The Dairy Calf and Heifer Association (DCHA) has recently established production and performance standards for Holstein heifers, from 6 months of age to freshening.
What follows are the parameters of the program:
Given calves that are healthy without morbidity from an earlier age, total death loss from all conditions, but primarily pneumonia, should be:
6 to 12 months of age: <1%
12 months to freshening: <0.5%
Defining pneumonia as a case of respiratory disease which requires individual animal treatment with an antibiotic (does not include use of feed- grade medication fed with regular ration), target morbidity rates are:
6 to 12 months of age: <3%
12 months to freshening: <1%
Target rates for morbidity (disease condition which requires treatment) from all other causes, including pinkeye, mastitis, heel warts, diarrhea, bloat, BVD, hardware disease and accidental injury are:
6 to 12 months of age: <4%
12 months to freshening: <2%
Growth rate and nutrition
Target growth rate is 1.7 lbs. to 2.0 lbs. average daily gain. Weight checks should be performed routinely; ideally, at least every three months.
Total ration protein content should be:
6 to 9 months of age: 15–16%
9 to 13 months of age: 14–15%
13 months of age to freshening: 13.5–14%
It’s recommended that producers work with a nutritionist to help formulate rations and monitor/consult routinely. Producers should also keep their herd veterinarian informed of rations for all ages of heifers.
By 13 to 15 months of age, producers should strive to achieve for their heifers:
Weight of 825–900 pounds
Hip height of >50 inches
Wither height of >48 inches
[Or 55% of the weight of mature cows in the herd].
Target weight of heifers immediately precalving is 1,350 pounds (or 85% of the weight of full-term, pregnant, mature cows in the herd). Target body condition score at freshening is 3.5 (on a 5-point scale).
Target feeding space for different ages of heifers should be:
6 to 12 months of age: 18 inches per head
12 to 18 months of age: 20 inches per head
18 months of age to freshening: 24 inches per head
3 weeks prior to freshening: 30 inches per head
For stocking density and pen assignments, free-stall or open-lot housing should provide total bunk space inches to allow all animals to eat at the same time. Feeding systems with headlocks or slants should provide an animal: stall stocking density of 1:1, or be stocked at a rate to accommodate target feeding space above (example: heifers three weeks prior to freshening in 24-inch stalls should be stocked at 80%). Pre-fresh heifers should be housed separately from close-up, adult cows.
As far as housing environment, heifers should have protection from direct sunlight any time the Temperature Humidity Index (THI) meets or exceeds:
77 for heifers 6 to 12 months of age
72 for heifers 12 months of age to freshening
Heifers should have shelter from wind and precipitation any time wind chill temperatures are 20°F or lower. Heifers 6 to 12 months of age should have overhead shelter in these conditions. Heifers 12 months of age to freshening should have a windbreak in these conditions. The housing environment for heifers of all ages always should be clean, dry and draft-free, with good air quality.
The target resting space for heifers 6 to 12 months of age should be 45 square feet per head, or one free stall per animal; for heifers 12 to 18 months of age 50 square feet per head, or one free stall per animal; for heifers 18 months of age to 2 to 4 weeks pre-freshening 60 square feet per head, or one free stall per animal; and for heifers 2 to 4 weeks pre-freshening, 100 square feet, or one free stall per animal.
Target free stall space for heifers should be:
6 to 9 months of age: 30 X 54 inches
9 to 12 months of age: 34 X 60 inches
12-18 months of age: 36 X 69 inches
18 months of age to 2 to 4 weeks pre-freshening: 40 X 84 inches
Vaccination and parasite control
Producers should work with a veterinarian and — in custom-rearing facilities — dairy owners, to develop a vaccination protocol appropriate to the disease challenges of their region and operation.
Diseases to consider addressing with vaccination include blackleg; BRSV, brucellosis; BVD (Types 1 and 2); clostridial disease; corna virus; E. coli mastitis; enteric disease caused by Salmonella; IBR; leptospirosis; papilloma (warts); PI3; pinkeye; pneumonia caused by Pasteurella multocida and Mannheimia haemolytica; rotavirus; trichomoniasis; vibriosis; and other diseases specific to the producer’s geographic region.
Dairies should implement internal and external parasite control based on geography and the herd veterinarian’s recommendations.
Begin breeding heifers at 13 to 15 months of age, with a proper weight of 825 to 900 lb., hip height of >50 inches, and wither height of 48 inches, [or at 55% of the weight of mature cows in the herd] so that heifers freshen at 22 to 24 months of age. At least 30 days prior to breeding, revaccinate all animals with a modified live vaccine.
Strive to achieve >70% first-service conception rate with conventional semen and 7 to 12% less with sexed semen. Inseminate at least 80% of animals within the first 21 days of moving to the breeding pen. Eight-five percent of heifers should be pregnant after three heat cycles. Pregnancy-check all heifers to confirm pregnancy before removing them from the breeding pen.
Some animals will abort after pregnancy diagnosis. Typical rate is approximately 3%. Run clean-up bulls with pregnant heifers if necessary. Perform routine health maintenance on bulls, including vaccination, deworming and breeding soundness exams, at six-month intervals. Rotate and replace bulls as necessary.
Reconfirm pregnancies 70–100 days after initial check. Reconfirm pregnancies prior to animals leaving custom-rearing operations, and communicate correct breeding dates back to the dairy. For heifers raised on site, reconfirm pregnancies before heifers are moved to the pre-fresh pen.
Revaccinate 4 to 8 weeks prior to calving when disease pressure is present and to boost colostrum antibody quality.
For more information, visit www.calfandheifer.org.