Dairy Tutorial 3

Tutorial 3 – Dry Cows Dry cow nutrition is the most important component of a successful lactation. Energy balance and mineral levels have been shown to influence the occurrence of post-calving metabolic disease as well as whole lactation performance. Feeding the dry cow is just one component of the dry cow program. Adequate grouping, housing, and management of the dry cows are equally important in determining the productivity in the upcoming lactation. CNCPSv4 has a new component added to the requirements of cows –3 weeks of parturition called Mammogenesis. Mammogenesis is the growth of the mammary gland. It begins in the late dry period and is often referred to ‘springing’ in the field. Mammary development continues during the first three weeks post-calving. The resulting growth requirements are .94 Mcal ME and 277 gms MP per day. This brings the total MP requirement up to approximately 1100 gms of MP resulting in diets in the range of 13.5 to 14.5% crude protein. Current guidelines (from: Managing the Transition Cow, L. Hutchinson, and L. Chase, 1997 Mid-Atlantic Dairy Management Conference) used to evaluate and formulate dry cow rations are: Early dry Close-up dry DMI 1.9-2.1% BW 1.6-1.8% BW NEl Mcal/lb .55 - .60 .60 - .70 Crude Protein % DM 12 –13 13 – 14 Soluble % CP 40 – 50 35 – 45 DIP % CP 65 –70 62 – 67 ADF % DM 35 – 40 33 – 38 NDF % DM 45 – 55 35 – 45 Ca % DM .5 - .6 .6 - .7 P % DM .25 - .30 .30 - .35 Mg % DM .20 - .25 .25 - ...