The relevance of methane emissions from beef production and the challenges of the Argentinean beef production platform.

The livestock sector faces the challenge to respond to the growing demand for animal protein from an expanding population while reducing environmental impact through GHG emissions. Globally about 2.836 million tons of CO2-eq were emitted by the beef production sector equivalent to 46,2 kg CO2-eq per kg carcass weight (CW). From the 1.485 million cattle head spread out over the world, 82% are on extensive grazing systems while only 18% are on high productive intensive systems. Among the top ten beef exporter countries, five are located in Latin America accounting a quarter of the global stock and two of them, Argentina and Uruguay, produce on temperate pastures under grazing systems. In Argentina, the livestock area was reduced in favor of increasing the grain cropping area, which took place in the last two decades. Production systems were intensified to maintain cattle stock. Cattle programs changed from 100% pasture to pasture supplemented with cereal grains and conserved forages, and confinement on grain feeding for fattening was incorporated. Due to land sharing competition with cash crops, no increment of cattle stock is expected therefore improving production efficiency appears as the only way to increase beef production while reducing methane emissions intensity. Beef produced on intensive grazing systems on supplemented pastures maintained organoleptic, nutritional and lipid profile than that of beef produced on pure grazing systems.

Effect of feeding treatment during the backgrounding phase of beef production from pasture on: I. Animal performance, carcass and meat quality.

This research evaluated effects of feedlot backgrounding on 40, 70 or 100% alfalfa hay diets (40 hay, 70 hay; 100 hay, respectively) or pasture grazing (Pasture) before pasture finishing, on performance and beef characteristics of Angus heifers. Ninety six female calves were allocated to the four feeding strategies. Backgrounding took place during 114 days and subsequent pasture finishing over 132 days. Heifers of each strategy were slaughtered after 114 days (end of the feedlot period) and at end of the study when all remaining animals were finished on pasture. Effects of backgrounding were associated with rate of gain. Backgrounding strategies 40 hay and Pasture resulted in the best performance. Beef attributes were similar. At the end of the feedlot period, 100 hay was smaller and leaner, less tender and less juicy. At the end of the study, Pasture and 40 hay heifers had on average the largest back fat thickness and intramuscular fat measurements. No treatment effects were detected for Warner-Bratzler shear force, muscle pH, muscle color and sensory panel attributes.

Effect of feeding treatment during the backgrounding phase of beef production from pasture on: II. Longissimus muscle proximate composition, cholesterol and fatty acids.

This study evaluated effects of feedlot backgrounding strategies (40, 70 or 100% alfalfa hay diets) or pasture grazing on moisture, protein, total lipids, ash, cholesterol concentration, and lipid profiles of the longissimus dorsi muscle (LM) of pasture finished Angus heifers. Ninety six calves were allocated to the strategies over a 114-day period, followed by pasture grazing over 132 days. At the end of the backgrounding stage, the concentration of omega-3 (n-3) fatty acids was highest in the Pasture group and this difference persisted (P<0.032) until the end of the 132 day pasture finishing phase. Similarly, the n-6/n-3 ratio was lowest in the Pasture group at the end of backgrounding and after pasture finishing. Backgrounding diets based on 70 and 100% hay or pasture grazing showed greater (P<0.041) conjugated linoleic acid (CLA) concentration in the lipid fraction than 40% hay. Results suggested that residual effects of backgrounding strategies could be detected in intramuscular fat of pasture finished heifers.

Environmental assessment of agriculture at a regional scale in the Pampas of Argentina.

Governments need good information to design policies. However, in the Argentine Pampas there are neither sufficient knowledge on environmental issues, nor clear perception of environmental alterations across space and time. The general objective of this work was to provide decision makers with a scientifically sound set of indicators aiming at the assessment of current status and future trends in the rural environment of this sensitive region. As driving criteria to select indicators, we assumed that they had to be sound, simple to calculate, easy to understand, and easily applicable by decision makers. They are related closely to significant ecological structures and functions. Twelve basic indicators were identified: (1) land use, (2) fossil energy use, (3) fossil energy use efficiency, (4) nitrogen (N) balance, (5) phosphorus (P) balance, (6) nitrogen contamination risk, (7) phosphorus contamination risk, (8) pesticide contamination, (9) soil erosion risk, (10) habitat intervention, (11) changes in soil carbon stock, and (12) balance of greenhouse gases. Indicators were geographically referenced using a geographic information system (GIS). The strength of this study is not in the absolute value of environmental indicators, but rather in the conceptualization of indicator and the identification of changing patterns, gradients and trends in space and time. According to our results, we can not definitely say that agriculture in the Pampas, as a whole, tends to be sustainable or not. While some indicators tend to improve, others keep stable, and the rest worsen. The relative importance among indicators must also be considered. The indicators that showed a negative net change are key to the identification of critical problems that will require special attention in the close future.

Supplemental corn grain for steers grazing native rangeland during summer.

Effects of supplemental corn grain on forage OM intake (FOMI), digesta kinetics, ruminal fermentation patterns, in vitro OM digestibility (IVOMD), and in situ OM digestion were examined in steers grazing summer blue grama rangeland in northeastern New Mexico during July and August 1988. Sixteen ruminally cannulated steers (average BW 507 kg) were allotted to four treatments and individually fed whole-shelled corn at 0, .2, .4, and .6% of BW in a complete random design with repeated measurements over time. Forage OMI decreased linearly (P = .02) with increasing levels of supplemental corn; however, a tendency toward greater FOMI, as well as faster particulate and fluid passage, was observed when corn was fed at .2% of BW compared with 0, .4, or .6% of BW. Molar proportions of butyrate increased (P less than .10) but molar proportions of acetate and propionate, ruminal pH, and total VFA concentration did not change (P greater than .10) with added corn. Added corn linearly decreased (P less than .10) ruminal ammonia N concentrations in July, but patterns were inconsistent in August. A cubic response (P less than .05) for in situ OM disappearance with added corn was noted after 24, 72, and 96 h of incubation. Supplemental whole corn fed at .2% of BW had no detrimental effects and tended to increase FOMI. However, supplemental corn fed at .4 or .6% of BW decreased FOMI compared with 0 or .2% of BW.