Breed
Effects, Dietary Energy Density Effects, and Retained
Heterosis on Different Measures of Gain Efficiency in Beef Cattle.
Authors:
K.E. GregorT, L.V. Cundiff, and R.M. Koch.
Source:
Journal of Animal Science. 1994. 72:1138-1154.
Abstract: Breed
effects were evaluated in nine parental breeds (Red Poll, Hereford, Angus,
Limousin, Braunvieh, Pinzgauer, Gelbvieh, Simmental and Charolais). Gain
efficiency was evaluated in time constant (0 to 207 d), gain constant (310 to
540 kg), carcass weight constant (333 kg), and retail product weight constant
(225 and 210 kg) end points and to different marbling score and longissimus
muscle fat end points. Significant differences were observed among breeds in all
measures of gain efficiency. Key points related to Limousin include:
*
Even though Limousin had relatively low initial weight, their high live weight
gain per megacalorie of Metabolizable Energy (ME), their high dressmg percentage
and high percentage of retail product resulted in the highest values for retail
product per megacalorie of ME.
*
Limousin were clearly superior in terms of retail product per Mcal of ME when
evaluated over a constant time on feed of 207 days. Limousin were 14% more
efficient than Charolais, 17% more efficient than Gelbvieh, 20% more efficient
than Simmental, and 29% more efficient than Angus when measuring retail product
with 8 mm of fat. At 0 mm fat the differences are greater with Limousin being
18% more efficient than Charolais and Gelbvieh, 24% more efficient than
Simmental and 34% more efficient than Angus.
*
Another very important finding is that Limousin and Hereford were clearly
superior in terms of estimated net energy for maintenance, with approximately
8.5% less maintenance energy than the other continental breeds.
*
When efficiency was compared on a gain constant basis there was a tendency for
the fastest growing breeds to be the most efficient. The exceptions were
Limousin which had below average gain and above average efficiency and the
Gelbvieh which had above average gain and below average efficiency.