mL Of Ruminal Fluid Research Articles

A comparison of rumen fluid sampled by oro-ruminal probe versus rumen fistula

Ten adult (height 63–85 cm) rumen-fistulated sheep were used to test the usefulness of an oro-ruminal probe and a suction pump for the acquisition of ruminal fluid. Use of these instruments in 50 samplings rendered 200 ml of ruminal fluid each time. Introduction of the probe to a length of 91.3 ± 3.5 cm took 18 ± 6.5 s. Collection of 200 ml of ruminal fluid took 7.4 ± 2.2 s. Sampling location was the ventral ruminal sack. Comparing fluid taken by the oro-ruminal probe with samples taken via ruminal fistula by a tube-like probe, no significant differences in pH, total acidity, reduction potential, ammonia, acetate, L-lactate, sodium and chloride concentrations were found. However, significant differences between oro-ruminal probe samples and fistula samples were observed with regard to the concentrations of total volatile fatty acids, propionate, n-butyrate, i-butyrate, n-valerate, i-valerate, calcium, phosphate, magnesium and potassium. The differences were independent of the sampling order (oro-ruminal probe prior to fistula and vice versa). These results indicate that samples taken by the oro-ruminal probe do not contain sampling-dependent saliva residues. Those samples collected via the fistula had consistently higher concentrations of total volatile fatty acids, propionate, n-butyrate, i-butyrate, n-valerate, and i-valerate, as well as higher concentrations of calcium, phosphate, magnesium and potassium than samples taken with the oro-ruminal probe. These results indicate that samples taken via fistula originated from more dorsal regions than the samples taken by oro-ruminal probe from the ventral ruminal sack. The oro-ruminal probe and the suction pump used proved to be useful for the collection of ruminal fluid from the ventral ruminal sack in adult sheep.

Avaliação dos protozoários ciliados no rúmen de búfalos (Bubalus bubalis L.) e bovinos (Bos indicus L.) em regime de confinamento

Num experimento de engorda em confinamento, foram utilizados nove bubalinos e nove zebuínos, todos machos castrados, de 18 a 24 meses de idade e peso médio de 340 kg, mantidos em baias individuais, consumindo dieta de 2,0 kg de soja crua moída, 2,0 kg de espigas de milho desintegradas (grão, palha e sabugo) e silagem de sorgo à vontade (controlando-se o consumo diário). Ao final do período de confinamento, todos os animais foram abatidos e o conteúdo ruminal de cada indivíduo foi homogeneizado, sendo colhidas amostras de 30 a 40 ml de liquido ruminal e, desta, retirou-se alíquota de 10 ml em tubo de ensaio com 20ml de formaldeído diluído em água destilada a 1:2,para fixação dos protozoários ciliados. As contagens de protozoários foram feitas em 100 campos e os resultados permitiram as seguintes conclusões: 1) adieta favoreceu maior concentração de protozoários ciliados/ml de liquido ruminal dos zebuínos que no de bubalinos, apesar destes apresentarem maior número de gêneros; 2) os protozoários ciliados digestores de fibra foram detectados em maior quantidade nos zebuínos que nos bubalinos; 3) o gênero Emodinium spp representou mais de 80% do total dos protozoários ciliados identificados nos zebuínos e nos bubalinos.

Performance of Steers Fed Crop Residues Supplemented with Nonprotein Nitrogen, Minerals, Protein and Monensin

Research was conducted to test nonprotein nitrogen (NPN)-protein supplements in a mineral mixture for growing steers fed crop residues free choice. Three trials involving 184 steers were conducted. Animal performance and ruminal parameters were measured. Results indicate: Supplements containing 7.5% sodium chloride, 10% dicalcium phosphate, 2.5% potassium carbonate, 2% magnesium sulfate, 1% elemental sulfur plus trace minerals, molasses and corn meal were readily consumed when combined with nitrogen sources to formulate 100% crude protein equivalent (CPE) mixtures. Cottonseed hulls were readily consumed (3.1% of body weight [BW] per day), but chopped straw (2.0% BW) and corn stover (1.4% BW) were very poorly consumed. Increasing nitrogen intake by the steers markedly increased cottonseed hull intake. Type of supplement and cottonseed hull intake (percent BW) were as follows: (a) negative control (no supplemental nitrogen source), 2.2%; (b) restricted 50% crude protein soybean meal control, 2.7%; and (c) 100% CPE supplements fed free choice, 3.1%. Growing steers gained an average of .54 kg daily during 140-day trials when fed cottonseed hulls free choice plus either biuret or urea 100% CPE supplements. Replacing 20% of the NPN nitrogen with fish meal or soybean meal nitrogen increased gains by 20%. Treating the soybean meal protein with .6% formaldehyde did not improve steer performance. Ruminal ammonia concentrations averaged 10 to 20 mg NH3-N/100 ml of ruminal fluid for steers fed the 100% CPE supplements. Monensin addition to the supplement resulted in a 1.9 acetate/propionate ratio compared to a 5.0 ratio for control steers but reduced supplement and cottonseed hull intake and steer performance.

The protozoa population in the rumen of fattening bulls fed varying feed and the effect of artificial transfer of protozoa

High protozoa concentrations were found in the ruminal fluid of fattening bulls weighing 400 kg which were raised for the first five months of age in a large-size calf-raising plant. The ruminal fluid of these bulls, however, contained no protozoa of the group Holotricha. If the animals were fed a mixture of concentrates and pelleted straw (pH 6, 12.5 mMole of volatile fatty acids per 100 ml) 1 ml of the ruminal fluid was found to contain 827,000 protozoa whereas if the animals received rations rich in concentrates (pH 5.8, 14 mMole of volatile fatty acids) 1 ml of ruminal fluid contained only 578,000. Through protozoa transfer carried out by infusing 41 of a mixture of ruminal fluid from other cows per animal it was possible to settle other species, viz. Isotricha, Dasytricha and Ophryoscolex; this, in turn, produced a concomitant decrease in the number of Entodinium and a noticeable decline in the total protozoa population. Further work will be necessary to find out whether it would be advisable to influence the protozoa population of growing cattle kept in large-size cow plants in similar ways as described above.

The effect of straw in ground and pelleted form on the rumen fermentation and protozoa

Cows possessing a large ruminal fistula were fed straw meal and pelleted wheat straw to investigate its effect on ruminal fermentation (concentration of NH3 and volatile fatty acids (FFS), pH, molar proportions of FFS, rates of FFS production) and on the protozoa population. The straw-concentrate mixture used in the present trial contained 40% of straw. The feeding of pelleted straw produced a significant rise in FFS concentrations (from 8.8. to 12.3 mMole/100 ml) and a corresponding decline of pH (from 6.7 to 6.1). With high molar proportions of acetate (72 mole%) the influence of the straw diet on molar FFS proportions was low. The NH3 peak observed 1 hr after feeding was higher with the pelleted straw than with the straw meal. The feeding of finely gound straw produced a higher level of FFS production (by 10%) than that of straw pellets. (3.88 and 4.29 mMole per gm DM). The number of protozoa (per ml of ruminal fluid) was 335,000 (straw meal) and 121,833 (pellets). The number of large infusorial cells (Isotricha, Diplodinium, Ophryoscolex) decreased correspondingly from 70,000 (straw meal) to 18,870 per ml (pellets). These results suggest that the feeding of pelleted straw-concentrate mixtures to cows as sole feed will not bring about optimum conditions for ruminal fermentation (FFS formation, protein synthesis) and for the layering of ruminal contents.