Estimating frame score from hip height and age

Frame score is a convenient way of describing the skeletal size of cattle. With adequate height growth curves most animals should maintain the same frame score throughout their life, while their actual height increases with age. Environmental factors can alter the normal skeletal growth rate. Nutrition level is a major factor. Cattle fed less than adequate nutrition will growth slower than the tables indicate, while cattle fed extremely high levels will growth faster. Large framed cattle grow faster and for a longer time than small framed cattle. Bulls grow faster than heifers. The accompanying tables and equations are currently the best estimates of cattle height growth rate and have been accepted be the Beef Improvement Federation

Visual body condition score of cows

Condition scores are often used to describe the fleshiness of cows. These scores range from 1 (extremely emaciated) to 9 (extremely fat)

Estimates of heritabilities and genetic correlations in polled Hereford cattle selected for feed conversion

Performance records of 1459 Polled Hereford cattle were analyzed to estimate heritabilities and genetic correlations of beef cattle traits from birth to maturity. Estimates of heritability (h2) for birth weight (BWT), weaning weight (WWT), yearling weight (YWT), scrotal circumference (SC), yearling height (YHT), mature height (MHT), and mature weight (MWT) were moderate to high, with the exception of WWT (h2 = .14), and ranged from .38 to .72. The traits associated with feed conversion, daily feed intake (INT), average daily gain (ADG), and feed conversion (CONV) had heritabilities of .24, .25, and .14, respectively. Genetic correlations (rg) between the growth traits (BWT, WWT, YWT, YHT, MHT, MWT, and SC) were positive and ranged from .20 to .88. The rg=.99 between milk production (MILK) and maternal weaning weight (MWW) indicates that the traits are essentially the same and supports the method in which many breed associations calculate and report expected progeny differences (EPDs) for milk production. The rg = .42 between ADG and INT, rg = .27 between INT and CONV, and the rg = -.82 between ADG and CONV suggest that faster gaining cattle have greater feed intakes and are more efficient

Yearling scrotal circumference prediction equation and age adjustment factors for various breeds of beef bulls

Scrotal circumference measurements and other data were collected on 4,218 Angus, Red Angus, Brangus, Charolais , Gelbvieh, Hereford, Polled Hereford, Limousine, Salers, and Simmental bulls born in the spring of 1991. All were participants in selected on-farm and central bull tests. Our objectives for the study were to develop 205-and 365-day age-adjustment factors for scrotal circumference and derive a 365-day scrotal circumference prediction equation based on adjusted 205-day scrotal circumference. We determined that a 205-day scrotal circumference of approximately 21 cm is necessary to reach 32 cm at 1 year. Age-of-dam adjustment factor for 205-day scrotal circumference is +.8 cm for 2- and 3- year-old dams. The factor for 365-day circumference is +.6 cm for 2-year-old dams

Flushing cows

Starting to flush cows 95 days before the breeding season began significantly increase conception rate and required less total feed

Effects of various uterine treatments on calving-to-conception interval

Cows were given intrauterine infusions of enzymes, antibacterials, bacteria, or a combination of enzymes and antibacterials after calving to study basic changes in the post-partum uterus and effect on rebreeding. The group given nitrofurazone, an antibacterial compound, had the highest conception rate; however, calving-to-conception interval was lengthened. Combining proteolytic enzymes with the nitrofurazone gave an intercal to conception similar to that of control cows. Nitrofurazone caused this uterine lining to erode. Combining enzymes with nitrofurazone prevented some of the erosion. Innoculating the uterus with bacteria (Lactobacillus acidophilus) after calving did not affect the calving-to-conception interval

Managing fast- vs. slow-growth genotypes to optimize quality and yield grades

Fast-growth genotype steers placed on a high energy ration a month after weaning were compared to a slow-growth genotype on a growing ration for 155 days, followed by a finishing ration for 62 days. The fast-growth genotype produced heavier, higher quality carcasses in less time than the slow-growth genotype, with similar energy conversion. Using contemporary prices. the fast-growth genotype cattle broke even, and the slow-growth genotype lost $124 per head

Comparison of feedlot and carcass characteristics of Angus, Hereford, Brahman, Charolais, and Gelbvieh crossbred steers

Feedlot performance of 207 steers with various percentages of Angus, Hereford, Charolais, Brahman, and Gelbvieh breeding were compared at a constant 1) days fed, 2) adjusted carcass backfat, and 3) slaughter weight. As the percentage of Angus, Hereford, or Brahman increased, growth rate decreased, whereas increasing the percentage of Charolais increased growth rate. Increasing the percentage of Gelbvieh increased weaning weight but had little effect on post-weaning gains. Increasing percentage of Charolais increased feed conversion efficiency, whereas the other breeds were similar, except that at a constant slaughter weight, greater percentage of Hereford improved feed conversion efficiency. Increasing the percentage of Charolais increased carcass weight and ribeye area and decreased yield grade, but marbling was not different from that of Angus. An increase in percentage of Hereford caused a decrease in carcass weight, ribeye area, marbling, and quality grade. Increasing percentage of Angus decreased carcass weight and ribeye area but increased marbling and quality grade. Increasing percentage of Brahman caused the greatest reduction of marbling and quality grade of any breed. Increasing the percentage Gelbvieh breeding resulted in increased ribeye area and decreased marbling at constant days fed and slaughter weight

Response of yearling steers to burning and fertilizing pasture and intensive early season stocking (bluestem pastures)

Nine pastures totaling 492 acres were summer grazed by yearling Hereford, Hereford-Angus cross, and Angus steers distributed equally by breed. Five pastures were burned April 22, 1975; four were not burned. Burned and nonburned pastures had 0, 40, or 80 lbs. of nitrogen per acre applied aerially April 29, 1975. Stocking rates were determined with herbage production data from experimental plots under similar treatments. Under equal fertilization and stocking ratios, burned and fertilized pastures produced as much or more average daily gain and more gain per acre than nonburned pastures. Fertilizing and heavier stocking tended to reduce average daily gains but increased gains per acre. Steers on the early season, intensely-stocked pasture gained the most per day (1.78 lbs.) and produced the highest gain per acre (70 lbs.)

Delayed winter supplemental feeding and year-round mineral supplementation of beef cows on native range

Polled Hereford cows on native Flint Hills pasture not supplemented until February lost more weight from December to February, lost less from February to May, and were in poorer condition before calving than cows supplemented beginning in November. But calf survival, birth weight, and calf average daily gain were similar for both groups. Feeding cows a calcium, phosphorus, trace mineral mix did not improve any measure of cow or calf performance