Royal Canin Nutritional Information

Royal Canin Nutritional Information

Focus on: Borage oil

Borage (Borago officinalis) is a plant originally from Syria. It is now grown in North Africa and various countries of Europe, including France, Britain, Germany and the Netherlands. The first traces of its use are from the first century AD. Traditionally, the young leaves were consumed in salads or soups and the flowers gave a refreshing flavor to wine.

Borage Seeds

Borage blooms over two months, which means that not all the seeds become mature at the same time. It is important to only harvest the mature seeds, which look like grains of pepper, as they have twice the oil content of green seeds (30% vs. 15%).

Harvesting may be done naturally – recovering the seeds as they fall by rolling out a tarp between the rows – or mechanically, using small carts to catch the seeds, which are loosened by vibration.

Borage Oil

The seeds dry out naturally somewhere cool in the shade. To avoid mold, they must be used shortly after harvesting. The oil is obtained by grinding and pressing the seeds. The procedure is performed in a cold environment. Above 50°C (122°F), the fatty acids risk being denatured.

Unparalleled Gamma-linolenic Acid (GLA) Content

The oil is obtained by pressing the borage seeds. Their unsaturated fatty acid content is 80% and they have a large content of a particular fatty acid of the omega-6 family, known as gamma-linolenic acid (GLA). GLA is normally synthesized from linoleic acid.

Most vegetable oils have a very high linoleic acid content, but the only oils that contain a beneficial quantity of GLA are borage oil, the oil of blackcurrant seeds and evening primrose oil.

Linoleic acid undergoes successive transformations to produce all the fatty acids of the omega-6 family. Each step is triggered by a particular enzyme. The metabolism of unsaturated fatty acids in cats remains a controversial subject. Some authors feel that desaturated D6 is ineffective in cats (Sinclair et al., 1979). More recent studies (Pawlosky et al., 1994) show that the conversion of linoleic acid to GLA is possible, with increased efficacy when the animal is deficient. This process however remains limited in the cat. In this study, the authors reported that only 0.06% of the ingested linoleic acid was converted to GLA.

Nutritional Benefit of GLA

Borage oil is widely used in nutrition and cosmetology. It is used in products designed to rejuvenate the skin. It is especially indicated for the dry skin of cats that tend towards seborrhea. Cats respond very well to the addition of GLA to the diet.

The supplementation of GLA promotes the increased production of type 1 prostaglandins over the production of type 2 prostaglandins, which are much more pro-inflammatory. Borage oil is accordingly potentially beneficial in all situations demanding an antiinflammatory effect.

The beneficial effects of GLA have been studied most in dermatology. Major alterations to the condition of the skin (dull hair, scaling and skin ulcers that do not heal easily) are observed in cats fed for 18 months with a food containing sunflower seed oil, which is rich in linoleic acid, as the sole source of fat (Frankel & Rivers, 1980). Substituting half the sunflower seed oil with evening primrose oil, which is rich in GLA, helps obtain a fast improvement in the condition of the skin in these animals. Reversion to the original diet results in deterioration of the condition of the skin again. This study therefore confirms the benefit of high GLA oil supplementation to alter linoleic acid desaturation.

Figure 15. Origin of the balance between type 1 and 2 prostaglandins.  

Other studies show the benefit of GLA intake in feline dermatology. In cats with papulo-squamous dermatitis, the dietary incorporation of evening primrose oil, helped to obtain better therapeutic results than sunflower oil, (Harvey, 1993a). With feline miliary dermatitis, the efficacy of GLA administration was improved when it was combined with fish oil (Harvey, 1993b).

Protein Composition of Cat Hair

There is little data on the amino acid composition of hair. It is determined through hydrolysis with hydrochloric acid for 24 hours. This method may however lead to the degradation of some amino acids or underestimate the content when hydrolysis is incomplete. Studies (Robel & Crane, 1972; Darragh et al., 1996) have reported alternative techniques to minimize these inaccuracies. Hendriks et al. (1998) reported that the color or sex of the animal has no impact on the amino acid composition of the hair.

The daily protein requirement to regenerate skin cells and stimulate hair growth is estimated at almost 30% of the daily protein intake (Scott et al., 2001). (©Yves Lanceau/Royal Canin - Persan ).

The total nitrogen content of cat hair is said to be 15.1% (Hendriks et al., 1998). This author also reported that amino acids represent 86% of the hair mass in this species. The remainder is divided between nonnitrogen compounds: minerals, sterols and complex lipids.

The amino acid composition of cat hair is similar to that of dogs, sheep, horses and humans, although the proline content in cats is lower than in the other species. The most abundant amino acids in cat hair protein are cysteine, serine, glutamic acid and glycine (Table 1). Sulphur containing amino acids can account for up to 37% of the total amino acids (Swift & Smith, 2000). They build cysteine bridges, which are essential to hair construction. Cysteine is also involved in the enzymatic production of pheomelanin (Granholm, 1996).

Key Points for Covering Protein Requirement with Respect to Hair Growth

The quantity of amino acids required for hair growth in a given period of the year can be estimated by multiplying the amino acid concentration in each cat hair by the hair growth rate during that period of the year (Hendriks et al., 1998). The daily protein requirement to regenerate skin cells and stimulate hair growth is estimated at almost 30% of daily protein intake (Scott et al., 2001).

The effects of general protein deficiency:

- Initially, a drop in the diameter of the hair and reduction in the size of the hair bulb
- Subsequently, the hair becomes dull and fragile, growing more slowly and falling out faster.

Isolated deficiency of sulfur amino acids (cysteine, methionine) may lead to the same clinical signs.

Studies show the impact of a deficiency of tyrosine and phenylalanine, a melanin precursor. After a few weeks red hairs begin to appear, especially in black cats. Supplementation reverses this phenomenon. The hairs of reddish cats (which have pheomelanin pigments) also take on a lighter color in response to deficiency (Morris et al., 2002; Anderson et al., 2002; Yu et al., 2001). Morris et al. (2002) show that around three times as much phenylalanine and tyrosine is needed to obtain optimal coloration of a black coat than is needed for the normal growth of a kitten. These authors recommend a minimum intake of 18 g/kg of dry dietary matter.

Around three times as much phenylalanine and tyrosine is needed to obtain optimal coloration of a black coat than is needed for the normal growth of a kitten. (©Yves Lanceau/Royal Canin - Bombay).