Growth, Behavior, and Carcass Traits of Fattening Hanwoo (Korean Native Cattle) Steers Managed in Different Group Sizes

Abstract

This study was conducted to evaluate growth, behavior and carcass traits of fattening Hanwoo (Korean native cattle) steers managed in different group sizes. A total of 48 animals, 6 months of age, were allocated to one of three group sizes and the experiment was conducted from 12 to 30 months of age. Groups were balanced for weight and the group sizes consisted of 4, 8, or 12 steers which were named 4sG, 8sG and 12sG, respectively. When animals were 12 months of age, initial fasted body weight (BW, 304.51 ±12.40 kg) was measured. All animals were housed at a constant space allowance of 8.82 m 2 per animal, and a feeder and drinker were provided per 4 animals. The whole fattening stage was divided into three phases: phase I (from 12 to 18 month of age), phase II (from 19 to 24 month of age), and phase III (from 25 to 30 month of age). Steers managed in 12sG showed low (p<0.05) growth rate and feed conversion rate (FCR) in phase I and phase II when compared to other treatment groups. However, this difference was not observed for the whole fattening phase (p>0.05). Steers managed in 4sG had a thick (p<0.05) ultrasound back fat thickness at 15 and 18 months of age. However, group size had no effect on meat yield and quality traits of area and marbling score. Animals managed in 8sG yielded a better meat grade of "A" than the "B" grade in other treatment group sizes. Lean color, fat color, firmness and maturity scores did not differ among group sizes. Hanwoo steers housed under 12sG spent less time on eating concentrate, relevant higher eating rate, less frequency of allogrooming, and more time on walking (p<0.05). It could be concluded that a large group size retarded growth rate and back fat thickness in the fattening stage, which was mainly focused on 15 and 18 months of age.

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

“…However, more walking and less time spent lying down behaviour was observed in steers of G4 and G2, respectively. This was similar to the study of Li et al (2010) on Hanwoo steers in groups of 4, 8, and 12 calves per area (8.4 × 4.2 m, 8.4 × 8.4 m, and 12.6 × 8.4 m). As expected, the effects of time and the interaction of time×group in both heifers and steers were significant except for standing and lying down behaviour concluding that as time passes from 8 to 14 months, the behaviour of the calves will be changed.…”

“…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

“…However, TRT 1.0 (TDN 1.0% down spec with SSL 0.1%) was shown to reduce body weight as compared with CON and TRT 0.5 (TDN 0.5% down spec with SSL 0.1%). During the early fattening period, steers need relatively high levels of TDN in their diets to support normal and sustained growth [ 23 , 24 ] and, even a 1% lower TDN may significantly affect growth performance despite SSL supplementation.…”

Identification of SNPs in TG and EDG1 genes and their relationships with carcass traits in Korean cattle (Hanwoo)

“…The c.-312A>G SNP was also significantly associated with yield index (YI), where AG animals were favorable for YI (p<0.05). Yield index or meat yield index becomes one of important economic traits in beef cattle (Lee et al, 2011), especially in Hanwoo (Li et al, 2010). Therefore, this SNP may be used as a valuable marker for selecting Hanwoo with high yield index.…”