Nulliparous versus primiparous crossbred females for beef

Area of Science:

• Animal Science
• Beef Cattle Production
• Meat Science

Background:

• Understanding the impact of reproductive status on beef quality is crucial for optimizing production.
• Nulliparous (heifers) and primiparous (heiferettes) females represent distinct physiological stages affecting growth and carcass characteristics.

Purpose of the Study:

• To compare feedlot performance and carcass traits between nulliparous and primiparous beef females.
• To evaluate the influence of breed type and parity on beef characteristics.
• To determine the competitiveness of beef derived from heiferettes versus heifers.

Main Methods:

• Evaluation of feedlot and carcass traits in eight breed types of nulliparous and primiparous females (Bos taurus and Bos indicus x Bos taurus crosses).
• Heifers were fed for 4 months; heiferettes were fed for 2 1/3 months post-weaning.
• Statistical analysis of traits including dressing percentage, fat thickness, carcass grade, lean color, and meat yield.

Main Results:

• Heifers exhibited higher dressing percentage, kidney fat, carcass grade, and leaner color compared to heiferettes.
• Heiferettes demonstrated greater feedlot average daily gain, fat thickness, and higher percentages of steak, roast, and bone.
• Parity did not significantly affect carcass weight, longissimus area, marbling, pH, or shear force. Breed type influenced marbling and meat yield components.

Conclusions:

• Beef derived from heiferettes is competitive with beef from heifers, offering comparable quality and yield.
• Reproductive status (parity) influences specific feedlot and carcass traits, but overall beef quality remains competitive.
• Breed type also plays a role in carcass composition and meat yield, indicating opportunities for targeted breeding programs.