Direct greenhouse gas emissions of the game industry in South Africa

Abstract

Previous greenhouse gas (GHG) inventories did not include game as an emissions source. Recently game farming has become a recognized commercial enterprise in the agricultural sector in South Africa, contributing approximately R10 billion to the sectorial gross domestic product. The objective of this study was to estimate methane (CH 4 ) and nitrous oxide (N 2 O) emissions from privately owned game animals based on international recognized methodologies. The emissions were calculated on the basis of a large stock unit (LSU) selecting different quality diets. Daily enteric methane emissions were estimated as 0.28, 0.22, and 0.18 kg CH 4 /LSU/day consuming diets of 55%, 65% and 75% digestibility, respectively. The game industry contributed an estimated 131.9 Giga grams (Gg) of methane annually to agricultural emissions with the provinces of Limpopo, Eastern Cape and Northern Cape being the three largest contributors with 43.4, 37.3 and 21 Gg methane, respectively. The total privately owned game population was estimated at 299 1370 animals, utilizing 20.5 million hectares. IntroductionGame or wild ungulates have always inhabited southern Africa, although the population size has fluctuated greatly over the past 100 years. The establishment and growth of the private game industry is largely responsible for an increase in the number of game in recent years (Eloff, 2002; Bothma & Van Rooyen, 2005). Similarly, the industry has shown a steady growth in the number of game farms from 2 280 in 1980 to 9 000 in 1992 (Nell, 2003) and approximately 10 000 currently (G. Dry, 2013, Pers. Comm., Wildlife Ranching South Africa, P.O. Box 23073, Gezina, 0031, South Africa). The private game ranching industry occupies 16.8% (20 500 000 ha) of South Africa's total land area. This figure equates to 24% of South Africa's 84 million hectares of grazing land (Dry, 2011). This is more than double the area of officially declared conservation areas and approximately fivefold the area of the national parks (Carruthers, 2004).Game farming or ranching has become an organized and recognized enterprise in the agricultural industry (Eloff, 1996;Van Der Waal & Dekker, 2000). According to a recent article by Van Rooyen (2013) the wildlife industry ranked fifth largest in the agricultural sector, contributing R10 billion to the country's gross domestic product (GDP). Game farming is defined as an agricultural system in which wild animals are maintained in order to harvest by-products such as meat and skins in a domesticated or semi-domesticated manner by being enclosed in relatively small areas and provided with regular supplementary feeding and water (Carruthers, 2004;Du Toit, 2007). Part of the success of the industry is the ability of game to produce higher returns, compared to conventional livestock farming, under particular circumstances that may enhance the utilization of land with low agricultural potential (ABSA, 2003).Herbivorous game, with the exception of elephant, rhinoceros, hippopotamus, zebra, warthogs and bushpigs, are rum...

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