نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه بهداشت و کنترل مواد غذایی، دانشکده دامپزشکی، دانشگاه آزاد اسلامی واحد شبستر، شبستر، ایران
2 گروه بهداشت و کنترل مواد غذایی, دانشکده دامپزشکی دانشگاه تهران, تهران, ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The productivity of Holstein dairy cattle herds is significantly influenced by prevailing climatic conditions. Given the potential variability in climates within a single province, this study aimed to investigate the impact of different climates across the country on the productive characteristics of these herds. The study examined average milk production, fat content, protein content, fat percentage, and protein percentage, analyzing data from 325,040 heifers belonging to 270 herds for the period between 2006 and 2021. The regions of the country were classified into five distinct climates, namely BSh, BSk, BWk, Csa, and Dsa, based on the Köppen classification system, which characterizes climates by varying temperature and humidity levels. The study found that the BWk climate, characterized by cold and dry conditions, exhibited the highest milk production levels despite the unfavorable climatic conditions. This outcome can be attributed to effective herd management practices implemented in cities such as Isfahan, which fall under this climate category. The Dsa climate, characterized by a continental climate with hot and dry summers, demonstrated the third-highest milk production levels and was found to be relatively suitable for livestock rearing, particularly during seasons other than summer. Additionally, the Dsa climate was highly conducive to the growth of fodder for livestock and exhibited the best performance in terms of both the quantity and percentage of fat and protein. Despite having the lowest number of herds among the different climates, the Dsa climate outperformed the other climates in terms of production traits. Moreover, in the period from 2007 to 2021, when increasing economic problems, such as the increase in inflation and currency rates, as well as the removal of livestock input subsidies, made it difficult for livestock farmers to cover the costs of providing animal feed, all regions except Dsa region experienced a decrease in the number of herds. From the findings of this research, it can be concluded that the climatic effect in terms of heat stress for livestock and in terms of the suitability of weather conditions for planting fodder and providing livestock feed can have a decisive effect on the productive traits of livestock.
کلیدواژه‌ها [English]
Extended Abstract
Introduction
Since the science of animal nutrition seeks to spend less money and more efficiency in the consumption of animal feed, so we seek to create new solutions and progress in the field of animal science. On the other hand, we are facing a shortage of fodder in our country (especially in the cold seasons of the year), the Bromus plant can be used as fodder in feeding livestock. Bromus is used as dry fodder and grazing. The mixed cultivation of this plant with alfalfa has a very high fodder quality and it can be kept as wet or semi-dry silage. Despite the searches, no report on determining the nutritional value or digestibility of Bromus has been found in Iran.
Materials & Methods
To determine the degradability of dry matter and crude protein of Bromus and compare it with alfalfa, white and red clover fodder using experimental nylon bags in the form of randomized design with 4 treatments (Bromus, alfalfa, white and red clover) And 3 repetitions were done. From each species, 10 plant stems were harvested randomly and simultaneously at different points of the habitat, and then they were taken to the laboratory to measure the degradability of dry matter and crude protein. In order to analyze the data, SAS statistical software was used. Data were statistically compared using Duncan's test at a significant level of five percent.
Results
The obtained results showed that the degradability of dry matter of Bromus with alfalfa and white and red clover in all hours except 96 hours after degradability has a significant difference with alfalfa plant. However, regarding the degradability of crude protein during the degradability hours of the Bromus plant up to 16 hours after the degradability, there is no significant difference with other treatments, but with the increase of the degradability hours, there is a significant difference (P<0.05). The slowly degradable part of the protein (b) and the degradability potential (a+b) have a significant difference between the experimental treatments, but the degradation rate (c) does not have a significant difference between the experimental treatments (P < 0.05). The slowly decomposing part of alfalfa has a significant difference with Bromus. The decomposition rate of Bromus with all experimental treatments has a significant difference (P<0.05). Also, the decomposition potential of Bromus has a significant difference only with red clover. In the passing rate of 2%, the difference is related to alfalfa treatment with white clover and red clover, but Bromus has no difference with other treatments. In the passing rate of 5% and 8%, the difference is related to alfalfa treatment and other treatments. At different passage speeds, the effective decomposition of dry matter in Bromus has a significant difference with all experimental treatments (P<0.05).
Conclusion
Based on the results of this research, Bromus pasture plant can be used in livestock feeding and can be used instead of forage as a source of livestock feed when the amount of forage is insufficient. Moreover the price of producing Bromus pasture is about same as forage production price.
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