INTRODUCTION
Turkey has a large animal production section with approximately 11 million cattle and 30 million sheep (Anonymous, 2008a,b). Despite these large numbers there are significant problems in terms of animal production largely due to the lack of sufficient amount and quality of roughage (Kilic, 2005). Of the 21.5 million hectares of cultivated land only 5.6% is used for fodder crop production (Anonymous, 2008b). The insufficient fodder crop production and limited availability of pastures due to over grazing has meant that only the basic energy needs of the animals for survival and perhaps limited milk production (4-5 kg/d) are being met (Kilic, 2000). This lack of roughage has prompted interest is alternative feed sources, including the 7-10 million tones of fruit and vegetable wastes produced each year in Turkey (Vural, 2000). There are several studies suggesting that such plant wastes could be potential feed sources for ruminants (Saricicek et al., 1994; 1997; Bakshi et al., 2006; Khorshed et al., 2006; Wadhwa et al., 2006; Meneses et al., 2007).
However, as the majority of these wastes have not been evaluated as animal feed, they instead generally become important environmental pollutants (Erdem, 2005; Khorshed et al., 2006). Utilizing these plant wastes as animal feeds would have benefits both in terms of the environment and animal production. In this way, both the national economy would be positively affected and the risks for human health would be prevented.
Fruit and vegetable wastes generally have a high moisture content and if left untreated will rot in 3-4 days (Hersom, 2006). However, they are rich in soluble carbohydrates and thus could be easily ensiled if the excessive moisture content was addressed. Ensilage is an effective and convenient way to conserve such plant wastes for long periods (Kilic 1986; Kinh et al., 2010).
Consequently, the aim of the study is to determine the potential of using ensiled vegetable wastes of different market mixtures as alternative feed sources for ruminants.
MATERIALS AND METHODS
Sampling procedures and analytical methods
The main material of the study was composed of vegetable wastes obtained from three different street markets. Components of the mixture were cauliflower leaves (33%), cabbage leaves (22%), artichoke leaves (17%), carrot (8%), spinach (7%), lettuce (5%), leek (4%) and celery (4%). Collected vegetable wastes (VW) were cleaned from foreign substance and roughly broken to 5-10 cm pieces, then mixed on a clean plastic bag by hand. Different amounts of wheat straw (WS), wheat bran (WB) and salt (S) with regard to fresh weights were added to the mixture in ensilage due to high water content and low feeding value of individual VW in the mixture. For this purpose, seven different groups were formed in the study: 100% VW (Group I, control), 90% VW+9% WS+1% S (Group II), 80% VW+15% WS+4% WB+1% S (Group III), 70% VW+20% WS+9% WB+1% S (Group IV), 90% VW+ 9% WB+1% S (Group V), 80% VW+15% WB+4% WS+ 1% S (Group VI) and 70% VW+20% WB+9% WS+1% S (Group VII). Obtained mixtures were placed in two liter plastic cans by hand, firmly compressed, closed and strapped to prevent air ingress. Each group was prepared as four replicates and plastic cans were left for fermentation at room temperature for 50 days.
Samples of vegetable wastes silage (VWS) were opened after fermentation and their physical analyses carried out according to DLG standards (DLG, 1987) and their pH values were measured using a digital pH-meter (Hanna, model: HI 8314). After taking suitable samples for chemical analyses, crude nutrient contents (dry matter, crude protein, ether extract, crude ash) of feed samples were determined by Weende analyses method (AOAC, 1995), crude fiber contents by Lepper method (Crampton and Maynard, 1938), and cell wall components were determined by Van Soest analyses method (Goering and Van Soest, 1970). Lactic-, acetic-, butyric acid contents of fresh ensilages were determined by distillation method (Naumann and Bassler, 1993). In-vitro metabolizable energy contents of ensilages were estimated by their crude nutrient contents (TS, 2004) and the regression equations with ADF (acid detergent fiber) (Kirchgessner et al., 1977). …
