A study was conducted to determine if sampling rumen contents via a ruminal cannula or oral lavage tube would yield similar denaturing gradient gel electrophoresis profiles of the bacterial community. Two species of ruminally cannulated animals were used for this study (cattle, n = 2; sheep, n = 3). All animals were allowed ad libitum access to feed. Cattle were fed baled unprocessed sorghum-sudan hay (12% CP, 68% NDF; DM basis), whereas sheep were maintained on chopped alfalfa (18% CP, 40% NDF; DM basis). Ruminal fluid was collected (approximately 20 mL) once per week for 3 wk from each animal using a poly tube equipped with a suction strainer with a hand-held suction pump through the rumen cannula or oral cavity. The denaturing gradient gel electrophoresis analysis demonstrates that yield of bacterial diversity was not different between the 2 sampling methods (P = 0.73). When samples were grouped according to band pattern similarity, groups were most stable according to individual animal and species rather than sampling method. Total VFA and molar proportions of individual VFA did not differ by sampling method (P> 0.40). Additionally, rumen ammonia concentrations were similar for both sampling methods (19.3 vs. 19.1 mM +/- 8.0 for cannula vs. lavage, respectively; P = 0.98). These data indicate that rumen samples collected via oral lavage or rumen cannula yield similar results. This knowledge will allow sample collection from a greater population of animals and an ability to maintain the value of research livestock that can be lost due to the surgical implantation of a ruminal cannula.

The digestive responses and degradation of ergovaline and production of lysergic acid in the rumen of sheep offered Neotyphodium coenophialum-infected tall fescue straw at 2 ergovaline levels were investigated. Six crossbred wethers (56 +/- 3.0 kg of BW) were used in a randomized crossover design involving 2 treatments, for a total of 6 observations per treatment. The experiment consisted of two 28-d feeding periods with a 14-d washout period between them. The treatments were 1) tall fescue straw containing <0.010 mg of ergovaline/kg (E-), and 2) tall fescue straw containing 0.610 mg of ergovaline/kg (E+). Feed, orts, and feces were measured and analyzed for DM, ADF, and CP, and used to determine digestibilities. Feed and water intake were monitored throughout the feeding periods. Body weight and serum prolactin levels were measured at the beginning and end of each feeding period. Ruminal fluid was sampled 3 times (d 0, 3, and 28) during each 28-d feeding period for determination of ergovaline, lysergic acid, ammonia, and pH. Samples were collected before feeding (0 h) and at 6 and 12 h after feeding. Total fecal and urine collection commenced on d 21 and continued until d 25 of each feeding period. Ruminal ammonia, ruminal pH, and rectal temperature were not influenced by ergovaline concentration (P > 0.10). Digestion of DM, ADF, and CP was not different between treatments (P > 0.10). Daily water intake was less for the E+ diet (2.95 vs. 2.77 L/d; P < 0.05) as was serum prolactin (22.9 vs. 6.4 ng/mL; P < 0.05). Ergovaline concentration in ruminal fluid increased over sampling days at each sampling time (P < 0.05). Lysergic acid concentration in ruminal fluid increased over time from d 0 to 3 (P < 0.05) but was not different between d 3 and 28 (P > 0.10). In the E+ treatment, ergovaline was not detectable in the urine, whereas the concentration in the feces was 0.480 mg/kg. Lysergic acid was detected in the diet of the E+ treatment at 0.041 g/kg, lysergic acid in the urine was 0.067 mg/kg and in the feces was 0.102 mg/kg. The apparent digestibility of the alkaloids was 64.2% for ergovaline and -12.5% for lysergic acid. Approximately 35% of dietary ergovaline and 248% of dietary lysergic acid were recovered in the feces and urine. The appearance of lysergic acid in the feces, urine, and ruminal fluid is likely due to microbial degradation of ergovaline in the rumen and further breakdown in the lower digestive tract.

Exposure time to the ergot alkaloids had a limited effect on the route of elimination or the amounts of ergovaline or lysergic acid excreted by horses. The primary alkaloid excreted was lysergic acid, and urine was the major route of elimination. These data will aid future research to improve animals' tolerance to toxic endophyte-infected tall fescue.

Two experiments were conducted to determine the influence of lipid extracted algae (LEA) on OM digestibility, N flow, and rumen fermentation. Six samples of LEA were evaluated representing 2 genus of microalgae (Nannochloropsis spp. [n = 3] or Chlorella spp. [n = 3]). Four dual-flow continuous flow fermenters (2,700 mL) were used in a Latin square design to evaluate LEA in forage or concentrate diets compared with soybean meal. Temperature (39 °C), pH, solid (5%/h) and liquid (10%/h) dilution rates, and feed schedule were maintained constant for all experiments. Each experimental period consisted of 6-d adaptation and 4-d sampling periods. There were 7 treatments consisting of 6 different samples of LEA and a soybean meal control (SOY). Diets for Exp.1 were formulated to be 13.0% CP (DM basis) using either soybean meal or LEA and met or exceeded the requirements of a nonpregnant and nonlactating beef cow (450 kg). The forage portion consisted of sorghum-sudan hay (6.4% CP and 46.2% TDN, DM basis) and alfalfa (26.1% CP and 82.3% TDN, DM basis). Concentrate diets used in Exp. 2 met or exceeded the nutrient requirements of a (400 kg) growing steer and contained 85% fine ground corn and included 7% (DM basis) soybean meal or LEA. Data were analyzed as mixed model considering the effect of each LEA compared with soybean meal. Orthogonal contrasts were used to determine the overall effect of LEA genus vs. SOY. True OM digestibility were not influenced by LEA addition to forage diets (P ≥ 0.08) but increased with Chlorella LEA addition to concentrate diets (P < 0.01) but not Nannochloropsis LEA. Degradation of N was greater for SOY with forage diets and LEA for concentrate diets (P < 0.0001). Total VFA production was greatest for SOY in forage diets and increased when LEA was added to concentrate diets (P < 0.0001). Microbial efficiency did not differ between SOY and LEA in forage diets (P ≤ 0.08). In concentrate diets Nannochloropsis decreased microbial efficiency (P < 0.01). Microbial efficiency results for Chlorella were more variable for Nannochloropsis with 1 Chlorella spp. increasing microbial efficiency by 36% over SOY (P < 0.05) and the other Chlorella spp. decreasing microbial efficiency by approximately 42% compared with SOY (P < 0.01). Overall, the results from both experiments are promising for LEA as a protein feedstuff in ruminant diets. Further research is necessary to fully understand the interactions and consequences of upstream processes and what role algal strain plays in LEA quality.

Cattle grazing dormant western rangelands may have a high ruminal acetate to propionate ratio (A:P) and may have low tissue clearance of acetate. Increasing propionate production could shift this ratio and improve animal performance. In Exp. 1, the effect of Propionibacterium acidipropionici P169 (PA) on forage digestibility and VFA production was evaluated in vitro using 2 substrates: 100% dormant warm-season grass extrusa and 50% sorghum-Sudan hay with 50% ground corn (DM basis). The objective of Exp. 2 was to evaluate the effect of PA or calcium propionate supplementation on digestibility, ruminal fermentation, acetate clearance, and BW change. Twelve 2-yr-old, pregnant Brangus heifers (BW = 416 ± 85 kg) were assigned to 1 of 3 treatments. All cattle were fed a basal ration of Old World Bluestem hay (Bothriochloa ischaemum; 5.8% CP and 76.5% NDF, DM basis) at 1.5% BW from d -10 to d 49. Treatments included a protein supplement (CON; 36% CP and 35% RUP, DM basis; 454 g/animal fed twice daily), CON plus 6 × 10(10) cfu PA/animal (BACT), and CON plus 80 g calcium propionate (PROP). After initiation of treatments (d 0), rumen fluid was collected via oral lavage every 3 d and analyzed for VFA, pH, and ammonia. Glucogenic potential of treatments was evaluated with an acetate tolerance test on d 49. In Exp. 1, PA addition increased (IVDMD; P < 0.001) and total VFA (P < 0.001) of 100% dormant warm-season grass extrusa but not 50% sorghum-Sudan hay with 50% ground corn (P ≥ 0.28). The addition of P169 decreased (P < 0.001) acetate, increased propionate (P < 0.001), and decreased A:P ratio (P < 0.001) for both substrates. In Exp. 2, total tract OM and NDF digestibility and ruminal pH, total VFA, and acetate did not differ (P ≥ 0.13) among treatments. Propionate concentration was least (P = 0.001) for CON, intermediate for P169, and greatest for PROP. Conversely, A:P ratio was greatest (P < 0.004) for CON, intermediate for P169, and least for PROP. Acetate clearance did not differ (P = 0.69) among treatments. Propionibacterium acidipropionici P169 increased IVDMD and total VFA of low-quality forage. Supplementation with PA and calcium propionate salts increased propionate and decreased A:P in the rumen. Supplementation of PA represents a potential way to increase ruminal propionate concentration when dormant forages are fed.