Effect of Total Mixed Ration Feeding System on Dry Matter Intake, Nutrient Intake, and Onset of Estrus in Growing Dairy Cattle

The objective of the study was to compare the advantages of total mixed ration (TMR) feeding versus component (COMP) feeding concerning dry matter intake (DMI) and nutrient intake in terms of crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) intake, and the onset of estrus. A total of ten growing Holstein Frisian (HF) x Jersey breeds were randomly assigned to participate in five months of feeding trials at the Dairy Training and Research Institute. The design structure employed a randomized complete block design (RCBD) comprising five blocking factors under two treatment groups. The TMR and COMP were composed of the same feed ingredients, including corn silage, Napier grass, concentrate mash, mixed legumes, molasses, and iodized salt, and they had the same quantity and nutrient requirements. The TMR was prepared and mixed in advance, prior to the commencement of the feeding trial. In contrast, the components of the COMP were offered separately to the cattle following the specified feeding schedule. The data were collected from the daily intake of the rations offered. The feed refusal was weighed daily before the morning feeding periods, while the body weight gain (BWG) was recorded every two weeks. While samples of the offered and refused feeds were collected once a week for nutritional analysis, the data were subjected to the ANOVA procedure of SAS Statistical Software. The results demonstrated that DM, CP, NDF, and ADF intake was higher in the TMR than in the COMP group. However, the differences in means for BWG, feed conversion ratio, and the onset of estrus were not significantly different. In conclusion, TMR is expected to be beneficial in raising growing dairy cattle.