STRATEGIES TO SAVE MONEY by Mike Mehren Ph.D.

Two different nutrition conferences provided some very interesting information about cow size and heifer development. Dr. Ryon Walker reported on formulating rations for different size cows at the Minnesota Nutrition Conference At the Pacific Northwest Animal Nutrition Conference, Dr. Rick Funston of the Univ of Nebraska gave an interesting presentation on raising heifers. Both address feed costs and the potential for saving money.

Beef Cow Size: Cow size dictates the amount of feed that the cow must eat to maintain her bodyweight and nurse a calf to weaning. Obviously, the bigger the cow the more she must eat. The question for us is, does a large cow produce a big enough calf to justify the extra feed? The following table is from Ringwall, 2008 Beef Talk.

Weaning Weights of calves from different size cows
Cow Weigh, lb	Calf Wean Weigh, lb	Calf Weight as % of Cow Bodyweight
1200	617	49.7
1300	611	45.0
1400	589	40.5
1500	598	38.6
1600 .	572	33.7

These weights came from the cowherd at the Dickinson Center, North Dakota. It was quite an eye-opener when the cows were broken into different weight groups and their calves were weighed. The large cows were not only weaning lighter calves, but they were weaning significantly less weight in relation to their own bodyweight. I don’t know anyone that has ever broken down their weaning weight records by cow weight. It would be interesting to see if that occurs here in the Pacific Northwest. To equal the 1200 lb cow weaning weights, the 1600 lb cows would have had to produce calves with an average weaning weight of 800 lb. That’s extremely difficult to achieve where part of the year the cattle are on dry feed. Spring calves will be about 7 months old and must get almost all of their nutrition from fall grass that has less protein than they need, so gain will be very low. Fall calves would be about 12 months old and would also need more protein than the grass could provide. If smaller cows were run, less hay could be purchased or more cows could be run on the same amount of feed.

It costs a lot more to maintain a 1600 lb cow than it does a 1200 lb cow. In the study mentioned above, the researchers reported that the 1200 lb cow group required 28 lb of dry matter daily while the 1600 lb cow group required 34.5 lb of dry matter intake during the winter. Extending that for a year amounts to almost 2400 lb.

Raising Replacement Heifers. Heifers represent a significant cost whether they are purchased or raised. Reducing that cost without delaying breeding and birth of the first calf would have a tremendous impact on ranch economy.

A very important biological principal governs heifer conception. Puberty happens at a genetically determined weight. Pregnancy will occur only when heifers reach that weight. This weight varies by breed and by different lines within a breed. Most typically we believe that heifers must weigh 60 to 65% of their mature weight before breeding can begin. Our goal after weaning is to achieve the target weight by a certain date. In some herds this means that the heifers are fed rations that promote gains of 2 lb/day through the winter.

If it was possible to delay rapid gains until just before breeding, would that have an effect on pregnancy? If it didn’t hurt pregnancy, then the replacement heifers could be fed hay through the winter. Two studies reported by Dr. Funston found that delaying gain until that last 47 to 56 days before breeding did not affect age at calving, the number of heifers calving and the calving performance at their second calving as three year olds.

We have all seen the tremendous progress that has been made in cattle genetics over the past 20 to 30 years. Scrotal circumference is a measurement taken on young bulls that is related to their potential fertility. It also turns out that this measure is related to age of their female offspring at puberty. Large scrotal circumference is related to earlier puberty.

Studies reported by Funston, Clark, and Deutscher in 2004 and Martin in 2007 found that heifers were successfully bred at 53 and 57% of mature weight. This is much lower than the 60% figure that we have used for so long. This change must be related to genetic improvement. These authors also reported that extending the heifer breeding season from 45 days to 60 days resulted in an extra 9.3% of the heifers getting bred. The difference between 55% and 60% of mature weight can represent a pretty substantial cost when you have to feed in a drylot versus grazing on range.

Mature Wt,lb	Heifer Breeding Weight
	55%	60%
	of mature wt.
1200	660	720
1400	770	840
1600	880	960

Further studies in this area found that heifers could be run out on dry range with protein supplement followed by drylot feeding in the winter, and achieve a satisfactory pregnancy rates when bred to calve as 2 yr olds. When protein supplement was omitted while the cattle were grazing, gains were low, and in some instances heifers lost weight. which delayed the onset of puberty.

Both of these subjects deal with reducing the cost of the producing herd. Data reported on last year’s total cost to run cow was $560.00; of that, $350 was made up of feed cost.
Spring and summer grazing along with mineral supplement only made up about 15% of the $350; so fall and winter feeding would appear to be the area that could provide the greatest potential saving. The single best way to achieve that goal is to know the nutrient content of your feed so that the ration you feed meets the cow’s or heifer’s needs without feeding too much or too little. A feed test provides you with that information.

As you get ready to starting feeding your cows, take a look at alternatives that you may not have considered previously. There are quite a wide variety of protein supplements out there. Here’s a partial list:

Feed Ingredient	% protein as fed	Approx Cost/ton
Alfalfa Hay	18	$100
Liquid Protein Supplement	30	$360
Compressed Block	30	$550
Protein Meal, bagged	36	$460
Molasses protein Tub	22	$900
Range Cube	36	$550
Dried Distlrs Corn w/ Solubles	28	$200

Some of these supplements require a Vitamin-Mineral Supplement to make them completely effective. Some just require plain salt. Some require no other supplement.
Make certain that you understand what else must be fed with the supplement you choose. These factors have a huge effect on relative value and total cost to you.

What if you reduced waste by 1 lb/cow/day? If you had 100 cows and fed them for 100 days, that amounts to 10,000 lb.

Thanks to old friend Jack Southworth (I’m old; he’s my friend) for firing me up about cow-size.

Michael J. Mehren, Ph.D. has apparently figured out how to reduce his own food waste and is working toward a body score of 7 in Hermiston, OR. He may be contacted by email at: mehrens@eotnet.net.