The poultry sector is facing many challenges as it must meet the increased demand for products of animal origin resulting from the constantly increasing population, mitigate the greenhouse gas emissions of its production chain and simultaneously counteract the negative effects that high temperatures have on animal welfare. The feed industry is strongly encouraged to find more sustainable alternative feed solutions to support poultry production such as the use of microalgae. The purpose of this thesis is to evaluate the effect of dietary supplementation with microalgae Chlorella vulgaris in percentages of 0% (C0), 3% (C1) and 6% (C2) on commercial Ross 308 hybrid broilers, analysing behavioural responses and animal welfare under conditions of thermoneutrality and heat stress. For this purpose, an in vivo test was conducted on male and female chickens fed on the three different diets and housed at normal temperatures (recommended by Aviagen 2018) or at high temperatures (+3,6 °C during the whole breeding cycle with peaks greater than +6 °C). The chickens were stocked and reared at the experimental facilities of the University of Padua from the day of hatching until slaughter at 42 days. The evaluation of the behavioural response was performed by a scan sampling method for 10 seconds every 15 minutes for 24 continuous hours on all animals detectable in the test at the age of 37 d through the observation of video recordings. The results show that microalgae have significantly reduced the characteristic behaviours resulting from heat stress, such as panting, raising the wings and spreading the leg on the ground. The measured behavioural response effects were also reinforced by rectal temperature data, which showed a significant reduction in body temperature in animals fed Chlorella vulgaris. In addition, the integration of the C2 diet with 6%, improved the comfort of animals. Overall, it can be said that the microalga Chlorella vulgaris could be an interesting supplement and food source to mitigate the effects of hot stress in broilers. However, further investigation integrating the behavioural analysis with physiological indicators of stress are desirable to strengthen the information gathered in this thesis and support the current results.
Il comparto avicolo si trova ad affrontare numerose sfide legate alla necessità di soddisfare l’aumento della domanda di prodotti di origine animale derivato dal costante incremento demografico, mitigare le emissioni di gas climalteranti e l’impatto ambientale della filiera e contestualmente contrastare gli effetti negativi che le elevate temperature esercitano sul benessere degli animali. L'industria mangimistica è fortemente stimolata a trovare soluzioni alimentari alternative più sostenibili per sostenere la produzione avicola e tra queste vi è l'impiego di microalghe. La presente tesi ha inteso quindi valutare l’effetto dell’integrazione della dieta con microalga Chlorella vulgaris in percentuali del 0% (C0), 3% (C1) e 6% (C2) su polli da carne ibridi commerciali Ross 308, analizzando le risposte comportamentali ed il benessere degli animali in condizioni di termoneutralità e stress da caldo. A questo fine, è stata condotta una prova sperimentale in vivo su polli maschi e femmine alimentati con le tre diete differenti e stabulati a temperature normali (raccomandazioni Aviagen 2018) o a temperature elevate (+3,6 °C in media durante l’intero ciclo di allevamento con picchi maggiori di +6 °C). I polli sono stati accasati e allevati presso le strutture sperimentali dell’Università di Padova dal giorno di schiusa fino alla macellazione avvenuta a 42 giorni. La valutazione della risposta comportamentale è stata eseguita con metodo scan sampling per 10 secondi ogni 15 minuti per 24 ore continuative su tutti gli animali individuabili in prova all’età di 37 d tramite l’osservazione di videoregistrazioni. Dai risultati ottenuti si può evincere che le microalghe hanno ridotto significativamente i comportamenti caratteristici derivanti dallo stress da caldo, come ansimare, alzare le ali e distendere la zampa a terra. Gli effetti misurati a livello di risposta comportamentale sono stati rafforzati anche dai dati relativi alla temperatura rettale, che hanno mostrato una riduzione significativa della temperatura corporea negli animali nutriti con Chlorella vulgaris. Inoltre, l'integrazione della dieta C2 con il 6%, ha migliorato il comfort degli animali. Nel complesso, si può affermare che la microalga Chlorella vulgaris potrebbe rappresentare un interessante integratore e fonte alimentare per mitigare gli effetti dello stress da caldo nei polli da carne. Tuttavia, ulteriori approfondimenti che integrino l’analisi comportamentale con indicatori fisiologici di stress sono auspicabili per rafforzare le informazioni raccolte nella presente tesi ed avvalorarne i risultati ottenuti.
Effetto dell'integrazione della dieta con Chlorella vulgaris sul comportamento di polli da carne sottoposti a temperature ambientali elevate
FACCHI, MATTEO
2023/2024
Abstract
The poultry sector is facing many challenges as it must meet the increased demand for products of animal origin resulting from the constantly increasing population, mitigate the greenhouse gas emissions of its production chain and simultaneously counteract the negative effects that high temperatures have on animal welfare. The feed industry is strongly encouraged to find more sustainable alternative feed solutions to support poultry production such as the use of microalgae. The purpose of this thesis is to evaluate the effect of dietary supplementation with microalgae Chlorella vulgaris in percentages of 0% (C0), 3% (C1) and 6% (C2) on commercial Ross 308 hybrid broilers, analysing behavioural responses and animal welfare under conditions of thermoneutrality and heat stress. For this purpose, an in vivo test was conducted on male and female chickens fed on the three different diets and housed at normal temperatures (recommended by Aviagen 2018) or at high temperatures (+3,6 °C during the whole breeding cycle with peaks greater than +6 °C). The chickens were stocked and reared at the experimental facilities of the University of Padua from the day of hatching until slaughter at 42 days. The evaluation of the behavioural response was performed by a scan sampling method for 10 seconds every 15 minutes for 24 continuous hours on all animals detectable in the test at the age of 37 d through the observation of video recordings. The results show that microalgae have significantly reduced the characteristic behaviours resulting from heat stress, such as panting, raising the wings and spreading the leg on the ground. The measured behavioural response effects were also reinforced by rectal temperature data, which showed a significant reduction in body temperature in animals fed Chlorella vulgaris. In addition, the integration of the C2 diet with 6%, improved the comfort of animals. Overall, it can be said that the microalga Chlorella vulgaris could be an interesting supplement and food source to mitigate the effects of hot stress in broilers. However, further investigation integrating the behavioural analysis with physiological indicators of stress are desirable to strengthen the information gathered in this thesis and support the current results.File | Dimensione | Formato | |
---|---|---|---|
Facchi_Matteo.pdf
accesso aperto
Dimensione
2.09 MB
Formato
Adobe PDF
|
2.09 MB | Adobe PDF | Visualizza/Apri |
The text of this website © Università degli studi di Padova. Full Text are published under a non-exclusive license. Metadata are under a CC0 License
https://hdl.handle.net/20.500.12608/61794