R.R. Schalles

Effect of forty-eight-hour calf removal, once- or twice-daily suckling and Norgestomet on beef cow and calf performance.

Trials were conducted in 1980 and 1981 to evaluate the effects of once-daily suckling, twice-daily suckling, 48-h calf removal, and Norgestomet on performance of spring-calving cows and their calves. Eighty-three and 73 Polled Hereford and 29 and 42 Simmental-cross cows were utilized in 1980 and 1981, respectively. Cows were allotted by age, breed, calving date and winter nutrition treatment to one of four groups: 1) once-daily suckle for 24 d starting 11 d before the beginning of the breeding season, 2) twice-daily suckle (same time frame as 1), 3) 48-h calf removal ending immediately before the breeding season, 4) calves remained with cows (controls). One-half.of each group was implanted with Norgestomet from 11 until 2 d before the start of the breeding season. Once- and twice-daily suckling increased (P<0.05) the percentage of noncycling cows showing estrus the first 3 wk after the start of treatment. Pregnancy rates for the breeding season were higher (P<0.1) in the once-daily suckle and 48-h calf removal groups for cows that had not exhibited estrus before the beginning of treatment. Norgestomet increased (P<0.05) the percentage of cows showing estrus within 3 wk after the start of treatment within the 48-h calf-removal and control groups. Milk production was not affected (P>0.1) by suckling treatment. Calf weight gains during suckling treatment were greater (P<0.05) in control and twice-daily suckled calves than in 48-h calf removal or once-daily suckled calves. Suckling treatment did not affect (P>0.1) adjusted weaning weights of calves or frequency and duration of suckling recorded 2 wk after the end of suckling treatment.

Influence of prepartum exposure of beef heifers to winter weather on concentrations of plasma energy-yielding substrates, serum hormones and birth weight of calves

The influence of exposure to ambient winter weather conditions (WW) during the final 90 d of gestation on serum hormones, plasma substrates, and birth weight of calves was evaluated in spring-calving, primiparous beef heifers. At of 192+/-14 d of gestation, heifers were assigned by expected calving date, breed, and sire of fetus to one of two treatments. Thirteen heifers were assigned to thermoneutral environment (TN; 12 degrees C) and housed in temperature-controlled rooms. Heifers in WW (n=16) were maintained outdoors in drylots without access to shelter and given additional dietary energy when average weekly windchill fell below -6.7 degrees C. Body weights, hip-heights and samples of serum and plasma were obtained biweekly until heifers were relocated, approximately 7 d prior to expected calving. Polynomial response curves for concentrations of glucose and nonesterified fatty acids (NEFA) in plasma and cortisol in serum were not influenced by treatment. However, average concentrations of NEFA in plasma were increased (P<0.02) and glucose tended to be higher (P=0.13) in WW heifers compared to TN heifers (172.5+/-8.9 vs 136.9+/-7.7 micromol/L and 87.8+/-2.4 vs 83.3+/-2.7 mg/100ml for NEFA and glucose, respectively). Time trends of concentrations of estradiol in serum (P<0.01) and hip-height to weight ratios were different (P<0.05) for WW and TN. Birth weights of calves from TN heifers were greater (P<0.06) than calves from WW heifers (42.3+/-2.0 vs 36.9+/-1.8 kg), but average calving difficulty scores were similar for both heifer groups (3.2+/-0.5 vs 2.7+/-0.4). These data suggest that exposing spring-calving cows to reduced effective ambient temperatures during the final 90 d of pregnancy may elevate energy-yielding metabolites in plasma and alter endocrine function. These changes may contribute to reduced birth weight of calves.

Comparison of feeding calves vs. yearlings

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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 2and 3year-old dams. The factor for 365-day circumference is +.6 cm for 2-year-old dams.

Performance and profitability of calves and yearlings in Southeast Kansas Steer Futurities (seven year summary)

Since the fall of 1976, 370 calves and 330 yearlings have been fed through the Southeast Kansas Steer Futurities. In four of the last seven years, both age categories have shown profits through the feedlot phase, using incoming market values assigned by professional market managers, actual feedlot performance and expenses, and slaughter value based on grade and yield date. Calves have been more profitable than yearlings in each of the seven years.

Effects of creep feeding and post-weaning ration on calf performance

We found no advantage for creep feeding calves for either all summer or 37 days prior to weaning. All calves were with their dams on native pasture. Calves not creep fed or creep fed only 37 days before weaning were sick less after weaning than those creep fed all summer. Rate of gain for 21 days after weaning was as good on a low energy weaning ration as on a high energy ration. However, more sickness occurred on the low energy ration.

Feeding value of four different hybrid sorghum grains for finishing cattle

This report is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Kansas Agricultural Experiment Station Research Reports by an authorized administrator of New Prairie Press. Copyright 1971 Kansas State University Agricultural Experiment Station and Cooperative Extension Service.

Genetic parameters for growth and carcass traits from crossbreeding

Growth and carcass data from 5 years of a long-term, rotational, crossbreeding project were used to calculate heritabilities and genetic and phenotypic correlations for direct and maternal birth and weaning weight, gain on feed, hot carcass weight, ribeye area, marbling score, and age at slaughter. Angus, Brahman, Hereford, Charolais, Simmental, and Gelbvieh breeds were involved. Heritabilities of traits ranged from low (maternal weaning weight 0.04) to moderate (direct weaning weight 0.41). Direct birth weight, direct weaning weight, gain on feed, and hot carcass weight had moderate to high genetic correlations. Marbling had negative genetic correlations with birth and weaning weight but positive correlations with slaughter age and hot carcass weight.

Effects of postweaning management system and breed on growth and carcass traits

Data from 5 years of a long-term, rotational, crossbreeding project were used to calculate heritabilities and correlations and to make breed comparisons for growth rate and carcass traits in two different postweaning management systems. The traits studied were weight per day of age, hot carcass weight, ribeye area, marbling score, and days of age at slaughter. One group was placed on full feed after weaning. A second group underwent a backgrounding phase for 7 months at Louisiana State University before being placed on feed at KSU. The breeds involved were Angus, Brahman, Charolais, Hereford, Simmental, and Gelbvieh. Differences in heritabilities between management systems were generally small, indicating similar genetic expression across management systems. Genetic correlations also were high except for marbling score, which indicates some difference in genetic expression between management systems for this trait. Some changes in rank of breeds occurred between management systems, but they generally were not significant.

Comparisons among crossbred beef cattle for growth and carcass traits

Data from 5 years of a long-term, rotational crossbreeding project were used to compare breeds for growth and carcass traits. The traits of interest were direct and maternal birth and weaning weights, gain on feed, hot carcass weight, ribeye area, marbling score, and slaughter age. Angus, Brahman, Hereford, Charolais, Simmental, and Gelbvieh breeds were involved. Simmental and Gelbvieh were used as terminal breeds, so maternal effects were not calculated for them. Brahman breeding caused an increased direct birth weight of the calves, but the maternal influence of Brahman decreased birth weight. No difference occurred in maternal weaning weight among the Angus, Brahman, Charolais, and Hereford breeds. Charolais and Simmental breeding increased gain on feed. Charolais, Simmental, and Gelbvieh breeding resulted in the heaviest hot carcass weights and largest ribeye areas. Simmental, Charolais and Angus breeding resulted in the most marbling. Hereford and Angus breeding reduced age at slaughter compared to the other breeds. All six breeds have some advantages in the traits studied. Which breed will work best depends on the production environment and goals of the producer.