BODY CONDITION SCORING AND CHANGES IN SOME BLOOD BIOCHEMICAL PARAMETERS IN COWS WITH SUBCLINICAL AND CLINICAL KETOSIS

Vania Marutsova 1 and Plamen Marutsov 2 . 1. Department of Internal Diseases, Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria. 2. Department of Veterinary Microbiology, Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria. ...................................................................................................................... Manuscript Info Abstract ..................... .......................................................................... Manuscript History


ISSN: 2320-5407
Int. J. Adv. Res. 4 (11), 405-412 406 including ketosis and fatty liver dystrophy (Herdt, 2000;Ingvartsen, 2006;Oltenacu and Broom, 2010;Suthar et al., 2013, Marutsova, 2016. The body condition of high-yielding cow's changes throughout the lactation, but until 1970, no method for assessment of body energy reserves was available (Stockdale, 2001). Lowman et al. (1973) were the first to develop for body condition scoring system for dairy cows using a scale from 1.0 -5.0; it was later improved and modified by other researchers (Edmonson et al., 1989;Ferguson et al., 1994). Body condition scoring is based on the visual assessment and palpation of specific areas of the cow's body by the investigator. A number of authors affirm that cows that are obese at the time of calving and during the lactation, were at a higher risk for development of metabolic diseases as ketosis and fatty liver, retained placenta, mastitis, metritis etc.  (Sordillo and Raphael, 2013), and outlined it as a primary quantitative parameter of ketosis, using BHBA concentrations to define subclinical and clinical ketosis (SCK and CK).
In cows with SCK, some authors (Whitaker et al., 1999;Wittwer, 2000;Oetzel, 2007 The inconsistent literature data about the body condition score of cows and its relationships with blood ВНВА and NEFA in high-producing dairy cows with SCK and CK were the incentive of this study.

Animals:
Studies were performed in dairy farms in the Republic of Bulgaria. A total of 158 Holstein cows with yearly milk yield of 9000-11000 L, in their 1 st to 4 th lactation and average body weight 450-550 kg were included in the study. Target cows were fed rations in concordance with their physiological condition (pregnant, recently calved and lactating) and norms for roughage and concentrate contents in diets given for each physiological condition.

Experimental design:
The cows were divided into 3 groups according to their physiological condition: I grouppregnant cows (from day 15 to day 0 pre-calving); II grouprecently calved (from day 0 to 15 postpartum) and III grouplactating (from day 30 to 45 postpartum). Blood concentrations of ВНВА were assayed in all target animals and on the basis of 407 results, they were classifies as healthy (control, BHBA <1.2 mmol/l), affected with SCK (BHBA from 1.2 to 2.6 mmol/l) and CK (BHBA >2.6 mmol/l).
The first group included 21 pregnant cows (9 healthy; 12with SCK). Blood BHBA concentrations indicative for CK were not established in this group. The second group comprised 90 recently calved cows (55 healthy, 27with SCK and 8with CK. The third group (47 lactating cows) included 24 healthy (control) cows; 15 animals affected with SCK and 8with CK.

Blood samples and analyses:
Blood samples for determination of BHBA and NEFA were obtained in the morning, before feeding, through puncture of the coccygeal vein using sterile 21G needles and vacutainers (with heparin and without anticoagulant, 5 ml, Biomed, Bulgaria).
Blood BHBA concentrations were determined in situ using a portable Xpress-I system (Nova Biomedical, UK). The values of NEFA in the blood serum determination using NEFA ELISA Kit (Changhay Crystal Day Biotech Co., LTD., Bioassay Technology Laboratory, China) and ELISA Reader Sunrise (Tecan, Switzerland).

Body condition scoring (BCS):
Body condition scores were evaluated using a 5-point scale (1.0-5.0, at intervals of 0.25). The cows were scored visually by two investigators according to the procedure of Edmondson et al. (1989) and Ferguson et al. (1994).

Statistical analysis:
Statistical analysis was done with ANOVA test,Statistica 6.0 (for Windows) and StatSoft, Inc. (USA, 1993). Results were presented as mean (x) ± standard deviation (SD). The level of statistically significance was р < 0.05.
The amount of blood BHBA in cows from group I (pregnantfrom pre-partum days 15 to 0) with SCK (1.65±0.63 mmol/l) was statistically significant increased vs that of the control group (0.52±0.09 mmol/l; р<0.001). In the second group of cows with SCK, blood BHBA concentrations were again considerably higher than controls (1.73±0.61 mmol/l and 0.43±0.25 mmol/l, р<0.001), as well as in group III with SCK -1.57±0.55 mmol/l as 408 compared to controls (0.30±0.16 mmol/l, р<0.05) (Fig. 1). The BHBA analysis of cows from group I did not exhibit concentrations higher than 2.6 mmol/l,е.g. clinical ketosis was not present.
The analysis of blood of recently calved and lactating cows with clinical ketosis showed statistically significantly increased BHBA levels 4.27±1.29 mmol/l for group II, р<0.001 and 4.75±1.36 mmol/l for group III, р<0.001) vs control cows (0.43±0.25 mmol/l for group II and 0.30±0.16 mmol/l for group III) and vs SCK cows (Fig. 1).
The body conditions scores of cows from the three groups (pregnant, recently calved and lactating) is illustrated on Fig. 2. BCS of all control groups was within the reference range -3.50±0.24 for group I; 3.25±0.28 group II and 3.55±0.27 for group III.
The BCS of cows with subclinical ketosis tended to decrease insignificantly vs control groups measuring 3.25±0.36 for group I; 3.0±0.41 for group II and 3.25±0.27 for group III. In recently calved and lactating cows with CK, these values were further lower: 2.75±0.32 and 2.51±0.31 respectively (р<0.05) (Fig. 2).
(Ccontrol group; SCKwith subclinical ketosis; CKwith clinical ketosis) Fig. 2: Evaluation of body condition scores of cows from groups I, II and III with subclinical and clinical ketosis.
Blood serum NEFA in control cows from the three groups were within the reference range -0.31±0.02 mmol/l for group I; 0.76±0.05 mmol/l for group II and 0.42±0.01 mmol/l for group III (Fig. 3).
The blood NEFA concentrations in cows with clinical ketosis from groups II and III changed in the same direction showing reduction vs controls: 0.68±0.02 mmol/l (р<0.05) in group II, and 0.35±0.01 mmol/l (р<0.05) in group III (Fig. 3).

Discussion:
A primary blood biochemical parameter used as an early marker of ketosis in cows, in blood BHBA (Oetzel,  The investigations of pregnant cows from group I showed that they were affected by subclinical but not by clinical ketosis, as BHBA levels in their blood did not exceed 2.6 mmol/l. High-yielding cows experience SCK and CK in the postpartum period and during peak lactation (groups II and III), when blood BHBA attained >1. . High blood ВНВА are a mechanism for compensation of occurring carbohydrate deficiency and the inhibition of the citric acid cycle (Ingvartsen, 2006). It is acknowledged that oxaloacetic acid and coenzyme A are important products in this cycle. Oxaloacetic acid is a product of carbohydrate degradation in tissues. It is an acceptor that stimulates the aerobic oxidation of acetylated radicals such as activated acetic acid. The end products of this process are СО2, water and energy. The deficiency of oxaloacetic acid results in accumulation of activated acetic acid in the animal body. The interaction of two molecules of activated acetic acid yields the main ketone bodyacetoacetic acid. The latter after dehydrogenation is converted to β-hydroxybutyric acid and after decarboxylationto acetone. In cases of excessive mobilization of fats accompanied by formation of large amounts of acetyl CoA, fatty acids are not completely metabolized via the citric acid cycle and as a result, acetyl CоА is converted to acetoacetate which is either reduced to BHBA by ВНВА-dehydrogenase or is spontaneously decarboxylated to acetone (Herdt, (Ferguson et al., 1994;Kim and Suh, 2003). The precalving increase in BCS results in increased loss of body weight at the beginning of lactation reduced dry matter intake and decreased milk yields (Lean et al., 2013;Roche et al., 2015).
According to others (Ruegg and Milton, 1995;Pugh, 2002) body weight loss during the lactation and metabolic diseases are not related. Our results, similarly to those of other authors (Markusfeld et al., 1997;Roche et al., 2015) suggest that obesity of dairy animals at drying off and during the dry period play a pivotal role for clinical ketosis, so the BCS is an important tool aiding the management of nutritional regimens of dairy herds.
The established changes in serum NEFA levels as indicator of systemic negative energy balance are not unidirectionalin dairy animals with SCK from the different groups (pregnant, recently calved, lactating) they increased vs controls attaining 0.84 mmol/l, especially in recently calved cows. These results support the thesis that the lipolysis, assisted by insulin resistance in the period of early lactation, occurred at a higher rate so the net quantity of NEFA was substantially higher that the amount that could be converted in the liver (

Conclusion:
The results from the present studies demonstrated that blood BHBA was a primary parameter serving for discrimination of the forms of ketosis in cows. Its amount in the blood showed that pregnant and recently calved cows were healthy, with SCK and CК. The pregnant cows from group I were affected by SCK, not by clinical ketosis (ВНВА <2.6 mmol/l). In the postpartum period and during intensive lactation (groups II and III), cows were affected by both forms of ketosis. The BCS is an important tool aiding the management of nutritional regimens of dairy herds. It provides information about the actual body reserves which the animal uses to cope with states associated with NEB, stress and disturbed nutrition. The changes in blood NEFA concentrations were in opposite directionsthey increased in cows with subclinical ketosis while were reduced in cows affected by clinical ketosis.