VARIOUS TYPES OF HYPOPHOSPHATAEMIA IN DAIRY COWS AND THE CLINICAL IMPLICATIONS DEPENDING ON THE INTENSITY OF THE DEFICIENCY

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1 ull Vet Inst Pulwy 54, 35-41, 21 VRIOUS TYPES OF HYPOPHOSPHTEMI IN DIRY COWS ND THE CLINICL IMPLICTIONS DEPENDING ON THE INTENSITY OF THE DEFICIENCY ŁUKSZ KUREK, KRZYSZTOF LUTNICKI, ND GNIESZK NCH Sub-Deprtment of Internl Diseses of Frm nimls nd Horses, Deprtment nd Clinic of niml Internl Medicine, Fculty of Veterinry Medicine, University of Life Science, Lublin, Polnd Received for publiction October 26, 29 bstrct The pper imed t defining the specific biochemicl prmeters, s well s the use of tretment methods, ccording to types nd intensity of the clinicl signs of non-complicted hypophosphtemi in cows. The investigtions were crried out on 3 HF cows in 15 herds in the Lublin Region. The men milk yield in the herds ws 36.8 ±2.8 dl. The cows were 3-9 yers old nd hd similr diet rtio. The nimls with hypophosphtemi symptoms in the erly stdium (2-7 d) were divided into three groups ccording to the intensity of clinicl signs wheres the control group consisted of cows with no clinicl signs of the illness. The inorgnic phosphorus (Pi), totl C, totl Mg, K, Fe, totl protein, Cu, bilirubin, FF, nd cretinine concentrtions, s well s ST nd P ctivity, were determined in serum nd plsm. The nimls with mrkedly exhibited signs (recumbency nd tremor) showed significntly decresed Pi, Mg, nd FF contents nd simultneously incresed ctivity of ST nd P. In the group exhibiting miniml signs (group I), there were no significnt disturbnces in homeostsis except the low Pi concentrtion, so it ws possible to use the specilised phosphorus preprtions in the tretment. In the other groups (II, III), which exhibited more mrked signs of the illness, it ws necessry to improve the prenchyml orgns functions in ddition to phosphorus level normlistion. Key words: diry cows, hypophosphtemi, symptoms, biochemicl prmeters. Phosphorus (P) belongs to the group of mcroelements tht hve key importnce to bovine constitution. Together with clcium ctions (C++), it tkes prt in mny biologicl processes. 85% of the totl pool of P is in the bones, being one of the most importnt elements needed in the norml functioning of the skeletl system (16). In the form of phosphtes, it is included in nucleic cids, TP, phosphocretine, nd phospholipids, s well s phosphoproteins of cellulr membrnes, both microsoml nd mitochondril.it tkes prt in glycolysis nd gluconeogenesis processes nd in keeping cid-lkline blnce in the body (16). The contents of non-orgnic phosphtes in physiologicl terms in diry cows blood is different nd rnge from bout 1.5 to 2.76 mmol/l - i.e. from 3.35 to 8.55 mg/dl (2, 9, 16, 19, 22, 24). It cuses gret interprettion problems during the nlysis of field smple scoring, which is the best to relte to referentil scores gin in the sme husbndry nd production conditions. Correct clcium-phosphorus (C/P) dministrtion, ssuring proper level of these ions in the serum nd congruent with current demnd of the niml, depends on mny endogenous nd exogenous fctors. The non-orgnic phosphorus level in the orgnism depends on the correct bsorption of P ions, minly in the smll intestine, level of N ions, correct excretion in urine, deposition nd mobilistion in bones, nd the dministrtion of C in the diet. Side products of cerel nd soy ben s limentry supplements re rich source of esily bsorbble P. Keeping the homeostsis depends on complicted hormonl regultion in which prthormone (PTH), clcitonin (Clc), nd ctive metbolic products of vitmins D nd ply the min role (3, 8, 1, 16). In mintining this homeostsis, prenchymtous orgns such s the liver nd kidneys re involved nd their conditions reflect inter li the ctivity of ST, LP, GGT, GLDH, nd the bilirubin level in the serum. The decrese in the non-orgnic phosphorus level in diry cows serum is nowdys one of the most common metbolic disorders in herds with both the intensive nd extensive type of utilistion. Clinicl mnifesttions of hypophosphtemi re of vrious chrcter nd intensifiction - from vrible ppetite nd decrese in milk production to lmeness nd recumbent position. The most common resons for the deficiency re: wrongly-blnced dose, simple deficiency of this mcroelement in the limentry dose, incorrect P/C rtio in feed, low bsorption of phosphorus compounds

2 36 vilble in the diet, nd disorders of hormonl system, s well s dministrtion of too big doses of C or Mg ions in treting other diseses like clinicl hypoclcemi (3, 8, 1, 16, 21, 27). It hs become the reson for reserchers interest in the most common cses of hypophosphtemi during the course of other diseses (3, 12, 22, 23, 3). The uthors of these reserch publictions emphsise tht P level hs in these cses the vitl influence on the formtion of the clinicl view, which is exctly seen for exmple in postprtum stroke (3, 12). Hypophosphtemi coexists with ftty liver disese in perintl period in highefficiency cows (15) nd in sinister torsion of the rumen, which is the generl fctor of in ppetite reduction (14). In the occurrence of the independent reduction in P level, we observe first of ll the cses with very dvnced clinicl chnges, mnifested by recumbent position, gret difficulty in stnding up nd problems with movement, pinful bones nd muscles, frequent deminerlistion, nd spontneous bone breks. To the less chrcteristic symptoms belong: loss of ppetite nd reduction in milk production (1, 9, 19, 26). Hypophosphtemi nd erythrocyte disintegrtion occur lso in the erly postprtum stge, fter suffering ketone cidosis cused by insufficient nutrition in the lst prt of pregnncy (18). ccessible essys completely omit the cses with less cler nd less dvnced symptoms, which cn hve gret importnce for the productivity of nimls, where erly-strted proper prophylxis nd correct tretment cn inhibit the development of significntly dvnced disorders in the orgnism, negtively ffecting the economic results on diry frms. griculturl frms spire to the intensifiction of milk production bsed not only on the best genetic mteril but on keeping pproprite niml helth too, becuse only such individuls re ble to produce quntittively nd qulittively stisfctory product. Feeding highly-productive nimls considering properly blnced feeds in terms of the mount of minerl, protein, nd vitmin components, brings the expected results. The whole of frmers ctivity leds to the less frequent ppernce of diseses with very high intensity of symptoms. However, there pper economic nd frming conditions connected with the incidence of diseses with wek or non-pthognomic symptoms (7, 11, 13, 17, 2, 27). On the other hnd, in herds of high productivity even smll dietry fult cn induce the disese. It is necessry to dpt prophylctic nd tretment procedures to chngeble conditions in the herd. In our observtions we found tht essentil for proper therpeutic conduct is determining the chrcter nd degree of intensity of disorders nd nlysis of chnging biochemicl prmeters (incidence in the cse of hypophosphtemi without other coexisting pthologicl chnges). It ppers tht depending on the kind nd degree of the intensity of clinicl mnifesttion of hypophosphtemi uncomplicted by other deficiencies, the biochemicl profile looks different, which requires individul therpeutic ttitude in every cse. The im of the undertken reserch ws defining the specific biochemicl profile of the blood s well s the use of the tretment methods ccording to types nd intensity of clinicl signs of non-complicted hypophosphtemi in cows. Mteril nd Methods Three thousnd diry cows from 15 herds in the Lublin Region were used in the 3-yer study. The herds hd from few to few dozen diry cows (verge 5), in good feeding conditions (non pdded), nd with milk yield bout 3 kg per dy in the culmintion of lcttion (verge 36.8 ±2.8). ll the nimls were of pure blood HF or NC with prt of HF blood nd were 3-9 yers of ge. For the unifiction of the reserch group, the exmined cows were from the herds with similr kind of feeding bsed on mize or silge mde from mize, hy silge, hy, cttle fodder with 18%-24% of proteins, fodder concentrte mde by owners from their own cerels nd premixes, strw nd minerl-vitmin supplements used in mounts depending on milk productivity. Feed doses were prepred by nutrition specilists in ccordnce with milk yield, the cows condition, nd current physiologicl sttus. t the beginning of the reserch, the nimls which exhibited very low C levels were eliminted from the investigtions, becuse this could hve hd n effect on the clinicl mnifesttion nd sttus of the nimls with hypophosphtemi. The nimls with orgnic chnges hindering movement (injury of the pelvis), nd muscle nd hoof disorders were eliminted, even if these cows showed low P level. The ffected nimls treted longer thn 2-7 d without effects were lso excluded from the reserch. Next, bsed on medicl history dt, the intensity of the disese symptoms, nd the results of clinicl exmintion, the nimls with lbortoryconfirmed hypophosphtemi were divided into four groups. Group I consisted of 2 cows with unchrcteristic nd poorly-expressed clinicl signs. In nmnesis, the owners emphsised decresed or periodiclly-chnged ppetite, decrese in milk production, uncertin movements in freestnding cow brns or difficulties when stnding up. Group II comprised 18 cows with men intensity of symptoms, minly in the motor system, both stressed in nmnesis nd observed in clinicl exmintions. In this group, the previling symptoms were: vrious types of lmeness, lboured stnding up, plption pin in vrious prts of the legs, in some cses oedem of joints nd muscles, nd the chrcteristic shifting of weight from foot to foot. ppetite nd thirst ws retined or only slightly smller thn norml. Group III included 14 cows which during exmintion were usully in recumbent (lying position), nd fter being forced to ssume stnding position they showed muscle tremble ll over the body nd n immedite need to lie down. In spite of such cler dvnced symptoms, most of the cows did not mnifest reduced ppetite nd thirst, or significnt decrese in milk production.

3 37 The control group (group IV), consisted of 2 cows from frms where no helth problems hd been noted six months before the reserch strted, nd which were in the middle of lcttion (on the verge from 7 d to one month fter prtum). lood smples were tken from the externl cervicl vein from ech niml during the first veterinry intervention fter the initil dignosis. efore blood smpling, detiled nmnesis nd clinicl exmintion were mde, s well s the evlution of the feeding system, the kind of given feed, nd milk production. In order to obtin the serum, blood ws smpled into test tubes without nticogulnts; to get plsm; test tubes with sodium heprin were used. The smpled mteril ws kept cool for not longer thn 3-5 h nd fter tht ws subjected to initil lbortory processing. fter centrifugtion, the mteril ws kept t -7 C till the nlysis ws completed. The following prmeters were determined in the serum: the content of inorgnic P (Pi) with Cormy dignostic kit using Spectrophotometer UV/VIS Mrcel S 33, totl C, totl Mg, Cu, nd Fe, using spectrophotometry tomic bsorption with Perkin Elmer 41 pprtus, K using VL 988-4, the ctivity of sprtte minotrnsferse (ST), lnine minotrnferse (LT) nd lkline phosphtse (P) using LPH DIGNOSTICS pprtus nd n Epoll- 2 photometer, glutmte dehydrogense (GLDH) with Rndox dignostic kits using Mrcel S 33 spectrophotometer, totl protein (TP) with Cormy dignostic kit nd the contents of totl bilirubin by Jędrsik nd Cleghorn method using Mrcel 33 pprtus. The plsm content of free ftty cids (FF) ws determined using the Front nd Dol method nd cretinine contents using colorimetry nd spectrophotometer UV/VIS Mrcel. The results were shown in the form of rithmeticl mens ± stndrd devition (SD) nd subjected to sttisticl nlysis using the Sttistic 6, PL progrm (SttSoft Inc. 23). Sttisticl differences were clculted ccording to the Student t-test for nonprmetricl vlues, with significnce level t P<.5. Results The studies reveled tht the serum level of P in ll the exmined groups ws significntly lower thn in the control group nd referentil vlues tken s the norm for cows (29). Men levels of Pi were lso sttisticlly significntly lower in the experimentl groups compred with the control group, in which the level ws 4.9 mg%. The lowest nd sttisticllysignificnt Pi level vlues were found in group III compred with the other two groups (Fig. 1). Totl C levels in ll groups with clinicl mnifesttions (groups I, II, nd III) were lower thn generlly-ccepted stndrds (29) nd sttisticlly differed from those in the control group (Fig. 2). The highest norml men Mg vlues were observed in cows with the most dvnced clinicl symptoms (group III) nd these vlues were sttisticlly significntly higher in comprison with the control group (Fig. 3). ST ctivity incresed in the cows from groups II nd III, nd the difference ws significnt. In these groups, n increse in P ctivity in comprison with groups I nd IV, nd with the ccepted stndrds (29), ws lso found; however, this difference ws sttisticlly significnt only in comprison with the mens in groups I nd IV (Fig. 4). 1 b 9 c 8 bc D 4 3 C 2 1 Pi mg/dl C mg/dl Mg mg/dl Cu µg/dl Fig. 1. The concentrtion of selected mcro- nd microelements in the studied groups. bcd P<.5; CD P<.1 significnce of differences between mens vlues within the groups.

4 Cb Cb ST iu/l LP iu/l Fig. 2. The men ctivity of ST nd LP in serum. bd P<.5; CD P<.1 significnce of differences between mens vlues within the groups. FF µmol/l Fig. 3. The men vlues of FF concentrtion in prticulr groups. P<.5; D P<.1 significnce of differences between mens vlues within the groups.

5 c b Totl ilirubin mg/dl Cretinine mg/dl Fig. 4. The men content of totl bilirubin nd cretinine in serum. bcd P<.5; D P<.1 significnce of differences between mens vlues within the groups. Tble 1 Men LT ctivity nd totl protein, Fe, nd K contents Totl protein (g/dl) LT (u/l) Fe (µ/dl) K (mmol/dl) Groups X ±SD I 7. ±.2 II 6.8 ±.3 III 7.1 ±.3 IV 6.9 ±.1 I 48.5 ±24.1 II 46.3 ± 28.6 III 5.1 ±31.1 IV 45.6 ±24.4 I 189 ±87.5 II 172 ±71.3 III 194 ±1.2 IV 178 ±56.3 I 3.9 ±.4 II 4. ±.3 III 3.9 ±.4 IV 4.2 ±.2 The highest verge content of totl bilirubin ws noted in group III but lso in group II the men vlues were bove the upper norml rnge (Fig. 5). The highest verge FF content ws observed in group III nd the difference ws sttisticlly significnt compred with the other groups in which men vlues were within the norml rnge. Similrly, the highest men cretinine vlues were found in group III but ws not bove the upper physiologicl norml rnge; the sttisticlly significnt difference ws between group III nd the other groups (Fig. 6). The highest verge Cu content in ll experimentl groups ws lower thn the men contents in the control group, but only the vlues of group III were significntly different (Fig. 7). The men ctivities of GLDH nd LT nd men contents of K, Fe, TP, nd crbmide were norml in the experimentl nd control groups (29). Discussion The regultion of systemic C/P mngement involves prenchyml orgns such s the liver nd kidneys, where the ctive forms of vitmin D re synthesised. ll the observed symptoms in prticulr experimentl groups hve been lso described by other uthors (1, 9, 19, 26) in publictions relted to disorders of C/P metbolism. In none of those publictions did the uthors ttempt to nlyse the described hypophosphtemi cses, in prticulr ensuing clinicl chnges. Most uthors think tht typicl symptoms of hypophosphtemi occur when the level of Pi is lower thn mg% (9, 13, 17, 24). Such concentrtions were observed in our studies in cows with serious nd typicl symptoms of P deficiency (groups II nd III). In

6 4 group I, where the men vlue of Pi ws higher, unchrcteristic symptoms or those wekly mnifested were dominnt. These symptoms hve probbly not been tken into considertion in other reserch works. It is worth noticing tht these symptoms re quite common nd in spite of high P level its men vlues were considerbly lower thn those in helthy nimls, which results in the occurrence of very lte clinicl symptoms of this type of P deficiency. Simultneously, C concentrtions in serum were lower thn those in the publiction of Ky et l. (19) but re in ccordnce with the observtions of other uthors (3, 9) who notice tht the ttempts of the orgnism to compenste the C level cn led to the development of hypophosphtemi s in the cse of postprtum prlysis. The growing ctivity of ST nd P bove the physiologicl rnge hs been recorded by mny uthors (6, 24); however, in our studies it ws not so high nd essentil s in other reserch publictions (19). It confirms the hypothesis tht frequently the cuse of this condition lies in coexisting diseses, nd reltively low levels of verge ctivity re connected with the elimintion from our reserch of nimls with dvnced chnges in the motor system, decubitus ulcers, nd illness without tretment for longer thn two dys. The increse in ST ctivity in frm nimls my lso be connected with muscle dmge, while the incresed P ctivity is observed in higher osteoblstic ctivity nd elevted remodelling of the bones. However, this ctivity is decresed in rre disese of hypophosphtsi, s well s in hypothyroidism. Serum bilirubin content s specific indictor of biliry duct diseses, heptic cellulr filure, nd disorders of the red blood cell system, is commonly used in the evlution of the heptic condition. Its increse is usully connected with the ccelerted disintegrtion of red blood cells, disorders of hemoglobin disintegrtion, nd during norexi nd stress in young nimls, or for exmple by P poisoning. However, hyperbilirubinemiconnected diseses re lwys ccompnied by chnges in other heptic indictors (GLDH, trnsminses). In the studied cses of spontneous bovine hypophosphtemi it ws difficult to explin the elevtion of totl bilirubin nd FF concentrtions bove the norml rnge (6, 24) in spite of the lck of evidence of coexisting liver diseses This condition my suggest tht the nimls hd problems in the pst but the symptoms were not noticed by their owners or tht the nimls in lying position hd limited ccess to feed, especilly high-energetic. The decrese in Cu concentrtion in serum in experimentl groups is in ccordnce with the results of Ky et l. (19). However, it is difficult to gree with these uthors suggestion tht this interesting phenomenon is connected only with feeding nd it needs further studies. Cows with the most dvnced signs of the onset of the disese, in ddition to decrese in P level, hve lredy chnges in heptic ctivity indictors, erly symptoms of disorders in muscle tissue, nd developing energy deficiency, resulting in the using by the cows reserves of their own ft. It my led to deep nd irreversible chnges in helth sttus if the therpy is not strted. The obtined dt indicte tht even in the group with mild nd unchrcteristic symptoms (group I), decrese in P content in serum ws s serious s in the limentry trct, nd usully-exclusively dietetic mesures were ineffective nd the disturbnces required intensive tretment. Concurrently, the bsence of necessry chnges in other prmeters of C/P restricts its use in tretment to only few phosphoric preprtions dministered orlly or in intrmusculr injections. Such procedures would not eliminte the stress connected with the tretment especilly in freestnding cow brns where the use of prenterl preprtions previls. The benefits re shorter tretment period nd lower costs. The dignosis of the deficiency sitution (hypophosphtemi) with insignificnt symptoms of the disese gives the possibility of n erly strt to effective prophylxis nd the suppression of the disese development. The contents of P in the liver tissue decreses significntly in the erly lcttion period s result of the reduced volume of heptic cell cytosol nd the P content in cytosol (15). Supplementtion of P in the form of sodium phosphorte (orlly, intrvenously, or in combintion with clcium gluconte), cuses n increse in Pi level shortly fter dministrtion but lter it is difficult to keep the norml level in the serum (5). Pi content in plsm is precise bio-ccessibility indictor of P dministered in feed (21). Its serum content my be distorted by the improper preprtion of the blood for nlysis (hemolysis) (25). Hypophosphtemi my be the cuse of hemoglobinuri syndromes, decrese in glicolysed hemoglobin, nd TP synthesis (28). 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