North Dakota State University * Dickinson Research Extension Center
1089 State Avenue, Dickinson, ND 58601-4642 Voice: (701) 483-2348 FAX: (701) 483-2005
The cow herd is divided into four groups during the early breeding season, in order to secure reproduction records for each of the sires used. The weaning weights of calves by each sire for two seasons are shown in Table 1.
|Table 1. Weaning Weights of Calves by Sire Groups|
|Sire 4||Sire 5||Sire 6||Sire 8|
|No. of Calves*||40||23||17||22||6||17||18|
|Age in days||172||194||177||176||185||191||176|
|Wt/day of Age||1.94||1.78||2.08||1.89||1.87||1.84||1.86|
|*Twelve calves of 1959 crop and 14 calves of 1960 crop were not included because of indefinite sire or date of birth.|
The bulls were turned with the same group of cows each year, therefore in many, but not in all cases, the calves within a sire group for 1959 and 1960 were brothers and sisters. Since weaning weight is only about 30% heritable, and at least one-half of the credit should go to the dam, the differences observed here between sires are quite small. The calves by sire number 5 have had the greatest weight per day of age at weaning in both years.
Calves from cows 3 years old and over averaged about 5 pounds lighter at weaning in 1960 than in 1959. The cows, however, gained 25 pounds per head during the summer of 1960, and lost 58 pounds per head during the 1959 summer. It would seem that they milked better in 1959 than in 1960. Average weights of cows in Table 2 show that the cow herd gained more during the winter of 1959-60 than they did in the preceding winter, yet we felt that the cow herd looked thinner and more rough of hair coat in the spring of 1960 than they had looked for many years.
Two-year old heifers weaned heavier calves in 1960 than in 1959. Fifteen calves from two-year old averaged 280 pounds at weaning 1959, and 11 calves from two-year olds weaned at 340 pounds in 1960. The reason for the boost in weaning weights from first calf heifers is not known. A different sire was used, and replacement heifers had been selected for rate of growth in both years.
|Table 2. Beef Breeding Herd Record for 1959 and 1960.|
|No. Cows, 3 Yrs. and older||81||82|
|Wt. at Weaning, Fall before||1057||1012|
|Wt. March 30 before calving||1094||1081|
|Wt. at Weaning, Current year||1036||1106|
|Daily Ration, Preceding Winter:|
|Corn Silage||25||12 1st half, None 2nd half|
|Crested & Brome Hay||12||12 1st half, 17 2nd half|
|No. Born alive||75||71*|
|No. Dry Cows||6||1|
|Av. Birth Wt.||71.7||73.6|
|Av. Weaning Wt.||344.1||338.5|
|Av. Weaning Age, Days||175||182|
|Av. Wt. Per Day of Age||1.97||1.86|
|*One additional calf was born dead, and 9 late calves were not included because we do not have birth weights.|