Changes and variations of body condition scoring values in dairy cows during production cycle

Procjenu metaboličkog i energetskog statusa mliječnih krava u bilo kojem stadiju proizvodnog ciklusa možemo izvršiti na osnovu analize krvi i usporedbom brojnih biokemijskih pokazatelja. Osim toga za procjenu nam može poslužiti jednostavna, jeftina i praktična metoda tzv. procjena tjelesne kondicije (body condition scoring (BCS)), a predstavlja određivanje količine tjelesnih rezervi (masnog i mišićnog tkiva) koje plotkinja posjeduje u određenom stadiju proizvodnje. Na brojčanoj ljestvici, ocjenama od 1 do 5 s preciznošću ocjene od 0,25 boda ocjenjuje se tjelesna kondicija plotkinje. Izrazito mršave plotkinje ocjenjuju se ocjenom 1, a pretile ocjenom 5. BCS manji od 2,75, ali i viši od 3,75 (po skali od 1 do 5) prilikom teljenja povezani su sa zdravstvenim problemima poput zamašćene jetre, ketoze i smanjene proizvodnje mlijeka. Prijelazno ili tranzicijsko razdoblje tj.razdoblje od 2 do 4 tjedna prije i 2-4 tjedna nakon teljenja okarakterizirano je dubokim endokrinim i metaboličkim promjenama kako bi se zadovoljila proizvodnja mlijeka tijekom rane laktacije. Unos suhe tvari i energije niži je od zahtjeva krava što rezultira negativnom energetskom ravnotežom (engl. negative energy balance (NEB)). Energetski zahtjevi povećavaju se tijekom prijelaznog razdoblja što rezultira hipoglikemičkim statusom. Takva situacija zahtijeva kompenzatorni odgovor organizma koji se sastoji od pojačane lipolize masnog tkiva, glukoneogeneze i glikogenolize u jetri, mobilizacije zaliha bjelančevina u mišićnom tkivu te mobilizacije minerala u kostima. Genetskom selekcijom, u cilju povećanja proizvodnje mlijeka tijekom rane laktacije, dobivene su krave koje uspješno mobilizraju više tjelesnih rezervi na štetu vlastitog zdravlja i plodnosti.We can evaluate the metabolic and energy status of dairy cows at any stage of the production cycle on the basis of blood analysis, and by comparing numerous biochemical indicators. In addition, we can use the simple, inexpensive and practical method of body condition scoring (BCS), which is a determination of the amount of body reserves (fat and muscle tissue) that the cow possesses at a certain stage of production. On the numerical scale, scores from 1 to 5, with score precision to 0.25 points, evaluate the physical fitness of breeder cows. Extremely skinny cows are rated 1, and obese ones with a grade of 5. A BCS less than 2.75, but also higher than 3.75 (on a scale of 1 to 5) around calving are associated with health problems such as fatty liver, ketosis and reduced milk production. The transition or transitional period is the period 2 to 4 weeks before and 2-4 weeks after calving, which is characterized by deep endocrine and metabolic changes that follow increased milk production during early lactation. The dry matter intake and energy status is lower and this results in negative energy balance (NEB). Energy requirements increase during the transition period, resulting in hypoglycaemic status. This situation requires a compensatory response by the organism, consisting of increased adipose tissue lipolysis, gluconeogenesis and glycogenolysis in the liver, mobilization of protein stocks in muscle tissue and mobilization of minerals in the bones. Genetic selection, with the aim of increasing milk production during early lactation, has resulted in cows successfully mobilizing more body reserves at the expense of their own health and fertilit