نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشیار گروه علوم دامی، دانشکده دام و شیلات، دانشگاه علوم کشاورزی و منابع طبیعی ساری
2 دانشجوی دکتری تغذیه دام، علوم دامی، دانشکده دام و شیلات، دانشگاه علوم کشاورزی و منابع طبیعی ساری
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction: Limited availability of high-quality forage resources and increasing pressure on water availability have challenged the conventional dependence of ruminant production systems on maize silage as the primary forage source. Climate variability, along with increasing competition for water resources in agricultural regions, has emphasized the need to identify alternative forage crops with lower water requirements while maintaining adequate biomass yield and nutritional value. Among potential alternatives, buckwheat (Fagopyrum esculentum) and forage rape (Brassica napus) have gained interest due to their rapid growth, short cultivation period, adaptability to diverse agroecological conditions, and favorable nutritive characteristics. These attributes indicate their potential as alternative forage resources, particularly in regions experiencing water scarcity or seasonal forage deficits. The source and quality of forage included in dairy cow diets substantially affect voluntary feed intake, nutrient utilization, ruminal fermentation patterns, and metabolic responses, thereby influencing animal productivity and health status. Ensiling is a widely adopted preservation technique for forage crops; however, variations in chemical composition and fermentation profiles among silage types can markedly alter their nutritive value and subsequent effects on animal performance. Although maize silage remains the predominant forage component in many dairy production systems, the evaluation of alternative silage crops may improve dietary flexibility and support more sustainable forage management strategies. Therefore, the present study aimed to investigate the effects of dietary inclusion of buckwheat, maize, and forage rape silages on performance, nutrient digestibility, blood biochemical parameters, and ruminal fermentation characteristics in lactating Simmental cows.
Materials and methods: The present study was conducted in 2025 at a Simmental dairy farm located in Amol, Mazandaran Province, Iran. Laboratory analyses were performed at the Animal Nutrition Laboratory, Faculty of Animal Science and Fisheries, Sari Agricultural Sciences and Natural Resources University. Fifteen lactating Simmental cows (30 ± 3 days in milk, second parity, and 650 ± 25 kg body weight) were selected based on health status and assigned randomly to three dietary treatments in a completely randomized design (five cows per treatment). The experimental period lasted 42 days, including a 14-day adaptation period and a 28-day data collection period. Experimental diets consisted of total mixed rations containing buckwheat silage, maize silage, or forage rape silage as the main forage source. After 28 days of ensiling, representative samples of each silage were collected for sensory evaluation and chemical composition analysis. Dry matter intake was determined daily by recording feed offered and refusals, while milk yield was recorded at each milking throughout the experimental period. Weekly milk samples were analyzed for fat, protein, and lactose concentrations. Apparent nutrient digestibility was estimated using fecal samples collected during the final days of the experiment and analyzed for chemical composition. Blood samples were collected from the coccygeal vein before morning feeding to determine selected biochemical metabolites related to energy and metabolic status. Additionally, rumen fluid samples were collected via oral stomach tubing to evaluate ruminal fermentation characteristics, including pH, ammonia nitrogen, and volatile fatty acid concentrations.
Results and discussion: The results showed that buckwheat silage had greater concentrations of dry matter, neutral detergent fiber, ether extract, crude protein, and texture score compared with the other experimental silages (P < 0.05). In contrast, organic matter, acid detergent fiber, and color score were higher in maize silage than in buckwheat and forage rape silages (P < 0.05). Forage rape silage exhibited greater non-fiber carbohydrate concentration, crude ash content, pH value, odor score, and overall silage quality score compared with the other silage treatments (P < 0.05). Dry matter intake was increased in cows fed forage rape silage compared with those receiving buckwheat or maize silages (P < 0.05). Cows fed buckwheat silage had greater milk total solids and protein percentages than cows fed the other experimental diets (P < 0.05). The proportion of preformed fatty acids was greater in milk from cows fed buckwheat and forage rape silages compared with the maize silage diet (P < 0.05). Moreover, neutral detergent fiber digestibility was higher in cows fed buckwheat silage than in those receiving the other diets (P < 0.01). Regarding blood metabolites, plasma glucose and non-esterified fatty acid concentrations were greater in cows fed forage rape silage compared with the other treatments (P < 0.05), whereas blood urea nitrogen and beta-hydroxybutyrate concentrations were increased in cows fed buckwheat silage (P < 0.05).
Conclusions: Overall, buckwheat and forage rape silages represent promising alternative forage sources to maize silage in diets of lactating Simmental cows. Buckwheat silage was associated with improved fiber utilization and favorable milk compositional characteristics, whereas forage rape silage enhanced dry matter intake and altered blood metabolites related to energy metabolism. These findings indicate that the inclusion of alternative silages may increase dietary flexibility and support more sustainable forage management strategies in dairy production systems.
کلیدواژهها [English]
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