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.

Applying assisted reproductive technology and reproductive management to reduce CO2-equivalent emission in dairy and beef cattle: a review

Methane emission from beef and dairy cattle combined contributes around 4.5-5.0% of total anthropogenic global methane. In addition to enteric methane (CH4) produced by the rumen, cattle production also contributes carbon dioxide (CO2) (feed), nitrous oxide (N2O) (feed production, manure) and other CH4 (manure) to the total greenhouse gas (GHG) budget of beef and dairy production systems. The relative contribution in standard dairy systems is typically enteric CH4 58%, feed 29% and manure 10%. Herds with low production efficiency can have an enteric CH4 contribution up to 90%. Digestibility of feed can impact CH4 emission intensity. Low fertility herds also have a greater enteric CH4 contribution. Animals with good feed conversion efficiency have a lower emission intensity of CH4/kg of meat or milk. Feed efficient heifers tend to be lean and have delayed puberty. Fertility is a major driver of profit in both beef and dairy cattle, and it is highly important to apply multi-trait selection when shifting herds towards improved efficiency and reduced CH4. Single nucleotide polymorphisms (SNPs) have been identified for feed efficiency in cattle and are used in genomic selection. SNPs can be utilized in artificial insemination and embryo transfer to increase the proportion of cattle that have the attributes of efficiency, fertility and reduced enteric CH4. Prepubertal heifers genomically selected for favourable traits can have oocytes recovered to produce IVF embryos. Reproductive technology is predicted to be increasingly adopted to reduce generation interval and accelerate the rate of genetic gain for efficiency, fertility and low CH4 in cattle. The relatively high contribution of cattle to anthropogenic global methane has focussed attention on strategies to reduce enteric CH4 without compromising efficiency and fertility. Assisted reproductive technology has an important role in achieving the goal of multiplying and distributing cattle that have good efficiency, fertility and low CH4.(AU)

Association of additives in supplemented grazing cattle during the finishing phase at the rainy season

The objectives were to evaluate the effects of monensin and virginiamycin, alone or combined, on supplemented Nellore cattle grazing tropical grass during the rainy season. Two experiments were conducted simultaneously to evaluate intake, digestibility, CH4 emissions, blood parameters, performance, and carcass characteristics (Exp. 1), and ruminal fermentation and relative abundance of ruminal microorganisms (Exp. 2). Animals (n = 92 Exp. 1 and n = 12 Exp. 2) were distributed in a completely randomized design and allocated in twelve paddocks composed of Urochloa brizantha (A. Rich.) Stapf. cv. Xaraés. A protein-energetic supplementation of 3 g/kg of BW per day was provided to all animals. Supplements were: without additives (WA), monensin alone at 80 mg/kg of product (MN), virginiamycin alone at 150 mg/kg of product (VM), and monensin (80 mg/kg of product) combined with virginiamycin (150 mg/kg of product; MNVM). Treatments did not affect intakes of total dry matter (DM), supplement DM, and nutrients. However, the intakes of forage DM and crude protein decreased in cattle fed MNVM compared with animals fed WA, MN, and VM. Total volatile fatty acids increased in animals fed VM. Ruminal NH3-N decreased, and pH increased in animals fed MN, VM, and MNVM. Relative abundance of total F. succinogenes and S. ruminantium decreased and R. flavefaciens increased in animals fed MN and VM at d 118. Treatments had no effect on enteric CH4 emissions. The average daily gain (ADG) and total gain were greater in cattle fed MNVM than in cattle fed MN. Combination of monensin and virginiamycin altered the rumen microbial populations but did not decrease enteric CH4 emissions. However, it decreased forage dry matter intake without altering the ADG and total weight gain, leading to an increase in feed efficiency. Results from this study indicate an advantage in including feed additives combined in the diet of supplemented Nellore cattle grazing tropical grass during the rainy season.

Dimethyl acetamide and dimethyl sulfoxide associated at glucose and egg yolk for cryopreservation of Pseudoplatystoma corruscans semen

This study aimed to develop a protocol for the cryopreservation of Pseudoplatystoma corruscans semen. For this, mature males were hormonally induced with a single dose of carp pituitary extract (5 mg/kg body weight). Semen was collected and evaluated. Two cryoprotectants were tested to compose the diluents: dimethyl acetamide (DMA) and dimethyl sulfoxide (Me2SO), in two concentrations (8% and 10%), + 5.0% glucose + 10% egg yolk. The semen was diluted in a 1: 4 ratio (semen: extender), packed in 0.5 mL straws and frozen in a dry shipper container in liquid nitrogen vapors. After thawing, sperm kinetics, sperm morphology and DNA integrity of cryopreserved sperm were evaluated. Pseudoplatystoma corruscans males produced semen with sperm motility > 80%. After thawing, all treatments provided semen with total sperm motility > 40%, with no significant difference (P < 0.05) between them, as well as between the other sperm kinetic parameters evaluated. The treatments with DMA provided a smaller fragmentation of the DNA of the gametes. Sperm malformations were identified in both fresh and cryopreserved semen, with a slight increase in these malformations being identified in sperm from thawed P. corruscans semen samples.(AU)

Este estudo teve como objetivo desenvolver um protocolo para a criopreservação do sêmen de Pseudoplatystoma corruscans. Para tal, machos maduros foram induzidos hormonalmente com uma dose única de extrato de hipófise de carpa (5 mg/kg de peso vivo). O sêmen foi coletado e avaliado. Sendo testados para compor os diluentes, dois crioprotetores: dimetil acetamida (DMA) e dimetil sulfóxido (Me2SO), em duas concentrações (8% e 10%), + 5,0% glicose + 10% gema de ovo. O sêmen foi diluído na proporção 1: 4 (sêmen: extensor), embalado em palhetas de 0,5 mL e congelado em container dryshipper em vapores de nitrogênio líquido. Após o descongelamento, foram avaliados os aspectos cinéticos espermáticos, a morfologia espermática e a integridade do DNA dos espermatozoides criopreservados. Os machos de P. corruscans produziram sêmen com motilidade espermática > 80%. Todos os tratamentos proporcionaram após o descongelamento sêmen com motilidade espermática total > 40%, sem diferença significativa (P < 0,05) entre eles, como também entre os demais parâmetros cinéticos espermáticos avaliados. Os tratamentos com DMA proporcionaram uma menor fragmentação do DNA dos gametas. Malformações espermáticas foram identificadas, tanto no sêmen fresco, como no criopreservado, sendo identificado um aumento discreto dessas malformações nos espermatozoides das amostras de sêmen descongeladas de P. corruscans.(AU)

Cryopreservation of jaguar (Panthera onca) sperm cells using different cryoprotectants and different thawing temperatures

The cryopreservation of jaguar semen must be improved to produce high-quality biobanking doses. Until now, the rare studies of semen freezing in the species have only evaluated glycerol, always with a significant reduction in sperm quality in thawed semen. The purpose of this study was to assess the efficacy of three cryoprotectants, dimethylsulfoxide (DMSO), glycerol (GLY), and methanol (MET), in the cryopreservation of jaguar semen in an LDL-based extender, as well as the effect of thawing temperature on dosage quality. Five mature males with a history of reproduction were used. On the males, an infrared thermal image (IRT) was captured, the spicules and testes were analyzed, and the CASA system was used to evaluate the quality of fresh and thawed sperm. The superficial IRT was 4.6 ± 1.2 °C cooler than the anal sphincter, and the semen measured between 27.3 and 28.7 °C shortly after exiting the urethra. The total motility of fresh sperm was 55.3 ± 22.6%, and progressive motility was 36.3 ± 18%. The total motility of thawed sperm was 5.28 ± 2.51%, 4.49 ± %2.49, and 0.51 ± 0.62% for DMSO, GLY, and MET, respectively. DMSO and GLY performed better than MET, and there was no difference in thawing temperature (37°C 30 s vs. 50°C 12 s). All animals exhibit a considerable level of morphological changes in sperm. Low amounts of total and progressive motility were found in the thawed sperm. Males with a high level of sperm morphological changes were found to be fertile, but the lone male with normospermia was infertile. Thus, we contest the applicability of the commonly used morphological classification for bovines to felid species.(AU)

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.

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.

Benzocaine and eugenol as anesthetics for pangasius juveniles, Pangasianodon hypophthalmus

The aim of this study was to evaluate the effect and efficacy of different concentrations of eugenol and benzocaine for pangasius juveniles (Pangasianodon hypophthalmus) and determine the anesthetic and concentration most appropriate for carrying out routine fish farming practices for this species. One hundred juveniles with an average weight of 32.10 ± 4.9 g and an average total length of 15.32 ± 0.57 cm were used. Four concentrations of both anesthetics were evaluated: 0, 25, 50, 75 and 100 mg/L, with four induction time stages and three recovery stages. During the time that the fish remained anesthetized, biometric procedures were performed. Then, they were transferred to a 10-liter aquarium containing clean water, without adding the anesthetic to observe the recovery time. After recovery, the animals were kept in aquariums for 72 hours to check for mortality. Eugenol, at all concentrations evaluated, and benzocaine, at a concentration of 25 mg/L, were not effective in sedating juveniles of pangasius. Benzocaine concentrations of 75 and 100 mg/L were effective for anesthesia and recovery of fish within the time span of five and seven minutes. However, considering animal welfare, the use of a concentration of 100 mg/L is recommended, as it resulted in shorter latency and recovery times.

O objetivo deste trabalho foi avaliar o efeito e a eficácia de diferentes concentrações de benzocaína e eugenol em juvenis de pangasius (Pangasianodon hypophthalmus) para determinar o anestésico mais eficiente e a concentração mais adequada para realização das práticas rotineiras em piscicultura para esta espécie. Foram utilizados 100 juvenis, com peso médio de 32,10 ± 4,9 g e comprimento total médio de 15,32 ± 0,57 cm. Foram avaliadas quatro concentrações para ambos os anestésicos: 0, 25, 50, 75 e 100 mg/L, sendo observados quatro estágios de tempo de indução e três estágios de recuperação. Durante o tempo em que os peixes permaneceram anestesiados, foram realizados os procedimentos de biometria. Em seguida, os animais foram transferidos para um aquário de 10 L contendo água limpa, sem adição do anestésico, para observar o tempo de recuperação. Após a recuperação, os animais foram mantidos nos aquários por 72 horas para verificação da mortalidade. O eugenol, em todas as concentrações avaliadas, e a benzocaína, na concentração de 25 mg/L, não foram eficazes na sedação de juvenis de pangasius. As concentrações de benzocaína de 75 e 100 mg/L foram eficientes para anestesia e recuperação dos peixes considerando a faixa de tempo pré-estabelecida de cinco e sete minutos, respectivamente. Entretanto, considerando o bem-estar animal, recomenda-se o uso da concentração de 100 mg/L, uma vez que resultou em menor tempo de latência e recuperação.

Evaluation of in vitro energy distribution and methanogenic potential of two forages with the addition of condensed tannins

The objective of this work was to analyze the effect of the addition of condensed tannins (CT) in the efficiency of digestion, methanogenic potential and energy distribution between the fermentation products of two forages. An assay was carried out using the in vitrogas production technique in which extracts of Quebracho (Schinopsis balansae) and Lotus corniculatuswere evaluated with fermentation patterns of derived products from Ryegrass (RG, Lolium perenne) and a tropical forage, Megathyrsus maximus(MM). Tannins were added to the substrate at a concentration of 30 mg g-1. MM presented higher and delayed gas production (GP), and in vitrodry matter, organic matter and fiber digestibilities (ivDMD, ivOMDand NDFD, respectively) were relatively high but lower than RG. In addition, MM presented higher CH4production (CH4p) than RG in 24 and 48h. Even though CT of Quebracho induced a decrease in the NDFD, contrary to what was expected, CH4p was greater, although this effect could not be attributed to the presence of CT. The stoichiometric evaluation indicated that while the highest CH4p in Quebracho treatments were associated with acetogenic profiles, CH4p with Lotus did not show any relationship with the volatile fatty acids (VFA) profile, but it did show a relationship with the highest total VFA production and the highest GP.(AU)

Perspectives of gene editing for cattle farming in tropical and subtropical regions

Cattle productivity in tropical and subtropical regions can be severely affected by the environment. Reproductive performance, milk and meat production are compromised by the heat stress imposed by the elevated temperature and humidity. The resulting low productivity contributes to reduce the farmer's income and to increase the methane emissions per unit of animal protein produced and the pressure on land usage. The introduction of highly productive European cattle breeds as well as crossbreeding with local breeds have been adopted as strategies to increase productivity but the positive effects have been limited by the low adaptation of European animals to hot climates and by the reduction of the heterosis effect in the following generations. Gene editing tools allow precise modifications in the animal genome and can be an ally to the cattle industry in tropical and subtropical regions. Alleles associated with production or heat tolerance can be shifted between breeds without the need of crossbreeding. Alongside assisted reproductive biotechnologies and genome selection, gene editing can accelerate the genetic gain of indigenous breeds such as zebu cattle. This review focuses on some of the potential applications of gene editing for cattle farming in tropical and subtropical regions, bringing aspects related to heat stress, milk yield, bull reproduction and methane emissions.(AU)

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.

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.

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.

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)

Energy value of babassu cake as substitute bulk in sheep diets / Valor energético da torta de babaçu em substituição ao volumoso na alimentação de ovinos

The aim of this study was to evaluate the energy value of diets containing babassu cake as a replacement for Tifton-85 hay (70, 140, 210, 280 and 350 g kg-¹ dry matter, DM), using the technique of indirect calorimetry. Twenty-five castrated male Santa Inês sheep, with an average body weight of 49.6 + 9.4 kg, were used in a completely randomised design. The trial was carried out in an individual open-flow respirometry chamber for small ruminants, with each animal remaining for 24 hours inside the chamber. Gross energy and net energy intake were not affected by adding the cake. Digestible energy intake and metabolisable energy intake showed a linear response, ranging from 145.44 to 178.40 and from 121.85 to 158.08 kcal kg-0.75 day-¹ respectively. The energy lost through faeces and methane (% of gross energy intake, GEI) showed decreasing linear behaviour, while the caloric increase, in %GEI, showed a quadratic response. The values for digestible energy and metabolisability presented an increasing linear response. The partial efficiency of use of metabolisable energy for maintenance ranged from 0.71 to 0.81, and showed a quadratic response; however, the net energy values did not differ. For every 10 g of added by-product, there was a reduction of 0.31 g of methane per kg of DM intake. The addition of babassu cake to replace up to 350 g kg-¹ DM in sheep diets increases the energy efficiency of the diet and reduces methane emission by the animals.

Objetivou-se avaliar o valor energético de rações contendo torta de babaçu em substituição ao feno de Tifton-85 (70; 140; 210; 280 e 350 g kg-¹ de matéria seca, MS), pela técnica da calorimetria indireta. Foram utilizados 25 ovinos da raça Santa Inês, machos castrados, com peso corporal médio de 49,6 + 9,4 kg, em delineamento inteiramente casualizado. O ensaio experimental foi realizado em câmara respirométrica individual de fluxo aberto para pequenos ruminantes, permanecendo cada animal por período de 24 horas no interior da câmara. Os consumos de energia bruta e energia líquida não foram influenciados pela inclusão da torta. Os consumos de energia digestível e energia metabolizável apresentaram resposta linear, variando de 145,44 a 178,40 e de 121,85 a 158,08 kcal kg-0,75 por dia, respectivamente. As perdas de energia pelas fezes e pelo metano (% do consumo da energia bruta, CEB) apresentaram comportamento linear decrescente, enquanto o incremento calórico, em %CEB, apresentou resposta quadrática. Os valores de energia digestível e metabolizabilidade apresentaram respostas lineares crescentes. A eficiência parcial de uso da energia metabolizável para mantença variou entre 0,71 a 0,81, com resposta quadrática, porém os valores de energia líquida não diferiram. Para cada 10 g de inclusão de subproduto, houve redução de 0,31 g de metano por kg de MS consumida. A inclusão de torta de babaçu, em substituição ao volumoso, na ração de ovinos, em até 350 g kg-¹ MS, aumenta a eficiência energética da ração e reduz a emissão de metano pelos animais.

Energy value of babassu cake as substitute bulk in sheep diets / Valor energético da torta de babaçu em substituição ao volumoso na alimentação de ovinos

The aim of this study was to evaluate the energy value of diets containing babassu cake as a replacement for Tifton-85 hay (70, 140, 210, 280 and 350 g kg-¹ dry matter, DM), using the technique of indirect calorimetry. Twenty-five castrated male Santa Inês sheep, with an average body weight of 49.6 + 9.4 kg, were used in a completely randomised design. The trial was carried out in an individual open-flow respirometry chamber for small ruminants, with each animal remaining for 24 hours inside the chamber. Gross energy and net energy intake were not affected by adding the cake. Digestible energy intake and metabolisable energy intake showed a linear response, ranging from 145.44 to 178.40 and from 121.85 to 158.08 kcal kg-0.75 day-¹ respectively. The energy lost through faeces and methane (% of gross energy intake, GEI) showed decreasing linear behaviour, while the caloric increase, in %GEI, showed a quadratic response. The values for digestible energy and metabolisability presented an increasing linear response. The partial efficiency of use of metabolisable energy for maintenance ranged from 0.71 to 0.81, and showed a quadratic response; however, the net energy values did not differ. For every 10 g of added by-product, there was a reduction of 0.31 g of methane per kg of DM intake. The addition of babassu cake to replace up to 350 g kg-¹ DM in sheep diets increases the energy efficiency of the diet and reduces methane emission by the animals.(AU)

Objetivou-se avaliar o valor energético de rações contendo torta de babaçu em substituição ao feno de Tifton-85 (70; 140; 210; 280 e 350 g kg-¹ de matéria seca, MS), pela técnica da calorimetria indireta. Foram utilizados 25 ovinos da raça Santa Inês, machos castrados, com peso corporal médio de 49,6 + 9,4 kg, em delineamento inteiramente casualizado. O ensaio experimental foi realizado em câmara respirométrica individual de fluxo aberto para pequenos ruminantes, permanecendo cada animal por período de 24 horas no interior da câmara. Os consumos de energia bruta e energia líquida não foram influenciados pela inclusão da torta. Os consumos de energia digestível e energia metabolizável apresentaram resposta linear, variando de 145,44 a 178,40 e de 121,85 a 158,08 kcal kg-0,75 por dia, respectivamente. As perdas de energia pelas fezes e pelo metano (% do consumo da energia bruta, CEB) apresentaram comportamento linear decrescente, enquanto o incremento calórico, em %CEB, apresentou resposta quadrática. Os valores de energia digestível e metabolizabilidade apresentaram respostas lineares crescentes. A eficiência parcial de uso da energia metabolizável para mantença variou entre 0,71 a 0,81, com resposta quadrática, porém os valores de energia líquida não diferiram. Para cada 10 g de inclusão de subproduto, houve redução de 0,31 g de metano por kg de MS consumida. A inclusão de torta de babaçu, em substituição ao volumoso, na ração de ovinos, em até 350 g kg-¹ MS, aumenta a eficiência energética da ração e reduz a emissão de metano pelos animais.(AU)

Effect of cryoprotectant on the motility, viability, fertilization, and DNA integrity of naleh fish Barbonymus sp. (Cyprinidae) sperm / Efeito do crioprotetor na motilidade, viabilidade, fertilização e integridade do DNA no sêmen de peixes naleh Barbonymus sp. (Cyprinidae)

Naleh fish Barbonymus sp. is a commercial freshwater fish, which is indigenous to Aceh, Indonesia. The population of this species has declined over the years as a result of habitat perturbations and overfishing. Hence, the crucial need to develop a cryopreservation method to support breeding programs. This involved the use of a cryoprotectant as an important component. The objective of this study, therefore, was to explore the best cryoprotectant for naleh fish spermatozoa, and a total of five types were tested. These include the DMSO, Methanol, Ethanol, Glycerol, and Ethylene Glycol at a similar concentration of 10%, which were individually combined with 15% egg yolk, and every treatment was performed in three replications. Conversely, Ringer's solution was adopted as an extender, and the sperm was cryopreserved in liquid nitrogen for 15 days. The results showed significant influence on sperm motility and viability, as well as egg fertility of naleh fish (P <0.05), although the DMSO provided the best outcome, compared to others at 47.17%, 50.13%, and 45.67%, respectively. Furthermore, DNA fragmentation had not occurred in the fresh and cryopreserved sperm samples, indicating the protective effect of tested cryoprotectants. It is concluded that the 10% DMSO and 15% egg yolk is the best cryoprotectant for naleh fish spermatozoa.(AU)

O peixe naleh Barbonymus sp. é um peixe comercial de água doce, originário de Aceh, Indonésia. Durante vários anos, as perturbações provocadas no seu habitat e a pesca predatória determinaram o declínio da sua população, cuja preservação deve apoiar-se em um programa de reprodução controlada, com o emprego de espermatozoides criopreservados. O presente trabalho realizou um estudo comparativo de cinco crioprotetores: dimetilsultóxido, metanol, etanol, glicerol e etileno glicol. Todos os crioprotetores foram testados na concentração de 10%, combinados a 15% de gema de ovo. Cada tratamento foi efetuado em triplicatas. A solução de ringer foi utilizada como extensor e o esperma foi criopreservado em nitrogênio líquido por 15 dias. Os resultados obtidos revelaram a existência de influência significante (P<0,05) na viabilidade e motilidade espermática bem como na fertilidade dos ovos do peixe naleh, em que o dimetilsulfóxido apresentou o melhor resultado com os valores de 47,17%, 50,13% e 45,67%, respectivamente. Por outro lado, a fragmentação do DNA não ocorreu nas amostras de esperma fresco e criopreservado, indicando o efeito protetor dos crioprotetores testados. A conclusão obtida foi que o dimetilsulfóxido e 15% de gema de ovo foram o melhor crioprotetor para os espermatozoides do peixe naleh.(AU)