Dairy sheep breeding play an important role in the agri-food sector in Italy. As for all the other compartments in this sector, a global challenge is underway to make the production processes related to agriculture and livestock more eco-sustainable and efficient, increasing the quality of the related finished products. This objective is achieved through techniques such as the selection and genetic improvement of plants and animals, the precision agriculture and animal husbandry or the implementation of activities associated with the circular economy, which see farms inter-operate with each other with the goal of transforming the output of one into input for the other and viceversa. In this context, the overall purpose of the project to which this thesis belongs is to increase the technological quality of sheep's milk through precision feeding techniques. Specifically, the goal is to find indicators of cheesemaking aptitude in dairy sheep and implement a series of actions to improve it through diet modulation. Being ruminants, sheeps host a complex structure of microbial communities in the rumen which, by fermenting and degrading what is ingested by the animal, regulates its digestion, absorption, the possible production of secondary substances and the correct functioning of the digestive system in general. It is also known that the composition of the rumen microbiota varies according to the type of diet that the host adopts, probably also affecting the products that derive from the animal, such as milk. In this study, we evaluated the differences in the ruminal microbial composition upon two diets that differed for the amount of alfalfa (Medicago sativa) and starches. The metagenomic analysis was conducted by sequencing the hypervariable regions V2-4-8 and V3-6, 7-9 of the 16S ribosomal gene with IonTorrent® technology. The results obtained did not highlight significant differences between the control group and the treated one; the predominant phyla were Bacteroidetes, Proteobacteria and Firmicutes. The most frequently found genera corresponded to Prevotella and unidentified Succinivibriaceae, genera which were associated with ruminants feed conversion efficiency. Milk parameters also did not show significant differences, indicating the need for further investigations on the effect of alfalfa on rumen microbiota and milk quality.
L’allevamento ovino e i prodotti alimentari che ne derivano occupano in Italia un’importante posizione nel settore agroalimentare. Come per tutti gli altri compartimenti di questo settore è in atto una sfida a livello globale per rendere più eco-sostenibili ed efficienti i processi produttivi legati ad agricoltura e allevamento, aumentando la qualità dei relativi prodotti finiti. Questo obiettivo si raggiunge attraverso tecniche come la selezione e il miglioramento genetico di piante e animali, come l’agricoltura e la zootecnia di precisione o l’implementazione di attività associate all’economia circolare, che vedono inter-operare allevamenti e aziende agricole in modo da trasformare l’output degli uni in input per gli altri e viceversa. Stringendo un po’ il campo, la finalità dello studio in cui si inserisce questa Tesi di laurea è quella di aumentare la qualità tecnologia del latte di pecora attraverso tecniche di alimentazione di precisione. Ciò significa trovare degli indicatori che permettano di stabilire l’attitudine casearia del latte prodotto dagli animali e mettere in atto una serie di azioni per migliorarlo attraverso la modulazione della dieta. Essendo ruminanti, gli ovini ospitano nel rumine una complessa struttura di comunità microbiche che, fermentando e degradando ciò che viene ingerito dall’animale, ne regola la digestione, l’assorbimento, l’eventuale produzione di sostanze secondarie e il corretto funzionamento del sistema digerente in generale. È inoltre noto che la composizione del microbiota ruminale varia a seconda del tipo di dieta che l’ospite adotta, andando probabilmente a influenzare anche i prodotti derivati, come appunto il latte. La correlazione che si ha provato quindi a dimostrare è quella che esiste tra composizione microbica del rumine e attitudine casearia del latte prodotto, mettendo a confronto questi due parametri ottenuti da due gruppi di animali sperimentali alimentati con due diete che differivano sulla quantità di alfalfa (Medicago sativa) e amidi. L’analisi metagenomica è stata condotta sequenziando le regioni ipervariabili V2-4-8 e V3-6, 7-9 del gene ribosomiale 16S con la tecnologia IonTorrent®. I risultati ottenuti non hanno messo in luce significative differenze tra il gruppo di controllo e quello trattato; i phyla predominanti erano Bacteroidetes, Proteobacteria e Firmicutes. I generi più ritrovati corrispondevano a Prevotella, Succinivibriaceae non identificate e Succinivibrio, generi associati all’efficienza di conversione alimentare dei ruminanti. Anche i parametri del latte non hanno mostrato differenze significative, indicando la necessità di ulteriori approfondimenti sull’effetto dell’erba medica sul microbiota ruminale.
Effetto della dieta sulle comunità microbiche ruminali della pecora tramite analisi NGS
BACCINI, ANITA
2021/2022
Abstract
Dairy sheep breeding play an important role in the agri-food sector in Italy. As for all the other compartments in this sector, a global challenge is underway to make the production processes related to agriculture and livestock more eco-sustainable and efficient, increasing the quality of the related finished products. This objective is achieved through techniques such as the selection and genetic improvement of plants and animals, the precision agriculture and animal husbandry or the implementation of activities associated with the circular economy, which see farms inter-operate with each other with the goal of transforming the output of one into input for the other and viceversa. In this context, the overall purpose of the project to which this thesis belongs is to increase the technological quality of sheep's milk through precision feeding techniques. Specifically, the goal is to find indicators of cheesemaking aptitude in dairy sheep and implement a series of actions to improve it through diet modulation. Being ruminants, sheeps host a complex structure of microbial communities in the rumen which, by fermenting and degrading what is ingested by the animal, regulates its digestion, absorption, the possible production of secondary substances and the correct functioning of the digestive system in general. It is also known that the composition of the rumen microbiota varies according to the type of diet that the host adopts, probably also affecting the products that derive from the animal, such as milk. In this study, we evaluated the differences in the ruminal microbial composition upon two diets that differed for the amount of alfalfa (Medicago sativa) and starches. The metagenomic analysis was conducted by sequencing the hypervariable regions V2-4-8 and V3-6, 7-9 of the 16S ribosomal gene with IonTorrent® technology. The results obtained did not highlight significant differences between the control group and the treated one; the predominant phyla were Bacteroidetes, Proteobacteria and Firmicutes. The most frequently found genera corresponded to Prevotella and unidentified Succinivibriaceae, genera which were associated with ruminants feed conversion efficiency. Milk parameters also did not show significant differences, indicating the need for further investigations on the effect of alfalfa on rumen microbiota and milk quality.File | Dimensione | Formato | |
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https://hdl.handle.net/20.500.12608/40615