Vpliv spreminjanja temperature med valjenjem na valilne rezultate pri lahkem tipu kokoši

Jakun, Ana (author), Terčič, Dušan (mentor)

Optimalna temperatura v času valjenja kokošjih jajc naj bi se gibala v razponu od 37,0 ℃ do 38,0 ℃. Osnovni namen raziskave je bil ugotoviti, kako izpostavitev valilnih jajc lahkega tipa kokoši robnim temperaturam optimalnega območja (37,0 ℃; 38,0 ℃) v različnih obdobjih predvaljenja, vpliva na valilnost, maso in telesno temperaturo piščancev ob izvalitvi, trajanje valjenja, razmerje med spoloma ter kasnejšo rast, velikost in telesno temperaturo jarčk. Skupno 3.405 valilnih jajc kokoši slovenske provenience prelux-G, predhodno skladiščenih dva do devet dni, smo po sistemu naključnega izbora razvrstili v pet tretmajev: v dveh tretmajih smo jajca v prvih šestih dneh valjenja izpostavili nižji temperaturi (tretma C-NZ; 37,0 ℃) in višji temperaturi valjenja (tretma D-VZ; 38,0 ℃), v drugih dveh tretmajih smo od sedmega do 18. dne valjenja jajca prav tako izpostavili nižji temperaturi (tretma A-NK; 37,0 ℃) ter višji temperaturi valjenja (tretma B-VK; 38,0 ℃), v petem tretmaju, ki je služil za kontrolo (tretma K), pa so bila jajca ves čas predvaljenja izpostavljena temperaturi 37,5 ℃. Tretma je značilno vplival na maso jajc ob prelaganju iz predvalilnikov v izvalilnik, izgubo mase jajc do 18. dne valjenja, trajanje valjenja, maso izvaljenih piščancev in temperaturo ter dolžino en dan starih piščancev. V pogledu trajanja valjenja, odstotka izvaljenih piščancev in mase piščancev ob izvalitvi, so bili najboljši rezultati doseženi pri tretmaju D-VZ. Ne glede na obdobje izpostavljenosti, so nižje temperature valjenja (tretmaja A-NK, C-NZ) v primerjavi z višjimi temperaturami (tretmaja B-VK, D-VZ) podaljšale trajanje valjenja in povzročile, da so bili izvaljeni piščanci lažji ter krajši. Tretma ni značilno vplival na delež neoplojenih jajc, deleža zgodaj in pozno zamrlih zarodkov ter na razmerje med spoloma piščancev. S trajanjem skladiščenja jajc se je podaljševal čas valjenja piščancev, valilnost pa se je značilno zmanjšala ob vlaganju osem dni skladiščenih jajc v primerjavi z jajci, skladiščenimi krajši čas. Učinek izpostavljanja jajc različnim tretmajem v času predvaljenja ni vplival na telesno maso, dolžino in telesno temperaturo 12 ter 27 dni starih jarčk.

• Language: Slovenian
• Keywords: perutninarstvo, kokoši nesnice, valjenje, temperatura, valilni rezultati
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Year: 2025
• PID: 20.500.12556/RUL-167778
• COBISS.SI-ID: 228643075
• Publication date in RUL: 12.03.2025

Secondary language

• Language: English
• Title: Effect of thermal manipulation during incubation on hatching performance in layer chickens

Abstract

The optimum incubation temperature for chicken eggs should be in the range of 37.0 ℃ to 38.0 ℃. The main objective of the study was to find out how the exposure of hatching eggs of laying hens to the marginal temperatures of the optimal range (37.0 ℃; 38.0 ℃) at different periods of incubation period affects in particular the hatchability, weight and body temperature of the chicks at hatching, duration of hatching, chick sex ratio and subsequent growth, size and body temperature of the pullets. A total of 3,405 hatching eggs from prelux-G hens of Slovenian origin, which had previously been stored for 2 to 9 days, were randomly allocated to five treatments: in two treatments, a lower temperature (treatment C-NZ; 37.0 ℃) and a higher incubation temperature (treatment D-VZ; 38.0 ℃) were used during the first six days of incubation; in two treatments, a lower temperature (treatment A-NK; 37.0 ℃) and a higher incubation temperature (treatment B-VK; 38.0 ℃) were used from day 7 to day 18 of incubation; and in the fifth treatment, which served as a control (treatment K), the eggs were exposed to a temperature of 37.5 ℃ for the entire incubation period. The temperature treatment had a significant effect on the weight of the eggs at the time of transfer from the setters to the hatcher, the weight loss of the eggs up to the 18th day of incubation and the weight and size of the day old chicks. In terms of hatching time, percentage of chicks hatched and weight of chicks at hatching, the best results were obtained with treatment D-VZ. Regardless of the time of application, lower incubation temperatures (treatments A-NK, C-NZ) compared to higher temperatures (treatments B-VK, D-VZ) prolonged the hatching time and caused the chicks to be lighter and smaller. The treatment had no significant effect on the proportion of unfertilized eggs, the proportion of early and late dead embryos and the sex ratio of the chicks. The hatching time of the chicks increased with the duration of egg storage, and the hatchability of eggs stored for 8 days decreased significantly compared to eggs stored for shorter periods. The effects of the different treatments to which the eggs were subjected in the first 18 days of incubation had no effect on the body weight, length and temperature of the 12- and 27-day-old pullets.

• Keywords: poultry breeding, laying hens, hatching, temperature, hatching performance