Grazioli, Raffaella (2017) Forage Provided By Mediterranean Area And Preserved As Hay: Assessment Of Nutritional Quality And Eco-Sustainability. [Tesi di dottorato]


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Item Type: Tesi di dottorato
Lingua: English
Title: Forage Provided By Mediterranean Area And Preserved As Hay: Assessment Of Nutritional Quality And Eco-Sustainability
Date: 10 December 2017
Number of Pages: 159
Institution: Università degli Studi di Napoli Federico II
Department: dep15
Dottorato: phd095
Ciclo di dottorato: 30
Coordinatore del Corso di dottorato:
Calabrò, SerenaUNSPECIFIED
Date: 10 December 2017
Number of Pages: 159
Uncontrolled Keywords: hay quality, sensory evaluation, methane
Settori scientifico-disciplinari del MIUR: Area 07 - Scienze agrarie e veterinarie > AGR/18 - Nutrizione e alimentazione animale
Date Deposited: 08 Jan 2018 12:33
Last Modified: 22 Mar 2019 11:07


The thesis is organized in six chapters: a general introduction, four experimental contributions and a main conclusion. The general purpose was to characterize the forages preserved as hay made in some regions of the Mediterranean area (Southern of Italy) and utilized as forage basis in the feeding plan of dairy cow bred to produce dairy products of high dietetic and nutritional quality. In particular, sensory evaluation, chemical composition, in vitro fermentation characteristics and kinetics, and methane production were determined. In the general introduction (Chapter 1.), the importance to evaluate the quality of hay, the principal fibre source in ruminant diets of temperate climate area is described; this aspect is more relevant when hay represents a significant fraction of the diet. The hay quality is very variable, mainly due to the characteristics of the starting forage and the growth stage at cutting, but also climate condition at harvesting and storage phases influence it consistently. The most reliable approach for evaluating the quality in hay is a combination of sensory, chemical and biological examination. The high quality of hay in ruminants’ nutrition guarantee high quality of meat and milk resulting; moreover, the use of forage elevated in value can limit the environmental impact of livestock, mainly due to the lower methane production, because the larger digestibility of the fiber fraction. In the first contribution (Chapter 2.), a database containing information on mixed hays (No. 56) produced in different agricultural farms of Southern of Italy and utilized in the diets administered to dairy cow is reported. The general propose was to characterize the local resources and, if possible, to identify some critical points in the production steps in order to improve their quality. A new method to evaluate the sensory characteristics of hay is proposed. A cluster analysis was used to assess whether distinct groups could be created on the basis of chemical constituents. The sensory evaluation system proposed has demonstrated to be a useful and practical tool to judge the hays; data obtained are often in line with the analytical characteristics determined in the laboratory. All the hays sampled were also tested with the in vitro fermentation, including methane production. Overall, the hay produced in the farms of the Mediterranean Area considered are characterized by a medium quality due to the low crude protein level, the high structural carbohydrates content, the low leafiness, but the good softness. The sensory evaluation system proposed has demonstrated to be a useful tool for assigning a first quality judgment at the hay, which is often in line with the analytical characteristics determined in the laboratory. In the second study (Chapter 3.), eight hays produced in four farms located in four Provinces of Southern of Italy, different for environmental condition, were characterized for sensory evaluation, nutritive value and in vitro fermentation characteristics and kinetics, including methane production. The differences observed between the farms evidenced that the forage produced in Avellino area is the most interesting in terms of chemical composition, nutritive value, in vitro characteristics and environmental impact. Data obtained allows having more information about forages produced in the study area, useful for farmers to make balanced rations to maintain animal health and guarantee high level of production. The objective of the investigation, reported in the third contribution (Chapter 4.), was to evaluate the environmental impact, in terms of in vitro methane production, of forages sampled over a 3-year period of collection provided by a farm located in Southern of Italy and preserved by haymaking. The substrates to test were incubated in vitro for 24 h with cow rumen fluid under anaerobic condition. The methane was measured by gas-chromatography and estimated with stoichiometric calculation. The results evidenced that the climatic condition can influence forages quality. In the fourth contribution (Chapter 5.), the effect of haymaking in three mixed forages, on the in vitro fermentation characteristics, including methane production was studied. The hypothesis was that the in vitro gas production technique could point out the changes due to the preservation method. The fermentation characteristics and kinetics were studied with the in vitro gas production technique utilizing a manual system and cow rumen fluid as inoculum source. Methane production was measured after 24 h of incubation by gas-chromatography. As results, a worsening of the in vitro fermentation characteristics emerged as direct consequences of haymaking process. The methane production also increased moving from fresh forage to hay. In the last chapter, some final considerations derived from the results obtained in the four experimental contributions are reported.


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