Original scientific paper
Maize silage supplementation to lower quality grass silage improves the intake, apparent digestibility and N retention in wether sheep
Marina Vranić
; Faculty of Agriculture, University of Zagreb, Svetošimunska cesta 25, Zagreb
Mladen Knežević
Krešimir Bošnjak
Josip Leto
Goran Perčulija
Hrvoje Kutnjak
Ivana Matić
Abstract
The objective of this experiment was to study the effects of interactions between lower quality grass silage (GS) dominated by orchardgrass (Dactylis glomerata L.) and maize silage (MS) (Zea mays L.) on ad libitum intake, digestibility and N retention in wether sheep. The study consisted of four feeding treatments involving GS and MS alone, and GS and MS mixtures in ratios of 67:33 or 33:67 (DM basis) fed twice daily. The GS was harvested at the beginning of flowering of orchardgrass (about 35 % of plants were in flower) while the MS used was of lower DM and starch concentration (264 g kg-1 fresh weight and 211 g kg-1 DM respectively). Mean DM content of GS was 408 g kg-1 fresh weight. MS was lower in crude protein (CP) (62 g kg-1 DM) than the GS (98 g kg-1 DM) (P<0.001). GS contained larger quantities of neutral detergent fibre (NDF) and acid detergent fiber (ADF) (P<0.001) than MS. Inclusion of MS in the diet (33 % vs. 67 %) had positive linear effects on fresh matter (FM) voluntary intake (P<0.05), digestibility of DM, organic matter (OM), digestible OM in the DM (D-value) (P<0.05), starch digestibility (P<0.05), N intake (P<0.01), N output in faeces (P<0.05) and absorbed N (P<0.05). A positive associative effect of GS and MS was observed for all intake parameters measured (FM, DM, OM, NDF) (quadratic, P<0.05 to P<0.01), digestibility of DM, ADF (quadratic, P<0.05), CP (quadratic, P<0.01), N intake and absorbed N (quadratic, P<0.01). It was concluded that positive interactions of GS and MS were recorded for a limited number of parameters because of the lower quality MS than required for the full benefit of two forages fed together.
Keywords
grass silage; maize silage; intake; digestibility; N retention
Hrčak ID:
45051
URI
Publication date:
10.12.2009.
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