**4. Early diagnosis of postparturient metabolic disease in dairy cow**

Ruminal fluid is one of the essential sources of energy metabolism in dairy cattle because they can ferment volatile fatty acids (acetate, propionate, and butyrate), which may complete some 60–70% of the energy requirements. Dairy cattle are usually in a negative energy balance (NEBAL) in the initial weeks of lactation. The energy intake during this period is less than half the energy requirements for milk production. Therefore, dairy cattle, through increased nonesterified fatty acid (NEFA) production, try to meet the gap between energy input and output during early lactation. The suppressed feed intake results in a lack of gluconeogenesis, which causes a lack of glucose for the complete oxidation of NEFA. The incomplete oxidation of fatty acids contributes to the increased production of ketone bodies (β-hydroxybutyrate/BHB/, acetone, and acetoacetate), which may cause ketosis and fatty liver [64, 65]. It is essential to mention that primiparous cows are more susceptible to metabolic stress during the transition period (3 weeks before to 3 weeks after calving) than multiparous cows [66]. According to Iwersen et al. [67], the electronic handheld BHBA measuring system using whole blood is a more valuable and practical tool for diagnosing subclinical ketosis than the commonly used chemical dipsticks, for example, Ketostix or Ketorolac. Szelényi et al. [68] reported that BHB concentrations measured at the farm by a portable handheld device (Precision Xtra, Abbot Laboratories) showed a significant correlation (*r* > 0.92, *P* < 0.001) with the results of samples evaluated in the laboratory before and after freezing.

More recently, metabolic health disorders (e.g., subclinical ketosis [69], subclinical hypocalcemia [70]) can be predicted with high accuracy during the transition period by using different wearable wireless biosensors such as ear-tag, halter (noseband), neck collar, or leg-tag-type sensors by measuring eating, ruminating, lying, and/or standing time reviewed recently by Cocco et al. [44] and Lee and Seo [48]. Paudyal et al. [71] suggested using "two indices that could identify different health disorders satisfactorily using animal level and pen level comparisons. The cow level index compared daily rumination with the 7-day rolling average of the same cow, and the pen level index compared daily rumination time with the average of the cows in the same herd. This approach utilized deviations in rumination, which accounts for variations in rumination time between the cows and daily variation within the same cow." Cows can be treated before developing clinical diseases, and in this way, costs associated with prolonged treatment and reduced milk yield can be decreased. The importance of early treatment of different metabolic disorders can be emphasized by the fact that dairy cows, after calving, may sacrifice their immune function to maintain lactation [69]. Therefore, they are also more sensitive to different infectious diseases such as metritis and/or mastitis [44, 45, 72].

Acute or subacute ruminal acidosis may develop due to decreased salivation during calving due to reduced period and intensity of chewing, especially when the ratio of concentrate is not limited to the days surrounding calving. Rumen acidosis may also negatively affect rumen motility and appetite. It can be diagnosed by measuring the pH value of the rumen fluid collected by a stomach tube or by

rumenocentesis in the field. However, the accuracy of diagnosing subacute ruminal acidosis is limited. Long-term measurement of reticuloruminal pH value using an indwelling and wireless data transmitting unit enables the evaluation of dietary composition. It allows for adjustments in feeding management in the field [73]. However, the currently available commercial bolus sensor systems with a pH sensor have an operational lifetime of no more than a few months; therefore, its general use in daily practice is presently limited [48].

As mentioned previously, a negative energy balance (NEBAL) can develop several days before calving and usually reaches its most negative level (nadir) about 2–3 weeks later and is used to be extended 10–12 weeks until the beginning of the usual breeding period [74]. A spontaneously NEBAL in dairy cows can represent a physiological state of undernutrition. The severity and duration of NEBAL are primarily related to differences in dry matter intake and its rate of increase during early lactation.

In the absence of precious livestock biosensors, it is essential to evaluate the body condition score (**Table 1**) using the 5-point condition scoring system (scale 0–5, in 0.25-point increments) to control nutritional management on the farm [75, 76]. Calving in moderate condition (3–3.5) and maintaining feed intake during the periparturient transition period are critical factors in reducing NEBAL and avoiding metabolic and reproductive disorders that are harmful to performance. Different levels of body condition score changes (ΔBCS) on fertility, milk yield, and survival of Holstein-Frieasian cows diagnosed with reproductive disorders (dystocia, twins, retained fetal membranes, metritis, and clinical endometritis), and other health disorders (subclinical ketosis, left displaced abomasum, lameness, clinical mastitis, and respiratory disease) between Days 5 ± 3 and Day 40 ± 3 after calving were examined in an extensive dataset involving almost 12 thousands dairy cows. It turned out that there were no significant interactions between body condition score changes and different health-related events. At the same time, excessive loss of BCS and reproductive diseases decreased reproductive performance and survival compared with other ΔBCS categories and health groups. It is essential to mention that excessive loss of BCS during early postpartum was characterized as having a higher milk yield [77].

Since body condition score is a strong predictor of subcutaneous fat reserves but, to a lesser degree, of skeletal muscle reserves, in periparturient dairy cows, a more precise evaluation of those reserves can be reached by separate ultrasonic examinations [78]. According to Schröder and Staufenbiel [79], backfat measurements can be done by placing a linear array transducer "lightly on the sacral area, vertically on an imaginary line connecting the pin (tuber ischii) and the hook (tuber coxa), at the point corresponding to the cranial end of the first coccygeal vertebra. The backfat measurements always include the skin thickness, and the profound fascia can be used as a landmark to distinguish backfat from the gluteal muscle." According to van der Drift et al. [80], "longissimus dorsi muscle thickness measurements can be done by placing linear-array transducer perpendicularly to the vertebral column on the transverse process of the fourth lumbar vertebra, at the site of the larger diameter of the muscle between the fasciae corresponding to the lateral edge of the multifidus dorsi muscle." The examination sites must be brushed to remove debris but not clip, and ultrasound gel must be applied to couple the probe surface with the skin [78]. Quantifying dairy cow body morphological traits by automatically processing images taken in a 3-D single-camera vision system makes it possible to predict body weight in dairy cows automatically. However, this model is unsuitable for monitoring short-term body weight variation or detecting anomalies in a cow's health status [81]. According to a recent review, while current research shows promising results in dairy cattle, there are still many


*Importance of Monitoring the Peripartal Period to Increase Reproductive Performance in Dairy… DOI: http://dx.doi.org/10.5772/intechopen.105988*

**Table 1.**

*The decision chart for body condition score (BCS) suggested by Ferguson et al. [75].*

avenues to be explored for better automation of the whole-body weight estimation process [82].

Following parturition, regardless of NEBAL, a wave of follicular development begins 5–7 days after calving due to elevated plasma follicle-stimulating hormone (FSH). Three types of follicular development (**Table 2**) have been described and can be diagnosed in the field using ultrasonography [83]. The re-establishing pulsatile LH secretion can induce ovulation of a dominant follicle during early lactation [84]. Conversely, the developing NEBAL in early postpartum may suppress pulsatile luteinizing hormone (LH) secretions and reduce ovarian responsiveness to LH stimulation, thereby deterring ovulation. Non-ovulatory dominant or cystic follicles may prolong the interval for the first ovulation to 40–50 days after calving [84, 85]. It is important to mention that prolonged anovulatory anestrus may occur in 11–38% of dairy herds and can be associated with reduced fertility caused by NEBAL [86]. NEBAL can influence the timing of first postpartum ovulation, which negatively affects fertility [84, 87]. If a cow remains anovulatory for >50 days of lactation, it will be less likely to become pregnant during lactation and will be culled [88].

Plasma progesterone (P4) concentrations generally rise during the first two or three postpartum ovulatory cycles [89, 90]. NEBAL may reduce or moderate the rate of increase in P4 [89, 90]. Meanwhile, the metabolic clearance of P4 in highyielding dairy cows can be increased by high energy and protein intake. As P4 plays an essential role in conceptus development and growth, a slower increase in P4 after ovulation may decrease embryo growth by Day 16 and may cause early embryonic mortality [91, 92].

Early postpartum NEBAL may adversely impact the quality of oocytes during the first 80–100 days after calving, which exerts another carryover effect on fertility [93, 94]. However, it is not easy to reconcile the impact of NEBAL on follicles and oocytes with the impact of high dietary energy on oocyte quality and the development of blastocysts in dairy cows [95, 96]. Extremes in BCS may negatively influence fertility [84].

Metabolic, endocrine, and postpartum health statutes may influence together fertility in dairy cows. Energy imbalance seems to be one of the most important factors, though we should consider the complex interactions of the factors mentioned earlier to improve fertility in our dairy farm [84]. Similarly, BCS, glucose, NEFA, or Insulin-like growth factor 1 (IGF-I) concentration from calving to AI cannot explain the low fertility rate [97, 98]. In contrast, Saby-Chaban et al. [99] have found a significant correlation between the prevalence of biochemical ketosis (BHB >0.15 mmol/l) measured by in-line in milk and fertility.

To prevent metabolic disorders in the periparturient period, such as milk fever, ketosis, fat cow syndrome, or rumen acidosis is essential to provide challenge fed during the dry-off period and early lactation. These diseases can increase the prevalence of reproductive disorders and reduce reproductive performance. Therefore, prevention is preferable to treatment and requires close attention to nutrition and management. Treatment of different metabolic diseases (hypocalcemia and ketosis) has been reviewed recently by Oetzel [100] and Mann et al. [101]. In addition, maintaining good body condition at calving and providing a


**Table 2.**

*Three types of follicular developments can be found immediately after calving [83].*

high-density energy diet that does not produce a fatty liver in early lactation are also essential in minimizing the detrimental effects of NEBAL on the return of the estrous cycle after calving.
