Lemon citrus pulp residues from the citrus juice industry; it belongsto the citrus by-product that are more extensively used for livestockfeeding. Furthermore, citrus pulp is a source of flavonoids such ashesperidin and naringin, which have antioxidant properties. Thisstudy aimed to investigate the effect of fresh lemon citrus pulp (LP)as natural antioxidant, on feeding behavior, milk yield and milk qualityof Valle del Belice lactating ewes in the hot summer season inSicily. A total of 15 second lambing ewes were individually allocated in3¥3 m box and fed with 3 diets in a 3 ¥ 3 Latin square design, with 3phases composed of 21 days. The diets were: LP0, mixed hay ad libitumplus 600 g/d of concentrate; LP1, mixed hay ad libitum plus 400g/d of concentrate and 1 kg/d of LP; LP2, mixed hay ad libitum plus 200g/d of concentrate and 2 kg/d of LP. The samples of offered and refusedforage, concentrate and LP were analyzed for the determination ofDM, CP, EE, ash, NDF, ADF and ADL. Individual milk samples wereanalyzed for lactose, fat, protein, casein, urea, SCC, pH, titratable acidity.At the end of the pre-experimental and experimental phases, totalpolyphenol intake, milk polyphenol content and milk antioxidantcapacity were also determined. Statistical analyses were performedusing the MIXED model where experimental phase (1, 2, 3) and diet(LP0, LP1, LP2) were fixed factors and the ewe was considered as randomfactor. On the basis of voluntary feed intake, the ewes of eachgroup ingested the same dry matter, around 2 kg/d/head, but the LP2group received lower net energy than other groups (1,27 vs. 1,33UFL), in average slightly higher of their nutritional needs. The LPresulted 10% and 20% of the total DM intake, in LP1 and LP2 grouprespectively. The effect of the high temperatures determined averagelow milk productions. The LP2 ewes produced significantly lower dailymilk yield than the other two groups (322 g/d vs. 369 g/d and 355 g/dfor LP2, LP0 and LP1 groups respectively), probably due to lower netenergy ingested. Milk fat did not differ significantly among groups,while milk protein and casein percentages showed higher values inLP2 than in LP1 group, probably due to higher availability of aminoacids for the intestinal absorption. The milk urea content of LP0resulted significantly lower than other groups. Polyphenol analysesare still under execution.
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2015|