Mir Hossein Najafi; saeed zeinoaldini; Abolfazl Zali; mahdi Ganjkhanlou; Hossein Mohammadi
Volume 23, Issue 1 , March 2021, , Pages 73-82
Abstract
This study was conducted to investigate the effect of reducing dietary ratio of omega-6/omega-3 essential fatty acid (EFA) on dry matter intake, yield and milk composition, ovarian performance and blood concentrations of estradiol and progesterone using 24 multiparous Holstein cows. Experimental treatments ...
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This study was conducted to investigate the effect of reducing dietary ratio of omega-6/omega-3 essential fatty acid (EFA) on dry matter intake, yield and milk composition, ovarian performance and blood concentrations of estradiol and progesterone using 24 multiparous Holstein cows. Experimental treatments including different n-6 to n-3 EFA ratio; namely, 2.5, 4.5, or 6.5 parts of n-6 to 1 part of n-3 EFA. Dry matter intake and milk yield of cows were recorded daily. Also, body condition score and milk composition were recorded and ovarian activity was monitored by transrectal ultrasound scanning. Dry matter intake and milk composition were not affected by treatments. Daily milk yield was significantly higher in low and medium n- 6/n-3 FA ratio diets in comparison to high diet (P<0.05). Cows assigned to high n-6/n-3 FA ratio diet had greater plasma Haptoglobin concentrations compared to other diets (P<0.05). Results indicated that number of large follicles was greater in medium diet than high diet (P<0.05). Progestrone concentration was significantly decrease in high diet treatment (P<0.05). Results of this study indicate that modulating dietary n-6/n-3 FA ratio could lead to a higher milk yield and improve ovarian performance in fresh cows.
Ayoub Laki; Mehdi Dehghan-Banadaky; Abolfazle Zali; Mehdi Ghanjkhanlou; Kamran Rezayadi
Volume 18, Issue 2 , June 2016, , Pages 249-260
Abstract
The aim of this study was to investigate the effect of feeding of steeped barley grain with lactic acid (LA) and citric acid (CA) on dry matter intake, feeding behavior, apparent nutrients digestibility, rumen pH and milk production. Eight early lactating Holstein cows in the second parities were ...
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The aim of this study was to investigate the effect of feeding of steeped barley grain with lactic acid (LA) and citric acid (CA) on dry matter intake, feeding behavior, apparent nutrients digestibility, rumen pH and milk production. Eight early lactating Holstein cows in the second parities were used in 4×4 Latin square change- over design. Treatments consisted of basis diet containing 1) dry rolled barley grain (DR), 2) dry rolled barley grain steeped in an equal quantity of tape water alone (W), 3) or in 0.75% LA, or 4) 1% CA for 24 h. The result of this study showed that dry matter intake, feeding behavior and apparent nutrients digestibility did not significantly different among treatments. Rumen pH was greater at 6 h after feeding in LA and CA diets (P<0.05). Treatments had no effect on fecal score and pH. Milk and Fat corrected milk production unaffected by treated barley. While milk protein and none- solids fat were significantly greater in CA diet in compared to others (P<0.05). Others milk composition had not influenced by type of processing. In conclusion, treated barley grain with LA and CA had increased rumen pH 6 h after feeding but other characters including milk production and composition, apparent nutrient digestibility and feeding behavior unaffected by barley grain processing method.