نوع مقاله : مقاله پژوهشی
نویسندگان
1 عضو هیات علمی بخش تحقیقات علوم دامی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان اصفهان، سازمان تحقیقات، آموزش و ترویج کشاورزی،
2 گروه تولیدی کشاورزی و دامپروری فوده سپاهان
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objective: The quality and quantity of water consumed are among the most important factors affecting feed intake and physiological welfare of animals that impact feed efficiency. Despite the vital importance of water, little information is available about the effects of different water sources or qualities on feed intake and performance of dairy cows. This study hypothesized that reducing water hardness through reverse osmosis may have a positive effect on the performance of high-yielding dairy cows. The aim of this study was to investigate the effect of reducing water total dissolved solids (TDS) through reverse osmosis compared to well water on feed intake, milk production and composition and blood parameters of high-yielding dairy cows.
Materials and methods: 16 second-calf cows with an average DIM of 122 ± 2 and an average milk production of 44 ± 1.2 kg per day were assigned to the experimental treatments. The experimental treatments included well water with high TDS (1955 mg/L) and reverse osmosis purified water with low TDS (404 mg/L). The experiment was conducted in a completely randomized design with 2 treatments and 2 experimental periods (8 cows per treatment). The experiment was conducted over two 28-day periods, including 21 days of acclimation and 7 days of sampling. All cows in the experiment consumed the same type of diet with the same amount of energy and protein. Cows were housed in individual pens and had free access to water and feed. Statistical analysis of the data from this study was performed using the Mixed procedure in SAS (2002) statistical software version 9.1. Means were compared using the Tukey test.
Results: The pH of the well water (7.75) was more alkaline than the purified water (7.10), and the reverse osmosis method caused a decrease in pH. The electrical conductivity of well water (dS/m 3.2) was significantly higher than that of treated water (dS/m 0.59). The mineral salts (Ca, Mg, Na, Cl, HCO₃, SO₄) in well water were significantly reduced after treatment. TDS (1955 mg/L) and nitrate concentration (3.9 mg/L) of well water after treatment reached 404 and 0.84 mg/L, respectively. Cows consuming well water (25 kg/day) consumed significantly more dry matter than the treated group (23.79 kg/d), but there was no significant difference in milk production between the two groups (41.59 vs. 41.30 kg/d, P = 0.79). Milk fat percentage in cows consuming well water (3.43%) tended to decrease compared to purified water (3.72%) (P = 0.06), but protein, lactose and daily production were not significantly different. Feed efficiency in cows consuming reverse osmosis purified water was significantly higher than that in the well water group. Blood parameters were not affected by the treatment.
Conclusion: In general, purification of well water by reverse osmosis significantly improved water quality and made it more suitable for dairy cattle consumption. Consumption of purified water by high-producing dairy cows had no effect on milk production and blood parameters, but milk fat increased and with reduced feed intake, improved milk production efficiency, indicating improved nutrient utilization.
کلیدواژهها [English]
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