The” magic circle” whose members include Dr Bichard, Dr Roden, Mr Bill Luff and Mr Chris Watson are concerned that the Jersey breed in the UK has “better” fertility as expressed by Calving Interval (average number of days for all cows in the herd between calvings) than does the Guernsey or the Holstein. Figures presented at the World Conference in Canada by Interbull stated that this figure had changed by an extra 10 days in the last 10 years when compared against the other breeds. However at the same conference Dr Bichard presented evidence that “production” of UK Guernseys had risen at a faster rate than either Holsteins and Jerseys in the UK or in the USA. Are we the victim of our own success?
All of the experts agree that “Fertility” has a very low heritability and therefore wish to multiply the number by a factor of 30 so as to make a difference!
I have used the listings supplied by Dairy Co for UK proven Guernsey bulls (more than 1000) and have produced two tables of the 13 bulls that are better than +7 for Fertility Index and for those 12 bulls at the “bottom” of the list with a Fertility Index of worse than -7 . Each group have an average of either +9 or -9 and in practical terms each point is equivalent to half of a day of improvement/loss of Calving Interval.
| Bulls better than +7 for Fertility Index | |||||||||||||
| Milk | Fat | Prot | Fat% | Prot % | SCC | Fert Ind | Legs/Ft | Mamm | £PLI | GMI | |||
| 603023 | Nedrow Farms Goliath Luke | -168 | -6.4 | -1.8 | 0.03 | 0.08 | -10 | 13.8 | -1 | 0.6 | 62 | -16 | |
| 41843 | Kenvin Petunias Prince | -388 | -4.2 | -7.2 | 0.29 | 0.13 | 14 | 11.1 | 29 | -63 | |||
| 603244 | Sherma Goliath Pams Galaxy | 41 | -3.9 | 1.2 | -0.11 | -0.01 | -27 | 10.5 | -0.2 | 0.6 | 90 | 2 | |
| 41927 | Leighgrange Flora Doras Trumpeter | -119 | -4 | -1.4 | 0.03 | 0.06 | 12 | 9.6 | 29 | -51 | |||
| 42266 | Tiresford Atlantic | -82 | -3.9 | -4.5 | 0 | -0.03 | -13 | 8.8 | 0.6 | 1.6 | 61 | -38 | 6 Ex |
| 603218 | Marodore Goliaths Ronald | 216 | 5.9 | 4.3 | -0.08 | -0.06 | 6 | 8.7 | -0.3 | 1.1 | 49 | 72 | |
| 42352 | Easby Jordans Rocket | -106 | -3.1 | -4.4 | 0.04 | -0.01 | -21 | 8.2 | -0.7 | 1.1 | 52 | -41 | |
| 42309 | Hunnyhill Prime Vectis | -84 | 1.5 | -2.9 | 0.11 | 0 | -7 | 7.9 | -1.7 | -0.4 | 45 | -35 | 1 Ex |
| 42304 | Brocklesby Gitas Clarion | -375 | -1.9 | -3.6 | 0.33 | 0.2 | -7 | 7.9 | 1.3 | 2.7 | 89 | 145 | |
| 601830 | Rozelyn Patmar Jay Greg | 34 | 4.6 | 4.2 | 0.06 | 0.06 | 14 | 7.7 | -1 | -0.6 | 77 | 77 | 4 Ex |
| 603024 | Nedrow Farms Goliath Lucas | -3 | 2.1 | 1.6 | 0.04 | 0.03 | -3 | 7.5 | -0.9 | -0.2 | 63 | 39 | |
| 42239 | Stroxworthy A C Greg | -249 | -2.9 | -1.4 | 0.18 | 0.15 | 1 | 7.2 | -0.5 | -1.3 | 51 | 8 | 2 Ex |
| 42296 | Shalford John | -114 | 0.9 | -1 | 0.12 | 0.06 | -4 | 7.1 | -0.8 | 0.4 | 43 | 37 | |
| -1397 | -15.3 | -16.9 | 1.04 | 0.66 | -45 | 116 | -5.2 | 5.6 | 740 | 136 | |||
| 13 avg | -107 | -1.177 | -1.3 | 0.08 | 0.051 | -3.46 | 8.9 | -0.4 | 0.4 | 56.9 | 10.5 |
These are the “best” bulls in the UK listings when ranked for Fertility Index and all bar three are minus for Milk and most are also minus for the important type characteristics, they have an average of 10.5 for GMI and none of them if semen was available would be used as sires of sons.
| Bulls worse than -7 for Fertility Index | |||||||||||||
| Milk | Fat | Prot | Fat% | Prot % | SCC | Fert Ind | Legs/Ft | Mamm | £PLI | GMI | |||
| 602216 | Jensgolden Proking Royal Oak | 293 | 13.9 | 9.3 | 0 | -0.02 | -7 | -14.7 | 0.4 | 2.5 | 29 | 264 | 24 Ex |
| 604670 | Sniders Option Aaron | 523 | 27.3 | 13.5 | 0.04 | -0.09 | -4 | -11.3 | 1.8 | 1.2 | 83 | 358 | 3 Ex |
| 43538 | Beechgroves Cornelius | 411 | 18.7 | 10.6 | -0.02 | -0.07 | -5 | -10.9 | 1.1 | 1.7 | 69 | 272 | |
| 602480 | Golden Whey Magic Enticer | 88 | -3.5 | 1.7 | -0.14 | -0.03 | -13 | -10.9 | 0.4 | 2.1 | 41 | 31 | 7 Ex |
| 42351 | Sunninghill Park Royal Oak | 371 | 18.5 | 8.1 | 0.01 | -0.09 | 2 | -10.2 | 1 | 1 | 30 | 214 | 9 Ex |
| 43490 | Tiresford Pedro | 346 | 22.8 | 9.1 | 0.11 | -0.06 | -16 | -9 | 0.3 | 1.6 | 83 | 301 | 4 Ex |
| 602442 | Rozelyn Patmar Perfect Tony | 5 | -2 | 1.3 | -0.04 | 0.02 | -31 | -8.2 | 2.6 | 1.6 | 39 | 93 | 4 Ex |
| 42348 | Shalford Teak | 129 | 3.8 | 4.4 | -0.04 | 0 | -18 | -8.2 | 0.6 | 0.3 | 23 | 96 | |
| 43549 | Boskenna Junes Royal Oak | 442 | 20.5 | 11.9 | -0.01 | -0.07 | -17 | -8 | 0.4 | 0.9 | 78 | 283 | |
| 42290 | Brymor Enticing Billy | 136 | 5.4 | 5.2 | -0.02 | 0.01 | -14 | -7.9 | 0.4 | 0.2 | 63 | 117 | |
| 42301 | Lancewood Focus | 441 | 12.1 | 10.2 | -0.15 | -0.1 | -18 | -7.8 | 1 | 1.4 | 49 | 193 | 1 Ex |
| 2001008 | Meadow Court Red Oak | -18 | 15.8 | 3.1 | 0.32 | 0.07 | -17 | -7.1 | -1 | 1 | 56 | 236 | 1 Ex |
| 3167 | 153.3 | 88.4 | 0.06 | -0.43 | -158 | -114.2 | 9 | 15.5 | 643 | 2458 | |||
| 12 avg | 263.9 | 12.78 | 7.367 | 0.005 | -0.036 | -13.2 | -9.5 | 0.75 | 1.3 | 53.6 | 204.8 |
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These 12 bulls are the” worst” for Fertility Index but as you can see have made a “real positive impact” for all of the other breed improvement goals as desired by GMI, the numbers in the last column are daughters scored Excellent in the UK and Beechgrove Cornelius and Boskenna Junes Royal Oak as yet have only second lactation daughters, but the best of those will score Ex with time.
The proposal from Interbull is that the Fertility Index figure of approx 9 for each group should be multiplied by 30 so the first group would then average +280 GMI whilst the second group would average -65 GMI and if that had been the case when these bulls were originally available then none of the second group would have been selected and the UK Guernsey breed would have not made the improvements in terms of production and type that have been achieved.
I am glad to say that the working farmers on the EGCS Council all confirmed their previous decision that the Fertility Index should be published but should not be included in the GMI, it will be interesting to see if the “Magic Circle” take any notice.