Fateme Ahamadi; hamid Amanlou; Najme Eslamian Farsuni; Tahere Amirabadi Farahani
Volume 23, Issue 3 , September 2021, , Pages 363-374
Abstract
The objective of this study was to investigate the effect of decreasing dietary protein content with supplementing protected methionine (pMet) and lysine (pLys) on intake, milk yield, metabolic status, and apparent digestibility of nutrients in Holstein fresh cows. Immediately after calving, 16 cows ...
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The objective of this study was to investigate the effect of decreasing dietary protein content with supplementing protected methionine (pMet) and lysine (pLys) on intake, milk yield, metabolic status, and apparent digestibility of nutrients in Holstein fresh cows. Immediately after calving, 16 cows with the similar BCS and parity were randomly assigned to two treatments. Experimental diets provided equal amounts of lysine (132 to 133 g/d) and methionine (40 to 43 g/d). The treatments were: a diet containing 18.35 % CP without supplementing pMet and pLys (HP); and a diet containing 16.45 % CP with supplementing rumen-protected amino acids (LPML). Individual dry matter intake and milk yield were recorded daily during fresh period. Blood samples were collected at 0, 3, 7, 14 and 21 d after calving to determine the serum concentrations of mineral and metabolites. Feed intake was not affected by experimental diets but milk yield was higher for HP cows than cows in LPML (P < 0.01). The yield of milk protein, lactose, fat and concentration of milk urea nitrogen (MUN) were higher in HP cows compared to LPML (P < 0.05). Compared to HP cows, cows in LPML had lower blood urea nitrogen (BUN) and higher serum concentrations of total protein and globulin (P < 0.01). Based on the results of the present study, reducing dietary protein content while maintaining the supply of limiting amino acids decreased lactational performance and feed efficiency of Holstein fresh cows.
Hossein Gholami; sayed abdoullah hosseini; kamran rezayazdi
Volume 21, Issue 4 , January 2020, , Pages 545-555
Abstract
This experiment carried out to determine the nutritional value of 18 sorghum forage varieties and to introduce superior cultivars using multicriteria decision-making technology. They sow in early June and harvested in mid-November. Random samples were taken from the center of each experimental ...
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This experiment carried out to determine the nutritional value of 18 sorghum forage varieties and to introduce superior cultivars using multicriteria decision-making technology. They sow in early June and harvested in mid-November. Random samples were taken from the center of each experimental plot in a way that ten plants were cut from 10 cm above soil. These samples were cut into 3 to 5 cm pieces, eachcultivar had three samples, in total 54 samples were collected. Yield and nutrient contents such as, crude protein, crude ash, ADF, NDF, water-soluble carbohydrates, starch and lignin measured in the experimental cultivars. The metabolizable energy of sorghum cultivars estimated by gas test method using the amount of gas produced in 24 hours and the amount of crude protein contained in it. Sorghumcultivars ranked based on 11 integrated traits. Among the domestic cultivars, Spidfeed ranked fifth among all varieties, followed by KFS-18 ranked seven and pegah ranked 10th and KFS-2 ranked 12th with moderate quantitative and qualitative performance. Overall, based on the results of the multi-criteria decision-making method, it was found that the top three sorghum cultivars are Siloking, FGCSI12 and PHFS-27, respectively, which are recommended for sorghum forage production and silage for dairy farmers.