Influence of increasing doses of Zea mays on isotopic carbon and nitrogen ratio of the unifeed diets and milk.

• 全文链接
• 请求原文

作   者：

Colombari, G.;  Zapparoli, G. A.;  Araldi, F.;  Migliorati, L.;  Buttasi, C.;  Perini, M.;  Bontempo, L.;  Camin, F.; 

作者机构：

Italy.;  46100 Mantova;  Struttura vigilanza e qualita dell'agroalimentre e supporto alla filiera lattiero-casearia;  ERSAF - Ente Regionale per i Servizi all'Agricoltura e alle Foreste;  Via Pilla 25/b; 

关键词：

lipids;  Zea mays;  Hordeum vulgare;  cows;  nitrogen;  Lolium;  milk;  casein;  forage;  Medicago;  barley;  cattle;  Festuca;  diets;  maize;  dairy cattle;  carbon;  isotopes;  dairy cows;  feeds; 

期刊名称：

Scienza e Tecnica Lattiero-Casearia

i s s n：

0390-6361

年卷期：

2008 年 59 卷 2 期

页   码：

97-112

页   码：

摘   要：

The stable isotope ratios (13C/12C, 15N/14N) of animal feed and milk were investigated, considering cows stabled in two farms of Po Valley and fed with diets made up of different kinds of forages and different amounts of maize. Maize was characterised by 13C values significantly higher as compared to the forages, while considering the forages, Festuca arudinacea had significantly higher content of 13C. The sigma 13C values of the overall diet and the 13C of milk casein and lipids were shown to be significantly correlated with the percentage of maize in the animal diet, The sigma 13C value of casein was shown to be a suitable parameter for evaluating the amount of maize in the diet: each 10% increase in the maize content corresponded to a shift of 0.7% to 1.0% in sigma 13C of casein. A threshold value of -23.5% for sigma 13C in milk casein, above which it is not possible to exclude the presence of maize in the diet was suggested. Among the feed components, soybean, lolium, medicago and barley showed minor content of 15N respect to maize, festuca and cotton. The sigma 15N values of the overall diet and casein were shown to be not influenced by the amount of maize in the feed. On the other hand, the sigma 15N values of casein seemed to differentiate the two farms, probably as a consequence of the presence of components with different 15N content in the two rations. The results obtained could be useful for characterising dairy products produced by pastured animals or PDO cheeses with an established amount of maize in the diet.