كليدواژه :
اﺳﯿﺪﻫﺎي ﭼﺮب ﻓﺮار , ﻋﻨﺼﺮ روي , ﮔﻮﺳﺎﻟﻪ ﺷﯿﺮﺧﻮار , ﻫﻤﺎﺗﻮﻟﻮژي
چكيده فارسي :
ﭼﮑﯿﺪه1
ﺳﺎﺑﻘﻪ و ﻫﺪف: ﻋﻨﺼﺮ روي در ﺗﻨﻈﯿﻢ ﺑﺴﯿﺎري از ﻓﺮآﯾﻨﺪﻫﺎي ﻣﺘﺎﺑﻮﻟﯿﮑﯽ ﺑﺪن ﻧﻘﺶ دارد و ﮐﻤﺒﻮد آن ﻣﯽﺗﻮاﻧﺪ ﺳﺒﺐ ﮐﺎﻫﺶ اﺷﺘﻬﺎ و ﺑﻪ ﺗﺒﻊ آن، ﮐﺎﻫﺶ ﻣﺼﺮف ﺧﻮراك ﺷﻮد. ﻫﻤﭽﻨﯿﻦ، ﮐﻤﺒﻮد ﻋﻨﺼﺮ روي، رﺷﺪ و وزنﮔﯿـﺮي ﺣﯿـﻮان را ﮐـﺎﻫﺶ ﻣـﯽ دﻫـﺪ. ﻧﯿـﺎز روزاﻧـﻪ ﮔﻮﺳﺎﻟﻪﻫﺎي ﺷﯿﺮﺧﻮار ﺑﻪ ﻋﻨﺼﺮ روي در ﺣﺪود 33 ﻣﯿﻠﯽﮔﺮم در ﮐﯿﻠﻮﮔﺮم ﻣﺎده ﺧﺸﮏ ﺟﯿﺮه اﺳﺖ. در ﺣﺎﻟﯿﮑﻪ ﻏﻠﻈﺖ اﯾﻦ ﻋﻨﺼـﺮ در ﺷﯿﺮ ﮔﺎو، ﺑﺴﯿﺎر ﮐﻢ و در ﺣﺪود 3-5 ﻣﯿﻠﯽﮔﺮم در ﻫﺮ ﮐﯿﻠﻮﮔﺮم ﺷﯿﺮ ﻣﯽﺑﺎﺷﺪ. ﻟﺬا ﺑﻪ ﻧﻈﺮ ﻣﯽرﺳﺪ ﮐﻪ اﺳﺘﻔﺎده از ﻣﮑﻤﻞ روي در ﺟﯿﺮه ﻣﻤﮑﻦ اﺳﺖ ﺳﺒﺐ ﺑﻬﺒﻮد ﻋﻤﻠﮑﺮد ﮔﻮﺳﺎﻟﻪﻫﺎي ﺷﯿﺮﺧﻮار ﺷﻮد. ﺑﺮ اﯾﻦ اﺳﺎس، اﯾﻦ ﭘﮋوﻫﺶ ﺑﻪﻣﻨﻈﻮر ﺑﺮرﺳﯽ اﺛﺮ ﺳﻄﻮح ﻣﺨﺘﻠﻒ ﻋﻨﺼﺮ روي ﺑﺮ ﻋﻤﻠﮑﺮد و ﺑﺮﺧﯽ ﻓﺮاﺳﻨﺠﻪﻫﺎي ﺧﻮﻧﯽ و ﺷﮑﻤﺒﻪاي در ﮔﻮﺳﺎﻟﻪﻫﺎي ﺷﯿﺮﺧﻮار ﻧﮋاد ﻫﻠﺸﺘﺎﯾﻦ اﻧﺠﺎم ﺷﺪ. ﻣﻮاد و روشﻫﺎ: اﯾﻦ ﭘﮋوﻫﺶ ﺑﺎ اﺳﺘﻔﺎده از 18 رأس ﮔﻮﺳﺎﻟﻪ ﺗﺎزه ﻣﺘﻮﻟﺪ ﺷـﺪه ﻫﻠﺸـﺘﺎﯾﻦ، از ﺳـﻦ 4 روزﮔـﯽ ﺗـﺎ از ﺷـﯿﺮﮔﯿﺮي ) 70 روزﮔﯽ( در ﻗﺎﻟﺐ ﻃﺮح ﮐﺎﻣﻼً ﺗﺼﺎدﻓﯽ اﻧﺠﺎم ﺷﺪ. ﺗﯿﻤﺎرﻫﺎي آزﻣﺎﯾﺸﯽ ﺷﺎﻣﻞ ﮔﺮوه ﺷﺎﻫﺪ )ﺟﯿﺮه ﭘﺎﯾﻪ(، ﺗﯿﻤﺎر 2 )ﺟﯿﺮه ﭘﺎﯾﻪ ﺑـﻪ اﺿـﺎﻓﻪ ﻣﻘﺪار 30 ﻣﯿﻠﯽﮔﺮم ﻋﻨﺼﺮ روي در ﻫﺮ ﮐﯿﻠﻮﮔﺮم از ﻣﺎده ﺧﺸﮏ ﺟﯿﺮه ﺑﻪ ﺻﻮرت ﺳﻮﻟﻔﺎت روي( و ﺗﯿﻤﺎر 3 )ﺟﯿـﺮه ﭘﺎﯾـﻪ ﺑـﻪ اﺿـﺎﻓﻪ ﻣﻘﺪار 60 ﻣﯿﻠﯽﮔﺮم ﻋﻨﺼﺮ روي در ﻫﺮ ﮐﯿﻠﻮﮔﺮم از ﻣﺎده ﺧﺸﮏ ﺟﯿـﺮه ﺑـﻪ ﺻـﻮرت ﺳـﻮﻟﻔﺎت روي( ﺑﻮدﻧـﺪ . ﮔﻮﺳـﺎﻟﻪ ﻫـﺎ در داﺧـﻞ ﺑﺎﮐﺲ ﻫﺎي اﻧﻔﺮادي ﺑﺎ ﮐﻒ ﺳﯿﻤﺎﻧﯽ ﻗﺮار داﺷﺘﻨﺪ و در ﻃﻮل دوره آزﻣﺎﯾﺶ، روزاﻧﻪ دو وﻋﺪه ﺷﯿﺮ در ﺳﺎﻋﺎت 8:00 و 19:00 درﯾﺎﻓـﺖ ﻣﯽﮐﺮدﻧﺪ. اﺳﺘﺎرﺗﺮ ﭘﻠﺖ ﺷﺪه و آب ﺗﺎزه ﻧﯿﺰ ﺑﻪﺻﻮرت آزاد در اﺧﺘﯿﺎر ﮔﻮﺳﺎﻟﻪﻫﺎ ﻗﺮار داﺷﺖ. از روز 15 آزﻣﺎﯾﺶ ﻣﻘﺪار 5 درﺻﺪ ﮐﺎه ﮔﻨﺪم ﺧﺮد ﺷﺪه و 5 درﺻﺪ ﯾﻮﻧﺠﻪ ﺧﺮد ﺷﺪه ﺑﻪ ﺗﺮﮐﯿﺐ اﺳﺘﺎرﺗﺮ اﺿﺎﻓﻪ ﺷﺪ. ﻣﻘﺪار ﻣﺎده ﺧﺸﮏ ﻣﺼﺮﻓﯽ ﺑﻪ ﺻﻮرت روزاﻧﻪ و ﺗﻐﯿﯿﺮات وزن ﮔﻮﺳﺎﻟﻪﻫﺎ ﻫﺮ دو ﻫﻔﺘﻪ ﯾﮑﺒﺎر ﺛﺒﺖ ﺷﺪ. در روز آﺧﺮ آزﻣﺎﯾﺶ )70 روزﮔﯽ( ﻗﺒﻞ از وﻋﺪه ﻏﺬاﯾﯽ ﺻﺒﺢ، از ﮔﻮﺳـﺎﻟﻪ ﻫـﺎ از ﻃﺮﯾـﻖ ﺳﯿﺎﻫﺮگ وداج ﺧﻮﻧﮕﯿﺮي ﺷﺪ ﺗﺎ ﻏﻠﻈﺖ ﻋﻨﺎﺻﺮ ﻣﻌـﺪﻧﯽ ﺳـﺮم ﺧـﻮن )روي، ﮐﻠﺴـﯿﻢ، ﻓﺴـﻔﺮ، آﻫـﻦ و ﻣـﺲ( و ﻧﯿـﺰ ﻓﺮاﺳـﻨﺠﻪ ﻫـﺎي ﻫﻤﺎﺗﻮﻟﻮژي ﺧﻮن )ﻏﻠﻈﺖ ﻫﻤﻮﮔﻠﻮﺑﯿﻦ، ﺗﻌﺪاد ﮔﻠﺒﻮلﻫﺎي ﻗﺮﻣﺰ، ﺗﻌﺪاد ﮔﻠﺒﻮلﻫﺎي ﺳﻔﯿﺪ و درﺻﺪ ﻫﻤﺎﺗﻮﮐﺮﯾﺖ( اﻧـﺪازه ﮔﯿـﺮي ﺷـﻮد ﻫﻤﭽﻨﯿﻦ، در روز ﭘﺎﯾﺎﻧﯽ آزﻣﺎﯾﺶ، 3 ﺳﺎﻋﺖ ﺑﻌﺪ از ﺧﻮراكدﻫﯽ ﺻﺒﺢ، از ﮔﻮﺳﺎﻟﻪﻫﺎ )ﺑﺎ اﺳﺘﻔﺎده از ﻟﻮﻟﻪ ﻣـﺮي و ﭘﻤـﭗ ﺧـﻼء ( ﻣـﺎﯾﻊ ﺷﮑﻤﺒﻪ ﮔﺮﻓﺘﻪ ﺷﺪ ﺗﺎ ﻏﻠﻈﺖ اﺳﯿﺪﻫﺎي ﭼﺮب ﻓﺮار ﺷﮑﻤﺒﻪ ﺗﻌﯿﯿﻦ ﺷﻮد.ﯾﺎﻓﺘﻪﻫﺎ: ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد اﺳﺘﻔﺎده از ﺳﻄﻮح ﻣﺨﺘﻠﻒ ﻋﻨﺼﺮ روي، اﺛﺮ ﻣﻌﻨﯽداري ﺑﺮ ﺿﺮﯾﺐ ﺗﺒﺪﯾﻞ ﻏـﺬاﯾﯽ در ﮔﻮﺳـﺎﻟﻪ ﻫـﺎ در زﻣـﺎن از ﺷﯿﺮﮔﯿﺮي ﻧﺪاﺷﺖ. اﻣﺎ اﻓﺰاﯾﺶ وزن روزاﻧﻪ در ﺗﯿﻤﺎرﻫﺎي 30 ﻣﯿﻠﯽﮔﺮم و 60 ﻣﯿﻠﯽﮔﺮم روي )ﺑﻪ ﺗﺮﺗﯿﺐ 724/29 و 765/00 ﮔـﺮم در روز( ﺑﻪ ﻃﻮر ﻣﻌﻨﯽداري ﺑﯿﺸﺘﺮ از ﮔﺮوه ﺷﺎﻫﺪ )ﺑﻪ ﺗﺮﺗﯿﺐ 628/29 و 1532/83 ﮔﺮم در روز( ﺑﻮد. ﻫﻤﭽﻨﯿﻦ، ﻣـﺎده ﺧﺸـﮏ ﻣﺼـﺮﻓﯽ روزاﻧﻪ در ﺗﯿﻤﺎر 60 ﻣﯿﻠﯽﮔﺮم روي )1692/41 ﮔـﺮم در روز(، ﺑـﻪ ﻃـﻮر ﻣﻌﻨـﯽ داري ﺑﯿﺸـﺘﺮ از ﮔـﺮوه ﺷـﺎﻫﺪ )ﺑـﻪ ﺗﺮﺗﯿـﺐ 628/29 و 1532/83 ﮔﺮم در روز( ﺑﻮد. ﻣﺼﺮف ﻣﮑﻤﻞ روي ﺳﺒﺐ اﻓﺰاﯾﺶ ﻣﻌﻨﯽدار ﻏﻠﻈﺖ ﻋﻨﺼﺮ روي در ﺳﺮم ﺧﻮن ﮔﻮﺳﺎﻟﻪﻫﺎ در ﺗﯿﻤﺎرﻫـﺎي 30 ﻣﯿﻠﯽﮔﺮم و60 ﻣﯿﻠﯽﮔﺮم روي )ﺑﻪ ﺗﺮﺗﯿﺐ 1/184 و 1/168 ﻣﯿﻠﯽﮔﺮم ﺑﺮ ﻟﯿﺘﺮ( ﺷﺪ. ﻫﯿﭻ ﺗﻔﺎوت ﻣﻌﻨﯽداري ﺑﯿﻦ ﻏﻠﻈﺖ ﺳﺎﯾﺮ ﻋﻨﺎﺻﺮ ﻣﻌﺪﻧﯽ ﺧﻮن )ﮐﻠﺴﯿﻢ، ﻓﺴﻔﺮ، آﻫﻦ و ﻣـﺲ( در ﺑـﯿﻦ ﺗﯿﻤﺎرﻫـﺎ ﻣﺸـﺎﻫﺪه ﻧﺸـﺪ. ﻫﻤﭽﻨـﯿﻦ، ﻣﺼـﺮف ﻣﮑﻤـﻞ روي اﺛـﺮ ﻣﻌﻨـﯽ داري ﺑـﺮ ﻓﺮاﺳﻨﺠﻪ ﻫﺎي ﻫﻤﺎﺗﻮﻟﻮژي ﺧﻮن ﻧﺪاﺷﺖ. ﻏﻠﻈﺖ ﮐﻞ اﺳﯿﺪﻫﺎي ﭼﺮب ﻓﺮار، اﺳﯿﺪ اﺳﺘﯿﮏ، اﺳﯿﺪ ﭘﺮوﭘﯿﻮﻧﯿﮏ، اﺳﯿﺪ ﺑﻮﺗﺮﯾـﮏ و ﻧﺴـﺒﺖ اﺳﯿﺪ اﺳﺘﯿﮏ ﺑﻪ اﺳﯿﺪ ﭘﺮوﭘﯿﻮﻧﯿﮏ در ﺷﮑﻤﺒﻪ ﻧﯿﺰ ﺗﺤﺖ ﺗﺄﺛﯿﺮ ﻣﺼﺮف ﻣﮑﻤﻞ روي ﻗﺮار ﻧﮕﺮﻓﺖ. ﻧﺘﯿﺠﻪﮔﯿﺮي: ﺑﻪﻃﻮرﮐﻠﯽ، ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد، اﺳﺘﻔﺎده از ﺟﯿﺮه ﭘﺎﯾﻪ ﺣﺎوي 29/68 ﻣﯿﻠﯽﮔﺮم ﻋﻨﺼﺮ روي در ﻫـ ﺮ ﮐﯿﻠـﻮﮔﺮم ﻣـﺎده ﺧﺸـﮏ، ﺑﺮاي ﺗﺄﻣﯿﻦ ﻧﯿﺎز ﮔﻮﺳﺎﻟﻪﻫﺎي ﺷﯿﺮﺧﻮار ﻫﻠﺸﺘﺎﯾﻦ ﮐﺎﻓﯽ ﺑﻮد. اﺳﺘﻔﺎده از ﻣﮑﻤﻞ روي ﺳﺒﺐ اﻓﺰاﯾﺶ وزن روزاﻧﻪ آﻧﻬﺎ ﺷﺪ.
چكيده لاتين :
Zinc is involved in the regulation of many metabolic processes and zinc deficiency resulting in low appetite, consequently decreased feed intake. Also, zinc deficiency decreases the growth and weight gain of the animal. It has been reported that the daily requirement of zinc for suckling calves is 33 mg/kg DM. While, the amount of this element in cow’s milk is 3-5 mg/kg. Therefore, zinc supplementation may improve the performance of suckling calves. So, this study was performed to investigate the effect of different levels of zinc on performance and some blood and ruminal parameters in Holstein suckling calves.
Materials and methods: This study was conducted using 18 newborn Holstein calves from 4 days of age to weaning (70 days) in a completely randomized design. Experimental treatments were treatment 1 (control, basal diet), treatment 2 (basal diet plus 30 mg / kg DM as zinc sulfate) and treatment 3 (basal diet plus 60 mg/ kg DM as zinc sulfate). The calves were housed in individual pens with cement floors and were offered with whole milk (approximately at 10% of weight) in two equal meals daily at 8:00 and 19:00 during the experimental period. They had free access to the pelleted starter and fresh-water. After 15 days, chopped wheat straw (5 %) and alfalfa (5%) were added to their starter. Daily feed and ort were measured to estimate daily dry matter intake and animals were weighed fortnightly to obtain average daily gain. Blood samples were taken from the jugular vein at the end of the trial (day 70) before the morning feeding for measurement of blood mineral (Zn, Ca, P, Fe, and Cu) status and the hematological parameters (hemoglobin concentration, red blood cell count, white blood cell count and hematocrit %). Also, the ruminal fluid samples were collected on day 70, 3 h after the morning feeding, by stomach tube and a vacuum pump for determination of ruminal volatile fatty acids concentrations.
Results: The results showed that the use of different levels of zinc had no significant effect on feed conversion ratio in weaning calves. However, average daily gain in treatments 2 and 3 (724.29 and 765.00 g / day, respectively) and dry matter intake in treatment 3 (1692.41 g / day), were significantly (P<0.05) higher than the control treatment (628.29 and 1532.83 g / day, respectively). Supplementation of zinc significantly increased (P<0.05) serum zinc concentration in treatments 2 and 3 (1.184 and 1.168 mg / l, respectively). However, no significant differences were observed among treatments for the concentration of other minerals in blood serum (calcium, phosphorus, iron and copper). Also, supplementation of zinc had no significant effect on blood hematological parameters. Ruminal total volatile fatty acids, acetic acid, propionic acid, and butyric acid concentrations, and acetic acid: propionic acid ratio were not affected by zinc supplementation.
Conclusion: Generally, the results showed that a basal diet containing 29.68 mg Zn/kg DM can supply the zinc requirement of Holstein suckling calves. But, zinc supplementation improved the performance of these animals.
