| Titles |
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English :
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Nutritional studies on dairy cattle
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Arabic :
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دراسات غذائية على ماشية اللبن
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| Abstract |
The experimental work of this study was conducted at ELKarada experimental station belonging to Animal Production Research Institute, Ministry of Agriculture and the laboratories of the same Institute and Animal Production Department, College of Agriculture Mansoura University.
Twelve Friesian cows calved recently, aged from 7 to 8 years, with average live body weight 499.61 kg were used.
They were randomly chosen after the peak of lactation period. All animals were in the fourth lactation season. they were allocated according to the switch back complete design into four equal groups, three cows each. All groups were individually fed according to NRC (1984) recommendations ,based on their live body weight ,milk yield and its fat percentage. Cows in all groups were fed on clover hay, rice straw and concentrate feed mixture with 1 % NaHC03 or KHC03 at 1% or both buffers together at 0.5% each of CFM intake.
The entire experimental period lasted for 84 days and was divided into three equal periods, 28 day each .The experimental rations were as follows:
Ration A (control): CFM+CH +RS.
Ration B: CFM+CH+RS+1%NaHC03 of CFM
Ration D: CFM+CH+RS+0.5% NaHC03+0.5% KHC03 of CFM.
Four digestion trials were conducted using the same experimental animals, three cows each to evaluate the feeding value of tested rations.
At the last two days of each digestion trial, rumen liquor samples were collected by rubber stomach tube to measure some rumen parameters
(pH, NH3- N and total VFA's) at different intervals after feeding 0, 2, 4, 6, 8 hrs. Blood samples were also taken twice a week for the two weeks of the collection period through the three experimental periods to determine white and red blood cells (WBC and RBC) and some plasma minerals (Na, K, Ca and MG)
The main results could be summarized as follows:
1- The addition of both buffers either separately or combined together resulted slight improving the DM intake as well as TDN intakes, since they were 8.11,8.36,8.33 and 8.18 Kg TDN/h/d for control, B, C and D treatments, respectively.
2- Concerning nutrient digestibility coefficients the results showed that the addition of buffers caused significant ( P<0.05) increases in all nutrient digestibility coefficients and feeding value (as TDN, and DCP%) tested rations.
3- The inclusion of buffers resulted in slight non significant increase in rumen pH values, NH3-N and total volatile fatty acids (VFA,s) concentration at all measured times, compared with the control.
4- Sodium (Na) potassium (K), Magnesium (Mg) and Calcium (Ca) of plasma were not significantly affected by the addition of buffers compared with the control.
5- Average daily milk yield was increased by 1.1,0.6, 0.6 Kg/h/d for rations B, C and D, and the corresponding values for 4% FCM yield were 1.70,0.90 and 1.00 Kg/h/d, compared with the control.
6- Fat percentage was increased by about 0.26, 0.15 and 0.17 percentage units for cows fed on rations B, C and D, respectively compared with the control, since fat (%) values were 3.87, 4.134.02 and 4.04% for rations A, B, C and D respectively.
7- Total solids (T.S) and solids non fat (SNF), protein and lactose percentages of milk of cows fed on buffered rations were slightly higher than that fed on unruffled ration (control). Milk density was also slightly higher for buffered rations than the control.
8- The economic efficiency was the best for ration B (supplemented with NaHC03), followed by ration D (0.5 % NaHC03 + 0.5 0/0 KHC03), while the lowest economic efficiency was that of ration C (KHC03), as compared with the control (ration A).
*- Under the experimental conditions, and from the economic point of view it could be concluded that although concentrate: roughage ratio obtained herein for tested rations did not exceed more than 54:46, addition of sodium bicarbonate to rations of cows was more effective and economic than potassium bicarbonate or both buffers together in improving nutrient digestibilities and nutritive value of tested rations, accordingly, enhancing milk yield as well as counteracting the depression of milk fat, without any adverse effects on blood or other milk characteristics and animal health in general.
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| Publication year |
1997
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| Pages |
95p.
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| Availability location |
مكتبة معهد بحوث الانتاج الحيوانى - شارع نادى الصيد- الدقى - الجيزة
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| Availability number |
559
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| Organization Name |
Animal Production Research Institute (APRI)
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| Country |
Egypt
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| Department |
Cattle Breeding Research Department
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| Author(s) from ARC |
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| Agris Categories |
Animal feeding
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AGROVOC
TERMS |
Clover.
Concentrates.
Cows.
Crude fibre.
Crude protein.
Dairy cattle.
Digestion.
Erythrocytes.
Hay.
Leukocytes.
Ph.
Rice straw.
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| Publication Type |
Master Thesis
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