It’s been our belief for quite sometime that because first calf heifers make up 10%-15% of most commercial herds that the heifers first calf has to be produce not only a LIVE CALF but one that also grows at a Rate that will sustain economic viability within the herd Model Florida the Set of 2yr olds. It is worth noting that heifers calves cannot equal growth rates of mature cows in the herd consider the following Data generated from Trangie Research Station in the early 1970’s, the Work was conducted by Roger Barlow et al.
This data illustrates the fact that at weaning a 2 yr old heifers calf will weigh 15% lighter than that of the Mature Cow, because her uterine environment is smaller therefore the calf will be lighter at birth than that of a mature cow. There is no doubting that the heavier the calf at birth the faster will be its growth rate and so mature weight of the progeny. Heavier calves have higher survival rates- one of the the reasons we don’t get bent out of shape about birth weight is because we don’t want too small a calf so as to hinder both SURVIVAL and ULTIMATE GROWTH RATE
Our plan has involved-:
- BUILDING PELVISES – A Viable Pelvis needs to have a) Capacity/Volume b) Correct Shape, the hips don’t need to be Prominent but they do need to be wide, the Thurl bones need to be set wide and allow for the Pin Bones to be lower than the Hips and widespread. Imagine the Pelvic set up of Animals in the wild e.g. Zebras,Water Buffalo, wilder beasts etc, Natural Selection over ‘000’s. Of years has produced the shape I am trying to describe. There is no doubting the most appropriate Pelvis Shape amongst this draft of Bulls belongs to Lot 54 D. Night Watch N263. It hasn’t happened by accident, this fella has in pedigree on both sides the Pelvis Builders we continually refer to e.g. D. UPTAKE U91, O’NEILL’S CRUSADER (both sides of pedigree). Other Pelvis Builders include D. REBUILD R112, T.C. Franklin B. FRANKEL NICHOLS EXTRA K205 ETC
- CULLING FOR FAILURE TO DELIVER A LIVE CALF AND RAISING THAT LIVE CALF – No Second Chances, we prefer to use heifer bulls born UNASSISTED from Maiden or first calf heifers
- WORKING ON GESTATION LENGTH – the Bovine Foetus grows at the rate of 1.75 lbs per day over the last 5-6 weeks of the gestation, this work was conducted in USA during the 1970’s-nothing much is new eh? Consider our New Calving SENSATION D. MONTJEU M013 ( used as a Yearling last year to mop up the Heifer A.I.- 21 unassisted calves all reared to weaning; used in the main Heifer A.I. this season 29 calves all delivered but one born dead), his Gestation Length is Minus 8.4 days. If he is mated to a set of Random heifers then we halve his EBV ( his genetic Contribution to the likely birth weight, the heifer contributes the other half), that is 4.2 days then multiply those days by the weight /day the foetus is growing at close to Parturition 1.75lbs. 4.2 x 1.75 = 7.35lbs or 3.3kg . Given BW will range from 30 to 37kg amongst 1st calf heifers then by using a bull like M013 the resultant calves as a result of reduced Gestation Length will weigh in the range 28-34kg not all that big an ask for a maiden heifer.
- Note the two bulls we are recommending as our preferred heifer bull sires are-; D. KIWI K100 – his EBV for gestation length is -8.0, he has been proven over heifers by A.I. in three commercial herds & D. Lonhro L16 his EBV for GL is -10.1 only proven here at Shannon vale and in the Commercial herd Branga North.
- Note these bulls also excel for Calving Ease and BW we believe L016 has significantly more Growth than his EBV would suggest
I guess I should also include our minimum weight requirements for joining and Calving Maiden Heifers-:
JOINING- 320kg minimum
CALVING- 460kg minimum
RECOMMENDATIONS
- TIER ONE- This set of Bulls have been used in the Dulverton Programme amongst females that have been selected within the Stud herd for 30 or so years
Lot13 N051. Lot 16 N040
Lot 14 N027. Lot 17 N108
Lot 15 N037
- TIER TWO-This set of Bulls haven’t been used but Iwould expect them to be very very heifer safe with more than adequate growth potential of progeny going forward
Lot 55 N018. Lot 57 N156. Lot 65 N155
Lot 56 N035 Lot 58 N115
- TIER THREE- This set of Bulls haven’t been used they will be very very safe calving with reduced growth potential
Lot 66 N114 through to Lot 72 N60
I do have a “Special” he is Lot 5 N137
- positive CED n CEM
- GL -7.5
- BW +3.3
- D. REBUILD R112- The Pelvis Builder
- abounds in Maternal Longevity
HAPPY HEIFER CALVING FROM THE DULVERTON TEAM
