Entity

Time filter

Source Type

Centurion, South Africa

Henning P.H.,Agricultural Research Council of South Africa | Horn C.H.,Agricultural Research Council of South Africa | Steyn D.G.,Agricultural Research Council of South Africa | Meissner H.H.,Agricultural Research Council of South Africa | Hagg F.M.,MS Biotech
Animal Feed Science and Technology | Year: 2010

The objectives were: (a) to select the most effective lactate-utilizing Megasphaera elsdenii (Me) isolates (strains) from mixed rumen cultures (Phase 1) and (b) to determine in vivo the efficacy of the two most promising isolates from Phase 1 to control ruminal acidosis (Phase 2). In Phase 1 batch cultures of nine strains of lactate-utilizing Me were isolated and compared with the Me type strain ATCC 25940 and a membrane-filtered supernatant of a centrifuged culture (Control). Culture concentration in the incubation tubes was ca 5 × 105 cfu's/ml. In Phase 2 forage-fed rumen-fistulated sheep were drenched intra-ruminally 100 ml containing 1011 cfu's of the promising Me isolates CH4 and CH7, following abrupt administration of 1 kg maize meal and 300 g maltose per sheep, and compared with Control sheep drenched with a placebo. For Me isolates CH3, CH4 and CH7 rumen pH remained below pH = 5.0 for <3 h/24 h compared to >5 h/24 h for the type strain and the Control (p<0.001) (Phase 1). At +6 h lactic acid concentration increased to 24 mmol/l in the case of the type strain and 38.5 mmol/l for Control, compared to respectively 14 mmol/l for Me isolate CH3 and <5 mmol/l for Me isolates CH4 and CH7 (p<0.001). Lactic acid concentration for all isolates decreased to <5 mmol/l at +10 h, but for Control it progressively increased to 79 mmol/l at +24 h. In Phase 2, rumen pH for Control was <5 from 8 h to 24 h post-drenching, for Me isolate CH7 <5.5 from 4 h to 24 h, but always >5.0 (p<0.001), whereas for Me isolate CH4 rumen pH was >5.5 for the total post-drenching period. Lactic acid concentration post-drenching consistently remained <10 mmol/l for the two isolates, whereas it progressively increased to >55 mmol/l at +10 h for Control (p<0.001). Forage intake of Control sheep decreased by 16-18% from pre- to post-drenching and for Me isolate administered sheep by only 3-9% (p<0.05). It is concluded that the selected Me isolates are promising in the control of ruminal acidosis. © 2010 Elsevier B.V. All rights reserved. Source


Henning P.H.,Agricultural Research Council of South Africa | Horn C.H.,Agricultural Research Council of South Africa | Leeuw K.-J.,Agricultural Research Council of South Africa | Meissner H.H.,Agricultural Research Council of South Africa | Hagg F.M.,MS Biotech
Animal Feed Science and Technology | Year: 2010

The objective in Trial 1 was to study feed intake and ruminal acidosis when the diet is rapidly transitioned from forage to concentrate and Megasphaera elsdenii (Me) NCIMB 41125 (strain CH4) is administered into the rumen. The objective in Trial 2 in addition was to investigate whether drenched CH4 can be measured in the rumen and will promote a viable lactate-utilizing population during transition. In Trial 1, 24 rumen-cannulated lambs were used and in Trial 2, 12 rumen-cannulated steers. The lambs were randomly allocated to one of four treatments in a 2 × 2 factorial design: drenched with either CH4 or a placebo, and fed forage ad lib. or restricted to 200 g/day. On day 1 of the trial, the lambs in addition to the forage were fed a concentrate mixture at 09:00 and 15:00, and dosed 1011 cfus at 12:00. Intake and lamb weight were measured for 50 days until slaughter to obtain dressing %. Rumen pH and lactic acid concentration were measured between days -1 and +14. In Trial 2, four treatments of three steers each received one of four dosages intra-ruminally: a placebo (Control), 109 cfus (low), 1010 cfus (medium) and 1011 cfus (high). The transition from forage to concentrate was in five steps, i.e. more gradual than in the lamb trial. Feed intake and weight gain were measured for 37 days. Rumen fluid was sampled for determination of pH, lactic acid concentration, VFAs and qrt-PCR analysis for Me presence between days -4 and +35. Lambs drenched with strain CH4 consumed more concentrate than Control (P<0.006), but less forage (P<0.049). Total feed intake was also higher and it fluctuated less (P<0.023). Lamb ADG and dressing % did not differ. Rumen pH declined less in CH4 than Control lambs (P<0.001) and lactic acid accumulated less (P<0.001) during days +2 and +3. In Trial 2, feed intake and ADG were higher in CH4 treatments than Control. The low, medium and high CH4 treatments did not differ in any parameter. qrt-PCR results reflect higher Me concentrations during days +2 and +3 (P<0.06) in CH4 treatments than in Control, coinciding with lower lactic acid concentrations (P<0.13). Rumen pH in Control approached pH = 5 between days +9 and +17, whereas pH in the CH4 treatments remained above 5.5. Total VFAs were similar in all treatments, but the proportional distribution shifted towards butyric acid in the CH4 treatments. It is concluded that strain CH4 should control ruminal acidosis during transition from forage to concentrate. © 2010 Elsevier B.V. All rights reserved. Source


Hagg F.M.,MS Biotech | Hagg F.M.,University of Pretoria | Erasmus L.J.,University of Pretoria | Henning P.H.,MS Biotech | Coertze R.J.,University of Pretoria
South African Journal of Animal Sciences | Year: 2010

Sixty high-producing multiparous Holstein cows were used in a randomized complete block design experiment to determine the effect of a direct-fed microbial (DFM), Megasphaera elsdenii NCIMB 41125 (Me), on dairy cattle productivity and health. The cows received one of two experimental diets (total mixed rations (TMR)) from calving until 60 days post partum. Two experimental diets were formulated, namely a low concentrate diet (40% roughage: 60% concentrate) and a high concentrate diet (30% roughage: 70% concentrate) that were fed as a TMR for the duration of the trial. The low and high concentrate diets contained respectively 181 g/kg and 178 g/kg of crude protein, 448 g/kg and 504 g/kg of non-fibre carbohydrate, 282 g/kg and 238 g/kg of neutral detergent fibre and 42 g/kg and 43 g/kg of ether extract. There were four experimental treatments, namely: (1) Low concentrate diet control (LCC), (2) Low concentrate diet and dosed with Me (LCD), (3) High concentrate diet control (HCC) and (4) High concentrate diet and dosed with Me (HCD). Dosing with Me did not show any advantage, regardless of level of concentrate. Dry matter intake, milk production, milk composition, feed efficiency, body mass and body condition score were not affected by treatment. Furthermore, treatment did not affect rumen pH, rumen lactic acid or volatile fatty acid concentrations. Faecal pH, however, was statistically significantly higher, and faecal starch content significantly lower in cows dosed with Me. Lack of results suggests that further research is needed on dose time and/or frequency as well as the option to use it as an infeed product. © South African Society for Animal Science. Source


Aikman P.C.,University of Reading | Henning P.H.,MS Biotech | Humphries D.J.,University of Reading | Horn C.H.,MS Biotech | Horn C.H.,Biotherapeutics, Inc.
Journal of Dairy Science | Year: 2011

This study investigated the effect of using the lactate-utilizing bacterium Megasphaera elsdenii NCIMB 41125 as a probiotic supplement on rumen fermentation and pH in dairy cows in the immediate postcalving period. Fourteen multiparous rumen-fistulated Holstein cows, blocked according to 305-d milk yield in the previous lactation, were used in a randomized complete block design. From d 1 to 28 postcalving, cows were fed ad libitum a total mixed ration with a forage to concentrate ratio of 392:608 and a starch concentration of 299g/kg of dry matter. Treatments consisting of a minimum of 1010 cfu of Megasphaera elsdenii NCIMB 41125 or autoclaved M. elsdenii (placebo) were administered via the rumen cannula on d 3 and 12 of lactation (n=7 per treatment). Mid-rumen pH was measured every 15min, and eating and ruminating behaviors were recorded for 24h on d 2, 4, 6, 8, 11, 13, 15, 17, 22, and 28. Rumen fluid for volatile fatty acid and lactic acid analysis was collected at 11 time points on each of d 2, 4, 6, 13, and 15. Yields of milk and milk protein and lactose were similar, but milk fat concentration tended to be higher in cows that received the placebo. Time spent eating and ruminating and dry matter intake were similar across treatments. Ruminal lactic acid concentrations were highly variable between animals, and no cases of clinical acidosis were observed. Both treatment groups had rumen pH <5.6 for more than 3h/d (a commonly used threshold to define subacute ruminal acidosis), but the length of time with rumen pH <5.6 was markedly reduced in the days immediately after dosing and fluctuated much less from day to day in cows that received M. elsdenii compared with those that received the placebo. Ruminal total volatile fatty acid concentrations were similar across treatments, but the acetate:propionate ratio tended to be smaller in cows that received M. elsdenii. Despite the lack of a measurable treatment effect on ruminal lactic acid concentration, supplementation of early lactation dairy cows with lactate-utilizing M. elsdenii altered the rumen fermentation patterns in favor of propionate, with potential benefits for energy balance and animal productivity. © 2011 American Dairy Science Association. Source

Discover hidden collaborations