نوع مقاله : مقاله کامل علمی- پژوهشی
نویسندگان
1 گروه علوم دامی، دانشکده کشاورزی، دانشگاه صنعتی اصفهان، ایران
2 علوم دامی، دانشکده کشاورزی، دانشگاه صنعتی اصفهان، اصفهان، ایران
3 گروه علوم دامی، دانشکده کشاورزی، دانشگاه صنعتی اصفهان
4 موسسه تحقیقات علوم دامی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives:
Increasing dietary concentrate level is a common diet-formulation approach to maximize dairy cow performance. However, strategies that reduced inclusion of corn and barley grains in diets may improve cow profitability if cow performance is not reduced. Using of forage fibre source in high producing dairy cow diets may limited feed intake as a result of the gastrointestinal tract distention. Therefore, our objective was to investigate of the effect of feeding sugar beet pulp in high producing dairy cow diets replaced for corn and barley grain. We hypothesized that replacing the corn and barley grain with sugar beet pulps is a method to reducing grains level and negative effects of high starch diets.
Materials and Methods: Eight second parity Holstein dairy cows (62 ±2 DIM and milk production: 54 ± 1.2 kg / day) were used in a replicated 4×4 Latin square design with a 2×2 factorial arrangement of 2 grain sources (corn or barley grain) and 2 levels of BP inclusion (5 or 15% of DM) in the diet with 21 d periods (15 d for diet adaptation and 6 d for sampling and data collection). Diets were formulated using the Cornell Net Carbohydrate and Protein System (version5.0). All samples were analyzed in triplicate for CP, ether extract (EE), ash, NDF and Non-fibrous carbohydrate component. For three consecutive days between d 17 to 19 of the study, TMR and orts were collected daily for determination of particle size. Feeding behavior were monitored visually for a 24-h (every 5 min) period. On day 20 of each period, blood samples (7 ml) were collected at 4 h after the a.m. feeding via the coccygeal vein.
Results:
N intake was greater for cows receiving corn compared with barley grain based diets, (p<0.05), as well as, cows fed corn based diets had higher (P < 0.05) N efficiency than those fed barley based diets. The result of this experiment data showed that cows receiving corn based diet had greater milk and urinary N excretion compared with barley based diet (p < 0.05). Rumination bout (no/day) was greater for corn compared to barley-based diets. Also, Cows fed corn based diets had greater rumination and chewing time per kg of NDF intake. Feeding time as minutes per unit of NDF intakes tended to be greater in corn-based diets (P < 0.1). Results demonstrate that cows consuming corn based diets increase the partitioning of energy into milk (P < 0.05). The backfat thickness of cows was influenced by the interactions of treatments, with an increase in the level of beet pulp in corn based treatments leading to an increase in backfat thickness (P < 0.05). Furthermore, substituting barley grain with beet pulp resulted in an increased energy flow towards milk production, whereas this effect was not observed in treatments based on corn grain (P < 0.05).
Conclusion: Results of this study show that reducing dietary starch content by a partial replacement of dietary corn and barley grain with sugar beet pulp has no adverse effects of high-yielding cow. Also, Nitrogen Metabolism and Meal patterns increased in corn-based diets. dietary treatment did not affect blood metabolites, and corn based diets increase the partitioning of energy into milk.
Keywords: Barley grain, Corn grain, Dairy cow, Sugar beet pulp.
کلیدواژه‌ها [English]
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