Helping you with your 2018 Dulverton Bull purchase.
We have decided to put together a number of hopefully helpful articles re this year’s draft of bulls that might just help in your decision making process with respect to your Dulverton bull purchase for 2018.
ARTICLE 1: HEIFER BULLS – The Dulverton Practise / Philosophy
- Here at Dulverton, we calve our heifers at 2yo, it is economic suicide not to do so and we cannot afford to lose a calf. Note that 15.5% of the 84 bulls offered in this draft are from maiden heifers. In addition to that, M006, M013 both by Black Pearl and M028 by Carabar Gun Smoke are being kept for Stud use, all three are out of heifers.
- Calving heifers at 2yo means joining them at 14 months. It also means the heifer needs a well developed/shaped pelvic area to enable easy ‘passage’ for this first calf. To assist this pelvic area issue be sure heifers are 300kg at joining and 460kg at calving (2yo). When selecting for pelvic shape watch for 1. Width at the pin bones,
- A ‘roll’ from point of hip to the pins, pins ideally need to be lower than the hips,
- Thurl bones also need to be full, wide and ‘roll’ down from the hip. Through the notes in the catalogue we refer to Mr Fundamental – bulls that get these basics right eg pelvic area construction. The 4 champions we have had are D. Uptake U91, Nichols Extra K205, TC Franklin and B. Frankel. They contribute to Calving Ease by building pelvises.
At Dulverton, our heifers get our best available nutrition.
- BIRTH WEIGHT: do we measure birth weight? NO, we DON’T and haven’t for 20 years or so. Basically, for two reasons:
- There are a number of genetic correlations but none stronger than birthweight and its relationship to growth – the heavier the calf within the normal range of 30-45kg, the greater the survival rate and more likely the individual to express a faster growth rate to a heavier growth end point – FINAL WEIGHT.
- Selection for lighter birthweight in the belief that very light birthweight will in fact result in safer and better calving rates in first calf heifers is correct BUT a very large percentage of the resultant light birth weight progeny will have ‘distressingly poor growth rates’ – not economical. These slower growth rates and smaller ‘all over’ resultant progeny also have smaller pelvic areas and so the heifer portion in particular will in the main have increased Dystocia problems.
- CALVING EASE: The calving ease measurement is far more useful to our program than Birth Weight.
- CALVING EASE DIRECT is a measure of the individual being investigated’s ability to produce calves that will be born with no assistance, keeping in mind of course that the heifer needs to have a ROOMY, well constructed pelvis as she too is a major contributor as to whether the calf will be born with no assistance. However, the environment has the largest say, nutrition during the days leading up to and during birth is of paramount importance. Energy in the diet, particularly in July on the New England, is the essential nutritional ingredient.
- CALVING EASE DAUGHTERS: a really important calving ease criteria, this is the measurement that helps describe the Pelvis Builders. This is the measure that acknowledges the calving female’s contribution to calving ease. The really potent Pelvis Builders we have used at Dulverton include D. Uptake U91 and his sire PARB Design Plus ’97, Hyline Right Time 338, Nichols Extra K205, Fertile Valley Farms The King, Praire Edge Marbul Design 931, TC Franklin, Booroomooka Frankel.
- GESTATION LENGTH. Why is gestation length important to Calving Ease? During the last six weeks of the pregnancy a bovine foetus grows at the rate of 0.7kg per day, therefore a calf born in the order of 3 days short of term will be 2kgs lighter than the average. If as is the case with M196 and his predicted gestation length is -8.3 days and the heifer he is mated to is breed average, then the resultant calf will be in the order of 4.0kg lighter than breed average. That is, 8 days plus 4 days (breed average) equals 12 divide by 2 = 6 days and 6 days multiplied by 0.7kg/day equals 4.2kg. This is why we continue to include gestation length as a selection criteria. Note one of our Top 3 cows Dulverton Queen F23 is -10.4 for gestation length.
- DO WE PULL CALVES FROM HEIFERS? Why sure we do and no doubt we will continue to do so, primarily because we do challenge the ‘system’. That is because our commitment to ensure each heifer’s calf must be born alive and have the ability to make a potential KEEP heifer (300kg @14 months) OR Sale Bull (730 – 760kg @ 23 months) we will have issues albeit minimal. Importantly though any calf that is ‘pulled’ is terminated; bulls made into steers, heifers join the cull mob for sale to slaughter. Likewise, the dam who experienced the calving trouble is terminated. This practice ensures potential future calving ease issues are kept to a minimum.
- DO WE PULL CALVES FROM COWS? NO! I can say that the only incident we have had at Shannon Vale where assistance had to be given to a calving cow was with a cow trying to deliver a back to front set of twins.
There is no doubt the practices we implement particularly that of ‘disposing’ of the ‘offender’, the dam that had to be assisted and the calves that had to be assisted goes a very long way to reducing the ongoing dystocia problem.
Pelvic Building is the other really important component of designing the ‘Fail Safe Calving Female’.
