نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم دامی دانشگاه بیرجند
2 دانشجوی علوم دامی دانشکده کشاورزی، دانشگاه بیرجند، بیرجند، ایران
3 موسسه تحقیقات علوم دامی کشور. کرج. ایران
4 گروه علوم دامی دانشگاه بیرجند. ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objective: Iran is located in an arid and semi-arid region, so the drought and salinity stresses cause lower production of crops. Therefore, it is inevitable to use crop species resistant to environmental stresses in area with water shortage and saline soils. Fodder beet is one of the root fodder crops that has good resistance to salt and drought conditions. The high moisture content of this fodder make it suitable to use in the preparation of TMR silage. Complete or total mixed rations (TMR) are produced by mixing forages, byproducts, concentrates, minerals, vitamins, and additives. From this mix, animals consume the nutrients necessary to meet the requirements of maintenance and production (Schingoethe et al., 2017). The interest of ensiling total mixed rations (TMR) for ruminants reemerged in the last decades. In many situations, ensiling TMR has been a sustainable alternative to efficiently handle wet byproducts in ruminant diets. An ensiled TMR typically has a markedly higher aerobic stability than its respective fresh TMR. An increase of feed efficiency by ruminants fed ensiled rations have been reported, due to the improved starch digestibility in TMR silages containing cereal grains (Bueno et al., 2021). Several benefits have been associated with TMR silages, such as a reduced requirement for labor and machinery (if TMR silage is purchased), uniform composition during storage under farm conditions, the potential for incorporating unpalatable byproducts (if their flavors and odors are altered by fermentation), and high aerobic stability after feedout (Nishino et al., 2003). Additionally, TMR silages, similar to other silages, have the potential for commercialization, especially if stored in smaller structures (e.g., bales, bags, and pouches). These technologies enable the transport of TMR silage and its flexible use by farmers. The purchase of TMR silage in bags or bales can be a plausible strategy adopted by small farmers without financial resources to invest in machinery and feed storage structures (Bueno et al., 2021). The current study was carried out with the aim of feasibility of using TMR silage containing fodder beet in feeding of lactating Sannen goats.
Material and methods: The diet of milking Sannen goats containing 25% fodder beet (DM basis) was formulated and as TMR silage (60-days) and non-silage TMR were used in two groups of 10 heads in a 64-days trial period (14 days of adaptation and 50 days of sampling). Fodder beet was harvested from Abarsij farm in Shahrood city (Semnan province) in a whole plant form (root and shoot). Fodder beet was chopped and a part of it was sent to the laboratory to determine the chemical composition, and the other part was mixed with other ingridiants of the experimental diet and ensiled on the ground for 60 days. Another part of fodder beet was placed in the cold room for daily use in the experimental period. Twenty lactating Sannen goats (average weight 41.6 ± 2 and average lactating days 40 ± 6) were selected from the industrial Sannen goat breeding herd of Biyarjmand city (Semnan province) and were randomly divided into two groups of 10 heads. After a two-week adaptation period, the goats entered the experimental period (50 days) and were fed with experimental rations twice a day after milking at 6 a.m and 6 p.m. Blood sampling (through the jugular vein), milk and rumen fluid sampling (through the esophageal tube) was done on the 50th day of the experiment and 3 hours after the morning meal. The collected samples were sent to the laboratory to measure blood parameters, milk composition and rumen fluid pH and ammonia nitrogen. These data were analyzed with GLM model of SAS statistical program. The comparison of the mean of the treatments, if significant, was done with Duncan's multiple range test. Also, the data of daily feed consumption, milk production, production efficiency and body weight were analysed using the method of repeated measurements in time with the random effect of goats, and the comparison of the means was done with Tukey's test (at the 5% error level).
Results and discussion:
The pH value of the TMR silage before ensiling was 6.02, which decreased to 3.97 after 60 days of ensiling (p<0.05), which was in the normal range of a quality silage (Table 2). The amount of silage starch, decrease and crud protein and Ammonia nitrogen incrise compared to first day of ensiling (p<0.05). Also, experimental diets had no significant effect (p>0.05) on pH and ammonia nitrogen concentration of lactating goat rumen fluid (Table 3) and rumen pH was in the physiological range (6-7).The DMI, milk yield, and milk solids no-fat (percentage) was higher in goats fed TMR than goats fed TMR silage (p<0.05). The milk fat percentage of goats fed TMR was significantly lower than the group receiving TMR silage (p<0.05), However, there was no significant difference in the amount of milk fat produced between the two groups (p>0.05). Experimental diets had no significant effect (p>0.05) on the concentration of alkaline phosphatase, alanine aminotransferase, cholesterol, albumin, total protein, blood urea nitrogen and white blood cells (Table 5). These results show that the animals did not have any specific metabolic problems after consuming the experimental diets. Serom glucose concentration of goats fed non-TMR silage was significantly lower than the group receiving TMR silage (p<0.05).
Conclusion: Based on the results of this study, it seems that using TMR silage containing 25% (DM basis) of fodder beet without negative effect on performance and health of lactating Sannen goats is applicable. However, in order to determine the appropriate level of using TMR silage, other studies are required.
کلیدواژه‌ها [English]
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