The Maternal Productivity Project aimed to study the impact of selection for body composition and net feed intake (NFI) on breeding herd efficiency under different nutritional environments. The project involved divergent lines of Angus and Hereford cattle selected for increased or decreased fatness and NFI. Animals were measured at two research stations with different nutritional levels. Preliminary results found genetically fatter cows appeared more fertile, especially under low nutrition. Selection for body composition was consistent across seasons and treatments. Cow fatness and NFI EBV had no effect on calf weaning weight. Selection for NFI was associated with changes in cow fatness. The study of these lines is ongoing to evaluate the effects on breeding herd efficiency under varying conditions.

1. Maternal Productivity Project (southern Aust) Jeisane Accioly, Fiona Jones and Michael Laurence (on behalf of a large team)

2. WA Maternal Productivity Team Brad Seib John Milligan Tex Hann Nola Mercer Ryan Drage Brian McIntyre Peter Jelinek Leonarda Paszkudzka-Baizert Greg Sawyer

3. Collaborators

5. Industry Push

6. Low Efficiency High Efficiency

14. Vasse (WA) Struan (SA)

15. Intensive measurements and estimation of food intake Research herds 3 calving seasons 4 Lines High Fat Low Fat High NFI Low NFI 2 Nutrition High Low 2 Sites Vasse, WA Struan, SA x x

16. EBV differences between the lines 0.48 0.42 2.10 2.40 EMA 0.3 -1.2 -1.8 -3.3 DTC 58.6 42.0 81.3 67.7 MCWT 60.6 47.6 83.8 75.9 Wt600 9.0 7.8 10.6 10.8 Milk 25.9 18.9 36.3 31.3 Wt200 4.6 2.9 4.9 3.8 BWt -0.87 0.77 NFI F -0.47 0.65 NFI P -0.6 3.0 -1.5 1.4 Rump P8 -0.4 3.2 -1.4 1.2 Rib fat Low NFI (n=81) High NFI (n=81) Low Fat (n=170) High Fat (n=170) EBV

17. Heifer management Nutritional treat’s applied 9 week joining Calving 9 week joining Nutritional treat’s applied Calving Weaning Weaning Vasse Struan 9 week joining 9 week joining Sep Oct Nov Dec Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec Jan Feb June July Aug Sep Oct Nov Dec Jan Feb Mar Apr May June July Aug Sep Oct Nov

18. Energy Supply & Demand: Early Calvers & Late Calvers

19. Rainfall (mm) 2006: 577 mm 2007: 810 mm 2008: 671 mm 2009: 679 mm 2010: 464.1mm

20. Nutritional control

22. Weight of Fat cows

23. P8 Fat

24. 1 st calvers pre-mating and pregnancy test 86.8 85.1 4.9 367 465 Low Fat 93.4 93.5 6.5 370 473 High Fat Adjusted conception rate* Conception rate* P8 fat (mm)*** Weight (kg) Age (days)* Line

25. Pre-mating and pregnancy test 2 nd calving Line Nutrition Weight (kg)*** P8 fat (mm)** Conception rate High Fat High 531 8.3 94.9 High Fat Low 488 5.4 88.4 Low Fat High 575 7.6 93.5 Low Fat Low 491 4.2 85.7

26. Days to calving for heifers *

27. Days to Calving 2 nd calvers

29. Birth weight

30. Calf weaning weight from 1 st calvers

33. Weight of NFI cows

34. P8 Fat – NFI cows

35. 1 st calvers pre-mating and pregnancy test Line Age (days) Weight (kg) P8 fat (mm)*** Conception rate Adjusted conception rate High NFI 493 306 10.4 91.9 91.8 Low NFI 492 315 8.2 91.6 91.6

36. Pre-mating and pregnancy test 2 nd calving Line Nutrition Weight (kg) P8 fat (mm)*** Conception rate High NFI High 478 11.9 95.1 High NFI Low 441 8.7 96.1 Low NFI High 488 8.8 87.4 Low NFI Low 438 6.1 88.7

37. Days to calving for heifers

38. Days to Calving 2 nd calvers

39. Birth weight

40. Calf weaning weight from 1 st calvers

43. To be continued …