The effect of feeding alfalfa in the starter diet on the performance of dairy calves with step-down milk feeding procedure

The future of any dairy farm depends on the success of the female calf rearing. In recent years, new aspects the use of forage in the starter feed has been discussed. Studies have reported that a starter without forage leads to the development of abnormally shaped villi in the calf's rumen, which will negatively affect rumen growth and development. However, today there are different opinions about the use of forages in the starter feed for dairy calves so that some researchers believe that the presence of forages in the starter feed reduces the performance of dairy calves. In this study, the effect of 15% alfalfa forage level in the ground starter diet on functional responses and skeletal growth traits of dairy calves fed a step-down milk feeding procedure was investigated.

The experiment was designed and conducted in a completely randomized design using 30 Holstein female calves (15 calves per treatment). Experimental treatments were as follows: 1- ground starter diet without forage (control) 2- ground starter diet consisted of 15% alfalfa hay. The milk feeding pattern was the same for both treatments and was a step-down procedure as 2 times per day(6 liters to 30 days, 4 liters to 45 days, and 2 liters to 56 days). All calves were weaned on day 56 of the experiment and keep until day 70 in the experiment. Feed intake and weight gain were measured and recorded weekly. Skeletal growth traits were measured on days 1, 56, and 70 of the experiment. Rumen fluid was measured on day 60 of the experiment. Statistical analysis was performed using the Mixed procedure as repeated measures for 3 periods (before weaning, after weaning, and the whole period).

The results of this study showed that adding 15% alfalfa hay to the starter feed did not have a significant effect on the mean daily weight gain, feed efficiency, and skeletal growth traits of dairy calves. Calves that received the forage treatment had higher starter feed intake in the post-weaning period than the starter diet without forage (P <0.05). Acetate concentration was higher for 15% forage and propionate concentration was higher for the control treatment (P <0.05). Rumen pH also tended to increase in calves consuming forage.

Feeding 15% of alfalfa forage mixed with the ground starter feed improved their feed intake after weaning. These results indicate that the use of alfalfa forage in the ground starter diet reduces the stress of weaning and improves rumen development.