Albumin: A predictor of survival rates in Angora goat kids
By Dr Mackie Hobson BSc(Agric),BVSc

1. Field Studies

Albumin (blood protein) levels play a vital role in the health of the Angora goat.

There are many conditions that may lead to a low Total Serum Protein and Albumin levels in the Angora goat. The most common are due to Parasites (Brown stomach worm, Wireworm and Coccidiosis), LPE (Lymphocytic Plasmacytic Enteritis) and Swelling disease.

For this reason as we often measure the Albumin level as part of a diagnostic evaluation of Angora goats.

Over time with data collection working with Angora goats we have seen a basic correlation between the Albumin ratio and the survival rate.

What is the normal Albumin level in Angora goats?

Albumin levels average 33 g/l (Range 30 -38)

At what Albumin levels are Angora goats likely to die

Data collected (n=36) suggest the following outcomes:

Why do the goats with low blood proteins continue to die after underlying cause has been treated?

Farmers often don’t understand why the goats continue to die after an initial diagnosis of hypoproteinaemia (following coccidiosis or brown stomach worm for example) is made- even after the underlying parasite problem has been treated?

1. Albumin plays a vital role in survival as pointed out in the section below and hence goats continue to die. The Albumin levels may take up to 50 days to return to normal level.

2. Immunoglobulins/antibodies are glycoproteins vital for a functioning and effective immune response. Their levels will be low until blood proteins return to normal. This is the reason that goats may die of many secondary causes such as pneumonia or septicaemia during the recovery period.

How long does it take for Albumin levels to return normal?

In normal patients, the rate of albumin degradation is about 4%/day.

With a half-life for albumin of 18 to 20 days and the fractional replacement rate, the return of serum albumin to normal may take 3 or more weeks.

In previous studies on Angora goats following brown stomach worm and coccidiosis it has been demonstrated that it may take as long as 50 days to return to normal levels (see graph below)

Why is Albumin so important?

• Maintains blood oncotic pressure.
• Role in transport of
• Calcium, Zinc, Sodium, Magnesium (Albumin has a strong –ve charge so attracts these + ions)
• Hormones,
• Fat soluble Vitamins (A,D,E,K)
• Bilirubin which is a yellowish pigment that forms during the normal breakdown of red blood cells. Bilirubin binds to albumin and is carried to the liver for conjugation and excretion. As long as it is bound, bilirubin is not toxic.
• Platelet function (blood coagulation). Albumin has a heparin-like activity by enhancing antithrombin III activity
• Free radical scavenger in inflammation. Albumin binds fatty acids and toxic substances to inactivate them when produced by inflammation and bacteria. Albumin also has antioxidant properties
• Albumin is necessary for the proper function and healing of the GI tract.
• It stabilizes the vascular endothelium and assists in maintaining capillary permeability to macromolecules.

What you should know when using drugs on Angora goats that have low Albumin levels

• NSAIDs (Anti-inflammatories) are generally more than 90% protein bound. Even slight displacement of the drug can cause toxic concentrations to accumulate in circulation.
• Several classes of drugs are dependent on albumin: Antibiotics (e.g., cephalosporins, penicillins, sulfonamides, tetracycline).

How it is Albumin made?

Albumin is produced exclusively by liver cells (hepatocytes)

Osmoreceptors within the liver can detect changes in circulating oncotic pressure in the liver blood vessels and this stimulates Albumin synthesis. Hepatocytes can also be stimulated by cortisol, thyroxine, and sex and growth hormones to produce Albumin.

As long as 10% to 15% of the liver is functioning normally and no excessive losses are present, movement of albumin from the interstitial pool keeps albumin synthesis and plasma albumin concentrations normal.

What can cause low albumin levels?

Snyman and Herselman (2004) suggested factors contributing to a lowered blood albumin level .

Protein deficiency – reduced production of plasma proteins

Malnutrition decreases synthesis, albumin is spared as a catabolic protein source and muscle protein is used. Therefore, the body maintains serum albumin levels at the expense of muscle protein.

Fasting for as little as 18 to 24 hours can cause a 50% decrease in albumin production

• Low-quality feed (low digestibility, low % crude protein)
• Low feed intake (only irrigated pastures – too high moisture content of feed)
• Low protein absorption from the intestines - LPE (lymphocytic plasmacytic enteritis), intestine mucosa damaged by parasites or coccidian.
• Interference with the metabolism of plasma proteins

 Decreased synthesis:

• Liver disease - The mechanisms responsible for the decreased albumin levels seen in most cases of the hepatocellular disease include:
• Increased immunoglobulin levels;
• third-space loss (extravasation into the extravascular space) and
• Direct inhibition of synthesis by toxins

Increased protein loss:

• Physiological protein loss: Mohair production
• Loss through intestinal tract - loss of albumin does not generally cause concern unless the loss is excessive or long-lasting.
• Loss through urine
• Pregnancy
• Increased permeability of capillary membranes: Allergic conditions, Infectious diseases
• Internal parasites: Brown stomach worm (Ostertagia circumcincta), Wireworm (Haemonchus contortus), Coccidiosis, Conical fluke (Paramphistomum)
• External parasites: Ticks, Blue lice, Blood parasites
• Any stress-inducing condition (Weaning, Shearing, Dipping, Castrating). In states of metabolic stress, albumin synthesis becomes a low priority

 Redistribution:

• Haemodilution - For the most part, the minor decreases in albumin concentration attributable to dilution alone do not seem to result in clinical consequences.
• Increased capillary permeability (leakage into the interstitium)
• Decreased lymph clearance.
• The inflammatory process - The most common cause of decreased plasma albumin levels is related to inflammatory processes (i.e., acute-phase response and chronic inflammatory disorders). “Capillary leak syndrome”

Where is most of the Albumin in the body?

About 30% to 40% of total body albumin is concentrated in plasma. The other 60% to 70% is found in the intracellular and interstitial spaces of the skin, muscle, liver, lung, heart, kidneys, and spleen.

Interstitial albumin is continuously returned to systemic circulation by lymphatic drainage into the cranial vena cava.

Approximately 10% of interstitial albumin remains tissue bound and unavailable for mobilization.

REFERENCES

Snyman MA, Herselman MJ    2004    Investigation into the probable cause, predisposing factors and effective treatment of swelling disease in Angora goats  The

Veterinary Technician: The Role of Albumin and Fluids in the Body ,Dana Call , RVT , VTS , (ECC)