Early Weaning for the Beef Herd
NDSU Carrington Research Extension Center
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 cows 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.
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.
Story, E.E., R.J. Rasby, R.T. Clark, and C.T. Milton. (2000) Age of calf at Weaning of Spring-calving beef cows and the effect on cow and calf performance and production economics. J. Anim. Sci. 78:1403-1413
Lusby, K.S., R.P. Wettemann, and E.J. Turman. (1981). Effects of Early weaning calves from first-calf heifers on calf and heifer performance. J. Anim. Sci. 53:1193-1197.
Schoonmaker, J.P, S.C. Loerch, F.L. Fluharty, H.M. Zerby, and T.B. Turner. (2002). Effect of age at feedlot entry on performance and carcass characteristics of bulls and steers. J. Anim. Sci. 80: 2247-2254.
Day, M.L., J.E. Huston, and D.E. Grum. (2001) Early Weaning, puberty and cow reproduction. J. Anim. Sci. 79 (Suppl. 2): 17.