Meat quality traits and muscle composition of cows differing in lactation performance

Abstract

Beef and dairy cows differ in the way in which they utilise nutrients and in accretion or mobilisation of body reserves during lactation. Thus far, little is known about the impact of lactation performance on body composition, meat quality, and the related muscle structure of cows with a defined, combined beef and dairy genetic background. In the described experiment, 50 F 2 cows, originating from mating Charolais bulls to German Holstein cows and a following intercross of F 1 individuals, were slaughtered during the second lactation, 30 days after calving. Cows were assigned to 3 groups, each containing representatives of 3 families, according to lactation performance. Standard carcass and meat quality traits were determined. Additionally, samples from longissimus muscle were investigated by histology and computer image analysis for muscle fibre profile, intramuscular fat cell size, and marbling traits. Subcutaneous fat cell size was measured to estimate the impact of lactation on body fat reserves. The results suggest no influence of the duration of the first lactation on body composition, meat quality or muscle structure. However, the amount of milk per day influenced body weight, body composition, and marbling traits. Relationships between traits were low, but showed consistently that increasing milk yield was negatively correlated with tissue accretion. Changes of muscle fibre and fat cell profile, indicating protein or fat mobilisation by lactation, could not be detected. In the presented study, lactation had only minor consequences for meat quality.

Variants of the bovine retinoic acid receptor-related orphan receptor C gene are in linkage disequilibrium with QTL for milk production traits on chromosome 3 in a beef × dairy crossbreed population

“…To address this issue, we took advantage of a crossbreed cow population of a dairy (German Holstein) and a beef breed (Charolais), which was raised and kept under dairy production conditions (Kühn et al 2002), but predominantly showed a beef phenotype (Hammon et al 2010). In this population, Hammon et al (2010) and Hamada et al (2012) had observed a negative correlation between milk yield (MY) on one hand and body fat deposition and carcass weight on the other hand.…”

Changes of muscle fibre profile and fat cell size around first parturition in cows differing in lactation performance

“…Details were described elsewhere (Hamada et al, 2012). Briefly, heifers were reared in a free-stall barn and were inseminated at 18 months of age with semen from German Holstein sires.…”

“…Muscle fibre traits were measured and muscle fibre types were determined with an image analysis system equipped with a Jenaval microscope (Carl Zeiss, Jena, Germany), an Altra20 CCD camera (OSIS), and a special muscle fibre measurement module (MAS, Freiburg, Germany) of the Cell\^D software (OSIS). Measurement of muscle fibre traits were performed as described earlier (Albrecht et al, 2011;Hamada et al, 2012).…”

“…Details of lactation performance of cows used in this study were previously described by Hamada et al (2012). Briefly, milk yield and lactation duration were used to generate 3 groups for further analyses.…”

“…In our earlier study (Hamada et al, 2012), we investigated the consequences of different lactation performance on carcass composition, muscle structure, and meat quality in 50 F 2 generation cows of a Charolais  German Holstein crossbred experiment (Kühn et al, 2002). The results were obtained after slaughter during the second lactation, 30 days after parturition, and revealed no significant differences in cellular traits between groups of cows with low or high lactation performance.…”