| چکیده انگلیسی مقاله |
Extended Abstract
Introduction and Objectives: Achieving proper growth and health during the pre-weaning period is the main goal in raising calves. While high mortality can reduce the profit-loss ratio. The health and growth of the calf as well as its functional characteristics and economic life in the future are affected by milk feeding in the pre-weaning period. Due to the high price of milk and milk substitutes, the commercial calf management program focuses on limiting the consumption of milk and milk substitutes. Calves are encouraged to consume more pellets and wean earlier, which reduces the potential for diarrhea and other illnesses. Any strategy that reduces the consumption of liquid feed and increases the consumption of starter will reduce each of these cases. How to feed calves before and after weaning is one of the most important stages of livestock breeding to have a regular and forward-looking program. Early feeding or intensive feeding programs, where more milk or milk substitutes are used, probably have the potential to improve growth rates and reduce age at first calving. Consumption of calf starter improves rumen development and causes weight gain in the days before weaning and also decreases weight loss in the days after weaning. In general, management of replacement heifers focuses on factors that increase physiological processes and subsequently maturity and production potential. Considering the role and importance of lysophospholipid in fat metabolism and limited studies regarding the mutual effects of these two additives, the purpose of this experiment is to investigate the possibility of increasing the digestibility of fats in the intestines of Holstein calves using the addition of lysophospholipid.
Materials and Methods: The present study was conducted with 48 calves with an average birth weight of 39.9 ± 4 kg and an average age of 3 ± 1 days in a completely randomized design with 4 treatments and 12 replications for 85 days. Experimental treatments include 1) control treatment, 2) control treatment with 3% fat rich in saturated fatty acids, 3) control treatment with two grams of lysophospholipid daily and 4) control treatment with 2 grams of lysophospholipid + 3% fat rich in saturated fatty acids. Saturated fatty acids. Lysophospholipid was added in milk from 6 to 40 days and in starter from 41 to 85 days. Calves had free access to feed and water throughout the experiment. The starter was mixed with 7% dry alfalfa before milking and mixed with 10% dry alfalfa after milking and offered to the calf. Feed consumption was measured for each calf once every 10 days. Calves were weighed at the beginning of the experiment and once every 10 days until the end of the project using a digital scale. The measurement of all parameters in the whole design was done at 14:00. Skeletal growth parameters including breast circumference, hip width, hip height, withers height, calf body length were measured at the moment of entering the project and once every 10 days. In order to measure the apparent digestibility of feed nutrients by the method of collecting all feces (9,10) in the last week before weaning and one week before the end of the project by connecting a special bag for collecting feces to the male calf, the amount of feces Excretion corresponding to 24 hours (for 3 days of feces collection) was measured for each animal. Statistical analysis of data using mixed models and considering the effect of treatment as a fixed effect and initial weight as an auxiliary variable was done)
Results: The results showed that there was no significant difference between the experimental treatments in terms of starter consumption, mean daily weight gain, feed efficiency, solids consumption and dry matter consumption. The experimental treatments had a significant difference in terms of body weight on day 85, so that between the treatment containing 3% saturated fat with the highest weight (109.2) and the treatment containing 2 grams of lysophospholipid with the lowest weight (105.3) in terms of There was a statistically significant difference. Differences between the experimental treatments in terms of digestibility of dry matter, organic matter, crude protein, crude fat, and insoluble fibers in neutral detergent, as well as biometric scores including wrist circumference, hip width, body length, chest circumference, height from the joint and height from the hip. There was no meaning.
Conclusion: In general, it can be concluded that the use of saturated fatty acid along with lysophospholipid had no significant effect on the growth performance of Holstein calves until the age of 85 days. The different results in different tests can be related to the amount, age of the calf and spatial and temporal conditions, which can be attributed to the type of saturated fatty acid and phospholipid, as well as the simultaneous use of fatty acid with lysophospholipid and the amounts used in the experiment. Presently communicated. Therefore, it is recommended to consider different amounts and origin of these materials. Overall, the results of the present experiment showed that the simultaneous daily use of 2 grams of lysophospholipid and 3 grams of saturated fatty acids has no significant effect on the performance of Holstein calves. |