Effects of Stocking Density or Group Size on Intake, Growth, and Meat Quality of Hanwoo Steers (Bos taurus coreanae)

Abstract

This study was conducted to investigate the effects of stocking density or group size on feed intake, daily gain, and carcass characteristics of Hanwoo (Korean indigenous breed) steers reared from 7 months to 31 months of age. Thirty Hanwoo steers were divided into four groups with three replicates each (a total of 12 pens). In each group, one (G1), two (G2), three (G3), and four steers (G4) per pen were allocated as treatments. Pen size was 32.0 m2, and therefore Hanwoo steers in G1, G2, G3, and G4 were reared under different space allowances, i.e. 32.0, 16.0, 10.6, and 8.0 m2/steer, respectively. Steers were reared following a conventional beef cattle management method in Korea, and were offered a fixed amount of commercial concentrate with ad libitum forages. Results were subjected to analysis of variance with stocking density as the main effect, and significance was declared at p<0.05. Although total feed intake was not significantly altered, it numerically increased in animals of low stocking density (G1) compared to those subjected to high stocking density treatment (i.e. G4). Feed conversion ratio was higher (p<0.05) in G3 compared to G1 and G2. Animals in G1 (low stocking density) grew faster (p<0.05) than those of high stocking density (G3 and G4). Back fat thickness, meat yield index, and meat yield grade were similar among all levels of stocking density. However, longissimus muscle area was larger in G1 and G2 (p<0.01) compared to G3 and G4, and animals in G3 produced smaller carcasses (p<0.05). Carcass quality traits, including marbling score, meat color, fat color, texture, maturity and meat quality grade, as determined by a group of experts, were not significantly different among the treatments. In conclusion, lower stocking density resulted in increased feed efficiency, daily gain, and carcass weight in Hanwoo steers. However it remains unclear whether such differences are the results of stocking density or group size, or a combination of both. Nonetheless, these results confirm previous studies reporting a negative effect of increased stocking density on animal productivity. Further, animal welfare under an intensive farming system in relation to economical return is discussed.

Comparison of Carcass and Sensory Traits and Free Amino Acid Contents among Quality Grades in Loin and Rump of Korean Cattle Steer

“…Similar strong MS with QG correlations have been reported previously ( Dow et al, 2011 ). In Korean cattle, beef with higher MS revealed better QG ( Lee et al, 2012 ).…”

Group sizes effects on growth performance and behavioural characteristics in Korean native calves

“…This may result in high intensive farming. Moreover, the role of high stocking density on the immune system, stress responses, and behavioural characteristics of cattle has been recently reported (Broom 2003;Lee et al 2012;Ha et al 2016). Additionally, cattle and calves, in particular, are social animals and known to be behaviourally influenced by stocking density (Friend and Polan 1974;Kondo et al 1984;Boe and Faerevik 2003).…”

“…High stock density is documented to lead to lower performance of the animals and impairs animal welfare and behaviour. Thus it can adversely affect the immune system of the animals (Rind and Phillips 1999;Kondo 2011;Lee et al 2012). For practical reasons and due to the labour costs, fattening Hanwoo steers are usually housed as 4-12 heads, forming a dynamic group based on their fattening characteristics and local environmental conditions (Ha et al 2017;Yang et al 2016).…”

“…For practical reasons and due to the labour costs, fattening Hanwoo steers are usually housed as 4-12 heads, forming a dynamic group based on their fattening characteristics and local environmental conditions (Ha et al 2017;Yang et al 2016). In Korea, stocking density with respect to the group size is one of the major concerns (Li et al 2010;Lee et al 2012) due to having over 70% mountainous areas and 12-16% arable land (Choi 2011;Park et al 2012). Increasing stocking density can be achieved by increasing the number of animals on a given area of land, or by decreasing the amount of land accessible to animals over the same amount of time (Yang et al 2015).…”

Effect of optimal sodium stearoyl-2-lactylate supplementation on growth performance and blood and carcass characteristics in Hanwoo steers during the early fattening period

“…Feeding of high-density concentrate diets is used to improve meat quality with high marbling, which is one of the main distinguishing factors determining Hanwoo quality grade [ 2 ]. However, feeding of high-density concentrate diets can have a negative effect on digestive metabolism, feed efficiency, and feed intake during the final fattening period [ 3 ]. To address these questions, various studies have been carried out on supplementation of emulsifiers in diet [ 4 , 5 ].…”