumination time, and chewing activity were significantly increased. There was no significant difference between treatments for DM intake, ruminal ammonia nitrogen, blood urea nitrogen, cholesterol, and triglyceride. The pH of rumen fluid significantly decreased in treatment containing biofloc. The results of the current study confessed that the use of biofloc (1.50% DM) as a supplement in Najdi goat's diet can improve the digestibility of the diet. It is recommended further and detailed trials with different levels of biofloc in sheep or different livestock species to know more about this untapped supplement source.

Investigation of rumen fermentation parameters and some blood metabolites of dromedary camels fed with C3 and C4 forages.

The aim of this experiment was to investigate rumen fermentation and some blood parameters of dromedary camels fed with C3 and C4 forage. Four fistulated dromedary adult camels were fed with diets as a changeover design, 30 days for each period. The diets included alfalfa hay + wheat straw (C3 forage) and atriplex+ suaeda + seidlitzia (C4 forage). At the end of the experiment, rumen and blood parameters, gas production of wheat straw and atriplex as a 2 × 2 factorial experiment were determined. The highest blood glucose and urea nitrogen levels were found for camels fed with C3 forage, 2 hr after feeding (p < 0.05). The maximum NH3-N concentration in the rumen was for diets C3 and C4, 2 and 4 hr after feeding (p < 0.05). The lowest rumen pH was observed for C3 diet at 2 and 4 hr and for C4 diet at 4 and 8 hr after feeding. The activity of rumen carboxymethylcellulase (CMCase) and microcrystalline cellulase (MCCase) enzymes was the highest for C3 and C4 diets, 8 hr after feeding, however, during feeding the enzyme activity in C4 was higher than that of 2 hr (p < 0.05). The rumen volatile fatty acid (VFA) concentrations were significantly higher in camels fed C3 forage in comparison with C4 (p < 0.05). The results showed that the gas production potential was significantly higher in treatments containing atriplex, however, the gas production rate was higher in treatment containing wheat straw (p < 0.05). The results suggested that for camels maintained in closed systems, the replacement of C3 forages instead of C4 could be possible and useful.

Effect of treated sunflower meal with tannin extracted from pistachio hulls on in vitro gas production and ruminal fermentation.

This experiment was conducted to study the effects of various amounts of treated sunflower meal (SFM) with extracted tannins from pistachio hulls on in vitro gas production and ruminal fermentation in ruminants. The SFM was treated with pistachio extract concentrate (PEC), which contained 111.40 g kg-1 total phenol and 71.30 g kg-1 total tannin per dry matter of extract, at six experimental treatment levels of 0, 7, 14, 21, 28 and 35 g PEC per 100 g SFM on a dry matter basis. In vitro gas production, in vitro organic matter digestibility (IVOMD), metabolizable energy (ME) and fermentative parameters of samples were measured. The PEC had no effect on fermentation rate, but asymptotic gas production was linearly decreased with increasing dose of extract. All fermentation parameters (i.e., apparent degraded substrate, short chain fatty acids, gas yield at 24 hr, partitioning factor at 96 hr, IVOMD, ME and microbial protein production (MP) linearly decreased with increasing PEC treatment. Inclusion of PEC linearly decreased ruminal ammonia nitrogen concentration (NH3-N), total protozoa population and pH in the all incubation times. In conclusion, the addition of PEC positively modified some rumen parameters such as NH3-N concentration and protozoa population.

Replacement of alfalfa hay (Medicago sativa L.) with subabul (Leucaena leucocephala) leaf meal in diets of Najdi goats: effect on digestion activity of rumen microorganisms.

This study investigated the effect of replacing alfalfa hay by subabul leaf meal (SLM) on digestion, fermentation parameters and rumen bacteria and fungi activity of Najdi goats. Six Najdi goats (150 ± 15 days of age and initial body weight of 35 ± 1.1 kg) were randomly assigned to one of two dietary treatments in a balanced completely randomized design (three goats per treatment) for 56 days. Experimental treatments included alfalfa hay as control group and diet containing SLM (SLM replacing alfalfa hay at 50% level). Bacterial and fungi activity and rumen fermentation parameters of animals fed experimental diets were determined. Dry matter disappearance (DMD) was unaffected by replacing SLM with alfalfa hay for both rumen bacteria and fungi in different incubation times, except for 48 h of incubation in specific culture medium of mixed rumen bacteria, which decreased for SLM group (P > 0.05). NDF disappearance (NDFD) and ADF disappearance (ADFD) after 24 and 48 h of incubation in specific culture medium of mixed rumen bacteria was not affected by experimental diets (P > 0.05). However, 72 h after incubation, NDFD in SLM treatment decreased (P > 0.05). Gas production parameters of rumen bacteria were similar for both experimental diets, but partitioning factor (PF), efficiency microbial biomass production (EMBP), microbial protein production (MP), and organic matter truly digested (OMTD) decreased (p < 0.05) in specific culture medium of mixed rumen fungi for SLM diet. There was significant decrease in total protozoa population for diet containing SLM (p < 0.05). Results indicated that replacement of alfalfa hay by SLM had no major effect on rumen microorganisms' activity of Najdi goats, so it may be used as an alternative for alfalfa (at 50% level) in susceptible areas.

Effects of physical form of diet on nutrient digestibility, rumen fermentation, rumination, growth performance and protozoa population of finishing lambs.

This study was conducted to compare effects of 3 physical forms of feed including mash (diet 1), pellet (diet 2) and complete feed block (CFB; diet 3) on digestion, fermentation and performance of lambs. Twenty-one lambs with an initial average body weight of 26 ± 2.5 kg and 6 ± 1.5 months of age were assigned through a completely randomized design to 3 treatments and 7 replicates. The experimental treatments had the same formulation. The results of present experiment showed that CFB significantly increased feed intake and nutrient digestibility (P < 0.05). There was no significant difference among the diets for rumen fluid pH, blood glucose, concentration of volatile fatty acids (P > 0.05), except acetic acid (P < 0.05). The rumen ammonia nitrogen (NH3-N), mixed rumen protozoa population (RPP), Entodiniums spp., Epidiniums spp., blood urea nitrogen (BUN) concentration, rumination time adjusted for dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF) intake, and total body weight gain of lambs in CFB diet were the highest among all diets (P < 0.05). Feed conversion ratio at days 31 to 45 and whole experimental period were better in CFB than in other diets (P < 0.05). Overall, according to the findings of the present study, among 3 physical forms of the diets, CFB had the best efficiency due to improvement of nutrient digestibility, rumen fermentation and performance of lambs. Therefore, the CFB diet offers the best result in lambs compared with mash and pellet diets.

The comparison of digestibility of treated sugarcane tops silage by bacteria or whole microorganisms of Holstein cow and buffalo rumen.

The aim of this study was to evaluate the effects of adding sulfuric acid to sugarcane tops silage on rumen bacteria and whole rumen microorganisms (WRM) and compare the digestibility of sugarcane tops treated with different amount of urea, molasses and sulfuric acid between Holstein cow and Khouzestan buffalo. Regardless of the type of the treatment, potential of gas production (B) by cow WRM (130.670 mL) was more than buffalo (104.060 mL) (p < 0.05), but the rate of gas production (C) by buffalo WRM was greater than cow (0.021 and 0.014 mL per hr, respectively) (p < 0.05). The C in treatment containing only 2.40% sulfuric acid (0.033 mL per hr) was significantly highest (p < 0.05). Regardless of the type of the treatment, the B by cow rumen bacteria (75.040 mL) was more than buffalo (67.150 mL), (p < 0.05), while the C by rumen bacteria of buffalo (0.030 mL per hr) was more than cow (0.017 mL per hr), (p < 0.05). Regardless of the type of the animal, the B coefficient of rumen bacteria in treatment only containing 2.40% sulfuric acid was higher than control (p < 0.05). Therefore, the addition of sulfuric acid not only had no negative effect on microorganisms particularly bacteria, but also probably due to present of sulfur in acid, had positive effect on nutrients digestibility, and growth of microorganisms. The digestibility of sugarcane tops silage treated by cow rumen bacteria and whole microorganisms was higher than buffalo.

Comparison digestibility and protozoa population of Khuzestan water buffalo and Holstein cow.

The major aim of this study was to compare the morphology and activity of rumen protozoa of Khuzestan water buffalo and Holstein cow using in vitro digestibility and gas production parameters of steam treated sugarcane pith. Rumen fluid obtained from two buffalo and cow steers fed the same diet, 30:70 concentrate: forage. To separate rumen protozoa, antibiotic solution and fungicides were added to rumen fluid. The results of present experiment indicated that the neutral detergent fiber (NDF; 7.8 vs. 1.69%) and acid detergent fiber (ADF; 6.24 vs. 3.24%) digestibility of steam treated sugarcane pith by rumen protozoal population of Khuzestan buffalo was higher than those of cow (p < 0.05). Also, digestibility of dry matter, NDF and ADF by whole buffalo micro-organisms was more than those in cow (p < 0.05). The results indicated that the potential of gas production of sugarcane pith by rumen protozoa in water buffalo was more than that of cow (p < 0.05). Total rumen ciliate protozoa numbers in water buffalo were significantly higher than those of cow (3.68 × 10(5) vs. 2.18 × 10(5) mL(-1) of rumen content) (p < 0.05). The number of Diplodinium in buffalo was more than that of cow (41.27 vs. 35.7% of total rumen protozoa, respectively). Percentage of Entodinium, Epidinium, Ophryoscolex and Isotricha in cow was more than those of buffalo. Therefore, in the same diet, protozoa and total rumen micro-organisms of Khuzestan water buffalo have higher digestion activity compared to Holstein cow.

Development and use of quantitative competitive PCR assays for relative quantifying rumen anaerobic fungal populations in both in vitro and in vivo systems.

This paper describes the use of a quantitative competitive polymerase chain reaction (QC-PCR) assay; using PCR primers to the rRNA locus of rumen fungi and a standard-control DNA including design and validation. In order to test the efficiency of this method for quantifying anaerobic rumen fungi, it has been attempted to evaluate this method in in vitro conditions by comparing with an assay based on measuring cell wall chitin. The changes in fungal growth have been studied when they are grown in in vitro on either untreated (US) or sodium hydroxide treated wheat straw (TS). Results showed that rumen fungi growth was significantly higher in treated samples compared with untreated during the 12d incubation (P<0.05) and plotting the chitin assay's results against the competitive PCR's showed high positive correlation (R(2)> or =0.87). The low mean values of the coefficients of variance in repeatability in the QC-PCR method against the chitin assay demonstrated more reliability of this new approach. And finally, the efficiency of this method was investigated in in vivo conditions. Samples of rumen fluid were collected from four fistulated Holstein steers which were fed four different diets (basal diet, high starch, high sucrose and starch plus sucrose) in rotation. The results of QC-PCR showed that addition of these non-structural carbohydrates to the basal diets caused a significant decrease in rumen anaerobic fungi biomass. The QC-PCR method appears to be a reliable and can be used for rumen samples.