[Effect of graduated vitamin D3 doses and different ration composition on the 25OH-vitamin D3 plasma concentration and fattening and slaughter production of bulls]. / Einfluss gestaffelter Vitamin-D3-Gaben und unterschiedlicher Rationsgestaltung auf die 25OH-Vitamin-D3-Plasma-Konzentration sowie Mast- und Schlachtleistung von Mastbullen.

In a individual feeding experiment (348 days) 24 fattening bulls were given either a ration high in roughage (2.8 kg concentrate mixture, wheat straw ad libitum: group I) or high in concentrate (5.6 kg concentrate mixture, wheat straw ad libitum group II) supplemented with various levels of vitamin D3 (0, 250, 500, 1,000, 2,000, 4,000 and 8,000 IU per 100 kg body weight (bw) and day) and minerals as required. After 58, 101, 134, 172, 205, 277 and 340 days 25-OH-D3 plasma concentration was estimated. Fattening and slaughtering parameters were measured. The 25OH-D3 plasma concentration was significantly influenced by vitamin D3 supply, kind of ration and day of taking samples. 25-OH-D3 plasma concentration decreased below 5 ng per ml when vitamin D3 supply was less than or equal to 250 IU per 100 kg bw and day. The initial plasma levels were maintained when 500 IU vitamin D3 per 100 kg bw and day was given (6.6 ng per ml). Administration of greater than or equal to 1,000 IU per 100 kg bw and day increased 25OH-D3 plasma level (greater than 10 ng/ml). Plasma 25OH-D3 concentration was significant higher when bulls consumed diets rich in concentrate (10.6 and 18.2 ng/ml for I and II after 340th day). Differences in content of cell walls and crude fat of rations may be responsible for results. Daily weight gain of bulls amounted to 712 and 945 g when fed diets I or II. Dry matter intake and live weight gain were not significantly influenced by different vitamin D3 supply. Clinical symptoms of rachitis did not appear.

[The effectiveness of oral and parenteral vitamin A doses in growing cattle with different vitamin A supplies]. / Untersuchungen zur Effektivität oraler und parentaler Vitamin-A-Gaben bei unterschiedlich mit Vitamin A versorgten wachsenden Rindern.

The effect of one single oral or parenterally administered dose of 1 million IU vitamin A on the vitamin A depot in the liver and on blood plasma vitamin A concentrations was investigated in 3 individual feeding experiments with involvement of 18 and 24 calves or 24 fattening bulls. 50% of all animals in each of the 3 experiments received feed without any vitamin A through 108 or 112 or 209 days, prior to vitamin A administration, or received 10.000 IU/100 kg live weight and day. Parenteral vitamin A administration in either group yielded rise in blood plasma from 0.06--0.35 to 26.2--30.2 mumol/l, after 1 or 2 days. The maximum value measured after oral administration was 1.9 mumol/l. Most of the plasma values had returned to normal (0.6--12. mumol/l) within 14 days from administration. Oral and parenteral vitamin A doses, after 14 days, caused significant rise in vitamin A concentrations in the liver (from 15.5 to 82.5), with the increase resulting from parenteral administration (from 13.7 to 99.1) being clearly higher than that resulting from oral administration (from 17.3 to 65.9 mumol/kg fresh liver tissue). The same trends were recorded from recovery of vitamin A from the liver (26.8% after parenteral administration versus 15.0% in the wake of oral doses). Storage in and recovery from vitamin-A depleted animals were below values recorded from young cattle with sufficient vitamin A supply. These findings are likely to confirm that one single parenteral vitamin A administration was of clearly higher effectiveness, as compared to oral application.

[The effect of avoparcin on apparent digestibility, characteristics of rumen fermentation and fattening and slaughter output of growing cattle]. / Untersuchungen zum Einfluss von Avoparcin auf scheinbare Verdaulichkeit, Kennzahlen der Pansenfermentation sowie Mast- und Schlachtleistung wachsender Rinder.

Four digestion experiments with 5 wethers each (0, 15, 30 or 60 mg avoparcin per animal and day), three individual feeding experiments (28, 18 or 56 bulls per experiment; 0 and 150/200; 0, 250 and 500 or 0 and 200 mg avoparcin per animal and day in the experiments 1, 2 or 3) and two group feeding experiments (60 bulls and 161 heifers per experiment; salt lick stones without or with 2.5 g avoparcin per kg) were carried out in order to investigate the influence of avoparcin on apparent digestibility, figures of rumen fermentation, fattening and slaughtering results as well as protein, fat and energy retention. Avoparcin supplementation did not significantly influence the apparent digestibility of organic matter and crude nutrients. Concentration of acetate of rumen liquid was decreased (16 or 36) and that of propionate was increased (25 or 50 mmoles per mol) when 200 or 500 mg avoparcin per animal and day were added. Acetate:propionate ratio decreased from 4.2 to 3.5 and 3.1:1. Avoparcin did not influence feed intake, enhanced daily weight gain (37 to 174 g per animal and day) and improved feed efficiency (5 to 26%). Salt lick stones with avoparcin increased weight gain (58 and 96 g per animal and day). Slaughtering results and body composition of bulls were not influenced by avoparcin. Daily retention of protein, fat and energy was significantly increased (16 to 18%; P less than 0.05) when avoparcin was supplemented.

[The effect of a monensin-containing bolus on the live weight increase and characteristics of rumen fermentation of growing cattle]. / Untersuchungen zum Einfluss eines monensinhaltigen Bolus auf die Lebendmassezunahme und Kennzahlen der Pansenfermentation wachsender Rinder.

Eight feeding experiments (4 on pasture and indoors each) with 401 growing cattle were carried out in order to measure the influence of a monensin device on daily weight gain. The monensin device effected on the average 7 g (1.4%) and 37 g (4.3%) higher daily weight gain on pasture and indoors resp. (P greater than 0.05). The weight gain of animals varied between 92.5 and 112.5% compared with the unsupplemented groups. The monensin device caused a higher weight gain of easier cattle than of heavier ones (greater than 300 kg body weight). The device has had no significant effect on figures of rumen fermentation. Probably the monensin level delivered from the device (100 +/- 50 mg per animal and day) is to low for heavier cattle.

[The vitamin A requirement and the vitamin A status of growing cattle. 1. Studies of calves]. / Untersuchungen zum Vitamin-A-Bedarf und zum Vitamin-A-Status wachsender Rinder. 1. Mitteilung. Untersuchungen an Kälbern.

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.

[The effect of various Ca and P supplies on the metabolic parameters of wethers and bulls and on the fattening performance of bulls with vitamin D deficiency]. / Einfluss unterschiedlicher Ca- und P-Versorgung auf Stoffwechselparameter von Hammeln und Bullen sowie auf die Mastleistung von Bullen bei Vitamin-D-Mangel.

The influence of different Ca- and/or P-supply on metabolic parameters and Ca-resp. P-balance was tested in 12 balance trials with mature wethers at different feeding regimes. Furthermore the influence of dietary Ca-excess on metabolic parameters and fattening performance of bulls was also tested. Increasing the P-intake at normal Ca-supply (Ca/P-ratio 1:1.7 ... 3.6) or at Ca-excess (Ca/P-ratio approximately 1.6:1) led to a higher P-concentration in blood and urine and lowered the Ca-content in serum as well as the apparent Ca-balance. These effects were greater in the ration rich in concentrate than in the ration rich in roughage. Increasing the dietary Ca-intake (Ca/P-ratio approximately 3.6:1) had no influence on metabolic parameters of wethers. In a vitamin-D-deficiency trial the Ca supplementation (Ca/P-ratio approximately 4.2:1) improved the performance of bulls and retarded the incidence of signs of rickets (lower feed intake, higher concentration of alkaline phosphatase in serum, lower bone mineralisation) for about 100 days compared with the control group (Ca/P ratio: 1.2:1).

Rumen dry matter degradability and apparent digestibility of variously treated rice hulls.

Rice hulls from Hungary, Colombia, and Cambodia were used for measuring with the nylon bag method the dry matter degradability in the rumen of sheep. After 48 h rumen incubation time the dry matter loss varied between 10.0 and 27.7%. The 48 h rumen dry matter loss of rice hulls from Hungary increased from 14.0 (untreated control) only to 17.9, 20.1, and 17.0% after chemical treatment with 2% NaOH, 4% CaO, and 4% urea, respectively. gamma-irradiation with doses of 0, 0.1, 0.25, 0.5, 1, and 2 MGy effected rumen dry matter losses of unground rice hulls from Hungary of 6.4, 14.5, 13.5, 21.3, 37.1, and 70.5%. The apparent digestibility of organic matter of untreated rice hulls from Hungary amounted to 19.2%, as found in tests with wethers. The main reasons of low digestibility and the negligible effect of chemical treatments are the high contents of lignin (ca. 15%) and silica (up to 23% of the dry matter). Therefore rice hulls are not suitable as feedstuff for ruminants.

Profile of isoacids in rumen fluid and influence of added isoacids on in sacco dry matter disappearance of untreated and ammonia treated wheat straw.

The influence of type of diet and time after feeding on concentration of isoacids in rumen fluid of 6 fistulated sheep were investigated. The concentration of isoacids in rumen fluid was higher in diets rich in concentrate and protein (5.6) than in roughage diets (3.4) or in straw-starch-urea diets poor in native protein (highest concentration: 2.1 mmol/l rumen fluid). Feeding of roughage diet or straw-starch-urea-diet effected a significant decrease of concentration of isoacids in the rumen fluid after morning feeding, but concentrate-roughage diet, increased the isoacids-concentration. Reasons for decreased concentration of isoacids may be a shortage of corresponding amino acids and a high activity of cellulolytic microbes. Infusion of isoacids (3 g per day) in the rumen of sheep fed with a straw-starch-sugar-urea diet did not significantly influence the in sacco dry matter degradability of untreated wheat straw, but increased the dry matter loss of ammonia treated wheat straw from 16.0; 26.6; 39.4; 54.0 and 58.8% to 17.3; 29.7; 43.1; 56.3 and 63.0% after 6; 12; 24; 48 and 72 h rumen incubation time respectively. Further experiments seem to be necessary. The effect of isoacids may be expected to occur with poor quality feeds, rich in fibre low in protein and hence low in branched-chain amino acids.

Influence of dietary niacin on volatile fatty acids in rumen liquid of sheep and rumen dry matter degradability of untreated and ammonia-treated wheat straw.

Three rumen fistulated sheep were fed with roughage (1200 g artificially dried grass) or a concentrate/roughage diet (600 g concentrate, 400 g artificially dried grass per animal and day). The diets were unsupplemented or 0.5, 1 and 2 g niacin per animal and day were added. After a 14-day adaptation period samples of rumen liquid were taken 0, 1, 2, 3, 4 and 6 h after morning feeding. In a second experiment untreated and NH3-treated wheat straw were incubated in nylon bags for 6, 12, 24, 48 and 72 h in the rumen of 5 sheep fed with 1.2 kg artificially dried grass and unsupplemented or supplemented with 1 g niacin per day. Niacin did not significantly influence the total concentration of volatile fatty acids, acetate and branched chain fatty acids in both types of diet (P less than 0.05). 0.5 and 1 g niacin in the roughage and 0.5 g niacin in concentrate/roughage diet increased the propionic acid concentration and reduced the butyric acid concentration in rumen liquid of sheep (P less than 0.05). Niacin resulted in a small decrease (P greater than 0.05) of dry matter degradability in rumen. After 48 h incubation time, the dry matter disappearance of untreated and NH3-treated wheat straw amounted to 35.4 and 46.2% resp. The effects of niacin on rumen fermentation may be useful in avoiding ketogenic situations in dairy cows.

Influence of beta-carotene supplementation on carotene content of ovaries of heifers.

Carotene is stored as a tissue reserve in the corpus luteum. With different carotene supplementations in heifers (0, 100, 200 and 300 mg/animal and day) it could be clearly seen that the carotene concentration in the corpus luteum (2.3, 27, 50 and 81 micrograms/g) was directly dependent on it. On the other hand, the weight of corpus luteum (3.8 to 4.6 g) was not influenced (P greater than 0.05) by carotene supplementation. Apart from corpus luteum carotene was also stored in orange coloured pigment corpuscles of ovary. The carotene concentration of the pigments was 6 to 70 times higher (158, 150, 334 and 487 micrograms/g) than in the corpus luteum. Weights of the pigments rose with increased carotene doses. However, the weights amounted to merely 4 to 11% of the corpus luteum's mass. The amount of carotene in corpus lutea of animals added with carotene contained was higher than that of pigments. Further investigations are necessary to characterize the physiological importance of the pigment corpuscles.