Articles 31-40

Effect of ovariectomy on daily energy requirement in beagle dogs

Jeusette 1 , J. Detilleux 2 , C. Cuvelier 1 , L. Istasse 1 , M. Diez 1

1 Animal Nutrition Unit, 2 Quantitative Genetic Unit, Veterinary Faculty, University of Liege, B-4000 Liege, Belgium

Ovariohysterectomy can result in significant weight gain in bitches fed ad libitum (Houpt, 1979), but when fed a restricted amount of food and exercised regularly ovariectomized bitches may not gain weight (Leroux, 1983). The aim of this study was to determine the daily energy requirement (DER) in adult bitches to maintain optimal body weight (BW) after ovariectomy.

Materials and Methods:
Four young adult 2 y -old female beagle dogs were ovariectomized. The bitches were housed together in their usual kennel. BW at the day of the sterilisation was (mean ± SEM) 13.7 ± 0.8 kg, and was considered their optimal BW, based on the body condition score using a 9-points scale. Food consumption and BW were checked weekly during 32 weeks, starting 6 weeks before surgery (period I) until 26 weeks after surgery (period II). After surgery, the amount fed was reassessed and adjusted if necessary each week to maintain optimal BW by a reduction or an increase of 5% of the amounts offered. Dogs received a food for adult maintenance (Royal Canin Premium Croc, crude protein 24.0 %, fat 16.1 %, and 3730 kcal/kg as fed) during the whole study. Statistics were proceeded by analysis of repeated measurements with an autoregressive AR (1) structure (Proc Mixed, SAS).

Mean BW during period I was 14.0 ± 0.3 kg. During period II, mean BW was 13.7 ± 0.1 kg which corresponds to optimal BW. Before ovariectomy, dogs received 171.6 ± 3.1 kcal/ kg BW 0.75 . After surgery, energy offered had to be significantly (p< 0.01) decreased to maintain ideal BW. During period 2, dogs received 120.9 ± 2.5 kcal/ kg BW 0.75 , which corresponds in a 30% decrease.

These results suggest that ovariectomy can induce a significant decrease of DER in female Beagle dogs. The underlying mechanism is unknown. A control of the food intake seems necessary to maintain ideal BW after gonadectomy.

Houpt K.A. et al., 1979. J Am Vet Med Assoc 174: 1083-1085.
Le Roux P.H., 1983. J S Afr Vet Assoc 54: 115-117.

Home made diets for cats and dogs: do calculated nutrients approximate analysed nutrients?

M. Hesta, J. Debraekeleer, S. Millet and G.P.J. Janssens

Laboratory of Animal Nutrition, Ghent University, Belgium

When homemade diets are used, two kinds of problems are prominent: the diet and the owner. Roudebush and Cowell (1992) noted that 90% of the hypoallergenic home made diets prescribed by 116 veterinarians in the US were not adequate for maintenance of adult dogs and cats. The second problem is the accuracy and precision by which the owner follows the guidelines of the veterinarian. Several recipes are available in literature, sometimes with calculated nutrient contents but few recipes are analysed or tested in vivo. The aim of the present experiment was to compare the calculated nutrient content with the analysed nutrient content of several recipes 1 3 4 5 8 indicated for food allergy in dogs and obesity in cats. For each indication, the pet owners also prepared diets that were formulated at the lab. Nutrient contents were calculated using tables 2 7 . Proximate analysis of the diets was performed. Ca, P, Na and K were analysed by ion chromatography. The differences between the calculated and analysed nutrient content were evaluated statistically.

Mean Median Range p p
Paired diff.±SD Anal./Calc.
|Anal.-calc.|Anal./Calc. Anal./Calc. Paired ttestR 2 Corr. N

Moisture 4.3 ± 12.5 1.14 9.05 1.01 0.9-1.9 NS 0.766 0.010 10
Protein% DM -0.14 ± 6.2 1.02 4.46 1.01 0.7-1.7 NS 0.934 <0.001 10
Fat % DM -1.8 ± 4.9 0.91 3.63 0.79 0.5-1.6 NS 0.640 0.046 10
NFE % DM -1.4 ±7.5 0.98 5.5 0.96 0.8-1.3 NS 0.919 <0.001 10
Fibre % DM 2.5 ±1.4 8.26 2.47 2.41 1.2-24 <0.001 -0.117 NS 10
Ash % DM 0.64 ± 2.6 1.14 2.14 1.18 0.5-2.4 NS 0.708 0.033 9
Ca % DM -0.04 ± 0.27 1.64 0.22 1.08 0.6-7.1 NS 0.941 <0.001 9
P % DM 0.20 ± 0.4 1.27 0.32 1.22 0.5-2 NS 0.814 0.004 10
K % DM 0.01 ±0.34 1.27 0.29 1.03 0.4-4.1 NS 0.795 0.006 10
Na % DM -0.05 ± 0.55 1.69 0.42 0.83 0.12-7.7 NS -0.266 NS 10
ME* -262 ± 159 0.86 262.3 0.86 0.7-0.95 0.001 0.666 0.035 10
* ME (kJ/100g DM) = 15*protein% + 36*Fat% + 15*NFE%

The correlation of moisture content was rather limited because of moisture absorption during the cooking process. Therefore all other nutrients were expressed on dry matter (DM) content. The nutrients that were best estimated by calculation were Ca, protein, NFE, and P. Nutrients that could not be estimated by calculation were fibre and Na. In some recipes a pinch of salt had to be added. This amount is difficult to estimate, explaining the low correlation. The analysed fibre content was significantly higher compared to the calculated. The opposite was true when comparing metabolisable energy (ME) derived from analyses versus ME derived from calculated values, although digestion trials probably would have revealed higher ME because of higher digestibility of high quality ingredients. If homemade diets are prescribed as a dietary treatment of diseases with very narrow allowances for certain nutrients, an analysis of the diet is recommended before long term prescription. In these cases a strict follow-up of the guidelines by the owner is also crucial.

1 Brown et al. 1995, Comp. Cont. Ed. Pract. Vet.17, 637-658
2 Debraekeleer et al. 2000, Small animal clinical nutrition p1123-1133
3 Kronfeld 1986, tijdschrift voor diergeneeskunde111, 137S-141S
4 Meyer 1990, Ernärhung des Hundes p227
5 Remillard et al. 2000, Small Animal Clinical Nutrition p163-181
6 Roudebush and Cowell 1992, Veterinary Dermatology 3, 3-28
7 Souci et al. 1986-1987 Food composition and nutrition tables
8 Strombeck 1999 Home prepared dog and cat diets: the healthfull alternative p217-236

Estimation of the mineral content of grass, hay and grass-silage

Brigitta Wichert 2) , Angela Glocker 1) and Ellen Kienzle 1)

1) Institute of Animal Physiology, Physiological Chemistry and Animal Nutrition, Ludwig-Maximilians-University Munich, Germany; 2) Kirchstrasse 4, 85410 Haag, Germany

The mineral content in grass, hay and grass-silage presents a problem for the ration calculation for horses. Mineral analysis may be considered too expensive and time consuming by the horse owners. Therefore in our investigation we reviewed the literature for the quantitative effects of well-known factors such as soil, fertilisation, plant age, plant type, and climate influencing the mineral content of plants. Our goal was to identify factors which affect mineral content in a predictable way and quantify their effect for each mineral, to be able to estimate the mineral content of fodder from parameters which may be known by the horse owner. For instance, most horse people know whether their hay is a first or second cut, and if it is a first cut, whether it is a late cut. Only effects relevant for ration calculation were considered. For the estimation of calcium and magnesium content the most important factors were the stage of vegetation (time of cutting, calcium: figure 1) and the plant type (grass, or legumes, or herbs). For the prediction of phosphorus content the effects of soil-pH, P-fertilisation and stage of vegetation were most relevant. To estimate the potassium content, potassium-content of soil, potassium-fertilization and stage of vegetation were most important. Sodium is unlikely to be predictable from parameters known to horse owners. However, in any fodder produced in Germany it is most likely that the sodium content is only a fraction of the requirements, and therefore is not relevant to the amount which has to be supplemented. ± 0 % - 25 % - 40 % + 20 % + 30 % + 40 % Figure 1: Influence of harvest time and plant age on the calcium content of grass-silage or hay 2 nd cut intermediate early late early intermediate calculated value 1 st cut late Mean without potassium-, N-, P- fertilization 3.5 mg Ca/kg TS

Nutrition and developmental orthopedic disease in horses : results of a survey on 76 yearlings from 14 breeding farms in Basse Normandie (France)

B.-M. Paragon*, J.-P. Valette**, Géraldine Blanchard*, and J.-M. Denoix**

*Nutrition Unit ** Horse biomechanics and locomotor pathlogy Unit Alfort National Veterinary School - 94704 Maisons Alfort cedex France

Developmental Orthopaedic Disease (DOD) in horses is a particularly common problem in breeding farms. The disease and its manifestations occur primarily in fast-growing light horse breeds. Lesions are reported to be present in 20 to 25% of Thoroughbreds. The majors factors predisposing the growing animal to any of the DOD are (1) rapid growth, (2) trauma to the bone growth plates or articular cartilage, (3) genetic predisposition and (4) nutritionalimbalances. The aim of this survey is to identify the main nutritional imbalances in mare and foal diets which can be linked to a poor radiological score in yearlings in some French breeding farms. During a three years survey (1997-1999) of 28 horse breeding farms of Western France (Basse Normandie), the diet of the 286 mares and their foals, and the growth of 439 foals from birth up to 2 years old have been followed. From this pool, X-ray scoring has been done on 79 yearlings in order to estimate the influence of the diet on DOD.

The energy requirement of the mares was correctly covered. The nitrogen and calcium requirements were generously covered while the copper and zinc requirements were hardly satisfied. This situation is a good reflection of the field quality in this part of the country. The breeding farms presenting the least DOD (mean X-ray score between 0 and 1) are those with the highest nitrogen (p<0.01) and calcium (p<0.05) supply of the mares. The energy and nitrogen requirements of 6 to 10 months old foals were met, while their mineral supply was generous however with a large variability. The breeding farms presenting the least DOD include foals who received a moderate energy and nitrogen supply, a generous calcium supply and a Ca/P ratio higher than 2:1. A copper and/or zinc supplementation, beyond the foals requirements, does not constitute a significant preventing factor against DOD.

Blanchard, G. Minéraux et vitamines dans la croissance et le développement du squelette chez le cheval. Conséquences pratiques. Thèse de Doctorat Vétérinaire, Créteil, 1994, 196p.

Burton, J.-H. et Hurtig, M.-B. Dietary copper intake and bone lesions in foals. Proc. 12 th Eq. Nut. Phys. Symp., 1991, 173-178. Denoix, J.-M. ; Valette, J. -P. et al. Etude radiographique des affections ostéo-articulaires juvéniles chez les chevaux de races françaises âgés de 3 ans. Bull. Soc. Vet. Prat., 1997, 81, 53-70.

Gabel, A.-A. ; Knight, D.-A. et al. Comparison of influence and severity of developmental orthopedic disease on 17 farms before and after adjustment of ration. Proc. 33 th Am. Ass. Eq. Pract., 1987, 162-170.

Jeffcott, L.-B. Osteochondrosis in the horse. Searching for the key to pathogenesis. Eq. Vet. J., 1991, 23(5), 331-338. Knight, D.-A. ; Gabel A.-A. et al. Correlation of dietary mineral to incidence and severity of metabolic bone disease in Ohio and Kentucky. Proc. 31 th Am. Ass. Eq. Pract., 1985, 445-461.

Knight, D.-A. ; Weisbrode, S.-E. et al. The effects of copper supplementation on the prevalence of cartilage lesions in foals. Eq. Vet. J., 1990,22(6), 426-432.

Martin-Rosset, W. Alimentation du cheval en croissance In Alimentation des chevaux. Ed. INRA, Paris, 1990, 232p. National Research Council. Nutrients requirements of Horses, 1989, 5 ème Ed, National academy press, 1989, 100p.

Paragon, B.-M. ; Blanchard G. ; Valette, J. -P. ; Medjaoui, A. et Wolter, R. Suivi zootechnique de 439 poulains en région Basse-Normandie. 26 ème J. Rech. Equine, 1 er mars 2000, 3-11.

Pearce, S.-G. ; Grace, N.-D. et al. Effect of copper supplementation on copper status of pregnant mares and foals. Eq. Vet. J., 1998a, 30(3), 200-203.

Pearce, S.-G. ; Grace, N.-D. et al. Effect of copper supplementation on the copper status of pasture-fed young Thoroughbreds. Eq. Vet. J., 1998b, 30(3), 204-210.

Schougaard, H. ; Falkronne, J. et Phillipson, J. A radiographic survey of tibiotarsal osteochondritis in a selected population of trotting horses in Denmark and its possible genetic significance. Eq. Vet. J., 1990, 22(4), 288-289.

Growth rates and the incidence of osteochondrotic lesions in Hanoverian Warmblood foals. - Preliminary data –

Vervuert 1 , M. Coenen 1 , A. Borchers 1 , M. Granel 1 , S. Winkelsett 1 , L. Christmann 2 , O. Distl 3 , E. Bruns 4 , B. Hertsch 5

1 Institute of Animal Nutrition, 3 Department of Animal Breeding and Genetics, School of Veterinary Medicine Hannover, D-30173 Hannover, 2 Hanoverian Breeders Association, D-27283 Verden, 4 Department of Animal Breeding and Genetics, D-37075 Göttingen, 5 Clinic for Horses, D-14163 Berlin

Rapid growth in foals is associated with a higher risk of osteochondrotic lesions. To date, there is limited information about the optimal growth rate in Warmblood foals. The available data encompass only a small number of foals, which may not reflect growth rates under normal conditions and the occurrence of osteochondrotic lesions. The presented study was performed to obtain information on growth rates and the incidence of osteochondrotic lesions in Hanoverian Warmblood foals under typical field conditions. This investigation was part of a larger project in which feeding, housing, and genetics were evaluated with special reference to the development of osteochondrosis in foals.

Material and methods:
629 Hanoverian Warmblood foals born between December 26, 2000 and July 01, 2001 (308 males, 321 females) from 82 farms in Germany were included in this study. Over a period of six month foals were weighed monthly on a portable electronic scale. The height of the withers at the highest point was measured using a standard measuring stick. Evaluation of osteochondrosis (OC) was performed between the fifth and tenth month afterbirth using x-ray. Radiology diagnosis showed 198 foals with signs of osteochondrotic lesions (OC lesions in foals: 64 tibiotarsal joints only, 112 fetlock joints only, and 22 both types of joints). The effects of sex, birth month, and growth rates on the incidence of OC were tested by analysis of variance. All results are presented as means ± SD.

Birth weights of the foals were 56.8 ± 8.0 kg (N=147). The patterns of growth rate are shown in the table below. Sex, birth month, the development of body weights, and withers heights were not statistically different between OC affected and unaffected horses.
Age (days) body weight (kg) withers height (cm) without OC with OC without OC with OC male female male female male female male female
0 – 30: 80 ±17 82 ±19 85 ±16 81 ±15 108±4.9 108±5.0 109±4.2 109±5.0
31 – 60: 120±18 119±20 122±21 119±18 116±8.9 116±4.4 117±4.7 117±4.4
61 – 90: 155±19 154±21 157±22 151±21 123±4.0 122±9.0 124±4.7 123±4.0
91 – 120: 189±21 188±23 189±25 183±22 129±5.5 128±4.3 128±4.6 128±3.6
121 – 150: 217±22 216±25 218±29 209±25 132±3.7 132±4.2 133±4.6 132±4.4
151 – 180: 243±25 241±26 237±35 234±27 135±3.9 135±3.9 135±4.7 135±4.3
181 – 210: 262±26 264±25 250±33 256±27 137±3.9 138±3.7 138±3.9 137±3.5

The weights used by the Gesellschaft zur Erhaltung alter und gefährdeter Haustierrassen (GEH, 1994) to calculate nutrient requirements for foals seem to be
appropriate. The present study did not indicate significant differences in body weights and withers heights between OC affected or unaffected Warmblood foals. These findings were confirmed by Jelan et al. (1996) in Thoroughbred horses (N= 798).

Jelan Z.A. et al., 1996. Pferdeheilkunde 3, 291-295.

Ultra trace element intake of Cercopithecinae in comparison with humans

W. Arnhold 1,2 ; G. Krische 3 ; M. Anke 1 ; M. Seifert 1 ; M. Jaritz 1 ; K. Eulenberger 4 ; A. Bernhard 4

1 Friedrich Schiller University, Biological-Pharmaceutic Faculty Institute for Nutrition and Environment, Dornburger Str. 24, D-07743 Jena, 2 ) BASU-Mineral Inc., Bergstr. 2, D-99518 Bad Sulza, 3 ) Fritz-Austel-Str. 100, D-04277 Leipzig,4 ) Zoological Garden Leipzig, Pfaffendorfer Str. 29, D-04105 Leipzig, Germany

The essentiality of ultra trace elements was determined for various animal species. Very low concentrations of these elements in semisynthetic diets cause deficiency symptoms, although no biological functions are known in animal and humans, yet. Their normal diets contain enough amounts of ultra trace elements to meet their requirements. However, the environmental overload of some of these elements are more important for the organism in practice than a marginal intake. Beside toxical primary effects the ultra trace elements interact with essential nutritional components and can cause secondary deficiency symptoms of minerals and trace elements. This aspect becomes important for the feeding of animals in zoos. That is why the vanadium (V), chromium (Cr), strontium (Sr), barium (Ba) and cadmium (Cd) intake of Cercopithecinae kept in captivity was investigated and compared with the ultra trace elements intake of humans. The trace element intake was determined in 24 clinically healthy individuals of 5 species of Cercopithecinae kept in 8 groups at the Leipzig Zoo. The animals were given 4 meals every day. Following the duplicate method, quantitatively and qualitatively identical samples of the offered feed, as well as feed residues, were registered (n = 7 per group) on 7 successive days. Thus, it was possible to determine the consumption of the different kinds of feed and the trace element intake of these species. After dry ashing at 450 ºC the ultra trace elements were determined with ICP-OES and AAS with graphite furnace. The daily dry matter intake of monkeys and humans produced considerable effect on the ultra trace element consumption. Related to the metabolic body mass, Cercopithecinae consumed 1.5 to 23 times more ultra trace elements than humans.

Mean dry matter and ultra trace element intake in Cercopithecinae in comparison to humans

Mean intake in µg/kg 0.75 body mass Species Mean dry matter intake in g/kg 0.75
body mass V Cr Sr Ba Cd

DeBrazza Guenon Hamlyn´s Guenon Diana Monkey Campbell´s Guenon Lion tailed Macaque
38 33 29 42 38 5.2 8.7 3.9 6.3 6.2 14171014166731065499780677149168112220189 2.1 3.2 1.9 3.2 2.1

Mixed diet (men) (women) Vegetarian diet(men) (women)
14 1320191.20.471. 60.3 30.3 10.7 10.54
Fp Cercopithecinae < 0.01 < 0.001 < 0.001 < 0.001 < 0.01 < 0.001
Fp together < 0.001 < 0.001 < 0.001 < 0.001 < 0.001 < 0.001
Cercop. : Humans 1.5 – 3.2 1.6–18.5 2.5 – 6.5 5.0 - 23 2.4 - 10 2.7 – 10

The monkeys‘ diet contained less V, Cr, Sr, Ba and Cd than the toxic levels in animals and humans. However, the monkeys took in more V and Cr than the recommended amounts for humans, and more Cd than the concentration in semisynthetic diet that caused Cd deficiency symptoms. Furthermore, the contribution of the various feed components, including beverages, to the daily ultra trace element intake were discussed and compared with the ultra trace element intake of people with mixed diets and vegetarians.

Runting, diarrhoea and cachexia in fallow deer responsive to micronutrient supplementation

D. Ranz 1 , C.A. Schmittinger 1 , M. Clauss 1 , Brigitta Wichert 1 , U. Wehr 1 , M. üller 2 ,O. Geisel 2 , Ellen Kienzle 1

1 Institute for Animal Physiology, Physiological Chemistry and Animal Nutrition, Ludwig-Maximilians-University, Veterinaerstr. 13, D-80539 Munich, Germany
2 Institute for Veterinary Pathology, Ludwig-Maximilians-University, Munich, Germany

A variety of different symptoms, (runting, reduced growth, cachexia and diarrhoea of unknown cause), were sporadically observed in a fallow deer (Cervus dama) enclosure in Upper Bavaria (district of South Germany). The enclosure is three hectares in size, located at 850m above sea level and houses a seasonally-varying stocking density between 35 to 40 animals. Two young animals perished and three other affected animals were shot down. A pathological examination of one perished and two shot animals showed no uniform cause of illness that related to the symptoms mentioned above. As a slight anaemia was discovered in the autopsied animals, the copper (Cu) content in the liver of some deceased and killed animals was investigated due to a provisional diagnosis of Cu deficiency. The mean Cu content in the liver (n = 3) was 11.55 mg/kg dry matter (range: 9.40 – 14.92 mg/kg DM) which was far below the lower ruminant reference range (35 mg/kg DM) and also below the Cu concentrations measured by Geisel et al. (1996) in fallow deer livers. Free-ranging fallow deer have even higher liver Cu concentrations (Anke et al., 1980).

The nutritional case history showed that the basic feed components consisted of hay, aftermath, grass and oats, but no mineral supplement was offered to the animals. The analysis of the basic feed components demonstrated a high hygienic food quality and Cu concentrations within the normal reference range. For practical reasons, the owner was not interested whether the disease is due to primary or secondary Cu deficieny and cobalt (Co) deficiency, but in solving his problem. Therefore, we did no further trace element analysis and focused on supplementing micronutrients to the dams diet.

In order to increase the Cu status of the herd, a special mineral supplement pecifically including Cu-sulphate was provided, so that the calculated Cu content of the ingested diet was 15 mg/kg DM. This is nearly twice as high as the recommended concentration of 8mg Cu/kg DM for nonlactating ruminants. As a Co deficiency can also cause anaemia, vitamin B12 was also added to the supplement, so that the ingested diet was enriched with 18µg vitamin B12/kg DM. The mineral supplement was incorporated into a pelleted feed on a crushed oats-basis. After feeding the new supplement to the pregnant dams during the following winter, no weak offspring were born, and all calves showed normal growth development.

Anke M. et al., 1980. Beiträge zur Jagd- und Wildforsch. XI: 47-74. Geisel O. et al., 1996. Mengen- und Spurenelemente 16: 897-902.

Apparent digestibility of calcium and phosphorus in growing beagles influenced by mineral supply

Dobenecker, B.

Institute for Animal Physiology, Physiological Chemistry and Animal Nutrition, Ludwig-Maximilians-University Munich, Germany

The importance of correctly supplying calcium (Ca) and phosphorus (P) for the healthy development of the skeleton for the healthy development of the skeleton, is commonly known by now. The negative effects of a lack in Ca supply was already shown by Marek and Wellmann (1931) as well as the consequences of an oversupply with Ca for skeletal health (Marek a. Wellmann 1931, also: Hedhammar et al. 1974, Hazewinkel et al. 1991). A general inability of young growing dogs to decrease the digestibility of Ca was assumed from investigations of Hazewinkel et al. (1985 and follow-up studies) where Great Danes were raised on a threefold Ca oversupply. Limited information is available about the digestibility of Ca and P in puppies with an insufficient supply with those minerals. A feeding trial with 20 Beagles was carried out from weaning until 6 months of age to determine and quantify the ability of growing dogs with malnutrition of Ca and P to modify the apparent digestibility (aD) corresponding to over- and undersupply at different ages during growth in order to regulate the uptake of these minerals. Four groups were formed to carry out 3 trials of approximately 6 weeks duration each. The Ca-supply was adjusted to 15, 50, 150 and 300% of the requirement while the P-supply met the requirements. A diet based on tripe, rice and cellulose was supplemented individually with minerals and vitamins. All but the nutrients in question were supplied after the requirement figures of Meyer and Zentek (1996), corresponding to 11g Ca and 8g P/kg dm in the control diet). Five dogs were raised as a control group, i.e. all nutrients met the requirements.

As intended no impairment of bone health was clinically evident. The weight curve was not influenced systematically by the feeding regime. At the age of 6.5 to 13.5 weeks of age (first trial) no statistically significant differences in the aD of Ca were seen among the groups independent of the feeding regime. In the second trial (13.5-19.5 weeks of age), a difference between the groups could be measured. Here, in the 15% group, a significant higher digestibility of Ca compared to the 300% group could be measured. In relation to the control group (100%) a distinct tendency to an elevated capacity to use the Ca in the food was visible. This was not true for the group which was fed with 50% of the Ca requirements. No down-regulation of the aD of Ca was detectable in the oversupplied group (300%). In contrast to the aD of Ca, the aD of P was influenced significantly in the youngest dogs. The results suggest that Beagles are not able to completely adjust the Ca uptake in relation to the -intake before the age of 4 to 5 months. The lack of capability in young growing dogs to down- or upregulate the aD of Ca depending on the supply , strongly indicates the need to supply them with the correct amounts of Ca.

HAZEWINKEL, H.A.W. et al. (1985) J.Am.Anim.Hosp.Assoc. 21, 377-391 HEDHAMMAR, A. et al. (1974) Cornell Vet. 64, S 5, 9-150
MAREK, J., O. WELLMANN (1931) Die Rhachitis. Gustav Fischer Verlag Jena MEYER, H., J. ZENTEK (1998) Ernährung des Hundes, Parey Verlag, Germany

A case study on commercial dry diets in two persian cats with struvite urolithiasis

Cristina Fanchi

via Soperga 65, 20127 Milano (Italia)

Two persian cats (cat 1: four-year-old intact male, BW= 4 kg, cat 2: six-year-old neutered male, BW= 4.5 kg) were presented for acute pollakiuria, dysuria and hematuria, inappetence, poor coat condition. As they refused moist foods, their usual diet was only dry. After having anaesthetized the animals and removed urine by urethral catheterization, a bladder lavage was performed. The urinalysis revealed a pH > 7, leucocytes, blood and struvite crystals. A therapy with enrofloxacin (at dose of 5 mg/kg orally) for 10 days and a calculolithic diet, in appropriated quantity, for a period of 2 months was administered. During the treatment, both cats had two micturitions per day, and the first cat had increased urinary volume (30%). Then the animals were fed a struvite prevention diet (diet A) with 92% of dry matter (DM), containing 1.09% DM calcium, 0.76% DM phosphorus, 0.49% DM sodium and 0.065% DM magnesium.

The first cat showed a normal condition and his urinary pH was 6.3 steadily. Six months later, it was fed diet A mixed with a maintenance acidifying diet ( 92.5 % of DM) in 50 % for one month. During this test, one micturition every 2 days was noted. It was recommended, therefore, to provide the cat only with a struvite prevention diet.
The second cat began to suffer from dysuria 2 months after feeding diet A. It produced concentrated urine with acid pH and struvite crystalluria. The calculolithic diet was administered again. After one week, dysuria disappeared and 3 months later urinary volume was about 60-70 ml/day.

The animal was fed a new struvite prevention diet (diet B) ( 92% of DM) rich in phosphorus (0.98% DM), potassium (0.92% DM) and magnesium (0.1% DM). Since first days of feeding this diet, it drank more water, consequently producing an increased volume of urine. Nevertheless, one month later, a reappearance of dysuria and pollakiuria were reported.
A further struvite prevention diet (diet C) didn’t improve the state of health. It was suggested to carry on feeding a calculolitic diet for 10-12 months at least with regular serum biochemical examinations (urea, creatinine, K, Cl, Na). Recently, the animal was in good health.

Recent developments in phytase research / Methods to improve thermostability of phytases

M. Van paemel, S. Millet, M. Hesta, G.P.J. Janssens

Laboratory of Animal Nutrition, Ghent University, Heidestraat 19, B-9820 Merelbeke;

Phytases, myo-inositol-hexakisphosphate phosphohydrolases (EC and EC, catalyse phosphomonoester cleavage of phytic acid, thereby releasing inorganic phosphate. Since phytic acid phosphorus is largely unavailable to monogastric animals, supplementation of the feed with microbial phytase increases the dietary availability of phosphorus. It was demonstrated in several animal experiments that supplementation of the feed with commercially available A. niger phytase could replace inorganic phosphate addition completely (1, 2, 3). As poultry and pig feed is commonly pelleted, a commercially attractive phytase should be able to withstand the temperatures that are reached temporarily during the pelleting process (60°C-90°C). To withstand high temperatures implies either that the enzyme keeps its functional conformation during heating (intrinsic thermostability) or that it undergoes a reversible heat denaturation and refolds to its active conformation when the high temperatures are no longer imposed. Despite an intensive search to isolate new phytases in thermophilic micro-organisms such as Thermomyces lanuginosus and Myceliophtora thermophila (4, 5), all known phytases unfold at temperatures between 56 °C and 69 °C. The A. fumigatus phytase is the only phytase that possesses the capacity to refold to a native like functional conformation after heat denaturation (6). Recent research has focused on the creation of phytases with higher intrinsic thermostability. Lehmann et al. (8) used the sequences of 13 phytases from six different fungal species, (the parent phytases), to construct a synthetic gene (consensus gene), containing at each position of the protein the amino acid occurring most frequently at that position in the fungal phytase family. The unfolding temperature of the consensus protein was 15 °C to 22 °C higher than that of each of the parent phytases and the catalytic properties were not compromised (7, 8). To investigate the contribution of the glycosylation level of the enzymes to their intrinsic thermostability, the yeasts Pichia pastoris and Saccharomyces cerevisiae, known as a hyperglycosylating organism, were used as expression hosts for the A. niger phy A gene, the A. fumigatus phy A gene and the E. coli r-AppA gene (EcAP). The resulting enzymes were heavier glycosylated and showed superior thermostability compared to their wild type counterparts while conserving their catalytic efficiencies (9, 10, 11, 12). The efficiency of the EcAP enzyme in improving the bioavailability of phytate phosphorus in corn-soybean meal diets to young pigs has already been tested and the enzyme turned out to be as effective as A. niger phytase (13).

1. Lei et al., 1993; Journal of Animal Science 71, 3368-3375
2. Han et al., 1997; Journal of Animal Science 75, 1017-1025
3. Harper et al., 1997; Journal of Animal Science 75, 3174-3186
4. Berka et al., 1998; Applied and Environmental Microbiology 64, 4423-4427
5. Mitchell et al., 1997; Microbiology 143, 245-252
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