Document Type : Research Paper

Authors

• alireza aghashahi ¹
• alireza Ashkvari ²
• Hasan Fazaeli ³
• Hasan Khamisabadi ⁴
• Mehdi Eftekhari ⁵

¹ Corresponding Author, Department of Animal Nutrition and Physiology, Animal Science Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran. E-mail: a.aghashahi@areeo.ac.ir

² Department of Animal Science, Faculty of Agriculture, University of Tarbiat Modares, Tehran, Iran. E-mail: alirezaashkvari1391@gmail.com

³ Department of Animal Nutrition and Physiology, Animal Science Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran. E-mail: fazaeli@areeo.ac.ir

⁴ Department of Animal Nutrition and Physiology, Animal Science Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran. E-mail: h.khamisabadi@areeo.ac.ir

⁵ Department of Animal Nutrition and Physiology, Animal Science Research Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Qazvin, Iran. E-mail: M.eftekhari@areeo.ac.ir

Abstract

Objective: Selecting the right method for making silage from high-moisture feed materials, such as fodder beet, is critical in animal nutrition and the results should be properly evaluated. Therefore, the aim of this study was to qualitatively assess fodder beet silage as a total mixed (TMR) and partial mixed ration (PMR) and investigate their effect on the diet of fattening calves.
Method: Cultivation and harvesting of fodder beet were performed at the proper time (root bulking stage – before the start of reproductive growth or seed production), and TMR and PMR silages were produced based on nutritional requirements of fattening calves (Holstein and Holstein- Montbéliard crossbreeds). Twenty fattening male calves (average weight of 287±25 kg) were equally assigned to two groups fed one of the experimental treatments (TMR and PMR silages). The experiment lasted 110 days (90 days’ main period) and the animals were weighed and samples of feed, feed residue, and feces were taken every 30 days after adaptation period to assess daily weight gain, feed intake, and digestibility.
Results: Silages were visually and qualitatively evaluated, which indicated that fodder beet silage as a PMR had lower pH and Fleig point compared to TMR; however, there was no difference between the two treatments in the color, odor, and texture of silage. The crude protein (CP) and ammonia nitrogen content showed that better conditions existed in in the PMR silage (P<0.05). Dry matter intake (DMI) and CP intake were higher for PMR silage than TMR (P<0.05). Nutrient digestibility in calves fed the PMR was superior and significantly different from that of TMR (P<0.05). Initial and final weights of calves were not affected by the two treatments; however, average daily weight gain was higher in the PMR (P<0.05), due to the higher DMI, but the feed conversion ratio was not significantly different. Economic analysis of diets and performance of the fattening male calves showed that income and profit from rearing male calves fed fodder beet silage as a PMR was higher compared to TMR (P<0.05).
Conclusions: The qualitative and visual conditions of silage showed that although both methods of preparing silage as TMR and PMR were adequate and can be used to preserve high-moisture forages in livestock farming, the qualitative performance of silage production was better in the PMR mode; nutrient intake and digestibility in the lambs fed PMR was higher than that with TMR silage, and given that fattening male calves gained more weight per day in this group and that they achieved more profit in this treatment, it appears that, if labor is available, PMR silage can be used instead of TMR silage. In general, because of  the lack of available research, further complementary studies are recommended to confirm these findings and to assess the effects of these findings on other livestock species.

Keywords

• Beet
• Fattening calves
• Net return
• Silage
• Total ration