Možnosti izboljšanja plodnosti v čredah krav dojilj

Strmšek, Metoda (author), Klinkon Ogrinec, Martina (mentor)

Telice spolno dozorijo pri 6?9 mesecih starosti, vendar še niso primerne za pripust. Doseči morajo 2/3 odrasle teže svoje pasme, to je pri okvirni starosti 15?16 mesecev. Namen učinkovite proizvodnje v čredi krav dojilj je povečanje števila odstavljenih telet na kravo letno ter povečanje odstavitvene teže telet. Pomembno je, da so sezonske telitve strnjene, kar pomeni, da niso daljše od 12 tednov. Pomemben ukrep v primeru ne strnjenih telitev v čredi je, da se krave, ki so izven ciljne telitvene sezone, iz reje izloči. Telitveno sezono je potrebno usklajevati s ceno in količino razpoložljive krme. Plodnost v čredi se izboljša ob prisotnosti bika, saj pozitivno vpliva na pojav estrusa pri kravah. Teleta, ki se rodijo v začetku telitvene sezone, so težja ob odstavitvi, kakor teleta, ki se rodijo kasneje v sezoni. Cilj pri plemenskih telicah je, da prvič telijo pri dveh letih starosti. Cilj telitev v čredi je več kot 95 %. Naslednji cilj je delež prvih telitev v 21. dnevih telitvene sezone in ta delež znaša več kot 65 %, nakazuje pa plodnost krav in bikov. Z doseženim ciljem so telitve strnjene, odstavitvena teža telet pa je v povprečju večja. Eden izmed kazalnikov uspešne čredne plodnosti je število odstavljenih telet na sto pripuščenih telic in krav. Ciljni delež znaša več kot 94 % in odraža rodnost in umrljivost telet. Ciljna ocena telesne kondicije krav dojilj ob telitvi znaša 2+ za spomladanske telitve in 3 za jesenske telitve. Ocena mora biti dosežena šest tednov pred telitvijo. Do oteženih telitev lahko prihaja, zaradi nestrnjene sezone telitev, kar pomeni, da se problematične krave kasneje obrejijo in se pred telitvijo zredijo. S križanjem krav dojilj se izboljša stopnja obrejitev in lahkotnost telitev. Poveča se mlečnost in število telet ob odstavitvi.

• Language: Slovenian
• Keywords: govedo, krave dojilje, plodnost, Slovenija
• Work type: Bachelor thesis/paper
• Organization: BF - Biotechnical Faculty
• Year: 2019
• PID: 20.500.12556/RUL-110985
• COBISS.SI-ID: 4296328
• Publication date in RUL: 21.09.2019

Secondary language

• Language: English
• Title: Possibilities for improving fertility in suckler cow herds

Abstract

Heifers reach sexual maturity at 6⠒9 months of age, but they are not ready for breeding yet. They must reach 2/3 of the adult weight of their breed, which occurs at roughly 15⠒16 months. The purpose of an effective production in a suckler cow herd is to increase the number of weaned calves per cow per year and to increase the calf weaning weights. It is important to maintain condensed calving seasons, keeping them no longer than 12 weeks. In the case of scattered calvings in a herd, it is important to cull those cows from the herd that fall outside the calving seasons. The calving season should also be coordinated with the price and amount of avaible feed. Herd fertility improves if a bull is present, as this has a positive effect on the occurrence of oestrus in cows. Calves that are born at the start of the calving season reach higher weaning weights than calves that are born later in the season. The goal with breeding heifers is to have them calving for the first time at two years of age. The goal of calvings in a herd is over 95 %. The next goal is to have an over 65 % share of first calvings in the first 21 days of the calving seasons, which indicates the cows and bulls fertility. If this goal is reached, the calvings are condensed and the calf weaning weights are generally higher. One of the indicators of successful herd fertility is the number of weaned calves per hundred bred heifers and cows. The goal share is over 94 % and reflects the calf fertility output and mortality. The suckler cows body condition score (BCS) upon calving is 2+ for spring calvings and 3 for autumn calvings. The BCS must be achieved six week before the calving. Difficult calvings can occur due to the uncondensed calving season, which means the problematic cows become pregnant later and gain weight before the calving. Cross-breeding suckler cows improves the pregnancy rate and the ease of calvings. It also increases the milk yield and the number of weaned calves.

• Keywords: cattle, suckler cows, fertility, Slovenia