[Food conversion in the digestive system of juvenile bulls. 1. Conversion of protein and amino acids]. / Untersuchungen über Nährstoffumsetzungen im Verdauungstrakt von Jungbullen. 1. Mitteilung--Protein-und Aminosäurenumsatz.

Fistulated bulls (duodenal bridge fistulas) received 10 rations containing 60% concentrate and combinations of carbohydrates from various sources to investigate the protein and amino acid flux in the digestive tract. With a constant crude protein concentration of 12-13% in the rations (adjusted by adding urea), an average of 85 +/- 8% of the crude protein ingested with the feed were found in the duodenum. The highest values were measured for rations containing wheat/dried sugar beet chips (97% and 67% resp.). The mean percentage of bacterial crude protein in the corrected total protein found in the duodenum was 69 +/- 11%. This fraction accounted for 53% and 51% respectively for the rations containing maize or fodder beet and increased to above 70% with the rations containing dried sugar beet chips. The amounts of lysine, threonine, methionine and glycine found in the duodenum were always higher than in the feed. The highest synthesis rates were found in animals receiving rations containing fodder beet or dried sugar beet chips, and the lowest was measured for dried sugar beet pulp. Glutamic acid was slight, and no histidine synthesis was detected. The concentration of the amino acids per kg dry matter digesta was similar for the individual amino acids. Crude bacterial protein productions was relatively low (80 to 113 g bacterial crude protein per kg digestible organic matter), but correlated with ration composition.

[Food conversion in the digestive system of juvenile bulls. 2. Digestion of carbohydrates]. / Untersuchungen über Nährstoffumsetzungen im Verdauungstrakt von Jungbullen. 2. Mitteilung--Verdauung der Kohlenhydratfraktionen.

Each of ten rations containing 60% feed concentrate were tested on two bulls which were a fistulated at the duodenum. The carbohydrate contents varied considerably. Carbohydrate digestion in the forestomach was estimated by the detergent and Anthron methods and by quantitative gas chromatographic analysis for carbohydrate monomers. Apparent starch digestibility for starch-rich rations varied between 97.8 and 99%. Between 60 and 144 g of starch was found at the duodenum/animal.d in the case of the cereal-containing rations, the highest values being found for the one containing maize. The apparent digestibility of sugar was about 99%. The amount of sugar found at the duodenum varied between 16 and 67 g animal.d. Analysis by gas chromatography revealed that the feeds yielded less hemicelluloses than calculated from the difference NDF-ADF. The only other sugars found in appreciable amounts at the duodenum were arabinose and xylose.

[Food conversion in the digestive system of juvenile bulls. 3. Rumen liquor investigations]. / Untersuchungen über Nährstoffumsetzungen im Verdauungstrakt von Jungbullen. 3. Mitteilung-Pansensaftuntersuchungen.

Two bulls with a permanent rumen fistula and a re-entrant cannula at the duodenum were fed various concentrates and straw (dry matter ration composition: 60% concentrate, 40% straw). Negative correlations were found between the pH value and total fatty acid concentration (r = -0.70). The animals were given the straw one hour before the concentrate. The pH value increased to not more than 7.3 one hour after they had received the straw. It did not drop below 6.4 after the concentrate with any of the rations. The addition of dried sugar beet pulp to the rations leads to a higher mean acetate concentration than the other rations and causes an unvarying high total fatty acid concentration.

[Dry matter and nutrient degradability of foodstuffs after incubation in the rumen (nylon bag technique)]. / Trockensubstanz- und Nährstoffverlust bei Futtermitteln nach Inkubation im Pansen (Nylonbeutel-Technik).

The digestion of dry matter and nutrients of wheat/barley, maize, potatoes, dried sugar beet chips dried sugar beet pulp and barley straw were studied by means of the nylon bag method on two steers with fistulated rumens. Compared with that of the other feedstuffs with a high starch content, the disappearance of maize was significantly lower in terms of dry matter (20%), starch (38%) and crude protein (23%). In the case of cereals, dry matter degradability correlated closely with the disappearance of crude protein and starch (r = 0.9), and for straw and dried sugar beet pulp it correlated closely with crude cellulose disappearance (r = 0.9). The high degree of crude cellulose of dried sugar beet pulp is due mainly to the low lignin content of the dried sugar beet pulp.

[The effect of flavomycin on digestion in fattening bulls]. / Einfluss von Flavomycin auf die Verdauung bei Mastbullen.

Three friesian bulls (Genotype 31) were fitted with re-entrant cannulas at the duodenum to investigate the influence of a flavomycin supplement of the digestion in the forestomachs and the other parts of the digestive tract. The supplement of flavomycin increased the total digestibility of the organic matter. The digestibility of starch and sugar was between 97% and 98%. The balance of the nutrients in the digestive tract shows, that by flavomycin supplementation the degradation of organic matter and crude protein in the fore stomach was decreased and the amount of the organic matter and crude protein in the gut was increased. The balance of the amino acids in the gut showed that after flavomycin ca. 30 g more amino acids were found in the gut. The synthesis of bacterial protein in the forestomachs was, after flavomycin application, slightly reduced as was the degradation rate of the feed protein.

[The effect of flavomycin on the fattening performance of bulls]. / Einfluss von Flavomycin auf die Mastleistung von Bullen.

An experiment with 36 fattening friesian bulls was conducted to investigate the effect of flavomycin (50 mg/d.animal). The additional flavomycin significantly enhanced the apparent digestibility of the organic matter, crude fibre and NFE. The animals in the experimental group consumed significantly more feed than the controls until the 56th day of the experiment. No appreciable differences between the two groups occurred thereafter. The daily gain of the animals in the experimental group was always higher than that of the controls except from day 140 to day 168 of the experiment. The mean daily gain for the animals in the control group was 949 g, whereas for those in the control group it was 916 g. This difference is statistically significant. The daily gains of the experimental animals were 3.5% higher than those of the controls. The animals receiving flavomycin tended to need a lower energy input than the controls. The control animals had a mean requirement of 3.80 kEFr/kg gain compared with 3.68 kEFr/kg for the experimental animals. This corresponds to a 3.2% improvement in energy conversion. As far as slaughter performance was concerned, the additional flavomycin had no effect on carcase composition, organ weight and chemical composition. Only the internal fat fraction was increased somewhat by flavomycin. The flavomycin had no influence on the fatty acid composition in the rumen. In particular, the ratio of acetic acid to propionic acid was unchanged. A trend to a slight increase in the total fatty acid concentration was observed. The treatment did not affect the number of protozoa in the rumen.

[Results of clinical tests on the fattening-stimulating action of the steroid estrogen mestranol in bulls]. / Ergebnisse klinischer Erprobungen zur mastfördernden Wirkung des Steroidöstrogens Mestranol bei Bullen.

Three experiments were conducted with 5 mg Mestranol per animal and die over 70 to 80 days and resulted in daily surplus gains of twelve, 14, and 18 per cent in terminal fattening of Frisian bulls. Also achieved were fodder savings by 1 kg dry matter and energy savings by 0.7 kEFr for each kilogram of gain as well as increase in slaughter weight by 8-9 kg per animal. Those favourable effects were attributed to anabolic and sexual-inhibiting action. A sedative effect on the nervous system is assumed. Combination with CAP failed to give any advantage regarding sexual inhibition and fattening result, but it rather entailed certain shortcomings, such as lower slaughter weight and stronger fat development. The development of an anabolic medicament for veterinary bio-engineering in terms of growth stimulation is suggested.

[The protozoa population in the rumen of fattening bulls fed varying feed and the effect of artificial transfer of protozoa]. / Die Protozoenpopulation im Pansen von Mastbullen beig verschiedener Fütterung and die Wirkung einer künstlichen Protozoenübertragung

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.

[Promotion of fattening in young bulls following the administration of mestranol]. / Untersuchunger über die mastfördernde Wirkung von Mestranol bie Jungbullen

Oral administration of 5 mg mestranol daily for 100 days to 70 German Black Peid bulls improved weight gain in 72% of the animals. Average additional increment ranged from 2 to 17%. During the first weeks of administration there was a weak and transient protein-anabolic action and improvement in digestion of crude protein. Appetite was slightly stimulated. Consumption of food and energy per unit of weight gain was improved; better growth led to higher slaughter weight. Treatment had no effect on meat to bone ratio, degree of fulness of the gastointestinal tract, or meat quality. Skeletal mineralization was improved by 10-30%, and there was a noticeable anabolic effect on mineral metabolism. After longer administration an antigonadotropic action became evident. Some veterinary indications for use in fattening cattle were derived from these effects. Further pharmacological and clinical investigation of this and more active anabolics seemed to be required.