عنوان مقاله [English]
Background and objectives: During the past decade, genetic selection for milk production has been very progressive in dairy cows. The postpartum stage in dairy cattle is one of the most important stages in the performance of dairy cattle. Providing food nutritious with feed processing at this time interval can be effective in meeting the needs of the livestock. Recent experience suggests that the use of processed grains instead of milled grains can greatly improve the production and reproductive conditions in dairy cattle. Therefore, the purpose of this study was to compare the production and reproductive performance of freshly-produced dairy cows in two modes of steam flaked-and-grained cereal grains.
Material and methods: This experiment was conducted in a completely randomized block design in a 100-day period in which 40 dairy cows were reared in 4 treatments: Milled barley and corn, corn steam flaked and milled barley, barley steam flaked and corn and barley stream flaked. Throughout the experiment, cows were housed in the straw yard. Treatment diets were: 1) Control diet (milled grains), 2): steam flacked corn with milled barley (SCGB) 3): steam flacked barley with milled corn (GCSB), 4): steam flacked corn and barley (SCSB). Diets were arranged in CNCPS software based on NRC requirements for dairy cattle. Productive performance (milk, fat, protein), feed consumption behavior, and reproductive performance were evaluated among the four groups. All statistical analyzes were performed in SAS software version 9.1.
Results: The results showed that the use of steam flaked barley and corn in ration increased the production efficiency in fresh cows (P <0.05), So that the simultaneous use of stream flaked corn and barley compared to the milled, increased the amount of cumulative milk from 3196 to 3731 kg, but the percentage of lipid and milk protein was not affected by experimental treatments. Pregnancy rates and open days in barley and corn treated with steam flaked were improved by 13% and 11 days, respectively (P<0.05). The chewing rates were higher in stream flaked corn and barley compared to the milled (64 times in treatment 4 to 58 times in treatment 1), which had a significant difference.
Conclusion: The use of steam flaked corn and barley improves reproductive, reproductive performance and improve production performance in freshly dairy cows instead of barley and corn milled also reduces open days, calving interval and increase conception rate, pregnancy rate in first 100 days and total pregnancy rate ,which can lead to economically important.