Increasing protein supply of ruminants – Retard urea products


Is a protein supplement with 75% retard urea content


  • Dairy cow: 100-120 g/animal/day (suggested dose)
  • Cattle, sheep, goat: maximum daily dosage 0.3 g/kg body weight (after training)

advantages (karba-go-75 and mela-go-50)

  • Unique protein- (nitrogen) and energy source for the ruminants.
  • Thanks to the special retardation manufacturing technology, the urea dissolves and hydrolyzes slowly and consistently in the rumen. As a result of this, the urea product can be used as protein-source with higher efficiency and without the danger of poisoning.
  • The safety of feeding with Mela-GO-50 is also improved by the easily utilizable carbohydrates (molasses, glucose) contained in the product.
  • It is well suited to substitute a portion of the protein sources (e.g.: extracted sunflower meal, rapeseed meal) that are easily degradable in the rumen in a cost-effective way.
  • By using this product the protein balance (MFN-MFE) of the ruminants can be influenced favourably in the rumen.
  • The protected fat (hydrogenated fat) used as a retardant material is digested in the small intestine without negatively affecting the rumen activity and the crude fibre digestion.
  • The energy-intake in the form of hydrogenated fat influenced the production of the animals favourably, furthermore improves the harmful effects (e.g.: metabolic diseases, fertilization problems etc.) of the negative energy balance (NEB) appearing in the postpartum period.


It is advised to give the suggested dosage in two portions daily. The expected dosage can be applied after a 10-14-day training. Overdosage should be avoided. Before total dosage feeding, it has to be checked whether the feed portion contains other NPN-materials. The product has to be given only to animals with full-grown rumen functioning and with healthy liver functioning. It can be used for feeding ruminants only.


25 kg, in paper bags lined with polyethylene.

important results of our own tests concerning the product

in sacco and rumen fermentation tests with the product (UWH, 2009-2010)

material and method

Place of the experiments: University of West Hungary (UWH), Faculty of Agricultural and Food Sciences, Animal Research Centre.


  • Natural, prill urea (studied crude protein content: 2900 g/kg feed)
    • fed quantity: 120 g/day/animal
  • Karba-GO-75 (studied crude protein content: 2225 g/kg feed)
    • fed quantity: 160 g/day/animal

analysis of crude protein and dry matter degradation in the rument with in situ procedure

The ruminal degradation of the crude protein of the urea treatments applied in the experiments was examined with 4 Holstein-Friesian steers, equipped with rumen cannulas, with in situ method (Oldham, 1987). The incubation period was 2 hours. The bags were washed out 5 times following the incubation, then on the temperature of 60°C they were dried until reaching the air-dry condition. The experiment was repeated 3 times.

analysis of ph and nh3-content of the rumen fluid

The steers were trained for natural and retard urea with a 10-day pre-feeding. The animals did not eat the urea, but it was directly passed through a cannula, to be sure that the steers pick up the required amount of feed.
After the 10-daypre-feeding, rumen fluid sample was taken through the cannula 4 times a week, before the morning feeding (at 7
⁰⁰), and after that 4 times (7³; 8⁰⁰; 9⁰⁰; 10⁰⁰). The rumen fluid sample was taken to the laboratory in a thermos, and its pH-value and NH3-content were observed there.

results - in situ tests

Shown by the data, that natural urea has degraded in 100% already 2 hours after being in the rumen. In contrast only 32.9% of the Karba-GO-75 products degraded, which proved to be significant at the P<0,001 level, during the statistical analysis.

Compared to the control results: *** P<0,001

results - the effect of retard urea on the ph-value and nh3-content of the rumen fluid














Natural urea






















NH3 (mmol/l)






Natural urea






















Within the vertical columns the figures with different subscripts are significantly different on the minimum level of P<0,05

Ábra 1 EN

Ábra 2

  • In the first 3 hours following the feeding, the pH-value and the ammonia-content of the rumen fluid samples show that the retard product (KARBA-GO-75) has significantly better effect than the natural urea.
  • The “ammonium-peak” occurring after applying the natural urea, in case of the KARBA-GO-75 was significantly smaller.
  • The produced product is suitable to use it in the feeding of ruminants – primarily steers and sheep, furthermore feeding of dairy cows.

karba-go-75 and mela-go-50

in sacco tests (2011, ÁTK)

aim of the test

Examination of the degrability of the two products in the rumen using 8 and 16 hour incubation time. The experiment justifies the retard (degradate slowly) or the bypass (rumen-protected) type of the product.


  • Karba-GO-75 (tested N-content: 34,55%; crude protein-equivalent: 2160 g/feed)
  • Mela-GO-50 (tested N-content: 24%; crude protein-equivalent: 1440 g/feed)


  • In the experiments we found that the products during the average time being in the rumen (approx.: 12 hours) were degraded nearly in 100%.
  • It justifies that the developed rumen protection is retard, and not bypass type.
  • At the same time the results strengthen the results of rumen fermentation tests, which were carried out previously



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