An economic and greenhouse gas emissions evaluation of pasture-based dairy calf-to-beef production systems

Performance, profitability and greenhouse gas emissions of alternative finishing strategies for Holstein-Friesian bulls and steers

Lundi : P.05 – P.08

Simple SummaryA spring calving herd (~350 beef cows) over two production cycles was used to compare the whole-farm greenhouse gas (GHG) emissions among calf-fed vs. yearling-fed production systems, with and without growth implants. Farm GHG emissions initially included enteric CH4, manure CH4 and N2O, cropping N2O, and energy use CO2. The carbon footprint ranged from 19.9–22.5 kg CO2e per kg carcass weight. Including soil organic carbon loss from annual cropping and carbon sequestration from perennial pastures and haylands further reduced the carbon footprint by 11–16%. The carbon footprint of beef was reduced by growth promotants (4.9–5.1%) and by calf-fed beef production (6.3–7.5%).A spring calving herd consisting of about 350 beef cows, 14–16 breeding bulls, 60 replacement heifers and 112 steers were used to compare the whole-farm GHG emissions among calf-fed vs. yearling-fed production systems with and without growth implants. Carbon footprint ranged from 11.63 to 13.22 kg CO2e per kg live weight (19.87–22.52 kg CO2e per kg carcass weight). Enteric CH4 was the largest source of GHG emissions (53–54%), followed by manure N2O (20–22%), cropping N2O (11%), energy use CO2 (9–9.5%), and manure CH4 (4–6%). Beef cow accounted for 77% and 58% of the GHG emissions in the calf-fed and yearling-fed. Feeders accounted for the second highest GHG emissions (15% calf-fed; 35–36% yearling-fed). Implants reduced the carbon footprint by 4.9–5.1% compared with hormone-free. Calf-fed reduced the carbon footprint by 6.3–7.5% compared with yearling-fed. When expressed as kg CO2e per kg carcass weight per year the carbon footprint of calf-fed production was 73.9–76.1% lower than yearling-fed production, and calf-fed implanted was 85% lower than hormone-free yearling-fed. Reducing GHG emissions from beef production may be accomplished by improving the feed efficiency of the cow herd, decreasing the days on low quality feeds, and reducing the age at harvest of youthful cattle.

Whole-farm systems modelling of greenhouse gas emissions from pastoral suckler beef cow production systems

The environmental sustainability of food production systems, including net greenhouse gas (GHG) emissions, is of increasing importance. In Norwegian pork production, animal performance is high in terms of reproduction, growth, and health. The development and use of an IPCC methodology-based model for estimating GHG emissions from pork production could be helpful in identifying the effects of progress in genetics and management. The objective was to investigate whether an IPCC methodology-based model was able to reflect the effects of the progress in genetics and management in pork production on the GHG emissions per kg carcass weight (CW). It is hypothesized that this progress has led to low GHG emissions intensities in Norwegian pork compared to global levels and that expected improvements will give a lasting reduction in GHG emissions intensities. A model ‘HolosNorPork’ for estimating net farm gate GHG emissions intensities was developed, including allocation procedures, at the pig production unit level. The model was run with pig production data from in average 632 farms from 2014 to 2019. The estimates include emissions of enteric and manure storage methane, manure storage nitrous oxide emissions, as well as GHG emissions from production and transportation of purchased feeds, and direct and indirect GHG emissions caused by energy use in pig-barns. The model was able to estimate the effects on net GHG emissions intensities from pork production on the basis of production characteristics. The estimated net GHG emissions intensity was found to have decreased from on average 2.49 to 2.34 kg CO2 eq. kg−1 CW over the investigated period. For 2019 the net GHG emission for the one-third lower performing farms was estimated to 2.56 kg CO2 eq. kg−1 CW, whereas for the one-third medium and one-third best performing farms the estimates were 2.36 and 2.16 kg CO2 eq. kg−1 CW, respectively. The net GHG emissions intensity for pork carcasses from boars was estimated to be 2.07 kg CO2 eq. kg−1 CW. For the health regimes investigated, Conventional and Specific-Pathogen Free (SPF), the estimated GHG emissions intensities for 2019 were 2.37 and 2.24 kg CO2 eq. kg−1 CW, respectively. The effects on net GHG emissions intensities of breeding and management measures were estimated to be profound, and this progress in pig production systems contributes to an on-going strengthening of pork as a sustainable source for human food supply.

Whole farm modelling the effect of grass silage harvest date and nitrogen fertiliser rate on nitrous oxide emissions from grass-based suckler to beef farming systems

Greenhouse gas emissions from beef production systems in Denmark and Sweden

In the Netherlands, the Dutch Retail Broiler (DRB) and Better Life one Star (BLS) production systems have been introduced with the aim to improve broiler welfare. Simultaneously, retailers set targets for reduction of greenhouse gas (GHG) emissions in the whole broiler production chain. The GHG emissions of DRB and BLS may differ from conventional systems because of differences in slaughter age, feed intake, and diet composition. The aim of this study was to estimate GHG emissions of the conventional, DRB, and BLS production systems. A deterministic, spreadsheet based model was developed that included the breeder, hatchery, and broiler farm stages. First, the model calculates feed intake of different diets and energy use, based on performance objectives and literature. Selection of feed ingredients for the different types of diets was based on least cost formulation with nutritional constraints for each diet. Second, GHG emissions were estimated from cradle to broiler farm gate for processes along the broiler production chain by using life cycle assessment, and expressed as kg CO2-equivalents per kg live weight (kg CO2-eq/kg LW). Results showed that BLS (3.55 kg CO2-eq/kg LW) had lower GHG emissions compared to conventional (3.65 kg CO2-eq/kg LW) and DRB (3.98 kg CO2-eq/kg LW) at the broiler farm gate. Emissions from land use change (LUC) from feed production, mainly from soybean products, had highest impact on total GHG emissions (>50%) for the systems and these soybean products had the lowest inclusion in the diets of the BLS production system. Sensitivity analyses showed that variation in slaughter weight and feed intake could result in overlap of GHG emissions between systems. When soybean products were sourced from a country with low LUC emissions, conventional (1.37 kg CO2-eq/ kg LW) had the lowest GHG emissions and BLS (1.79 kg CO2-eq/kg LW) the highest. This study showed that origin of and including or excluding LUC emissions from soybean production results in different conclusions for achieving the GHG emissions reduction targets set by retailers.

Simple SummaryGrass-fed beef is becoming popular; however, there is little research information on optimising beef cattle performance in such production systems. In grass-forage-only beef systems, the removal of dietary concentrates increases the difficulty in achieving target live-weight performance and carcass fatness. Post-grazing sward height can potentially influence animal live-weight gain at pasture, whilst sire breed maturity (genotype) can potentially influence carcass fatness and, therefore, the duration required to achieve a commercially acceptable carcass fat score. Therefore, contrasting post-grazing sward heights and beef steer genotypes were evaluated within a grass-forage-only and grass-forage + concentrate production system. The high post-grazing sward height (6 cm) increased intake and live-weight gain at pasture and resulted in a heavier carcass after an indoor finishing period compared to the low post-grazing sward height (4 cm). The early-maturing genotype had a greater intake, live-weight gain and carcass fatness, but similar carcass weight and lower conformation score compared to the late-maturing genotype. Although concentrate supplementation indoors increased carcass weight and fatness, grass-forage-only steers still achieved a commercially-acceptable fat score when slaughtered at 24 months of age. In conclusion, grazing higher sward residuals and utilising early-maturing animal genotypes can increase live-weight pasture gain and carcass fatness, respectively, in grass-forage beef production systems.This study evaluated the effects of post-grazing sward height (PGSH, 4 or 6 cm) on herbage production, its nutritive value, dry matter (DM) intake, grazing behaviour and growth of early- (EM) and late-maturing (LM) breed suckler steers (n = 72), and the subsequent effect of indoor finishing diet (grass silage + 3.8 kg concentrate DM/head daily (SC), or grass silage only (SO)) on performance and carcass traits. Animals rotationally grazed pasture for 196 days, followed by indoor finishing for 119 days. At pasture, daily live-weight gain (LWG) was 0.10 kg greater for PGSH-6 than PGSH-4, resulting in a tendency for carcass weight to be 11 kg heavier. Although EM had a 0.10 kg greater daily LWG at pasture than LM, carcass weight did not differ between the genotypes. There was a genotype × PGSH interaction for carcass fat score, whereby there was no difference between EM-4 (8.83, 15-point scale) and EM-6 (8.17), but LM-6 (7.28) was greater than LM-4 (6.33). Although concentrate supplementation during indoor finishing increased carcass weight (+37 kg) and fat score (1.75 units), the majority of steers (83% of EM and 78% of LM) achieved a commercially-acceptable carcass fat score (6.78) at slaughter in the grass-forage-only system.

Context Within grass-based beef production systems in temperate climates, cattle are generally housed during winter and offered grass silage ad libitum with sufficient supplementary concentrates to reach commercial target growth rates. The concentrate is generally cereal-based with barley and wheat predominating but there is growing interest in oats due to it’s agronomic suitability and role in tillage production systems. Aims This study compared the effect of replacing barley with oats in a concentrate supplement on feed intake, growth, carcass and selected meat quality traits of beef cattle offered grass silage ad libitum. Methods Twenty-four late-maturing breed steers were assigned to either: (1) barley-based (862 g rolled barley/kg fresh weight) or (2) oats-based (853 g rolled oats/kg fresh weight), supplementary concentrate treatments. Concentrates were prepared as coarse mixtures and formulated to have similar levels of metabolisable protein. Steers were individually offered 4.0 kg dry matter of the respective concentrates daily, as a supplement to Lolium perenne-dominant grass silage (dry matter digestibility, 713 g/kg) for 124 days prior to slaughter. Key results Replacement of barley with oats in the concentrate supplement had no effect on grass silage or total dry matter intake, final live weight, daily live weight gain or feed conversion ratio. Ultrasonographic measurements of rib fat and lumbar muscle gain were greater for barley compared to oats, but there was no difference between the two cereal-based concentrates for lumbar and rump fat gain. Carcass weight, fat and conformation score, subcutaneous fat depth and estimated carcass composition did not differ between the two concentrate types. Replacing barley with oats in the concentrate supplement had no effect on subcutaneous fat colour, or M. longissimus dorsi muscle pH, drip loss, colour or sensory characteristics but increased the polyunsaturated to saturated fatty acid ratio in muscle lipid. Conclusion Rolled oats can replace rolled barley in a concentrate supplement to moderately-high digestibility grass silage without negatively affecting intake and performance or selected meat quality traits of beef cattle. Implications The findings of this study will assist producers when selecting the most attractive supplement composition for grass-silage finished beef cattle.

Climate-smart livestock production at landscape level in Kenya

BackgroundSocietal pressures exist to reduce greenhouse gas (GHG) emissions from farm animals, especially in beef cattle. Both total GHG and GHG emissions per unit of product decrease as productivity increases. Limitations of previous studies on GHG emissions are that they generally describe feed intake inadequately, assess the consequences of selection on particular traits only, or examine consequences for only part of the production chain. Here, we examine GHG emissions for the whole production chain, with the estimated cost of carbon included as an extra cost on traits in the breeding objective of the production system.MethodsWe examined an example beef production system where economic merit was measured from weaning to slaughter. The estimated cost of the carbon dioxide equivalent (CO2-e) associated with feed intake change is included in the economic values calculated for the breeding objective traits and comes in addition to the cost of the feed associated with trait change. GHG emission effects on the production system are accumulated over the breeding objective traits, and the reduction in GHG emissions is evaluated, for different carbon prices, both for the individual animal and the production system.ResultsMultiple-trait selection in beef cattle can reduce total GHG and GHG emissions per unit of product while increasing economic performance if the cost of feed in the breeding objective is high. When carbon price was $10, $20, $30 and $40/ton CO2-e, selection decreased total GHG emissions by 1.1, 1.6, 2.1 and 2.6% per generation, respectively. When the cost of feed for the breeding objective was low, selection reduced total GHG emissions only if carbon price was high (~ $80/ton CO2-e). Ignoring the costs of GHG emissions when feed cost was low substantially increased emissions (e.g. 4.4% per generation or ~ 8.8% in 10 years).ConclusionsThe ability to reduce GHG emissions in beef cattle depends on the cost of feed in the breeding objective of the production system. Multiple-trait selection will reduce emissions, while improving economic performance, if the cost of feed in the breeding objective is high. If it is low, greater growth will be favoured, leading to an increase in GHG emissions that may be undesirable.

The impact of uncertainties on predicted greenhouse gas emissions of dairy cow production systems

The influence of strain of Holstein-Friesian cow and feeding system on greenhouse gas emissions from pastoral dairy farms

This study evaluated the effects of different lamb production systems on live weight gain (LWG), carcass quality and meat quality. Four production systems for weaned intact male lambs were examined: indoor feeding with grass silage and concentrate (group 1), grazing on cultivated pasture with (group 2) or without (group 3) concentrate, and grazing on semi-natural pasture (group 4). Live weight, carcass weight, dressing percentage, carcass conformation, fatness and pH decline were recorded at slaughter, and M. longissimus thoracis et lumborum was analysed for colour, thawing and cooking loss, pH after 24 hours and 6 days, and Warner-Bratzler shear force. LWG was strongly affected by production system, being highest for group 1 and lowest for group 4 (p<0.001). Group 4 had the lowest conformation (p=0.002) and fat scores (p<0.001). Hence, production system affected age at slaughter, live weight gain, weight at slaughter, carcass conformation and fatness scores, but caused no differences in meat quality attributes in intact male lambs.