Title Utjecaj izvora kalcija u hrani na koncentraciju kalcija u krvi kokoši nesilica Author Josip Belezni Mentor Krešimir Salajpal (mentor)Committee member Krešimir Salajpal (predsjednik povjerenstva)Committee member Zlatko Janječić (član povjerenstva)Committee member Goran Kiš (član povjerenstva)Granter University of Zagreb Defense date and country 2016-02-25, Croatia Scientific / art field, BIOTECHNICAL SCIENCES Abstract Kalcij je esencijalan mineral koji je neophodan za normalno funkcioniranje životinjskog organizma, te ga je potrebno svakodnevno unositi hranom. Kod kokoši nesilica kalcij ima posebno važnu ulogu, ponajviše zbog njegove ugradnje u ljusku jajeta, te ga je važno dodavati u hrani kako bi se zadovoljile potrebe za kalcijem. Ljuska jajeta zbog velikog udjela kalcija može se upotrebljavati kao izvor kalcija kako kod kokoši nesilica, tako i kod drugih životinjskih vrsta. Stoga je cilj ovog rada bio utvrditi utjecaj ljuske jajeta kao izvora kalcija u hrani na koncentraciju kalcija u krvi kokoši nesilica. Istraživanje je provedeno na 75 kokoši nesilica ISA Hisex Brown, starosti 22 tjedna. Kokoši su podijeljene u pet grupa s obzirom na omjer ljuske jajeta i vapnenca u krmnoj smjesi: 100% vapnenca, 100% grubo mljevene ljuske jajeta, 100% fino mljevene ljuske jajeta, fino mljevena ljuska jajeta i vapnenac u omjeru 50:50%, grubo mljevena ljuska jajeta i vapnenac u omjeru 50:50%. Uzorci krvi za analizu uzeti su punkcijom krilne vene 15. i 30. dana pokusa, a analizom je određena koncentracija kalcija.
Upotreba ljuske jajeta kao izvora kalcija u hrani kokoši nesilica nije imala značajnog utjecaja na koncentraciju kalcija u krvi. Tretmani koji su uključivali 100% sitnu i 100% krupnu ljusku, samo vapnenac, i smjesu vapnenca i krupno mljevene ljuske jajeta u omjeru 50:50% nisu pokazivali značajne razlike u koncentraciji kalcija u krvi. Značajno niže vrijednosti koncentracije kalcija u krvi zabilježene su kod kokoši nesilica koje su hranjene smjesom vapnenca i sitno mljevene ljuske u omjeru 50:50%. S obzirom da tretman koji sadržava isti omjer vapnenca, ali ima veću veličinu čestica ne pokazuje niže vrijednosti, možemo zaključiti da veličina čestica igra ulogu u iskorištavanju kalcija iz hrane. Stoga se preporučuje da se u hrani kao izvor kalcija upotrebljava ljuska jajeta s većom veličinom čestica, što pridonosi duljem zadržavanju kalcija u želucu i pospješuje njegovu iskoristivost. Ljuska jajeta kao nusproizvod u korištenju jaja može se upotrebljavati kao izvor kalcija u hrani kao zamjena ili dopuna vapnencu, najčešće korištenom izvoru kalcija u hrani kokoši nesilica. Nadalje, navedeno smanjuje i količinu otpada koja zaostaje prilikom korištenja i proizvodnje jaja što predstavlja ekološki vrlo prihvatljiv postupak.
Abstract (english) Calcium is an essential mineral which is necessary for normal functioning of the animal organism, and it should be supplied daily in food. In laying hens calcium plays a particularly important role, mainly because of its incorporation into the eggshell, and it is important that it is supplemented in food in order to fulfil calcium requirements. The eggshell, due to its large proportion of calcium, can be used as a source of calcium both for laying hens and for other animal species. Therefore, the aim of this paper was to determine the influence of the eggshell as a source of calcium in food on the blood calcium concentration of laying hens. The study was conducted on 75 Hisex ISA Brown hens aged 22 weeks. The laying hens were divided into five groups based on the ratio of eggshells to limestone in the compound feed: 100% limestone, 100% coarsely crushed eggshells, 100% finely crushed eggshells, finely crushed eggshells and limestone in the ratio 50:50%, coarsely crushed eggshells and limestone in the ratio 50:50%. Blood samples for analysis were taken by wing vein puncture on the 15th and the 30th day of the experiment; calcium concentration was determined by the analysis.
The use of eggshell as a source of calcium in the food of laying hens had no significant influence on blood calcium concentration. The treatments that involved 100% finely crushed eggshells and 100% coarsely crushed eggshells, 100% limestone, and a mixture of limestone and coarsely crushed eggshells in the ratio 50:50%, did not show significant differences in blood calcium concentration. Significantly lower blood calcium concentration was recorded in laying hens that were fed with a mixture of limestone and finely crushed eggshells in the ratio 50:50%. Since the treatment that contains the same ratio of limestone but has a larger particle size does not show lower values, we can conclude that particle size plays a role in the exploitation of calcium from food. It is therefore recommended that eggshell with a larger particle size is used as a source of calcium in food, which contributes to longer retention of calcium in the gizzard and enhances its usability. The eggshell as a by-product of the use of eggs can be used as a source of calcium in food as a substitute or supplement to limestone, the most frequently used source of calcium in the food of laying hens. Furthermore, this also reduces the amount of waste generated in the use and production of eggs, which is a very environmentally friendly process.
Keywords
ljuska jajeta
izvor kalcija
kokoši nesilice
Keywords (english)
eggshell
source of calcium
laying hens
Language croatian URN:NBN urn:nbn:hr:204:092827 Study programme Title: Animal Genetics and Breeding Type of resource Text File origin Born digital Access conditions Open access Terms of use Created on 2016-06-06 08:19:46
