Genetic Parameters for Growth, Ultrasound and Carcass Traits in New Zealand Beef Cattle and Their Correlations with Maternal Performance

Abstract

Research has shown that enhancing finishing performance in beef cows is feasible; however, any adverse impact of selection strategies for finishing performance on the performance of the maternal herd should be taken into account. The aim of this research was to examine the inheritance of growth, ultrasound and carcass traits in finishing beef cattle and to evaluate their correlations with maternal performance traits. Data were collected from a nationwide progeny test on commercial New Zealand hill country farms comprising a total of 4473 beef cows and their progeny. Most finishing traits were moderately to highly heritable (0.28–0.58) with the exception of meat or fat colour and ossification (0.00–0.12). Ultrasound scan traits had high genetic correlations with corresponding traits measured at slaughter (rg = 0.53–0.95) and may be used as a selection tool for improved genetic merit of the beef carcass. Fat content determined via ultrasound scanning in the live animal or at slaughter in finishing cattle is positively genetically correlated with rebreeding performance (rg = 0.22–0.39) in female herd replacements and negatively correlated with mature cow live weight (rg = −0.40 to −0.19). Low-magnitude associations were observed between the genetic merit for carcass fat traits with body condition in mature cows.

Comparison of Pure and Crossbred Japanese Black Steers in Growth Performance and Metabolic Features from Birth to Slaughter at a Spanish Fattening Farm

“…We confirmed the adequate health status of all animals on the Spanish farm at all time points, with all metabolites falling within physiological ranges [37][38][39][40][41][42][43][44][45][46], although one report indicated that Wagyu cattle may reduce feed intake during summer due to heat stress [47]. Therefore, this type of production system, under Spanish climatic conditions with no restriction of exercise and with a locally sourced, high-olein diet, is appropriate for rearing and fattening Wagyu and Wangus animals.…”

“…The BHB level was significantly higher in the ACL animals than in the two other breeds at weaning, perhaps reflecting a higher level of stress in the ACL animals, which can reduce their feed intake [71]. The BHB level in Japanese animals was slightly higher at other time points than at weaning, but it was always within the physiological range [37][38][39][40][41][42][43][44][45][46]. We found no significant differences in NEFA levels between the ACL and Wagyu animals, which was similar to the finding of another study that compared Holstein and Wagyu [65].…”

“…The body fattening rate was measured based on monthly ultrasound exams in a representative sample of the animals, using the PieQuip technology and a MyLab One ® ultrasound system (Esaote, Barcelona, Spain) with an animal science probe (ASP) of 18 cm length and a frequency of 3.5 Mhz [41,42]. Measurements were assigned to four time intervals (8-14, 15-16, 17-18, and 19-20 months of age), which were defined to minimize the variations within each interval.…”

“…The following ultrasound features were analyzed because of their association with growth and fat deposition [42]: depth of the gluteus medius muscle (GMD, in mm), measured at the "P8" site, on the rump, at the intersection of a line going forward from the pin and a line down from the high point in the hindquarter, at the intersection of the gluteus medius and biceps femoris muscles; ribeye area (REA, in cm 2 ) of the longissimus dorsi muscle, measured between the 12th and 13th ribs; back fat (BF, mm), defined as the thickness of fat between ribs 12 and 13; rump fat thickness (RF, mm), also measured at the P8 rump site; and percentage of intramuscular fat (IMF, corresponding to marbling), which was calculated by the ultrasound software when the transducer was situated at longissimus dorsi between ribs 12 and 13.…”

Efeito da idade a primeira concepção como critério de seleção em características de crescimento e carcaça em bovinos Nelore

“…Estimativas moderadas de herdabilidade para AOL, EG e P8 foram similares as relatadas na literatura para bovinos Nelore, variando entre 0,17 a 0,34 (6,17,19,20) . Estimativas moderadas de herdabilidade para MAR e PCQ também foram relatadas por Gordo et al (34) , Tonussi et al (35) e Weik et al (36) avaliando bovinos Nelore. Os resultados obtidos indicaram que parte da variação dessas características é atribuída aos efeitos aditivos e que as características de carcaça podem responder à seleção genética, modificando a composição corporal em um curto espaço de tempo se a pressão da seleção genética for intensa (20) .…”