How does reproduction account for dairy farm sustainability?

Sustainability - the new hype of the 21st century has brought discomfort for the government and society. Sustainable agriculture is essential to face our most concerning challenges: climate change, food security, and the environmental footprint, all of which add to consumers' opinions and choices. Improvements in reproductive indexes can enhance animal production and efficiency, guaranteeing profit and sustainability. Estrus detection, artificial insemination (AI), embryo transfer (ET), estrus synchronization (ES), and multiple ovulations are some strategies used to improve animal reproduction. This review highlights how reproductive strategies and genetic selection can contribute to sustainable ruminant production. Improved reproductive indices can reduce the number of nonproductive cows in the herd, reducing methane emissions and land use for production while preserving natural resources.(AU)

Methane emission, milk yield and behavior of ewes kept on pastures or supplemented with concentrate based on corn grain or whole cottonseed / Emissão de metano, produção de leite e comportamento de ovelhas mantidas em pastagem ou suplementadas com concentrado à base de milho grão ou caroço de algodão

This study aimed to evaluate methane emission, milk yield and behavior of ewes kept exclusively on irrigated pasture of Tifton 85 grass (Cynodon spp.) or supplemented with ground corn or whole cottonseed (WCS) based concentrates. Twelve Lacaune x Santa Ines ewes (43.07±0.83 kg of body weight, 77±24 days after parturition, on average) were distributed in replicated 3x3 Latin square. Treatments consisted of three diets: pasture (no concentrate supplementation); corn (pasture + corn-based supplement); whole cottonseed (pasture + whole cottonseed-based supplement), offering 0.5 kg/ewe/day. The WCS group showed the highest concentrate dry matter intake (DMI) (p=0.049) and crude protein (CP) intake (p=0.001) compared to the others. There was no difference on total DMI (p=0.115) for the tested diets. Animals exclusively kept on pasture had the greatest forage DMI (p=0.004), lowest CP digestibility (p=0.015), showed longer grazing time (p=0.01) and shorter idle time (p=0.01) compared to the supplemented groups. Milk yield (0.36 kg/ewe/day) (p=0.15) and methane emission (33.12 g/ewe/day) (p=0.95) were similar for all three evaluated groups. Supplementation with concentrate based on corn or whole cottonseed does not improve productive performance nor decrease methane emission. However, lactating ewes kept exclusively in pasture show longer grazing time, without changes in milk yield and methane emission.

Objetivou-se avaliar a emissão de metano, a produção de leite e o comportamento de ovelhas mantidas exclusivamente em pastagem irrigada de Tifton 85 (Cynodon spp.) ou suplementadas com concentrados à base de milho grão ou caroço de algodão. Doze ovelhas Lacaune x Santa Inês (43,07±0,83 kg de peso corporal e 77±24 dias após a parição, em média) foram distribuídas em quadrados latinos 3x3 replicados. Os tratamentos consistiram em três dietas: pastagem (sem suplementação concentrada); milho (pastagem + suplemento à base de milho); caroço de algodão integral (pastagem + suplemento à base de caroço de algodão), oferecendo 0,5 kg/ovelha/dia. O grupo caroço de algodão apresentou maior consumo de matéria seca (CMS) (P=0,049) e consumo de proteína bruta (PB) (P=0,001) em relação aos demais. Não houve diferença no CMS total (P=0,115) para as dietas testadas. Os animais exclusivamente em pastagem apresentaram maior consumo de forragem (P=0,004), menor digestibilidade da PB (P=0,015), maior tempo em pastejo (P=0,01) e menor tempo em ócio (P=0,01), em relação aos grupos suplementados. A produção de leite (0,36 kg/ovelha/dia) (P=0,15) e a emissão de metano (33,12 g/ovelha/dia) (P=0,95) foram semelhantes nos três grupos avaliados. A suplementação com concentrado à base de milho grão ou caroço de algodão não melhorou o desempenho produtivo e não reduziu a emissão de metano. Entretanto, as ovelhas lactantes mantidas exclusivamente em pastagem apresentaram maior tempo em pastejo, sem alterações na produção de leite e na emissão de metano.

Effect of amino acid supplementation and choline chloride for low protein diet on nitrogen efficiency and methane emission of dairy cows / Efeito da suplementação de aminoácidos e cloreto de colina para dieta pobre em proteínas na eficiência de nitrogênio e emissão de metano de vacas leiteiras

Ruminants are one of the largest anthropogenic methane and nitrous oxide emissions. Therefore, the hypothesis was to study the effects of reducing dietary crude protein (CP) level on environmental contaminators when rumen-protected amino acids and choline chloride were supplemented. Sixty Holstein dairy cows were used during the experiment. Test diets were: (1) CD = Control diet with16.2 g of crude protein/ Kg of DM); (2) LM = Low protein diet with 14.2 g of crude protein/ Kg of DM + methionine ; (3) LL = Low protein diet with 14.2 g of crude protein/ Kg of DM + lysine; (4) LML = Low protein diet with 14.2 g of crude protein/ Kg of DM + methionine + lysine; (5) LMLC = Low protein diet with 14.2 g of crude protein/ Kg of DM + methionine + lysine + choline. Dry matter and NDF intake were not different, but the control group received higher CP and ADF compared with other groups (P < 0.05). Fecal CP and ADF of control group were lower (P < 0.05), but no differences were observed for fecal dry matter (DM) and NDF. Milk yield and protein content were higher for LML and LMLC like control group (P < 0.05). Nitrogen intake, urinary N, urinary urea N and total excreta N decreased (P < 0.05) when animals fed low protein. There was no difference in ruminal pH and acetate to propionate ratio, whereas the ruminal ammonia-N decreased with the low protein (P < 0.05). The 120-h gas production test, showed no difference on the kinetics of digestion and in vitro methane emission. However, the inclusion of DMI in the calculations revealed that low protein can reduce (P < 0.05) methane emission. Overall, our findings indicated that low protein can be compensated for by adding rumen-protected amino acids, not only to maintain the animal performance, but also to decrease nitrogen excretion and methane emission.(AU)

Os ruminantes são uma das maiores emissões antropogênicas de metano e óxido nitroso. Portanto, a hipótese foi estudar os efeitos da redução do nível de proteína bruta (PB) na dieta sobre os contaminantes ambientais quando aminoácidos protegidos no rúmen e cloreto de colina foram suplementados. Sessenta vacas leiteiras Holstein foram utilizadas durante o experimento. As dietas teste foram: (1) CD = dieta controle com 16.2 g de proteína bruta / Kg de MS); (2) LM = Dieta pobre em proteínas com 14.2 g de proteína bruta / Kg de DM + metionina; (3) LL = Dieta pobre em proteínas com 14.2 g de proteína bruta / Kg de MS + lisina; (4) LML = Dieta pobre em proteínas com 14.2 g de proteína bruta / Kg de DM + metionina + lisina; (5) LMLC = Dieta pobre em proteínas com 14.2 g de proteína bruta / Kg de DM + metionina + lisina + colina. O consumo de matéria seca e FDN não foi diferente, mas o grupo controle recebeu maior PB e FDA em comparação com os outros grupos (P < 0.05). A PB e FDA fecal do grupo controle foram menores (P < 0.05), mas não foram observadas diferenças para matéria seca (MS) e FDN fecal. A produção de leite e o teor de proteína foram maiores para LML e LMLC como grupo controle (P < 0.05). A ingestão de nitrogênio, N urinário, N urinário urinário e N excreta total diminuíram (P < 0.05) quando os animais foram alimentados com baixa proteína. Não houve diferença no pH ruminal e na relação acetato / propionato, enquanto o N-amônia ruminal diminuiu com o baixo teor de proteína (P < 0.05). O teste de produção de gás de 120 h, não mostrou diferença na cinética de digestão e emissão de metano in vitro. No entanto, a inclusão do CMS nos cálculos revelou que a baixa proteína pode reduzir (P < 0.05) a emissão de metano. No geral, nossos resultados indicaram que o baixo teor de proteína pode ser compensado pela adição de aminoácidos protegidos no rúmen, não apenas para manter o desempenho animal, mas também para diminuir a excreção de nitrogênio e a emissão de metano.(AU)

Anaerobic co-digestion of swine manure and forage at two harvesting ages / Co-digestão anaeróbia dos dejetos de suínos e forragem em duas idades de colheita

The co-digestion of swine manure with vegetable waste is an alternative that can increase the production of biogas and methane generated by the isolated digestion of manure. However, recommendations that are based on the best ratio between manure and forage, as well as the age of harvest, are still scarce in the literature. This study was conducted to evaluate inclusions (0, 25, 50, 75 and 100%) of the total solids (TS) of Elephant grass (Pennisetum purpureum Schum) harvested at two ages medium age (MA) at 45 days of growth and advanced age (AA) at 90 days in co-digestion with swine manure, using an entirely randomized design in a 5x2 factorial scheme. Batch digesters were used and biogas production was monitored for 12 weeks. There was influence of forage age (P <0.05) on the degradation of solids and neutral detergent fiber, with higher values for the substrates containing MA forage. The highest CH4 yields were obtained by the substrates containing MA forage in the inclusion of 27.7 and 31.6%, being 253.7 and 222.2 L of CH4 per Kg of total or volatile solids. The age of the forages influenced the onset and persistence of biogas production, being advantageous only in the inclusion of 25% of MA forage. The AA forage inclusion is not recommended for co-digestion with swine manure.

A co-digestão dos dejetos suínos associados a resíduos vegetais é uma alternativa que pode elevar as produções de biogás e metano alcançadas pela digestão isolada do dejeto. No entanto, recomendações que se baseiem na melhor proporção entre dejeto e forragem, assim como na idade de colheita ainda são escassas na literatura. O objetivo do trabalho foi avaliar inclusões crescentes (0, 25, 50, 75 e 100% dos sólidos totais (ST) de capim elefante (Pennisetum purpureum Schum.) colhido em duas idades de corte mediana (MA) aos 45 dias de crescimento e avançada (AA) aos 90 dias, empregado em co-digestão com o dejeto suíno, adotando-se delineamento inteiramente ao acaso, em esquema fatorial 5x2. Foram utilizados biodigestores batelada de bancada, sendo as produções de biogás acompanhadas durante 12 semanas. Houve influência da idade da forragem (P<0,05) na degradação de sólidos e fibra em detergente neutro, com maiores valores para os substratos que continham a forragem MA. Os maiores rendimentos de CH4 foram alcançados pelos substratos que continham forragem MA na inclusão de 27,7 e 31,6 %, sendo de 253,7 e 222,2 L de CH4 por Kg de ST ou sólido volátil adicionado. A idade das forragens influenciou o início e a persistência das produções de biogás ao longo do período de digestão, sendo vantajosa apenas na inclusão de 25% de forragem com MA.

Effect of essential oils and aqueous extracts of plants on in vitro rumen fermentation and methane production

The objective of this study was to evaluate in vitro rumen fermentation and methane production under the influence of two sources of phytochemicals: essential oils (EOs) and aqueous extracts (AEs). Treatments were set up in a completely randomized block design, with 4×2+1 factorial arrangement of four species, S (garlic, G; cinnamon, C; rosemary, R; eucalyptus; EU) × two types of presentation, P (essential oil, EO; aqueous extract, AE) and a basal diet, BD (50% concentrate, 20% alfalfa and 30% corn silage). Rumen fermentation was evaluated using the in vitro gas production technique. All experimental units were incubated with 500 mg of BD for 72 hours. Treatments were added at a single dose of 900 mg/L of rumen inoculum. Gas pressure was recorded at 0, 2, 4, 6, 8, 10, 14, 18, 24, 30, 36, 42, 48, 60 and 72 h postincubation. There was an interaction effect (P × S) between plant extract presentation (P) and plant species (S) for all variables. Treatments GEO, CEO, REO decreased volatile fatty acids (mmol/200 mg), microbial mass production (mg/g), CH4 production (mL/g), in vitro dry matter digestibility (P < 0.05), and total gas production at 24 and 72 h post-incubation (P < 0.05; mL/g DM, mL/g OM). No differences (P > 0.05) were observed between AEs and BD. In conclusion, the use of EOs negatively affected rumen fermentation parameters and the production of CH4. Garlic and cinnamon EOs effectively reduced methane emissions; however, they also reduced in vitro dry matter digestibility.

CH4 and N2O fluxes from planted forests and native Cerrado ecosystems in Brazil

Forest soils are N2O sources and commonly act as CH4 sinks. This study evaluated the dynamics of the CH4 and N2O fluxes of soils under Eucalyptus plantations and native Cerrado vegetation, as well as possible interactions between environmental factors and fluxes. The study was carried out in the Distrito Federal, Brazil, during 26 months, in three areas: in two stands of the hybrid Eucalyptus urophylla × Eucalyptus grandis, planted in 2011 (E1), and in 2009 (E2) and native Cerrado vegetation (CE). Measurements to determine the fluxes in a closed static chamber were carried out from Oct 2013 to Nov 2015. Soil and climate factors were monitored. During the study period, the mean CH4 fluxes were –22.48, –8.38 and –1.31 μg CH4 m–2 h–1 and the mean N2O fluxes 5.45, 4.85 and 3.85 μg N2O m–2 h–1 from E1, E2 and CE, respectively. Seasonality affected plantations in the studied sites. Cumulative CH4 influxes were calculated (year-1: –1.86 to -0.63 kg ha–1 yr–1; year-2: –1.85 to –1.34 kg ha–1 yr–1). Cumulative N2O fluxes in the three sites were ≤ 0.85 kg ha–1 yr–1. The change in land use from Cerrado to Eucalyptus plantations did not significantly changed regarding greenhouse gases (GHG), compared to the native vegetation. Flux rates of both gases (N2O and CH4) were low. Temporal variations in GHG fluxes and different ages of the stands did not cause significant differences in cumulative annual fluxes.

The neglected contribution of mound-building termites on CH4 emissions in Brazilian pastures

Based on previous reports, our study aimed to obtain the first estimate on the contribution of termite mounds to CH4 emissions in Brazilian Cerrado pastures. We estimated that termite mounds occupy an area larger than 200,000 ha in degraded pastures, an important loss of grazing area considering the current scenario of land-use change of pastures to other crops in Brazil. Moreover, mound-building termites in degraded pastures may be responsible for CH4 emissions greater than 11 Mt CO2 eq. yr−1, which would notably affect the greenhouse gases (GHG) balance of grass-fed cattle production in Brazil. In this sense, it is urgent to conduct field-scale studies about the CH4 emissions by mound-building termites in pastures and its contribution to the C footprint of Brazilian beef.

CH4 and N2O fluxes from planted forests and native Cerrado ecosystems in Brazil

Forest soils are N2O sources and commonly act as CH4 sinks. This study evaluated the dynamics of the CH4 and N2O fluxes of soils under Eucalyptus plantations and native Cerrado vegetation, as well as possible interactions between environmental factors and fluxes. The study was carried out in the Distrito Federal, Brazil, during 26 months, in three areas: in two stands of the hybrid Eucalyptus urophylla × Eucalyptus grandis, planted in 2011 (E1), and in 2009 (E2) and native Cerrado vegetation (CE). Measurements to determine the fluxes in a closed static chamber were carried out from Oct 2013 to Nov 2015. Soil and climate factors were monitored. During the study period, the mean CH4 fluxes were –22.48, –8.38 and –1.31 μg CH4 m–2 h–1 and the mean N2O fluxes 5.45, 4.85 and 3.85 μg N2O m–2 h–1 from E1, E2 and CE, respectively. Seasonality affected plantations in the studied sites. Cumulative CH4 influxes were calculated (year-1: –1.86 to -0.63 kg ha–1 yr–1; year-2: –1.85 to –1.34 kg ha–1 yr–1). Cumulative N2O fluxes in the three sites were ≤ 0.85 kg ha–1 yr–1. The change in land use from Cerrado to Eucalyptus plantations did not significantly changed regarding greenhouse gases (GHG), compared to the native vegetation. Flux rates of both gases (N2O and CH4) were low. Temporal variations in GHG fluxes and different ages of the stands did not cause significant differences in cumulative annual fluxes.(AU)

In vitromethane production from silages based on Cenchrus purpureusmixed with Tithonia diversifoliain different proportions

Climate change (CC) affects food production, mainly those based on livestock systems. Producers must identify adaptation strategies to ensure the production, during periods of drought, and lack of forage. Besides contributing to CC, high emissions of ruminal methane (CH4) are energy loss potentially usable for livestock production. The objective was to estimate in vitroruminal gas production (RGP) and determine the CH4emissions from silages. Treatments were made with forage of Cenchrus purpureusmixed with Tithonia diversifoliaT1= C.purpureusat 100%; T2= C.purpureus/ T.diversifoliain 33/67 percent ratio; T3= C.purpureus/ T.diversifolia67/33; and T4= T.diversifoliaat 100%. Samples of silages were analyzed, andthey were inoculated with strains of Lactobacillus paracasei(T735); then they were fermented in vacuum-sealed bags for 67 days. RGP and CH4 were measured at 2, 4, 8, 12, 18, 24, 30, 36, and 48 hours. Additionally, modeling of CH4 production kinetics was conducted, using different equations. The results indicate that the highest cumulative CH4 production was for T1. This kinetics was represented using the Gompertz model. In conclusion, the inclusion of T.diversifoliato C.purpureussilages contributes to the decrease of methane at the ruminal level, which constitutes an adaptation practice at climate change.(AU)

In vitromethane production from silages based on Cenchrus purpureusmixed with Tithonia diversifoliain different proportions

Climate change (CC) affects food production, mainly those based on livestock systems. Producers must identify adaptation strategies to ensure the production, during periods of drought, and lack of forage. Besides contributing to CC, high emissions of ruminal methane (CH4) are energy loss potentially usable for livestock production. The objective was to estimate in vitroruminal gas production (RGP) and determine the CH4emissions from silages. Treatments were made with forage of Cenchrus purpureusmixed with Tithonia diversifoliaT1= C.purpureusat 100%; T2= C.purpureus/ T.diversifoliain 33/67 percent ratio; T3= C.purpureus/ T.diversifolia67/33; and T4= T.diversifoliaat 100%. Samples of silages were analyzed, andthey were inoculated with strains of Lactobacillus paracasei(T735); then they were fermented in vacuum-sealed bags for 67 days. RGP and CH4 were measured at 2, 4, 8, 12, 18, 24, 30, 36, and 48 hours. Additionally, modeling of CH4 production kinetics was conducted, using different equations. The results indicate that the highest cumulative CH4 production was for T1. This kinetics was represented using the Gompertz model. In conclusion, the inclusion of T.diversifoliato C.purpureussilages contributes to the decrease of methane at the ruminal level, which constitutes an adaptation practice at climate change.

Methane mitigation and ruminal fermentation changes in cows fed cottonseed and vitamin E

Inherently, ruminant production of methane (CH4), a greenhouse gas (GHG), causes animal energy losses. Cottonseed is a lipid source and is used sometimes to enhance energy density in cattle diets. It also can mitigate enteric CH4. Lipids release peroxides in the rumen, and antioxidants have the ability to neutralize them. Thus, a lipid and antioxidant source can benefit rumen fermentation. The aim of this study was to evaluate rumen fermentation parameters from cows fed cottonseed and vitamin E. Six cannulated cows were arranged in a replicate 3 × 3 latin square. Treatments were: 1) Control, 2) CS (30 % corn replaced by cottonseed) and 3) CSVitE (30 % corn replaced by cottonseed, plus 500 IU VitE). Results were compared by orthogonal contrast. When compared to the control diet, cottonseed inclusion reduced enteric CH4 emissions by 42 %. Production of acetate, butyrate and the acetate to propionate ratio were respectively 34 %, 47 % and 36 % lower with the cottonseed treatments. Energy lost in the rumen as CH4 and energy release as butyrate were reduced by 26 % and 32 % respectively. Propionate and intestinal energy release were, respectively, 43 % and 35 % higher with cottonseed treatments. Furthermore, as a nutritional strategy to mitigate enteric CH4, cottonseed has positive effects on short chain fatty acid (SCFA) production and gastrointestinal energy release. Vitamin E did not result in improvements in ruminal fermentation. Further studies evaluating levels of vitamin E in association with different amounts and sources of lipids are required.

Methane mitigation and ruminal fermentation changes in cows fed cottonseed and vitamin E

Inherently, ruminant production of methane (CH4), a greenhouse gas (GHG), causes animal energy losses. Cottonseed is a lipid source and is used sometimes to enhance energy density in cattle diets. It also can mitigate enteric CH4. Lipids release peroxides in the rumen, and antioxidants have the ability to neutralize them. Thus, a lipid and antioxidant source can benefit rumen fermentation. The aim of this study was to evaluate rumen fermentation parameters from cows fed cottonseed and vitamin E. Six cannulated cows were arranged in a replicate 3 × 3 latin square. Treatments were: 1) Control, 2) CS (30 % corn replaced by cottonseed) and 3) CSVitE (30 % corn replaced by cottonseed, plus 500 IU VitE). Results were compared by orthogonal contrast. When compared to the control diet, cottonseed inclusion reduced enteric CH4 emissions by 42 %. Production of acetate, butyrate and the acetate to propionate ratio were respectively 34 %, 47 % and 36 % lower with the cottonseed treatments. Energy lost in the rumen as CH4 and energy release as butyrate were reduced by 26 % and 32 % respectively. Propionate and intestinal energy release were, respectively, 43 % and 35 % higher with cottonseed treatments. Furthermore, as a nutritional strategy to mitigate enteric CH4, cottonseed has positive effects on short chain fatty acid (SCFA) production and gastrointestinal energy release. Vitamin E did not result in improvements in ruminal fermentation. Further studies evaluating levels of vitamin E in association with different amounts and sources of lipids are required.(AU)

Biodiesel co-products modified the rumen parameters of feedlot lambs but did not change methane production in vitro

Background: Intensification of livestock is a strategy that increases productivity, but the diets used to increase animal production efficiency are composed mainly of corn and soybean, thereby increasing competition between animals and humansfor the same food crops. This study evaluated nutrient intake, apparent digestibility of dry matter (DM) and nutrients, kinetics of gas production, and concentration of volatile fatty acids on diets with or without inclusion of biodiesel co-productsformulated for feedlot lambs. So, the hypothesis is that replace of traditional ingredients by biodiesel co-products changesrumen parameters and methane emissions.Materials, Methods & Results: The experiment was developed in São Paulo State University (Unesp), Jaboticabal, SP,Brazil, in Sheep Production Laboratory, which is owned to Animal Science Department. All trials developed in this studyused a feedlot system, where animals were kept in individual pen. Forty Ile de France lambs male non-castrated wereused in in vivo trial. To obtain rumen fluid, that was used in in vitro trial, four Santa Inês lambs with rumen cannula wereused. The treatments evaluated were four diets: Control diet: roughage + concentrate; PM20: roughage + concentrate withpeanut meal (PM) at 20% of DM; CG25: roughage + concentrate with crude glycerin (CG) at 25% of DM; and PMCG:roughage + concentrate with PM at 10% of DM and CG at 12.5% of DM. The roughage:concentrate ratio was 40:60 for allthese diets. The parameters of the in vitro and in vivo experiments used were completely randomized with four treatments.When significant, the means between treatments were compared using Tukey test (P < 0.05). There was no effect of coproduct inclusion on intake, except ether extract and neutral detergent fiber, which were higher for PM20 compared withCG25 diet. Apparent digestibility of dry matter (79.87%) and some nutrients (organic matter, crude protein, and neutraldetergent fiber)...(AU)

Biodiesel co-products modified the rumen parameters of feedlot lambs but did not change methane production in vitro

Background: Intensification of livestock is a strategy that increases productivity, but the diets used to increase animal production efficiency are composed mainly of corn and soybean, thereby increasing competition between animals and humansfor the same food crops. This study evaluated nutrient intake, apparent digestibility of dry matter (DM) and nutrients, kinetics of gas production, and concentration of volatile fatty acids on diets with or without inclusion of biodiesel co-productsformulated for feedlot lambs. So, the hypothesis is that replace of traditional ingredients by biodiesel co-products changesrumen parameters and methane emissions.Materials, Methods & Results: The experiment was developed in São Paulo State University (Unesp), Jaboticabal, SP,Brazil, in Sheep Production Laboratory, which is owned to Animal Science Department. All trials developed in this studyused a feedlot system, where animals were kept in individual pen. Forty Ile de France lambs male non-castrated wereused in in vivo trial. To obtain rumen fluid, that was used in in vitro trial, four Santa Inês lambs with rumen cannula wereused. The treatments evaluated were four diets: Control diet: roughage + concentrate; PM20: roughage + concentrate withpeanut meal (PM) at 20% of DM; CG25: roughage + concentrate with crude glycerin (CG) at 25% of DM; and PMCG:roughage + concentrate with PM at 10% of DM and CG at 12.5% of DM. The roughage:concentrate ratio was 40:60 for allthese diets. The parameters of the in vitro and in vivo experiments used were completely randomized with four treatments.When significant, the means between treatments were compared using Tukey test (P < 0.05). There was no effect of coproduct inclusion on intake, except ether extract and neutral detergent fiber, which were higher for PM20 compared withCG25 diet. Apparent digestibility of dry matter (79.87%) and some nutrients (organic matter, crude protein, and neutraldetergent fiber)...

Energy efficiency and emissions of CO2, CH4, and N2O in organic and conventional rice production / Eficiência energética e emissões de CO2, CH4 e N2O em arroz sob cultivo orgânico e convencional

Rice is the second-most produced cereal worldwide and actively contributes to greenhouse gas (GHG) emissions, particularly methane, especially under deepwater production. Assessments of energy efficiency (EE) and GHG emissions can indicate the sustainability level of agrosystems and support decisions related to the reduction of production costs and environmental pollution. This study aimed to assess both EE and GHG emissions in organic and conventional rice production in the Southern region of Brazil. For this study, eight rice fields were evaluated. Energy inputs and outputs were calculated by multiplying the production input amounts by their respective calorific values or energy coefficients at each stage of production. EE was determined using the ratio between the total energy output and the total energy consumed during the production process. GHG emissions were estimated using the principles of the lifecycle assessment methodology in addition to the Intergovernmental Panel on Climate Change (IPCC) recommendations. Each 1.0 MJ consumed during the production of organic and conventional rice produced renewable energy averages of 10.5 MJ and 7.90 MJ, respectively, as grains. The primary energy expenses for organic rice were represented by seeds, fuel, tractors, and agricultural machinery and implements, and those for conventional rice were seeds, fuel, and fertilizers. Each kilogram of organic and conventional rice produced accounted for the emission of 0.21 and 0.32 kg of CO2eq, respectively, during the production cycles and delivery to the warehouse, with seeds, fuel, and fertilizers being the main sources of CO2eq emissions to the atmosphere.

O arroz é o segundo cereal mais cultivado no mundo e contribui ativamente nas emissões de GEE, principalmente em áreas produzidas sob inundação, com destaque para a produção de gás metano. A eficiência energética (EE) e as emissões de gases de efeito estufa (GEE) podem indicar o nível de sustentabilidade dos agrossistemas e a tomada de decisões relativas à redução dos custos de produção e poluição do ambiente. O objetivo deste trabalho foi avaliar a EE e emissões de GEE nas culturas do arroz sob cultivo orgânico e convencional na região sul do Brasil. Para isso, foram avaliadas oito áreas de arroz. As entradas e saídas de energia foram calculadas pela multiplicação da quantidade de produtos utilizados para a produção de arroz pelos seus respectivos poderes caloríficos ou coeficientes energéticos em cada etapa de produção. A EE foi obtida pela razão entre a quantidade de energia total de saída e o consumo total de energia durante o processo produtivo. Para estimar a emissão de GEE, foram aplicados princípios da metodologia de avaliação do ciclo de vida e recomendações do Painel Intergovernamental sobre Mudanças Climáticas (IPCC). Para cada 1,0 MJ de energia consumida na produção orgânica de arroz sob os sistemas orgânico e convencional, se produziram respectivamente em média, 10,5 MJ e 7,90 MJ de energia renovável, na forma de grãos. Os principais gastos energéticos no arroz orgânico foram com sementes, combustível, tratores, máquinas e implementos agrícolas e para o arroz convencional foram sementes, combustível e fertilizantes. Para cada 1 kg de grãos dos sistemas orgânicos e convencional são emitidos respectivamente 0,21 e 0,32 kg de CO2eq durante seus ciclos de produção e entrega no armazém, sendo as sementes, combustíveis e fertilizantes as principais fontes de emissão de CO2eq à atmosfera.

Energy efficiency and emissions of CO2, CH4, and N2O in organic and conventional rice production / Eficiência energética e emissões de CO2, CH4 e N2O em arroz sob cultivo orgânico e convencional

Rice is the second-most produced cereal worldwide and actively contributes to greenhouse gas (GHG) emissions, particularly methane, especially under deepwater production. Assessments of energy efficiency (EE) and GHG emissions can indicate the sustainability level of agrosystems and support decisions related to the reduction of production costs and environmental pollution. This study aimed to assess both EE and GHG emissions in organic and conventional rice production in the Southern region of Brazil. For this study, eight rice fields were evaluated. Energy inputs and outputs were calculated by multiplying the production input amounts by their respective calorific values or energy coefficients at each stage of production. EE was determined using the ratio between the total energy output and the total energy consumed during the production process. GHG emissions were estimated using the principles of the lifecycle assessment methodology in addition to the Intergovernmental Panel on Climate Change (IPCC) recommendations. Each 1.0 MJ consumed during the production of organic and conventional rice produced renewable energy averages of 10.5 MJ and 7.90 MJ, respectively, as grains. The primary energy expenses for organic rice were represented by seeds, fuel, tractors, and agricultural machinery and implements, and those for conventional rice were seeds, fuel, and fertilizers. Each kilogram of organic and conventional rice produced accounted for the emission of 0.21 and 0.32 kg of CO2eq, respectively, during the production cycles and delivery to the warehouse, with seeds, fuel, and fertilizers being the main sources of CO2eq emissions to the atmosphere.(AU)

O arroz é o segundo cereal mais cultivado no mundo e contribui ativamente nas emissões de GEE, principalmente em áreas produzidas sob inundação, com destaque para a produção de gás metano. A eficiência energética (EE) e as emissões de gases de efeito estufa (GEE) podem indicar o nível de sustentabilidade dos agrossistemas e a tomada de decisões relativas à redução dos custos de produção e poluição do ambiente. O objetivo deste trabalho foi avaliar a EE e emissões de GEE nas culturas do arroz sob cultivo orgânico e convencional na região sul do Brasil. Para isso, foram avaliadas oito áreas de arroz. As entradas e saídas de energia foram calculadas pela multiplicação da quantidade de produtos utilizados para a produção de arroz pelos seus respectivos poderes caloríficos ou coeficientes energéticos em cada etapa de produção. A EE foi obtida pela razão entre a quantidade de energia total de saída e o consumo total de energia durante o processo produtivo. Para estimar a emissão de GEE, foram aplicados princípios da metodologia de avaliação do ciclo de vida e recomendações do Painel Intergovernamental sobre Mudanças Climáticas (IPCC). Para cada 1,0 MJ de energia consumida na produção orgânica de arroz sob os sistemas orgânico e convencional, se produziram respectivamente em média, 10,5 MJ e 7,90 MJ de energia renovável, na forma de grãos. Os principais gastos energéticos no arroz orgânico foram com sementes, combustível, tratores, máquinas e implementos agrícolas e para o arroz convencional foram sementes, combustível e fertilizantes. Para cada 1 kg de grãos dos sistemas orgânicos e convencional são emitidos respectivamente 0,21 e 0,32 kg de CO2eq durante seus ciclos de produção e entrega no armazém, sendo as sementes, combustíveis e fertilizantes as principais fontes de emissão de CO2eq à atmosfera.(AU)

Effect of cashew nut shell liquid at varying inclusion levels on rumenfermentation and methane production in vitro

Essential oils are possible natural antibioticalternatives for manipulating ruminal fermentation in order to improve the utilization of nutrient in ruminants. This studyevaluated the effect of cashew nut shell liquid (CNSL) at varying inclusion levels on in vitro gas production, nutrient degradation, and post-incubation parameters. Experimentaldiets consisted of Panicum maximum (Ntchisi) grass as basal diet and supplemental pellets treated with 0, 5, 10 and 15 ml/kg of cashew nut shell liquid. Proximate composition ofexperimental diets was analysed. In vitro experiment was carried out on experimental diets (P. maximum and concentrate pellets at ratio 70:30) for 24 hours using goat rumen liquor as inoculum. Results showed that CNSLinclusion had a significant effect (P < 0.05) on the ether extract and metabolizable energy of experimental pellets. Dietary treatment with 15 ml/kg of CNSL had the lowest (P < 0.05) invitro gas production. Inclusion of CNSL significantly inhibited methane production at 5 ml/kg (18%), 10 ml/kg (34%) and 15 ml/kg (57%) CNSL inclusion levels (P < 0.05).Ammonia-N and TVFA decreased significantly with CNSL inclusion. Significant reduction (P < 0.05) in short-chain fatty acid, metabolizable energy, and organic matter degradabilitywere recorded with increasing CNSL inclusion levels.(AU)

Effect of cashew nut shell liquid at varying inclusion levels on rumenfermentation and methane production in vitro

Essential oils are possible natural antibioticalternatives for manipulating ruminal fermentation in order to improve the utilization of nutrient in ruminants. This studyevaluated the effect of cashew nut shell liquid (CNSL) at varying inclusion levels on in vitro gas production, nutrient degradation, and post-incubation parameters. Experimentaldiets consisted of Panicum maximum (Ntchisi) grass as basal diet and supplemental pellets treated with 0, 5, 10 and 15 ml/kg of cashew nut shell liquid. Proximate composition ofexperimental diets was analysed. In vitro experiment was carried out on experimental diets (P. maximum and concentrate pellets at ratio 70:30) for 24 hours using goat rumen liquor as inoculum. Results showed that CNSLinclusion had a significant effect (P < 0.05) on the ether extract and metabolizable energy of experimental pellets. Dietary treatment with 15 ml/kg of CNSL had the lowest (P < 0.05) invitro gas production. Inclusion of CNSL significantly inhibited methane production at 5 ml/kg (18%), 10 ml/kg (34%) and 15 ml/kg (57%) CNSL inclusion levels (P < 0.05).Ammonia-N and TVFA decreased significantly with CNSL inclusion. Significant reduction (P < 0.05) in short-chain fatty acid, metabolizable energy, and organic matter degradabilitywere recorded with increasing CNSL inclusion levels.

Methane emission from a flooded rice field under pre-germinated system

Local greenhouse gas flow measurement studies have been encouraged at a global level as a subsidy for national and state inventories. This study aimed to evaluate the seasonal methane emission during the 2008/2009 harvest, from an irrigated rice plantation, under pre-germinated system, in the municipality of Tremembé, State of São Paulo, using the static chamber technique and gas chromatography. The study showed high seasonal emission of methane (CH4) for the studied area, probably due to the long flooding period. It was estimated the CH4 emission factor (6.2 kg CH4 ha-1 dia-1), the partial global warming potential (pGWP, 26.2 Mg CO2eq growing season-1 ha-1) and the yield-scaled pGWP (YpGWP, 3.9 kg CO2eq kg grain).(AU)

Estudos locais de mensuração de fluxos de gases de efeito estufa em sistemas agrícolas têm sido incentivados a nível global como base para subsidiar estimativas nacionais e estaduais de emissão. Este estudo objetivou quantificar a emissão sazonal de metano (CH4) em cultivo de arroz irrigado, sob sistema pré-germinado, no município de Tremembé, Estado de São Paulo, na safra de 2008/2009, utilizando o método de câmara estática e cromatografia gasosa. O estudo mostrou elevada emissão sazonal de CH4 para a área estudada, em função, provavelmente do longo período de inundação. Foi estimado o fator de emissão de CH4 (6,2 kg CH4 ha-1 dia-1), o potencial de aquecimento global parcial (PAGp, 26,2 Mg CO2eq estação de crescimento-1 ha-1) e o PAGp escalonado pelo rendimento (R) de grãos (PAGpR, 3,9 kg CO2eq kg-1 grão).(AU)

Development and evaluation of prediction equations for methane emission from Nellore cattle

Dry matter intake (DMI), nutrient intake and enteric CH4 emission were evaluated in 48 Nellore cattle (392 ± 27 days of age). Equations were generated from intake data and evaluated using root mean square prediction error (RMSPE), and validated by cross-validation. Equations that included DMI and hemicellulose intake (HEMI) [ CH4(MJd−1)=4.08(±1.65)+11.6(±2.34)DMI(kgd−1)−33.4(±7.21)HEMI(kgd−1)] ; DMI and total carbohydrate intake (TCHI) [CH4(MJd−1)=5.26(±1.69)−6.3(±1.47)DMI(kgd−1)+8.8(±1.81)TCI(kgd−1)]; metabolizable energy intake (MEI) and cellulose intake (CELI) [CH4(MJd−1)=5.16(±1.72)−0.13(±0.048)MEI(MJd−1)+7.37(±1.53)CELI(kgd−1)] , and non-fiber carbohydrate intake (NFCI) [CH4(MJd−1)=3.14(±1.48)+3.65(±1.05)NFCI(kgd−1)] resulted in the lowest RMSPE (14.3, 14.1, 14.3 and 14.7%, respectively). When literature equations were evaluated using our database, the most accurate predictions were obtained with equations that included DMI and lignin intake (RMSPE = 15.27%) and MEI, acid detergent fiber intake and lignin intake (RMSPE = 15.7%). The mean error of predicting enteric CH4 emission with the equations developed in this study based on DMI and nutrient intake is 17% and the most accurate predictions are obtained with equations including DMI, carbohydrate intake and MEI.(AU)