The nutritional value of complete silage feed based on fodder beet root and corn forage in Shal sheep

Du to limitation of feed resources in Iran, recently research workers tried to find new feed resources, where they introduce new fodder beet varieties to farmers. Regarding the characteristics of the fodder beet, it must be preserved as silage for progressively use in animal feeding, but no appropriate technology was stablished for ensiling of fodder beet. Ensiling is the well nown technology for preserving of fresh forages, but it is difficult to ensile the fodder beet, because of very low dry matter (DM) content. However, using additives (dry roughages and concentrates) as total mixed ration may be applied as a technology for preserving fodder beet silage. Therefore, this research was conducted to prepared a total mixed ration (TMR) silage based on fodder beet in comparison to corn silage and determine their nutritive values in sheep.

Three experimental diets including: 1) TMR based on corn silage (CTMR), 2) TMR silage (CTMRS) based on similar formula of treatment 1 and 3) TMR silage based on fodder beet (FBTMRS) were prepared. Digestibility and voluntary intake of the treatment diets were determined with three treatments and five replicates by in vivo method, using of 5 mature male Shal sheep (with 5 years old age and 80 kg body weight).

The DM contents of the CTMRS and FBTMRS waere 40 and 39.7 percent with pH of 3.95 and 4.06 respectivly. Average daily DM intake (DMI) was 1294g in control, 1301g in CTMRS but 1579g in FBTMRS that were significantly higher (P<0.05) in FBTMRS. Organic matter (OM) intake was significantly (p<0.05) higher (1450 vs 1206 and 1214 g) for the FBTMRS than the other treatments. Similar trend was obsereved when the intake was calculated based on methabolic body weight. Digestibility of DM, OM, organic mater in dry mater (DOMD) and neutral detergent fibre (NDF) were respectively 71.6, 74, 69.1 and 51.5 percent for CTMRS that were statistically (p<0.05) higher than those of the other treatments but no differences were obtained between the control and FBTMRS. The rumen pH, was affected (p<0.05) by the treatments before morning feeding so that it was the lowest in control, but the highest in FBTMRS (6.11 vs 6.85 and 7.01). However, rumen pH was not varied between the treatments at 3h and 6h post feeding. The rumen ammonia nitrogen (NH3-N) showed an increasing tendency in all treatments from morning feedint to 3h post feeding with the highest amount for treatment FBTMRS (from 17.85 to 32.89 mg/dL) and the lowest for the control (from 13.35 to 31.32 mg/dL) but it showed a decreasing trend from 3h to 6h post feeding with slower tendency for the treatment FBTMRS.

Results of the experimental diets on sheep nutrition indicated that, the highest DM and OM intake was obtained when the animals received TMR silage based on the fodder beet. However, the TMR corn silage showed the highest nutrients digestibility that may be due to the nutritional improvement during the silage fermentation and preservation. Improvement the nutrients digestibility of TMR corn silage is considered as an advantage when compared to the normal TMR (contained corn silage). Therefore, TMR silage based on corn forage recommended as superior treatment in this study. However, practicing and utilization of TMR silage based on the fodder beet is recommended, where the fodder beet is available.