The profitability and production of a beef herd on transitional Cymbopogon – Themeda veld receiving three different levels of lick supplementation

Abstract

A study was conducted over a three year period with 250 Drakensberger cows to identify a supplementation regimen that would bring about the most profit when offered to cows grazing transitional Cymbopogon-Themeda veld. Four production groups were identified namely: Young Heifers (YH) (wean to 22 months old); Heifers (H) (22 to 34 month old); First-calf-heifers (1CH); and Cows (C). Each production group was then randomly divided into one of three supplementation treatment groups. The supplementation treatments offered differed in crude protein (CP) content, percentage non-degradable protein (NDP), metabolisable energy (ME) content, and recommended daily intake. The level of supplementation was similar to the levels commonly recommended by animal nutritionists and typical of levels used under practical farming conditions. Treatment 1 of the YH (YH1) and the 1CH (1CH1) consisted of a winter production supplement and a summer production supplement. Treatment 2 of the YH (YH2) and the 1CH (1CH2) consisted of a cotton-oil-cake and urea based protein and mineral supplement in winter and a mineral supplement containing 15% CP in summer. Treatment 3 of the YH (YH3) and 1CH (1CH3) consisted of a urea based protein and mineral supplement in winter and a mineral supplement in summer. Treatment 1, Treatment 2 and Treatment 3 of the H (H1, H2 and H3) consisted of the same urea based protein and mineral supplement in winter and a mineral supplement in summer. Treatment 1 of the C (C1) consisted of a cotton-oil-cake and urea based protein and mineral supplement in winter and a mineral supplement containing 15% CP in summer. Treatment 2 of the C (C2) consisted of a urea and cotton-oil-cake based protein and mineral supplement in winter and a mineral supplement in summer. Treatment 3 of the C (C3) consisted of a urea based protein and mineral supplement in winter and a mineral supplement in summer. Significant differences (P < 0.05) in body weights and body condition scores (BCS) were measured between the YH treatment groups. All three YH treatment groups were, however, able to reach target breeding weight (60 to 65% of mature body weight) eight months prior to the breeding season. The cost incurred (R145/animal/year) in developing the YH3 treatment group was much lower than that of the YH1 treatment group (R466/animal/year) and the YH2 treatment group (R228/animal/year). No significant differences were measured in weight gain between the H supplementation treatment groups, however, in Year 2 the H2 had a lower final BCS (5.55 ± 0.52) than the H1 treatment group (6.11 ± 0.33) and the H3 treatment group (5.90 ± 0.57) and in Year 3 the H1 treatment group had a significantly (P < 0.05) heavier final body weight (513 kg ± 41) than the H2 treatment group (497 kg ± 24) and the H3 treatment group (478 kg ± 33). Significant (P < 0.05) differences in body weight and BCS were measured between the 1CH treatment groups in Year 2 and Year 3 however mean weaning weight between the 1CH treatment groups did not differ significantly (P < 0.05). When looking at profitability, the production attained by the 1CH treatment group (mean weaning weight 227 kg, conception rate 87%) and the 1CH2 treatment group (mean weaning weight 222 kg, conception rate 97%) compared to that of the 1CH3 treatment group (mean weaning weight 218 kg, conception rate 89%) could not compensate for the higher supplementation costs of the 1CH1 (R1033/animal/year) and the 1CH2 (R466/animal/year) compared to the 1CH3 treatment group (R265/animal/year). Despite the fact that significant (P < 0.05) differences in body weights and BCS were measured between the C supplementation treatment groups no significant differences were measured in the production attained (C1: mean weaning weight 224 kg, calving rate (CR) 91%, inter calving period (ICP) 387 days; C2: mean weaning weight 219 kg, CR 90%, ICP 378 days; C3: mean weaning weight 216 kg, CR 94%, ICP 387 days). The higher supplementation cost of the C1 treatment group (R540/animal/year) and the C2 treatment group (R395/animal/year) made the supplementation regimen of the C3 treatment group (R322/animal/year) the most profitable. The conclusion made is that the provision of a urea based protein and mineral supplement in winter and a mineral supplement in summer to an entire cow-calf production system grazing transitional Cymbopogon - Themeda veld which is in good condition realizes the most profit as it enables the animals to operate within their optimum weight range.