Early Weaning for
the Beef Herd
Jon Schoonmaker
NDSU Carrington Research Extension Center
Introduction
Early weaning can provide an attractive alternative in
certain situations where large amounts of purchased forage would be necessary
to maintain a cow herd through to normal weaning time. Early weaning would be
ideal for fall calving herds, where harvested forage is fed during the cow’s
greatest nutritional demand, and for cases of drought in spring-calving herds.
Cows that are too thin to re-breed, or have difficulty re-breeding such as
first calf heifers and anestrous cows, are also candidates for early weaning.
Early weaning can also offer producers an additional
marketing option. Early-weaned steers placed on an accelerated finishing
program in the feedlot can reach market weight at less than a year of age, thus
spring-born calves can be marketed the following spring when fat cattle prices
are seasonably high. Since early-weaned steers are generally on a high grain
diet for a longer period of time, high quality carcasses result. Producers
looking to market their calves as high quality may be able to use early weaning
as a tool. Dairy steers that are typically weaned at 90 days of age can easily
be placed on an accelerated finishing program in the feedlot.
Early weaning prior
to the breeding season
Lactation roughly doubles the daily energy and protein requirement for a typical beef cow. Removing the calf at 30 – 60 days of age eliminates the need for lactation and reduces the quantity and quality of forage needed to maintain the cow herd. Cows are then able to gain condition – the primary determinant of the duration of post-partum anestrous – prior to being bred. Removing the suckling stimulus – the principle cause of anestrous – also causes hormonal changes in the cow that can stimulate estrus. Researchers at Oklahoma State demonstrated that weaning first calf heifers at 6-8 weeks of age decreased the days open from 91 to 73 days, and increased pregnancy rates from 59.4 to 96.8 percent compared to first calf heifers weaned at seven months of age. (Lusby et al 1981) However, the benefits of early weaning on cow reproduction may be offset by negative effects on calf performance. Calves that are weaned at 30 – 60 days of age may be too light for feedlot entry.
Early-weaning after
the breeding season
If feeding 30 to 60-day-old calves is not
feasible, early weaning calves after the breeding season still offers
advantages for producers. Forage yield and quality can decline in mid to late
summer in many parts of the United States. As a result, cow body condition and
milk production can decline. Spring-born calves, therefore, may experience
decreased gains at a time when their growth potential is high. Cows that calve
in the fall in northern climates experience their greatest nutritional demands
in winter when harvested feed is being fed. Early-weaning the calf decreases
the nutrient requirements of a mid- to- late lactation cow, and can increase
cow condition and reduce feed intake. Reducing intake of the cow can increase
the carrying capacity of the land by approximately 20 percent or more in the
summer for spring calving herds, or can reduce harvested feed costs
approximately 20 percent or more in the winter for fall calving herds. Cows
that have calves early weaned in spring calving herds can then enter the winter
in better condition, thus reducing harvested feed costs. Cows that have their
calves early-weaned can also enter the calving season in better condition, and
recover from calving quicker. Retaining ownership of the calves after weaning
would increase feed costs for the calf from early-weaning time until
normal-weaning time. However feeding a calf harvested feed can be cheaper than
feeding the cow harvested feed. In addition, intake from feedlot entry until
slaughter is not different between steers placed in the feedlot at 100 days of
age and steers placed in the feedlot at 205 days of age.
Managing the calf
Researchers at the University of Nebraska observed that early weaning heifers intended for use as replacements in the cow herd increases costs up to $10 per head. (Story et al. 2000)However, research at Ohio State has demonstrated that early-weaned heifers placed on a high energy diet reach puberty 94 days earlier (260 vs. 354 days of age) and are 159 lbs. lighter (695 vs. 854 lbs.). (Day et al 2001)Decreasing the weight and age at puberty allows heifers to be bred sooner and can increase conception rates. However, the effect of early-weaning on heifers as well as bulls intended for breeding on production later in life is unknown.
Creep feeding is a common attempt to increase calf gain and
cow body condition that is currently under investigation. Creep feeding adds
feed and labor costs, but can improve 205-day weaning weights of calves.
However, feedlot performance of creep fed calves and non-creep fed calves is
not significantly different, and creep feeding has not been shown to improve
cow condition.
Large framed continental cross steers, weighing at least 300
lbs. at feedlot entry work the best in an accelerated finishing program. Small
framed cattle may get too fat too quickly, and steers weighing less than 300
lbs. at feedlot entry may be too small to reach bunks and may not be large
enough to compete for feed. Early-weaned calves typically do not have many
health problems once they enter the feedlot, however, pre-weaning vaccinations
are recommended, especially if calves are going to be mixed with cattle from
other sources. Researchers at Ohio State vaccinate steers against IBR, BVD, PI3,
BRSV, Leptospirosis, Haemophilus and Pastuerella, and a 7-way clostridial six weeks prior to
early weaning, and re-vaccinate with a booster shot two weeks prior to
early-weaning. (Schoonmaker et al. 2002)
Steers were de-wormed at feedlot entry. Early-weaned steers in the feedlot
experience their greatest health problems when they come in contact with cattle
from other sources. Therefore, it is recommended that early-weaned calves be
re-vaccinated three weeks prior to arrival of any normal-weaned calves. This is
probably the most critical vaccination given to early-weaned calves. Sick
calves are treated with antibiotics for respiratory disease if rectal
temperature exceeds 103.5oF.
Once in the feedlot, early-weaned steers should gain from
2.5 – 3.0 lbs./day until 205 days of age. To achieve
this target, calves should be fed a mid – high forage grower diet, or limit-fed
a high concentrate finisher diet. From 205 days of age until slaughter, steers
should gain from 3.0 – 3.5 lbs./day. To achieve these
gains, an 85 percent concentrate diet should be fed. Calves should be fed a 14
- 16 percent CP from 100 – 205 days of age, and a 12 – 14 percent CP diet from
205 days of age until slaughter. Intake of calves should be limited to 10 lbs./head/day
for the first day, and then increased 1 lb./head/day until ad libitum intake is
achieved.
Early-weaned steers require a relatively aggressive implant regimen to increase carcass weight and decrease carcass fat. A long lasting estrogen implant (encased in rubber) at feedlot entry works well followed by an implant containing trenbolone acetate (TBA) 100 days prior to slaughter. Steers gaining 3.0 – 3.5 lbs./day will need a second implant when they reach 850 – 900 pounds. Early-weaned cattle on this type of implant regimen will gain 10 – 15 percent faster, will finish 2 – 3 weeks earlier at a heavier weight, and will produce carcasses that are approximately 15 percent leaner compared to early-weaned cattle that are not implanted.
Early weaning is easier in a drylot
environment.
Summary
Early weaning calves and placing them on an accelerated
finishing program is a viable management option, although it is not recommended
for all producers all of the time. Cows that have calves early weaned generally
carry more condition, thus reducing feed costs and improving reproductive
performance.
Early weaned steers have to spend more time in the feedlot and generally weigh less compared to steers that are normal-weaned and fed as calves or yearlings. However, early-weaned steers gain faster from weaning time to slaughter, and finish at a younger age compared to normal-weaned and yearling-fed steers, while still consuming similar amounts of feed. When slaughtered, 70 – 80 percent of early-weaned steers produce carcasses that grade low choice or above, while achieving a yield grade of 3.0. Table 1 summarizes performance and carcass data for early-weaned, normal-weaned, and yearling management systems.
