Short-Term Effect of the Inclusion of Silage Artichoke By-Products in Diets of Dairy Goats on Milk Quality

Abstract

Artichoke by-products represent a high amount of waste whose removal entails several costs. Moreover, feed is the main cost in a farm. So, including these by-products in ruminant diets would lower feed costs. Two experiments were conducted to evaluate the effect of two levels of inclusion, 12.5% and 25.0%, of two silages of artichoke by-products (artichoke bracts, AB and artichoke plant, AP) in the diet of goats on the milk yield, composition and quality and on the metabolic profile of the animals. AB presented the lowest blood urea content and there were no differences in milk yield in the two experiments. However, with 25.0% of silage by-product in the diet, a higher fat content was observed in AB and of protein in AP, as well as this treatment showing a slightly higher Se content. Regarding the milk lipid profile, milk from 12.5% of AP treatment presented a higher PUFA content. In conclusion, the use of silage artichoke by-products in dairy goat diets does not jeopardise milk yield and quality and health status of animals and, from a nutritional point of view for human health, a slightly better mineral and lipid profile is observed in milk from AP treatments.

Long-Term Feeding of Dairy Goats with Broccoli By-Product and Artichoke Plant Silages: Milk Yield, Quality and Composition

“…BB animals showed a lower feed consumption than C and AP animals, because the diet that included BB contained a higher concentration of fermentation products, such as acetic acid, ethanol and ammonia N (Table 1), which had a depressive effect on feed consumption, as observed by Huhtanen et al [38] through a meta-analysis of 240 studies. As in Monllor et al [20], the higher moisture content of the BB diet and, therefore, the higher ration volume, decreased consumption. Other causes that affected feed consumption were the higher content of polyphenols in BB, which limits intake, as observed by Oliveira et al [39] in growing calves and in grazing Sardinian goats, as shown by Decandia et al [40].…”

“…For the analysis of dietary and milk minerals, the same procedures were followed as in Monllor et al [20], with a previous digestion of the samples performed according to González Arrojo et al [4]. Na, Mg, K, Ca, P, S (g/kg DM) and Se, Zn, Cu, Fe and Mn (mg/kg DM) were determined by prior microwave digestion (Ethos Easy, Milestone, Italy) and identified with an ICP-MS octupole chromatograph (Agilent 7500 Reaction System, USA), using an internal standard.…”

“…The dairy yield and macrocomposition were determined similarly to Monllor et al [20]. The milk production of each animal (kg/day) was recorded during milking using a Lactocorder ® device (Lactocorder, Switzerland), which collected a 100 mL individual sample for subsequent analyses.…”

“…On the same day that the milk sampling was performed, blood samples were taken from fasting animals for an analysis of glucose, urea, β-hydroxybutyrate (BHB), cholesterol, nonesterified fatty acids (NEFAs) and haematocrit, similarly as published by Monllor et al [20]. Blood samples were analysed by enzymatic spectrophotometry.…”

“…Broccoli by-product and artichoke plant silages were tested in a previous short-term study for 5 weeks [20], showing favourable results. With the present experiment, we aimed to study during a full lactation the effect of the inclusion of 40% (on a dry matter basis) of the same by-product silages in the ration of dairy goats on the milk yield, composition, mineral and lipid profile and health status of the animals.…”