Relationship between frequent milking or suckling in early lactation and milk production of high producing dairy cows

A 2 x 2 factorial study evaluated effects of cow wintering system and last trimester CP supplementation on performance of beef cows and steer progeny over a 3-yr period. Pregnant composite cows (Red Angus x Simmental) grazed winter range (WR; n = 4/yr) or corn residue (CR; n = 4/yr) during winter and within grazing treatment received 0.45 kg/d (DM) 28% CP cubes (PS; n = 4/yr) or no supplement (NS; n = 4/yr). Offspring steer calves entered the feedlot 14 d postweaning and were slaughtered 222 d later. Precalving BW was greater (P = 0.02) for PS than NS cows grazing WR, whereas precalving BCS was greater (P 0.32) by PS. Calf weaning BW was less (P = 0.01) for calves from NS cows grazing WR compared with all other treatments. Pregnancy rate was unaffected by treatment (P > 0.39). Steer ADG, 12th-rib fat, yield grade, and LM area (P > 0.10) were similar among all treatments. However, final BW and HCW (P = 0.02) were greater for steers from PS-WR than NS-WR cows. Compared with steers from NS cows, steers from PS cows had greater marbling scores (P = 0.004) and a greater (P = 0.04) proportion graded USDA Choice or greater. Protein supplementation of dams increased the value of calves at weaning (P = 0.03) and of steers at slaughter regardless of winter grazing treatment (P = 0.005). Calf birth and weaning BW were increased by grazing CR during the winter. Calf weaning BW was increased by PS of the dam if the dam grazed WR. Compared with steers from NS cows, steer progeny from PS cows had a greater quality grade with no (P = 0.26) effect on yield grade. These data support a late gestation dam nutrition effect on calf production via fetal programming.

/pdf/winter-grazing-system-and-supplementation-during-late-130p8eqgm3.pdf

Winter grazing system and supplementation during late gestation influence performance of beef cows and steer progeny.

Increased Weight Gain and Effects on Production Parameters of Holstein Heifer Calves That Were Allowed to Suckle from Birth to Six Weeks of Age

/pdf/nutrition-in-the-reproduction-of-farm-animals-udg4r62vb5.pdf

Nutrition in the reproduction of farm animals.

https://ainfo.cnptia.embrapa.br/digital/bitstream/CPPSE/15193/1/PROCIRTB2004.00030.pdf

Sexual development in early- and late-maturing Bos indicus and Bos indicus × Bos taurus crossbred bulls in Brazil

/pdf/effects-of-milk-and-forage-intake-on-calf-performance-4lbxa4btoi.pdf

Effects of milk and forage intake on calf performance.

Simmental and Hereford bulls were individually fed varying levels of the same diet to determine the effect of energy intake after weaning on rate of sexual development. For 200 d, 29 Simmentals were fed an average of 14.6, 19.2 or 23.8 Mcal and 27 Herefords were fed 13.4, 17.5 or 22.2 Mcal metabolizable energy per bull daily. Higher energy did not hasten sexual development, as measured by serum testosterone, age at first mating or age at puberty. As energy level increased, weight at puberty increased (P less than .05) for both breeds, and scrotal circumference at puberty increased (P less than .05) for Simmentals. When adjusted for breed and energy level, bulls that were heavier at 1 yr of age had larger scrotal circumference (P less than .05) and were younger at puberty (P less than .01). Bulls that had higher serum testosterone at 1 yr of age reached puberty earlier (P less than .01). At a constant age there was no relationship between testosterone and scrotal circumference. Although higher levels of energy increased scrotal circumference of Simmentals, it did not hasten sexual development for either breed.

Effect of Energy Intake after Weaning on the Sexual Development of Beef Bulls. II. Age at First Mating, Age at Puberty, Testosterone and Scrotal Circumference

R. J. Pruitt

Papers

Effects of milk and forage intake on calf performance.

Effect of Energy Intake after Weaning on the Sexual Development of Beef Bulls. II. Age at First Mating, Age at Puberty, Testosterone and Scrotal Circumference