K. Gruhn

The effect of selenium deficiency on reproduction and milk performance of goats

Even with a high vitamin E offer, Se deficiency (less than 38 micrograms/kg DM of the ration) led to a 33% lower conception rate (P less than 0.05) in goats and to a greater than 50% lower number of kids on the 91st day of life. The Se deficiency reduced the milk production significantly by 23% during the first 56 days of lactation, the milk fat production by 11% and the milk protein production by 12%.

[Ruminal 15N-straw degradation in sacco and the in vivo digestibility of 15N from straw in the sheep and pony].

The nylon-bag method was applied for determination of the rumen degradation of dry matter and nitrogen of 15N-labelled wheat straw. For the experiment 4 wethers fitted with a rumen cannula were used. The bags containing 15N straw were introduced into the rumen and withdrawn 3, 6 or 12 h after incubation. In a second experiment the apparent 15N-digestibility of the same straw was determined in wether and pony. The dry matter disappearance varied between 6 and 23%. For 15N-labelled straw the disappearance of 15N was higher than that of total N. 12 h after incubation 71% of 15N and only 25% of total N were disappeared. It was calculated that after incubation rumen microbial-N in the nylon bag increased from 31% (3 h) to 45% (6 h) and 61% (12 h) resp. The apparent 15N digestibility amounted 53 +/- 2% for wethers and 51 +/- 2% for ponies.

Untersuchungen zum Einfluß gestaffelter Gaben an Soja- extraktionsschrot auf die scheinbare Verdaulichkeit der Rohnährstoffe und Aminosäuren bei kolostomierten Legehennen

Four colostomized laying hens per group were given a ration of barley and soya bean oil meal (SBM) with 12.5, 25.0 and 37.5% SBM resp. The crude protein intakes were 14.0, 17.7 and 21.4 g per animal and day. The lysine intake raised from 681 mg (group 1) to 1275 mg (group 3) per animal and day. The digestibility of dry matter and of the N-free extracts of the ration decreased with the rising SBM portion in the ration. The digestibility of crude protein remained constant. The investigated amino acids (Lys, His, Arg, Cys, Met) were higher digested in the 37.5% SBM ration than in the 12.5% SBM ration. The following digestibility values for SBM were found by means of the difference method: Dry matter 52.5%, crude protein 83.1%, crude fat 51.7%, crude fibre 5.5%, N-free extracts 50.6%. The level of the SBM did not influence the digestibility of the crude nutrients. The apparent digestibility of lysine from SBM depended on the level of intake and was found to be 82.3, 83.4 and 89.0%, resp. There were no differences in the digestibility of other amino acids.

Investigations on Vanadium Deficiency in Ruminants

The essentiality of V for the fauna is controversial since it was not possible to induce specific V deficiency symptoms. Up to now, there have been no long-term V deficiency experiments in which the influence of V deficiency on feed-intake, growth, reproduction and life expectancy was investigated and which resulted in V deficiency symptoms.

Einfluß nativer Rohfaser auf die Verdaulichkeit der Aminosäuren bei Legehennen der Mastrichtung

One-year-old colostomised laying hens of the fattening species received 120 g of a basic ration approximately meeting their requirements (control group) and the animals of the test group 10, 20, 30 resp. 40 g wheat straw meal in addition. Straw meal admixtures of up to 30 g had no drastic influence on the apparent digestibility of amino acids. 40 g straw meal in the ration increased the excretion of the essential amino acids by 19% and of the non-essential ones (particularly glycine, zystine and serine) by 39% in comparison with the basic ration. The amount of free amino acids and of peptide in feces was significantly lower when the ration contained 20 g straw meal. On an average of the five variants checked, the amount of amino acid nitrogen soluble in TCA in the total-N in feces was 12%. Due to the partial digestion of the amino acids of the straw meal and the favourable influence of 10...20% straw meal in the ration on absorption, 2...3% additional nitrogen in the form of essential and non-essential amino acids was available to the hens in this range of admixture according to the analysis of feces.

Der Einfluß der Nüchterung auf Den N-Stoffwechsel des Broilers

: Four male broilers each were killed 3, 6, 12 and 24 hours after the last food intake and divided into nine parts, The significant diminishing of the fresh liver mass in the test period amounted to 31%. With the increasing fasting time the N-content per g dry matter increased in liver, pancreas, muscles and the rest of the carcass. Because of the decrease in mass a statistically proved diminishing of the total N mass could be registered. The most significant changes were established in the total content of N soluble in TCA in the organs. The decrease in % from the first to the fourth measuring point amounted to 44% (liver), 40% (kidneys) and 28% (small intestines). Concerning these three organs we can maintain that the changes in the total N-content registered in the 24 hours fasting are chiefly limited to the TCA-soluble quota.

Der Einfluß der Nüchterung auf den Stoffwechsel der freien Aminosäuren verschiedener Gewebe des Broilers

16 male broiler chicken fed with commercial-grade broiler fattening feed were killed in groups of four in intervals of 3, 6, 12 and 25 hours after the last food intake. The content of free amino acids was quantitatively determined in the small intestines, the liver and the complete muscular system. The highest concentration of free amino acids per gram of tissue could be detected in the small intestines between 3 and 6 hours and--phase shifted--in the liver between 6 and 12 hours after the last food intake. The changes of the concentration in the muscular system between the four measuring points were in most cases not statistically significant. The content of free amino acids in the three proofed tissues of fattening hybrids with a high demand of amino acids and a high protein synthesis performance was considerably above the values for rats as they are given in technical literature. The rhythmic changes of the concentration of free amino acids in the tissues in dependence on the interval between the last food intake and the killing require standardized conditions for metabolism-kinetic investigations of which the calculation of the content of free amino acids is part.

Die Verwertung des Eiweißes gemischter Futterrationen beim laktierenden Schwein unter Berücksichtigung des Gehaltes der Rationsproteine an essentiellen Aminosäuren

Nitrogen trials were performed on lactating pigs to investigate the utilization of protein from some feeding rations. The basal ration fed to the sows consisted of ground barley+oats+flaked potatoes or ground barley+sugar beet chips. The basal ration was supplemented with a protein source. The protein feeds used were extracted soya bean meal, horse bean meal, fish meal, maize gluten and waste liquor yeast. Data for the average biological value of the dietary proteins were as follows (in the given order of protein feeds): 61%, 59%, 54%, 58% and 37%. PPV data were: 44%, 43%, 39%, 44% and 28%. The proteins of nearly all rations were deficient in lysine when compared with the range of amino acids present in the proteins of sow milk.

Die Substitution von Eiweißfuttermitteln durch lysinergänzten proteinreichen Weizen während der Aufzucht und Legeperiode von Hennen

In the present work 8 hens taken from each of the 16 experimental groups (90 birds per group) were killed at the end of the trial period (52 weeks). The weight of the organs was determined and bones, the utilizable parts and the residual carcass were analyzed for their crude nutrient content. The experimental birds received rations containing a large proportion of high-protein wheat supplemented with varying levels of lysine. Variations in the lysine supply did not affect the mass of blood, feathers, bones, liver, stomach, heart and ovaries, including ovarian follicles. An analysis of the utilizable parts (flesh, stomach, heart, liver, follicles, fat) for crude nutrients showed that the heavier birds receiving adequate amounts of lysine contained less crude protein and more crude fat than the smaller birds. A positive correlation was found to exist between the crude ash content of these samples (expressed as %) and the levels of lysine supplied during the laying period. All the birds receiving the lysine-deficient ration during the time of rearing or during the laying period contained significantly less crude ash in their bones. Alongside with the crude ash content the phosphorus content of the bones decreased when the birds where fed the diet for laying hens.

Bestimmung der Verdaulichkeit der Rohnährstoffe und Aminosäuren zweier Ackerbohnensorten (Vicia faba L.) an kolostomierten Legehennen

The apparent digestibility of crude nutrients and the amino acids in the varieties Fribo and Erfordia of horse bean (Vicia faba L.) was determined in a digestibility and N-balance experiment with 32 colostomised laying hen hybrids. For this purpose 4 rations each with a rising quota of horse beans (10%, 20%, 40%, 50%) were tested with 4 hens each in a 6-day collecting period; the digestibility values were determined according to the regressive method. The average apparent digestibility is (formula; see text) The values of the apparent digestibility of the 17 amino acids vary for the variety Fribo between 68.6% (methionine) and 90.6% (arginine) and for the variety Erfordia between 47.7% (cystine) and 89.5% (arginine).