Löhnert Hj

Überhöhte orale Eisengaben an Schafe

4 digestibility trials (4 male sheep per group) and 2 growth trials were carried out with 24 (V 1) and 32 (V 2) fattening lambs to investigate the effect of abundant oral Fe doses on the digestibility of crude nutrients in a ration of barley + dried green feed and on the results of fattening and carcass yields. Fe supplementation (less than 1400 mg per sheep/day) did not significantly change the digestibility coefficients of crude nutrients. Increasing Fe levels in the concentrates decreased the rates of liveweight increase and food consumption in both growth trials. Well-established statistical evidence was provided for the decline in absolute carcass yields resulting from the lower weight of the lambs at the end of the fattening period after Fe supplementation.

Investigations on vitamin-A-requirements and vitamin-A-status of growing cattle. 1. Experiments with calves.

Five experiments with 18 to 36 male calves each of the black and white dairy cattle breed (age: 14-21 days, initial live weight: approximately 45 kg per animal) were carried out in order to investigate the influence of various vitamin A supply (0-80,000 IU per 100 kg LW and day) on dry matter intake and weight gain as well as the vitamin A status of liver and blood plasma over 84 days. The calves consumed a diet free of carotene and vitamin A consisting of milk replacer, concentrate and chopped wheat straw. The calves were fed in three experiments for a longer time in order to observe the further vitamin A depletion. Nine animals consumed an unsupplemented ration, nine other one got 10,000 IU vitamin A per 100 kg LW and day. Biopsies of liver and plasma samples were taken from 4 animals per group every four weeks. The various vitamin A supplementation did not significantly influence the dry matter intake (Mean: 1.67; 1.48 to 1.80 kg DM per animal and day) and the weight gain of calves (Mean: 702, 599 to 770 g per animal and day). First vitamin A deficiency symptoms (reduced feed intake, decreased weight gain, diarrhoea etc.) were observed in animals of unsupplemented group after 100 days of experiments. After 84 days the vitamin A concentration of liver of animals of unsupplemented groups decreased to 1.3-32.2% compared with the begin of experiments (60.6-155.7 mumol/kg fresh matter). Up to 51% of initial concentration were found when 10,000 IU vitamin A per 100 kg LW and day were fed. About 25,000 IU vitamin A per 100 kg LW and day were required in order to keep the initial level of vitamin A concentration of liver. The plasma vitamin A concentration is unsuitable for estimation of vitamin A status of calves. The concentration of vitamin A of liver and plasma amounted to 114 mumol per kg and 0.25 mumol per litre at the begin of experiments. The vitamin A concentration of liver of unsupplemented group decreased to 20 mumol per kg, that of plasma increased to 0.28 mumol per 1 at the end. A strong vitamin A deficiency (liver concentration: less than 10 mumol/kg) may cause a decrease of vitamin A concentration of blood.

Untersuchungen zum Einsatz von dekantierten Feststoffen der Schweinegülle in der Mastrinderernährung

: 3 feeding trials were carried out in which dried and decanted solids from pig faeces were used in varying proportions. A total of 55 fattening bulls were slaughtered at the end of the trial period. Additionally, a number of characteristic data on ruminal physiology were determined in these trials. The molar proportions of acetate and propionate found with the feeding of rations containing faecal solids were intermediate between those observed in concentrate feeding and those established with the feeding of commercial food pellets containing 40% or 50% straw. Slight increases in the molar proportion of butyrate were noticed when rations were fed containing faecal solids. Nonfasted animals fed rations containing a higher proportion of coarse fodder had a significantly lower slauglitered bady mass (0; 50% straw; 25% straw + 25% faecal solids; 50% faecal solids: 55.7%; 51.9%; 51.1%; or 52.2% of the final fattening weight). They developed a lower proportion of flesh and contained a higher proportion of digesta in the stomach and intestines (11.4%; 18.4%; 17.0%; or 16.3% of the final fattening weight). The proportion of fat contained in the stomach & bowels decreased with the feeding of straw or faecal solids. Other organs and tissues were not affected by the different types of feeding used. An analysis of the results of slaughtering showed that the feeding of faecal solids did not produce any specific effect.

Untersuchungen zum Einfluß des Polyäther-Antibiotikums „Monensin“ auf Mast- und Schlachtleistung sowie Protein- und Energieansatz von Bullen

: In an individual feeding experiment (150-500 kg live weight) the influence of the polyether antibiotic Monensin on the fattening, slaughtering and retention performances of crossbreeding dairy bulls (genotype 31) and fattening hybrids (genotype 61) was ascertained. The supplementation of the polyether antibiotic on average resulted in a decrease by approximately equal to 11% of the dry matter and energy expenditure per kg weight gain due to a lower feed intake and a higher live weight gain. The slaughtering parameter investigated and the chemical composition of the empty body remained uninfluenced. The daily nutrient retention values were positively influenced by the Monensin supplementation since the fattening bulls of the test group required 30 days less to achieve the attempted fattening weight. The additional retention of protein, fat and energy per animal and day in the dairy bulls approximately equal to 10.9; 13.5 and 16.4% and in the fattening hybrids 1.9; 3.2 and 2.6%. Due to a higher energy retention at a lower level of feed and energy intake after Monensin supplementation an average of approximately equal to 11.3 and 15.4% resp. more of the consumed digestible protein and the digestible energy resp. were retained in the empty bodies. One can conclude that Monensin improved the utilisation of feed energy; obviously the effect of the polyether antibiotic is due to its influence on processes in the rumen or directly or indirectly on metabolism.

Der Einfluß des Polyätherantibiotikums “Monensin” auf Pansenfermentation und Mastergebnisse von Milchrindkreuzungsbullen und Masthybriden

The influence of the polyether antibiotic Monensin on the rumen fermentation and the fattening results of fattening hybrids (genotype 61) and crossbreeding bulls of dairy cattle (genotype 19) was ascertained in two feeding experiments (E1 and E2). Caused by the supplementation of the antibiotic, the molar acetate quota decreased (1.9 to 4.8 Mol %) and the molar propionate concentration increased (0.2 to 2.9 Mol %) in the rumen fluid of crossbreeding bulls of dairy cattle and of fattening hybrids, it is, however, below the range described in literature. With the exception of the fattening hybrids in E1, the supplementation of Monensin resulted in the diminished intake of dry matter, the daily increase of the live weight of all groups of fattening bulls was higher (E1: fattening hybrids: 1106 resp. 1199g; crossbreeding bulls of dairy cattle: 1037 resp. 1058 g; E2: 997 resp. 1024 g; 895 resp. 981 g without resp. with Monensin). After the Monensin supplementation the crossbreeding bulls of dairy cattle showed a distinctly bigger decrease of the feed intake and a rise of the live weight increase than the fattening hybrids. For this reason the genotypes of dairy cattle showed in both experiments after the Monensin supplementation a bigger decrease of expenditure (0.8 resp. 7.1% and 5.6 resp. 11.3% in experiments 1 and 2) than the fattening hybrids.