CAN WE IMPROVE REPRODUCTIVE PERFORMANCE IN DAIRY CATTLE?

Ottó Szenci

Abstract
The successful genetic selection for higher milk production in Holstein cows has nearly doubled the average milk production in the United States since 1960, to over 11,000 kg/year. Over the same time period, there has been a dramatic decline in the reproductive performance of dairy cows. The average number of days open [interval from calving to conception] and the number of services per conception have increased substantially. In order to decrease the longer lactations and the number of cows culled for reproductive reasons it is very important to improve our reproductive management practices. Achievement of optimum herd reproductive performance [calving interval of 12 or 13 months with the first calf born at 24 months of age] requires concentrated management activities especially during the first 100 days following calving.
The following management activities are needed to pursue during the early postpartum period to reach or approach the optimal calving interval: careful surveillance and assistance at calving, prevention of post parturient diseases, early diagnosis and treatment of postpartum uterine abnormalities, accurate detection of oestrus, correct timing of insemination, reducing the effect of heat stress and early pregnancy diagnosis.

Key words: dairy cow, dystocia, metabolic disorders, post partum uterine abnormalities, detection of oestrus, timing of insemination, summer heat stress, pregnancy diagnosis

POATE FI ÎMBUNĂTĂŢITĂ PERFORMANŢA REPRODUCTIVĂ A TAURINELOR DE LAPTE?

Ottó Szenci

Rezumat
Selectia genetica aplicata în Statele Unite înca din 1960 a fost încununata de success, dublând aproape productia de lapte, ajungând la peste 11000 kg/an. Pe parcursul aceleiasi perioade, s-a înregistrat un declin dramatic al performantelor reproductive la vacile de lapte. Numarul mediu de zile alocate pentru service period [perioada fatare-conceptie] si numarul de însamântari pentru o gestatie confirmata au crescut substantial. Pentru a descreste numarul de lactatii prelungite si proportia de vaci reformate pe sezon de reproductie este foarte important a îmbunatati practicile privind managementul reproductiv. Atingerea unor performante optime de reproductie în cadrul efectivelor [calving interval de 12 - 13 luni, prima fatare la vârsta de 24 luni] impune eforturi concentrate de management al reproductiei, mai ales pe parcursul primelor 100 zile post-partum. Urmatoarele activitati de management sunt necesare a fi derulate pe parcursul perioadei post-partum timpurii, pentru a atinge un interval optim între fatari: supravegherea atenta si asistarea fatarilor, profilaxia bolilor post-partum, diagnosticul precoce si tratamentul afectiunilor uterine dupa fatare, detectarea cu acuratete a caldurilor, realizarea însamântarii în momentul optim, reducerea efectelor stresului termic si aplicarea unui diagnostic de gestatie cât mai precoce.

Cuvinte cheie: vaca de lapte, distocie, boli metabolice, afectiuni uterine post-partum, detectia caldurilor, momemntul însamântarii, stres termic pe timp de vara, diagnostic de gestatie