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Titolo:
Effects of level of nitrogen fertilizer application and various nitrogenous supplements on milk production and nitrogen utilization of dairy cows given grass silage-based diets
Autore:
Shingfield, KJ; Jaalkola, S; Huhtanen, P;
Indirizzi:
Agr Res Ctr Finland, Anim Prod Res, FIN-31600 Jokioinen, Finland Agr Res Ctr Finland Jokioinen Finland FIN-31600 31600 Jokioinen, Finland
Titolo Testata:
ANIMAL SCIENCE
, volume: 73, anno: 2001,
parte:, 3
pagine: 541 - 554
SICI:
1357-7298(200112)73:<541:EOLONF>2.0.ZU;2-V
Fonte:
ISI
Lingua:
ENG
Soggetto:
ABOMASAL INFUSIONS; ANIMAL NUTRITION; RAPESEED MEAL; PROTEIN; DIGESTION; ENERGY; FEEDS; UREA; ACID; METABOLITES;
Keywords:
dairy cows; digestibility; grass silage; milk production; nitrogen fertilizer;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
57
Recensione:
Indirizzi per estratti:
Indirizzo: Shingfield, KJ Univ Reading, Sch Food Biosci, POB 226, Reading RG6 6AP, Berks, England Univ Reading POB 226 Reading Berks England RG6 6AP England
Citazione:
K.J. Shingfield et al., "Effects of level of nitrogen fertilizer application and various nitrogenous supplements on milk production and nitrogen utilization of dairy cows given grass silage-based diets", ANIM SCI, 73, 2001, pp. 541-554

Abstract

Sixteen Finnish Ayrshire dairy cows were used in a cyclic change-over experiment with four 28-day experimental periods and a 4 x 2 factorial arrangement of treatments to evaluate the effects of dietary nitrogen (N) source ondry-matter (DM) intake., diet digestibility, milk production, blood metabolite concentrations and N utilization. Experimental treatments consisted oftwo silages prepared from timothy and meadow fescue swards fertilized witheither 52 or 104 kg N per ha (S-L and S-H, respectively) offered ad libitum supplemented with one of four concentrate supplements offered at 10 kg/day. A basal concentrate (control) was formulated from (g/kg on an air-dry basis) barley (307), oats (460), molassed sugar-beet pulp (200) and vitamins and minerals (33). Three isonitrogenous concentrates were prepared by replacement of basal concentrate ingredients (g/kg) with urea (14.4), wheat-gluten meal (WGM; 57.2) and heat-moisture treated mechanically expelled rapeseed cake (RSC; 188), respectively. Harvesting of secondary growths receiving higher applications of fertilizer N increased silage N content (19.2 and 23.6 g/kg DM, for S-L and S-H, respectively) but decreased water-soluble carbohydrate concentrations (respective values 149 and 93 g/kg DM). Increases in N fertilizer had no effect on silage DM intake, output of energy-corrected milk, milk fat or milk protein secretion, while provision of additional Nin concentrate supplements improved all of these parameters. However, the magnitude of silage DM intake responses to additional N in concentrates washigher (P < 0.05) for S-L than S-H silage-based diets. Increases in dietary N content derived from silage or inclusion of urea, WGM or RSC in concentrate supplements led to a decline in the proportion of N intake secreted inmilk. Relative to N derived from silage or urea, WGM and RSC supplements had beneficial effects on milk production. Both the quantity and quality of dietary N sources should be considered in future attempts to improve the efficiency of on-farm N utilization.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/12/20 alle ore 19:07:42