Hoffmann M

Harnstoffbestimmungen im Pansensaft von Schafen

Low values for urea were found in samples of ruminal fluid of sheep fed concentrate rations if urea determination was carried out by the urease method. The present paper describes a both simple and sensitive colorimetric method of analysis using diacetyldioxime. The method is suitable for determining urea in coloured solutions such as ruminal fluid or silage extracts.

Untersuchungen zur Wirkung einer reduzierten Tränk-wassergabe auf die Futteraufnahme, die scheinbare Verdaulichkeit von Rohnährstoffen und die Pansenfermentation bei Schafen

Based on the fact that the insufficient supply of agricultural domestic animals with drinking water in tropical and subtropical regions is often the factor limiting their performance, the effect of different drinking water supply of sheep (ad libitum, 54% of ad libitum and 27% of ad libitum) on various parameters was studied. A water supply reduced to 54 and 27% resp. diminished dry matter intake to 84% and 45% resp. A water supply reduced to 54% improved the digestibility of organic matter, crude fibre, crude cellulose and N-free extractives, it was, however, not significant. A reduction to 27% of the ad libitum water supply improved the digestibility of all crude nutrients, significantly, however, only that of organic matter, crude fibre, crude cellulose and N-free extractives. In comparison with a supply of water reduced to 54%, a water supply reduced to 27% also resulted in an improvement of the digestibility of all crude nutrients. Both the reduction of the ad libitum water supply and the increasing time interval for the sampling of rumen fluid resulted in an increased concentration of volatile fatty acids in the rumen fluid, which was sampled 15 min, 1 hour and 2 hours after feeding.

Untersuchungen zum Einfluß verschiedener Faktoren auf Kennzahlen der Pansenprotozoen bei Mastbullen

(1982). Untersuchungen zum Einflus verschiedener Faktoren auf Kennzahlen der Pansenprotozoen bei Mastbullen. Archiv fur Tierernaehrung: Vol. 32, No. 3, pp. 209-220.

Möglichkeiten der Vorhersage der Verdaulichkeit der Rohnährstoffe bei ausgewachsenen und wachsenden Schafen aus dem Rohnährstoffgehalt der Ration

Eight variants of recipes for mixtures of straw and concentrated feed with 10 to 60 per cent straw more or less finely ground (86 to 314 g crude fibre per kg dry matter) and fattening feed for lambs (50 g crude fibre per kg dry matter) were checked concerning the digestibility of crude nutrients for fullgrown wethers and 60 to 80-, 80 to 100-and 100 to 120-day-old lambs which had been ablactated at an age of 60 days. The digestibility for wethers was significantly higher than for lambs, between the age groups of which there were no significant differences concerning the digestibility. In accordance with the results with rations on the basis of concentrated feed as checked and described in the first piece of information, the content of crude fibres in the rations had a negative influence on the digestibility of organic matter, NFE and energy whereas there was a positive relation with the digestibility of crude fibres. The regression functions established for mixtures of straw and concentrated feed concerning the dependence of the digestibility on the content of crude fibres showed a relatively good coincidence in the range of a low content of crude fibres with the corresponding regression functions which were described in the first piece of information for rations of concentrated feed. The equations for the digestibility of crude fibres were an exception. In contrast to this, the quantitative relations between crude fibres and the digestibility as established in the first piece of information for rations with a low content of crude fibres cannot be transferred to rations with a higher content of crude fibres.

Einfluß von Emulgatoren und Fettmischungen auf die Verdaulichkeit und den Ansatz von Fettsäuren bei Kälbern

In a digestibility experiment with 4 X 4 calves the animals received 100 g mixture for calves, 50 g dried green fodder and either 656 g dried whole milk and 164 g dried skim milk (VM) or 656 g dried whole milk and 164 g added fat. The added fat consisted of a mixture of tallow and lard in a 1:1 ratio plus 10% emulgator ES 20 (FE) or 8% ES 20 and 2% soybean lecithin (FL) or 25% lard, 25% tallow, 40% rape/sunflower oil with 10% ES 20 (FO). The apparent digestibility of the fat amounted to 91% in group VM and in groups FE/FL/FO to 66/70/67% resp. The composition of fatty acids and the use of an unsuitable charge of dried skim milk are considered to be the causes of the low apparent digestibility. The apparent digestibility of the fatty acids decreased with their growing chain length. The higher digestibility of the unsaturated fatty acids is largely caused by changes due to bacterial activity in these fatty acids in the intestines and by the influence of metabolically changed faecal fat. The combination of the synthetic emulgator with lecithin did not improve fat digestion but diminished the total fat content in the blood.

Zur Bestimmung der mittleren Verweildauer des Futters im Verdauungstrakt von Schafen

The average time the test feed remains in sheep was determined with ewes during three stages of the reproduction cycle. The feed was labelled with 51Cr2O3. Experiment conditions are described under which the experiments can be carried out within the permissible limits.

Untersuchungen zur Pansenfermentation unter Besonderer Berücksichtigung der Produktionsraten Flüchtiger Fettsäuren an Mutterschafen im Verlaufe der Reproduktion

Methods and results of the measuring of the rumen volume and the passage rate as well as the dependence of the production of volatile fatty acids on the parameters mentioned are described. The correlative relations between rumen volume on the one hand and feed passage on the other hand to the production quotas are investigated. Passage rates and rumen volumes were determined with the help of the isotope dilution method. In the course of reproduction rumen volumes of 7.81, 6.41, 8.91, 7.11 in experiment 1 and 5.41, 5.81, 9.51 and 4.71 in experiment 2 were measured in the sequence early stage of gestation, late stage of gestation, lactation and the period between pregnancies. The average total production of volatile fatty acids within 12 hours amounted to 475 mmol, 265 mmol, 313 mmol and 351 mmol in experiment 1 and 155 mmol, 175 mmol, 271 mmol and 144 mmol in experiment 2 in the same sequence. The average passage duration of the feed through the digestive tract of the ewes was 32.4 h in experiment 1 and 33.6 h in experiment 2. The relatively high feed intake of the ewes resulted in a short passage duration and could be a cause of the low production quotas of the volatile fatty acids.

Einfluß der Trächtigkeit und der Laktation auf Verdauungsvorgänge beim Schaf

The average passage time, the rumen fluid volume and the digestibility of the organic matter were determined in addition to 3 individual feeding experiments with fertility oriented crossbreed ewes, which received pelleted straw-concentrate mixtures. The average passage time of the feed particles through the digestive tract is shorter in pregnant animals than in lactating ones. It is longest in non-pregnant sheep. High quotas of straw and coarse particles prolong the passage time, increasing feed intake and supplements of long straw shorten it. The volume of rumen fluid is lower in ewes fed ad libitum in the stage of late pregnancy and after lactation than during lactation. The rumen fluid volume is also lower in restrictively fed animals during the stage of late pregnancy than during lactation. In animals in the stage of late pregnancy it correlates negatively with the weight of the litter. On an average of all experiments at maintenance level the digestibility of the organic matter in ewes in the 4th month of pregnancy gravidity amounted to 56.6%, in the 2nd month of lactation to 59.8% and in wethers to 59.5% Due to an increase of energy intake from maintenance to 2. maintenance digestibility of the straw-concentrate mixture with 40% straw decreased by 5.5 units and of that with 60% straw by 17.8 units in the period before delivery. Pregnancy in the 4th month resulted in a digestion depression of between 3.0 and 5.8 units.

Untersuchungen zum Stoff- und Energieansatz wachsender Lámmer

A total of 90 lambs (fattening hybrids of either sex of three different genetic constructions and male merino meat sheep) were butchered at the beginning (9...16 kg live weight) or at the end (29...33 kg live weight) of a growth experiment. Total body and the meat of carcass, cutlet and loin were analysed. Significant differences between the genotypes could only proved in the crude ash content. The female animals showed a significantly higher content of fat, dry matter and energy as well as a significantly lower content of crude ash--at the end of the experiment also of protein--in the total body than the male animals. The content of nutrients and energy in the total body could be much more precisely derived regressively from the corresponding content values in the meat of the carcass than from the values of cutlet and loin.

Untersuchungen zur Futteraufnahme von Mutterschafen im Geburtsnahen Zeitraum

8 individual feeding experiments served the ascertainment of the consumption performance of ewes in the perinatal phase. In 6 experiments with a total of 176 fertility oriented ewes the daily intake of pelleted straw-concentrate mixtures between the 4th week ante partum and the 6th week post partum was determined. On average the ewes consumed 1701 g dry matter in the last phase of gestation and 2271 g DM during lactation per animal and day. Intense grinding and NaOH-treatment increased feed intake; high straw content, limited duration of feeding and NH3-treatment decreased it. A higher number of lambs had, in the last phase of gestation, a decreasing and during lactation an increasing effect on consumption. Maize silage in the last phase of gestation resulted in very low feed intake. In contra to this, rations of alfalfa hay and maize silage were consumed well during lactation. There were no significant differences due to species or age with regard to consumption performance.