Canine sperm vitrification with nonpermeable cryoprotectants and coconut water extender

This study was aimed to assess the efficiency of coconut water extender with addition of soy lecithin and sucrose as nonpermeable cryoprotectants for canine semen vitrification, using a simple method that yields a high survival rate of spermatozoa for clinical use. Twelve ejaculates from 12 adult normozoospermic dogs were collected separately by digital manipulation and only the second semen fraction was used in this study. After evaluation of volume, concentration, viability, total and progressive motility, velocity parameters and morphology, semen was diluted with a coconut water extender (50% (v/v(volume per volume)) coconut water, 25% (v/v) distilled water and 25% (v/v) 5% anhydrous monosodium citrate solution) with addition of soy lecithin and fructose at 1% and 0.25M sucrose until final concentration of 100x106 spermatozoa/ml. After equilibration at 5ºC for 60 minutes, semen was vitrified by "direct dropping method" into liquid nitrogen in spheres with a volume of 30 µl. After a week of storage the spheres were devitrified as three of them were dropped into 0.5 mL of CaniPlus AI medium (Minitüb, Germany), which was previously warmed in a water bath at 42ºC for 2 minutes and evaluated about the above mentioned parameters. It was found that vitrification resulted in a lower percentage of viable sperms, normal morphology, total and progressive motilities (p0.05) compared to fresh semen samples. In conclusion, our results demonstrate that vitrification with coconut water extender with addition of 1% soy lecithin and 0.25M sucrose as cryoprotectants, has an excellent potential for routine canine sperm cryopreservation.(AU)

Effect of emulsifier addition on metabolizable energy reduction in broiler diets / Adição de emulsificante nas rações de frangos de corte com redução dos níveis de energia metabolizável

This study aimed to evaluate the effect of including soy lecithin emulsifier (SL) in broiler diets with reduced metabolizable energy levels and to correlate it with nutrient metabolizability coefficients, as well as to determine apparent metabolizable energy (AME). Two metabolic trials were conducted in a completely randomized design with a 3x2 factorial arrangement (diet with three levels of metabolizable energy, with or without the inclusion of emulsifier), totaling six treatments. In the starter phase, chicks received diets with 2,950, 3,050, and 3,150 kcal/kg of metabolizable energy, with six replications of 10 birds each, totaling 360 birds. In the grower phase, the energy levels of 3,100, 3,150, and 3,200 kcal/kg of feed were tested in 210 birds were used in seven replications of five chicks each. An interaction effect was observed in the starter phase, with the nitrogen metabolizability coefficient increasing when the emulsifier was added to diets with reduced energy. Additionally, emulsifier inclusion increased nitrogen-corrected AME (AMEn). An interaction effect was also present in the grower phase, with AME and AMEn increasing when the emulsifier was added to diets with lower energy levels. In summary, emulsifier inclusion in broiler diets can reduce metabolizable energy while improving AMEn in both the starter and grower phases, as well as AME in growing broilers.

Objetivou-se avaliar a adição do emulsificante, lecitina de soja, nas rações de frangos com redução dos níveis de energia metabolizável e correlacioná-las com os coeficientes de metabolizabilidade de nutrientes, além da determinação da energia metabolizável aparente (EMA). Realizou-se dois ensaios metabólicos em delineamento inteiramente casualizados, esquema fatorial 3x2 (ração com três níveis de energia metabolizável, com ou sem a inclusão do emulsificante na dieta), totalizando seis tratamentos. Na fase inicial, os pintos receberam dieta com 2.950, 3.050 e 3.150 kcal/kg de energia metabolizável, com seis repetições com 10 aves, totalizando 360 aves. Na fase de crescimento foram utilizadas 210 aves, sendo sete repetições com cinco frangos e os níveis de energia testados foram: 3.100, 3.150 e 3.200 kcal/kg de ração. Na fase inicial, observou-se efeito de interação, apresentando aumento do coeficiente de metabolizabilidade do nitrogênio (CMN) ao adicionar o emulsificante em dietas com energia reduzida e também, efeito do emulsificante no aumento da energia metabolizável aparente corrigida pelo balanço do nitrogênio (EMAn). Na fase de crescimento, observou-se efeito de interação, apresentando aumento da EMA e EMAn ao adicionar o emulsificante em dietas com menores níveis de energia. Conclui-se que a inclusão do emulsificante é indicada para frangos de corte, pois permite reduzir a energia metabolizável da dieta, melhorando a EMAn nas fases inicial e de crescimento, bem como a da EMA com frangos em crescimento.

Sperm cryopreservation of Prochilodus brevis using different concentrations of non-permeable cryoprotectants

Abstract The action of substances with non-permeable cryoprotectant potential, besides glucose, has not yet been studied for the species Prochilodus brevis. The objective of this work was to evaluate the action of four non-permeable cryoprotectants on this species sperm cryopreservation. Five pools were cryopreserved in a solution of 5% glucose and 10% dimethyl sulfoxide (Me2SO) associated or not (control) with cryoprotectants egg yolk (5, 10 or 12%), soy lecithin (2.5, 7.5 or 10%), sucrose (5, 10 or 20%) and lactose (5, 8 or 15%). After thawing, samples were evaluated for sperm kinetics (total motility, motility duration, velocities, and wobble - WOB), morphology and membrane and DNA integrity. The treatments containing egg yolk improved significantly (P<0.05) results when compared the control for the membrane integrity parameter. When compared to other treatments, egg yolk, at any concentration, presented higher results (P<0.05) for membrane integrity, total motility, curvilinear velocity (VCL) and average path velocity (VAP) parameters. Egg yolk also showed the best results for WOB, but it did not differ from 5% and 8% lactose and 5% and 20% sucrose. Soy lecithin had the lowest percentages of morphologically normal sperm (P<0.05), while the other treatments did not differ from each other. There was no difference regarding DNA integrity data. Thus, 5% egg yolk is indicated as a non-permeable cryoprotectant for P. brevis, in association with 5% glucose and 10% Me2SO.

Sperm cryopreservation of Prochilodus brevis using different concentrations of non-permeable cryoprotectants

The action of substances with non-permeable cryoprotectant potential, besides glucose, has not yet been studied for the species Prochilodus brevis. The objective of this work was to evaluate the action of four non-permeable cryoprotectants on this species sperm cryopreservation. Five pools were cryopreserved in a solution of 5% glucose and 10% dimethyl sulfoxide (Me2SO) associated or not (control) with cryoprotectants egg yolk (5, 10 or 12%), soy lecithin (2.5, 7.5 or 10%), sucrose (5, 10 or 20%) and lactose (5, 8 or 15%). After thawing, samples were evaluated for sperm kinetics (total motility, motility duration, velocities, and wobble - WOB), morphology and membrane and DNA integrity. The treatments containing egg yolk improved significantly (P<0.05) results when compared the control for the membrane integrity parameter. When compared to other treatments, egg yolk, at any concentration, presented higher results (P<0.05) for membrane integrity, total motility, curvilinear velocity (VCL) and average path velocity (VAP) parameters. Egg yolk also showed the best results for WOB, but it did not differ from 5% and 8% lactose and 5% and 20% sucrose. Soy lecithin had the lowest percentages of morphologically normal sperm (P<0.05), while the other treatments did not differ from each other. There was no difference regarding DNA integrity data. Thus, 5% egg yolk is indicated as a non-permeable cryoprotectant for P. brevis, in association with 5% glucose and 10% Me2SO.(AU)

Equine semen cooled with chemically defined extender containing soy lecithin / Sêmen equino refrigerado com diluidor quimicamente definido contendo lecitina de soja

Equine semen has historically been chilled using milk-based media. However, the use of animal-based components presents several potential concerns, such as variability in formulations, microbial contamination and regulatory issues. We aimed to evaluate the potential of including different concentrations of soy lecithin (LS) in chemically defined Biggers, Whitten and Whittingham (BWW) medium for cooling equine semen to 15°C. Ejaculates were diluted as six different experimental groups: 1) BotuSêmen® (control); 2) BWW; 3) BWW + 1% LS; 4) BWW + 2% LS; 5) BWW + 4% LS and 6) BWW + 6% LS. BWW medium, did not preserve motility, velocity, straightness (STR), linearity (LIN), amplitude of lateral sperm head displacement (ALH), cross flagellar beat frequency (BCF), functional and structural integrity of equine spermatozoa during 24 h of refrigeration when compared to BotuSêmen® (P <0.05). The use of BWW for cooling equine semen was only possible with the addition of LS, being the concentrations equal or higher than 2% better, because they preserved total motility, curvilinear velocity (VCL) and LIN with the same potential of BotuSêmen® (P >0.05). Nevertheless, BotuSêmen® showed superiority in preserving the percentage of sperm progressive motility, average path velocity (VAP), linear progressive velocity (VSL) and BCF during cooling compared to the other extenders (P <0.05). The inclusion of soy lecithin, from 2 to 6% in the BWW medium, allowed maintaining the viability of equine semen cooled at 15ºC for up to 24 hours.

O sêmen equino tem sido historicamente refrigerado usando meios à base de leite. No entanto, o uso de componentes de origem animal causa várias preocupações potenciais, como variabilidade nas formulações, contaminação microbiana e questões regulatórias. Objetivou-se avaliar o potencial de inclusão de diferentes concentrações de lecitina de soja (LS) no meio quimicamente definido BWW - Biggers, Whitten e Whittingham para refrigeração de sêmen equino e armazenamento na temperatura de 15°C. Os ejaculados foram diluídos em seis diferentes grupos experimentais: 1) BotuSêmen® (controle); 2) BWW; 3) BWW + 1% lecitina de soja (LS); 4) BWW + 2% LS; 5) BWW + 4% LS e 6) BWW + 6% LS. O meio BWW, não preservou a motilidade, a velocidade, a retilinearidade (STR), a linearidade (LIN), a amplitude do deslocamento lateral da cabeça (ALH), a frequência de batimento flagelar cruzado (BCF), a integridade funcional e estrutural dos espermatozoides equino durante 24 h de refrigeração quando comparado ao BotuSêmen® (P <0,05). O uso de BWW para refrigeração de sêmen equino só foi possível com adição de lecitina de soja, sendo as concentrações igual ou superior a 2% melhores, pois preservaram a motilidade total, a velocidade curvilinear (VCL) e LIN com mesmo potencial do BotuSêmen® (P >0,05). Ainda assim, o diluidor comercial BotuSêmen® apresentou superioridade em preservar o percentual de espermatozoides progressivamente móveis, a velocidade média da trajetória (VAP), a velocidade linear progressiva (VSL) e a frequência do batimento flagelar cruzado (BCF) durante a refrigeração comparado aos demais diluidores (P <0,05). A inclusão de lecitina de soja, de 2 a 6% no meio BWW, permitiu a manutenção da viabilidade do sêmen equino refrigerado a 15ºC por até 24 horas.

Effect of exogenous emulsifier and different fat sources on the performance, carcass characteristics, nutrient digestibility, and serum lipid profile of broiler chickens / Efeito de emulsificante exógeno e diferentes fontes de gordura no desempenho, características de carcaça e digestibilidade de nutriente e perfil lipídico sérico em frangos de corte

A study was conducted to evaluate the effect of an emulsifier on reduced-energy diets using two fat sources for broilers. The study was designed as a 2 x 3 factorial arrangement of treatments. The first factor was 2 fat sources (poultry fat or beef tallow). The second factor was a basal diet with the recommended energy levels, a diet with a 0.83 MJ/kg of energy reduction, and a diet with an energy reduction and inclusion of 1 g emulsifier/kg of diet. The emulsifier used in this study was composed of soy lecithin and polyethylene glycol ricinoleate. The emulsifier increased apparent metabolizable energy (AME) and apparent metabolizable energy corrected for nitrogen balance (AMEn) in beef tallow diets compared to energy-reduced diets (P<0.001). Broilers fed poultry fat had higher weights and weight gains at 35 and 42 d of age (p=0.001), and they had higher daily deposition of fat in the carcass (P = 0.025) when compared to diets with beef tallow. The inclusion of emulsifiers in broiler diets improves AME and AMEn but did not affect the energy reduction diets, which resulted in reduced performance, decreasing daily fat deposition, but without effects on serum lipid profile in broilers.(AU)

Um estudo foi conduzido para avaliar o efeito de um emulsificante em dietas com baixo teor de energia usando duas fontes de gordura para frangos de corte. O estudo foi delineado em arranjo fatorial 2 x 3 de tratamentos, o primeiro fator foi 2 fontes de gordura (gordura de frango ou sebo bovino) e o segundo fator uma dieta basal com os níveis de energia recomendados, uma dieta com 0,83 MJ / kg de redução de energia e uma dieta com redução de energia e inclusão de 1 g de emulsionante / kg de dieta (composto de lecitina de soja e ricinoleato de polietilenoglicol). O emulsificante aumentou a energia metabolizável aparente (EMA) e a energia metabolizável aparente corrigida para o balanço de nitrogênio (EMAn) em dietas com sebo bovino em comparação com dietas com redução de energia (P <0,001). Frangos de corte alimentados com gordura de frango apresentam maiores pesos e ganhos de peso aos 35 e 42 dias de idade (p=0,001), e maior deposição diária de gordura na carcaça (P=0,025) quando comparados às dietas com sebo bovino. O emulsificante incluído nas dietas de frangos de corte melhora a EMA e EMAn, mas não supre a redução energética, causando efeitos negativos no desempenho, diminuindo a deposição diária de gordura, mas sem efeitos no perfil lipídico sérico em frangos de corte.(AU)

Emulsifier and enzymatic complex in diet for free range broiler chicken in the western amazon / Emulsificante e complexo enzimático em dieta para frangos de corte de linhagem caipira na Amazônia ocidental

Abstract This study aimed to evaluate the effects of adding levels of emulsifier based on soy lecithin and enzymatic complex (xylanase, ß-glucanase;-glucanase, galactosidase, protease, amylase, and ß-mannanase) on the basal diet during the raising of free-range broiler chickens. The experimental design was completely randomized, with five treatments and six replications. Treatments were: T1: control diet, without enzymatic complex and emulsifier; T2: 0.2 kg t-1 of enzymatic complex; T3: 0.5 kg t-1 of emulsifier; T4: 0.2 kg t-1 of enzymatic complex + 0.5 kg t-1 of emulsifier; and T5: 0.3 kg t-1 of enzymatic complex + 1 kg t-1 of emulsifier. Performance data were collected every 14 days, and the animals were euthanized at 70 days to obtain carcass, breast, drumstick, and thigh yield and intestine collection for pH analysis and morphometry. The periods from 1 to 56 and 1 to 70 days showed a difference (P<0.05) in the parameters of zootechnical performance, the feed intake was lower in T4 and T5, and weight gain was better in T1, T2, T3, and T4. Feed conversion was better in T1, T2, and T4. No difference (P>0.05) was observed for poultry livability, carcass yield, viscera, and pH of duodenum and cecum. A difference was found for intestinal morphometry (P<0.05), and T5 showed the best villus/crypt ratio. The level with 0.3 kg t-1 of enzymatic complex and 1 kg t-1 of emulsifier indicated a better relationship between villi and crypts. However, the level with 0.2 kg t-1 of enzymatic complex and 0.5 kg t-1 of emulsifier added to the commercial diet led to benefits such as decreased feed intake, without affecting weight gain, thus inducing a good feed conversion.

Resumo Objetivou-se avaliar os efeitos da adição de níveis de emulsificante à base de lecitina de soja e complexo enzimático (Xilanase, ß-Glucanase, Galactosidase, Protease, Amilase, ß-Mananase) na ração basal durante a criação de frangos de corte de linhagem caipira. O delineamento experimental foi inteiramente casualizado com 5 tratamentos e 6 repetições. Os tratamentos foram: T1: ração controle, sem complexo enzimático e emulsificante; T2: 0,2 kg t-1 de complexo enzimático; T3: 0,5 kg t-1 de emulsificante; T4: 0,2 kg t-1 de complexo enzimático + 0,5 kg t-1 de emulsificante; T5: 0,3 kg t-1 de complexo enzimático + 1 kg t-1 de emulsificante. A cada 14 dias foram coletados os dados do desempenho zootécnico e após 70 dias as aves foram eutanasiadas para obtenção do rendimento de carcaça, peito, coxa, sobrecoxa e coleta do intestino para análise de pH e morfometria. Nos períodos de 1 a 56 e 1 a 70 dias houve diferença (P<0,05) nos parâmetros de desempenho zootécnico, o consumo de ração foi menor no T4 e T5, e o ganho de peso foi melhor no T1, T2, T3 e T4. A conversão foi melhor em T1, T2 e T4. Não houve diferença (P>0,05) na viabilidade das aves, no rendimento de carcaça, cortes de vísceras e no pH de duodeno e cecos. Houve diferença na morfometria intestinal (P<0,05), sendo o T5 o que obteve melhor relação vilo/cripta. O nível 0,3 kg t-1 complexo enzimático com 1 kg t-1 emulsificante indicou melhor efeito na relação vilosidade e criptas. O nível com 0,2 kg t-1 do complexo enzimático com 0,5 kg t-1 do emulsificante adicionado a dieta comercial trouxe benefícios como diminuição do consumo de ração, sem afetar o ganho de peso, tendo assim uma boa conversão alimentar.

Avanços na andrologia de grandes felinos neotropicais / Advances in neotropical big cats andrology

O desenvolvimento de tecnologias reprodutivas e conhecimentos sobre a andrologia de grandes felinos caminham a pequenos passos, com avanços na última década. Estudos sobre o comportamento de onças-pintadas (Panthera onca) revelam as sequências de comportamentos sócio-sexuais e levantam a possibilidade de a ovulação poder ocorrer por estímulos sensoriais, e não somente pela estimulação mecânica durante a cópula. Um grande avanço na andrologia dos felinos foi o desenvolvimento da colheita farmacológica com α2-agonistas, que já se mostrou eficiente também nos grandes felinos neotropicais. Este foi um verdadeiro divisor de águas para a criopreservação de sêmen, especialmente em animais de vida livre. Pouco se avançou, no entanto, no meio de criopreservação, ainda hoje os meios indicados são à base de TRIS-gema-glicerol, porém a gema não é estável suficiente para uso em animais de vida livre, sendo necessária avaliação de substitutivos como as lipoproteínas de baixa densidade e lecitina de soja. O aprimoramento de reprodução assistida nos felinos neotropicais é pungente, em especial a onça-pintada visto que em alguns biomas a espécie está criticamente em perigo.

The development of reproductive technologies and knowledge about the andrology of big cats are taking small steps, with advances in the last decade. Studies on the sexual behavior of jaguars (Panthera onca) reveal the sequences of sexual behaviors and raise the possibility that ovulation may occur through sensory stimuli and not only through mechanical stimulation during copulation. A significant advance in feline andrology was the development of pharmacological semen collection with α2-agonists, which has proved efficient in neotropical big cats. It was disruptive for semen cryopreservation, especially in free-living animals. Little progress has been made; however, in the cryopreservation environment, even today, the indicated means are based on TRIS-yolk-glycerol. However, the yolk is not stable enough for use in free-living animals, requiring the evaluation of substitutes such as low-density lipoproteins and soy lecithin. The improvement of assisted reproduction in neotropical felines is poignant, especially the jaguar, since in some biomes, the species is critically endangered.

Impact of in vitro fertilization by refrigerated versus frozen buffalo semen on developmental competence of buffalo embryos

The objective of this study was to evaluate the fertility of buffalo semen for in vitro embryo production (IVEP) by comparing the effectiveness of refrigerated versus frozen semen. Three OPU sessions were held at 30-day intervals. For oocyte fertilization three buffalo bulls were used, one per session. At each OPU-IVEP session, one ejaculate was collected and divided into two equal aliquots. Each aliquot was either refrigerated at 5ºC/24 hours or frozen. A TRIS extender containing 10% low density lipoproteins, 0.5% lecithin and 10 mM acetylcysteine was used adding 7% glycerol for freezing. Sperm motility/kinetic was evaluated by CASA and sperm membrane integrity by the hypoosmotic swelling test. The evaluations were performed at 0 h (post final dilution at 37ºC), at 4 and 24 hs post-incubation at 5ºC and post-thaw. At 24 hs incubation and immediately post thaw sperm cells were used for in vitro fertilization of buffalo oocytes equally distributed between both groups. Cleavage rates and embryo development were followed. The embryo/matured and embryo/cultured rates were 25.4 x 14.0% and 29.4 x 18.5% (P 0.05), for chilled and frozen semen, respectively. It is concluded that cooled semen can be used for in vitro embryo production in buffalo and that a better efficiency may be expected for cooled compared to frozen semen.

Impact of in vitro fertilization by refrigerated versus frozen buffalo semen on developmental competence of buffalo embryos

The objective of this study was to evaluate the fertility of buffalo semen for in vitro embryo production (IVEP) by comparing the effectiveness of refrigerated versus frozen semen. Three OPU sessions were held at 30-day intervals. For oocyte fertilization three buffalo bulls were used, one per session. At each OPU-IVEP session, one ejaculate was collected and divided into two equal aliquots. Each aliquot was either refrigerated at 5ºC/24 hours or frozen. A TRIS extender containing 10% low density lipoproteins, 0.5% lecithin and 10 mM acetylcysteine was used adding 7% glycerol for freezing. Sperm motility/kinetic was evaluated by CASA and sperm membrane integrity by the hypoosmotic swelling test. The evaluations were performed at 0 h (post final dilution at 37ºC), at 4 and 24 hs post-incubation at 5ºC and post-thaw. At 24 hs incubation and immediately post thaw sperm cells were used for in vitro fertilization of buffalo oocytes equally distributed between both groups. Cleavage rates and embryo development were followed. The embryo/matured and embryo/cultured rates were 25.4 x 14.0% and 29.4 x 18.5% (P 0.05), for chilled and frozen semen, respectively. It is concluded that cooled semen can be used for in vitro embryo production in buffalo and that a better efficiency may be expected for cooled compared to frozen semen.(AU)

Concentration of soybean lecithin affects short-term storage success of goat semen related with seminal plasma removal

The objective of this study was to investigate the need of seminal plasma removal for short-term cooling of buck semen in soybean lecithin (SL) based extender. Each pool was divided equally, and one half was subjected to centrifugation to remove seminal plasma (SP-), while the other half remained with seminal plasma (SP+). Then, both SP+ and SP- samples were diluted in two SL extenders (extender A = 1% SL; extender B = 2% SL), cooled to 5ºC and stored for 48 hours. The sperm kinetics, evaluated by CASA, and plasma membrane integrity (PMI), acrosomal integrity (ACI) and high mitochondrial membrane potential (HMMP), evaluated by epifluorescence microscopy, were determined within five minutes after reaching 5°C (T0), as well as after 24 (T24) and 48 (T48) hours of storage. Interactions (seminal plasma vs. extender vs. time;) were observed for all variables assessed. Total and progressive motility and other variables of sperm kinetics decreased after 24 hours of cooling in the SP+ group, and after 48 hours of storage, these same variables were lower in SP+/B compared to SP-/B groups. Furthermore, SP+ reduced PMI (extender B, T48), HMMP (A and B extenders, T48) and ACI (extender A, T0) compared to SP- samples. The interactions between seminal plasma and soybean lecithin phospholipids seemed to occur in a time-dependent manner. It was concluded that the removal of seminal plasma improves the quality of goat semen that was cooled in a soybean lecithin-based extender, especially when using 2% soybean lecithin.(AU)

Concentration of soybean lecithin affects short-term storage success of goat semen related with seminal plasma removal

The objective of this study was to investigate the need of seminal plasma removal for short-term cooling of buck semen in soybean lecithin (SL) based extender. Each pool was divided equally, and one half was subjected to centrifugation to remove seminal plasma (SP-), while the other half remained with seminal plasma (SP+). Then, both SP+ and SP- samples were diluted in two SL extenders (extender A = 1% SL; extender B = 2% SL), cooled to 5ºC and stored for 48 hours. The sperm kinetics, evaluated by CASA, and plasma membrane integrity (PMI), acrosomal integrity (ACI) and high mitochondrial membrane potential (HMMP), evaluated by epifluorescence microscopy, were determined within five minutes after reaching 5°C (T0), as well as after 24 (T24) and 48 (T48) hours of storage. Interactions (seminal plasma vs. extender vs. time;) were observed for all variables assessed. Total and progressive motility and other variables of sperm kinetics decreased after 24 hours of cooling in the SP+ group, and after 48 hours of storage, these same variables were lower in SP+/B compared to SP-/B groups. Furthermore, SP+ reduced PMI (extender B, T48), HMMP (A and B extenders, T48) and ACI (extender A, T0) compared to SP- samples. The interactions between seminal plasma and soybean lecithin phospholipids seemed to occur in a time-dependent manner. It was concluded that the removal of seminal plasma improves the quality of goat semen that was cooled in a soybean lecithin-based extender, especially when using 2% soybean lecithin.

Low Density Lipoprotein - important player in increasing cryoprotective efficiency of soybean lecithin-based bull semen extenders

Currently, considering cryopreservation of bull semen, there is no clear consensus over the comparability of cryoprotective efficacy of extenders with soybean lecithin and those based on egg yolk. The objective of this study was to prove the use of Low Density Lipoprotein (LDL) extracted from hen-egg yolk as an enhancing factor for soybean lecithin-based extenders. In total, 35 ejaculates of (seven bulls x five ejaculates per bull) were collected and cryopreserved at a commercial insemination centre. The effect of the LDL addition to the extenders AndroMed® and Bioxcell® was tested in a 6% (v/v) concentration on spermatozoa after thawing. Modified extender composition effects were assessed on sperm functional parameters motility, plasma membrane, mitochondrial membrane potential and acrosomal integrity after thawing by CASA, flow cytometry and fluorescent microscopy, respectively. Based on kinematic parameters determined from CASA, k-means cluster analysis was used to classify individual spermatozoon into specific subpopulations (fast, medium fast and slow). A subpopulation of fast spermatozoa was increased in the presence of LDL in both selected extenders (P 0.05). The percentage of sperm with intact acrosome was improved when LDL was added to Bioxcell® extender (P < 0.05). On the other hand, addition of LDL to AndroMed® extender improved mitochondrial intactness after thawing (P < 0.05). In conclusion, our results showed that adding LDL to selected soybean lecithin-based extenders considerably ameliorated the functional parameters of spermatozoa after thawing and thus this lipoprotein could represent an improving agent for soybean lecithin-based extender for bull semen.

Low Density Lipoprotein - important player in increasing cryoprotective efficiency of soybean lecithin-based bull semen extenders

Currently, considering cryopreservation of bull semen, there is no clear consensus over the comparability of cryoprotective efficacy of extenders with soybean lecithin and those based on egg yolk. The objective of this study was to prove the use of Low Density Lipoprotein (LDL) extracted from hen-egg yolk as an enhancing factor for soybean lecithin-based extenders. In total, 35 ejaculates of (seven bulls x five ejaculates per bull) were collected and cryopreserved at a commercial insemination centre. The effect of the LDL addition to the extenders AndroMed® and Bioxcell® was tested in a 6% (v/v) concentration on spermatozoa after thawing. Modified extender composition effects were assessed on sperm functional parameters motility, plasma membrane, mitochondrial membrane potential and acrosomal integrity after thawing by CASA, flow cytometry and fluorescent microscopy, respectively. Based on kinematic parameters determined from CASA, k-means cluster analysis was used to classify individual spermatozoon into specific subpopulations (fast, medium fast and slow). A subpopulation of fast spermatozoa was increased in the presence of LDL in both selected extenders (P < 0.05). Moreover, the positive effect of LDL on sperm motility was confirmed by decreasing the percentage of sperm in slow subpopulation (P < 0.05). The effect of LDL addition on the incidence of spermatozoa with intact plasma membrane was not demonstrated in any case of extender used (P > 0.05). The percentage of sperm with intact acrosome was improved when LDL was added to Bioxcell® extender (P < 0.05). On the other hand, addition of LDL to AndroMed® extender improved mitochondrial intactness after thawing (P < 0.05). In conclusion, our results showed that adding LDL to selected soybean lecithin-based extenders considerably ameliorated the functional parameters of spermatozoa after thawing and thus this lipoprotein could represent an improving agent for soybean lecithin-based extender for bull semen.(AU)

Otimização da atividade de herbicidas com diferentes adjuvantes na fitotoxicidade de Digitaria insularis no estádio de florescimento / Optimizing activity of herbicides with different adjuvant on phytotoxicityof Digitaria insularis at flowering stage

O presente trabalho teve como objetivo quantificar o efeito proporcionado pela interação entre os herbicidas clethodim e paraquat associados com diferentes classes de adjuvantes na fitotoxicidade de Digitaria insularis no estádio de florescimento. Os herbicidas foram aplicados nas doses de 0; 6,25; 12,5; 25; 50; 75 e 100% da recomendada pelo fabricante, de forma isolada e em mistura com os adjuvantes: nonil fenoxi poli (etilenoxi) etanol (0,05%); copolímero de poliéter e silicone (0,1%); lecitina e ácido propiônico (0,5%) e óleo mineral (0,5%) no delineamento inteiramente casualizado com cinco repetições em esquema fatorial (doses dos herbicidas x adjuvantes). O efeito fitotóxico foi visualmente avaliado aos 12 dias após aplicação (DAA) para o herbicida paraquat e aos 21 DAA para o herbicida clethodim. Verificou-se em plantas de D. insularis fitotoxidade potencializada para o herbicida clethodim nos tratamentos com os adjuvantes nonil fenoxi poli (etilenoxi) etanol, lecitina e ácido propiônico e óleo mineral .Para o herbicida paraquat, a potencialização da fitotoxicidade nas plantas de D. insularis foi proporcionada somente pelo tratamento com o adjuvante lecitina e ácido propiônico.(AU)

The aim of this paper was quantify the effect of the herbicides clethodim and paraquat associated with different adjuvants class on phytotoxicity of Digitaria insularis at flowering stage. The herbicides were applied at 0, 6.25, 12.5, 25, 50, 75 and 100% of recommended label isolated or associated with the adjuvants: nonylphenoxy polyethoxy ethanol at 0.05%; silicone polyether copolymer at 0.1%; lecithin-based adjuvant and acid propionic at 0.5% and mineral oil at 0.5%. The experimental design was completely randomized with five replications in factorial scheme (herbicides rates x adjuvants). The phytotoxicity effect was visually assessed for paraquat at 12 days after treatment (DAT) and at 21 DAT for clethodim. The treatments applied clethodim with the adjuvants nonylphenoxy polyethoxy ethanol, lecithin-based adjuvant and acid propionic and mineral oil significantly increased the phytotoxicity of D. insularis plants. For the paraquat the increase phytotoxicity of D. insularis plants was provided by the treatment with the lecithin-based and acid propionic adjuvant.(AU)

Otimização da atividade de herbicidas com diferentes adjuvantes na fitotoxicidade de Digitaria insularis no estádio de florescimento / Optimizing activity of herbicides with different adjuvant on phytotoxicityof Digitaria insularis at flowering stage

O presente trabalho teve como objetivo quantificar o efeito proporcionado pela interação entre os herbicidas clethodim e paraquat associados com diferentes classes de adjuvantes na fitotoxicidade de Digitaria insularis no estádio de florescimento. Os herbicidas foram aplicados nas doses de 0; 6,25; 12,5; 25; 50; 75 e 100% da recomendada pelo fabricante, de forma isolada e em mistura com os adjuvantes: nonil fenoxi poli (etilenoxi) etanol (0,05%); copolímero de poliéter e silicone (0,1%); lecitina e ácido propiônico (0,5%) e óleo mineral (0,5%) no delineamento inteiramente casualizado com cinco repetições em esquema fatorial (doses dos herbicidas x adjuvantes). O efeito fitotóxico foi visualmente avaliado aos 12 dias após aplicação (DAA) para o herbicida paraquat e aos 21 DAA para o herbicida clethodim. Verificou-se em plantas de D. insularis fitotoxidade potencializada para o herbicida clethodim nos tratamentos com os adjuvantes nonil fenoxi poli (etilenoxi) etanol, lecitina e ácido propiônico e óleo mineral .Para o herbicida paraquat, a potencialização da fitotoxicidade nas plantas de D. insularis foi proporcionada somente pelo tratamento com o adjuvante lecitina e ácido propiônico.

The aim of this paper was quantify the effect of the herbicides clethodim and paraquat associated with different adjuvants class on phytotoxicity of Digitaria insularis at flowering stage. The herbicides were applied at 0, 6.25, 12.5, 25, 50, 75 and 100% of recommended label isolated or associated with the adjuvants: nonylphenoxy polyethoxy ethanol at 0.05%; silicone polyether copolymer at 0.1%; lecithin-based adjuvant and acid propionic at 0.5% and mineral oil at 0.5%. The experimental design was completely randomized with five replications in factorial scheme (herbicides rates x adjuvants). The phytotoxicity effect was visually assessed for paraquat at 12 days after treatment (DAT) and at 21 DAT for clethodim. The treatments applied clethodim with the adjuvants nonylphenoxy polyethoxy ethanol, lecithin-based adjuvant and acid propionic and mineral oil significantly increased the phytotoxicity of D. insularis plants. For the paraquat the increase phytotoxicity of D. insularis plants was provided by the treatment with the lecithin-based and acid propionic adjuvant.

Cholecystectomy during ceftriaxone therapy. A translational study with a new rabbit model

Purpose: To evaluate the actual incidence of both microlithiasis and acute cholecystitis during treatment with intravenous ceftriaxone in a new rabbit model. Methods: New Zealand rabbits were treated with intravenous ceftriaxone or saline for 21 days. Ultrasound monitoring of the gallbladder was performed every seven days until the 21st day when histopathology, immunohistochemistry for proliferating cell nuclear antigen (PCNA), pro-caspase-3 and CD68, liver enzyme biochemistry, and chromatography analysis of the bile and sediments were also performed. Results: All animals treated with ceftriaxone developed acute cholecystitis, confirmed by histopathology (P < 0.05) and biliary microlithiasis, except one that exhibited sediment precipitation. In the group treated with ceftriaxone there was an increase in pro-caspase-3, gamma-glutamyl transpeptidase concentration, PCNA expression and in the number of cells positive for anti-CD68 (P < 0.05). In the ceftriaxone group, the cholesterol and lecithin concentrations increased in the bile and a high concentration of ceftriaxone was found in the microlithiasis. Conclusion: Ceftriaxone administered intravenously at therapeutic doses causes a high predisposition for lithogenic bile formation and the development of acute lithiasic cholecystitis.(AU)

USO DE EMULSIFICANTE EM DIETAS DE FRANGOS DE CORTE

Foram realizados dois experimentos com objetivo de avaliar a energia metabolizável aparente (EMA) corrigida pelo balanço de nitrogênio (EMAn) e o coeficiente de metabolizabilidade da matéria seca (CMMS), do extrato etéreo (CMEE), da energia bruta (CMEB) e do nitrogênio (CMN), bem como o balanço do nitrogênio (BN) em frangos de corte alimentados com dietas contendo emulsificante e diferentes níveis de energia metabolizável (EM). Fora avaliado, também, o desempenho, rendimento de carcaça, percentual de extrato etéreo nas excretas, histomorfometria intestinal e perfil sérico de frangos de corte alimentados com dietas contendo emulsificante e duas fontes lipídicas. No primeiro experimento, o delineamento foi inteiramente casualizado, em fatorial 3 x 2 (três níveis de EM: 2.950, 3.050 e 3.150 kcal/kg na fase inicial e 3.100, 3.150 e 3.200 kcal/kg na fase de crescimento, com ou sem a adição de 0,125% de emulsificante a base de lecitina de soja). Foi avaliada a EMA, a EMAn, BN e o CMEB nos períodos de 10 a 14 dias e de 30 a 35 dias de idade. Na fase inicial, a inclusão do emulsificante em dietas com 2.950 e 3050 kcal/kg de EM aumentou o CMMS, o CMN e o BN. Na fase de crescimento houve aumento da EMA e EMAn, em dietas com menor nível de EM (3.100 kcal/kg), e a adição do emulsificante em dietas com 3.150 e 3.200 de EM proporcionou aumento do CMEE. No segundo experimento, o delineamento foi inteiramente casualizado em fatorial 2x2 (com ou sem a adição de 0,05% de emulsificante a base de lecitina de soja e duas fontes de lipídeo: gordura de frango e óleo de soja), com oito repetições com 18 aves, cada. Dietas com emulsificante melhoraram o peso vivo dos frangos aos 35 dias de idade, independente, da fonte lipídica utilizada na dieta, bem como o índice de eficiência produtiva (416,69) aumentou a altura das vilosidades no intestino de frangos alimentados com óleo de soja, não apresentando diferença para a gordura de frango, enquanto no jejuno a maior altura de vilosidade foi em dietas com gordura de frango e no íleo com óleo de soja, ambas com emulsificante. O emulsificante não influenciou a histopatologia do fígado. O colesterol total e o High Density Liporotein (HDL) foram maiores em dietas com gordura de frango para pintos com 7 dias de vida. A enzima Iransaminase Glutâmico Oxalacética (TGO) apresentou menor valor para dietas com óleo de soja e emulsificante e a Transaminase Glutâmico Pirúvica (TGP) foi maior para gordura de frango, não havendo efeito do emulsificante para pintos com 7 dias de idade. Aos 21 dias de idade, os frangos alimentados com dieta contendo gordura de frango apresentaram maior TGP. O peso relativo dos órgãos (fígado, pâncreas e intestino delgado) e o rendimento de carcaça não foram alterados com ou sem a inclusão do emulsificante. Conclui-se, portanto, que a inclusão do emulsificante em dietas com menor nível de EM melhorou o CMN e o BN na fase inicial e a EMA e EMAn na fase de crescimento, podendo ser utilizado em dietas de frangos com níveis reduzidos de EM. Além disso, melhorou o peso vivo dos frangos aos 35 e 42 dias de vida, o índice de eficiência produtiva e a altura das vilosidades do duodeno e do jejuno.

Two experiments were conducted. The first one aimed to study the effects of the emulsifying in diets using three different levels of metabolized energy (ME) (low, recommended and high) in the initial and growth phases of broilers, with a 3x2 factorial. In the initial phase, the diets had 2.950, 3.050, and 3.150 kcal/kg, and in the growth phase, 3.100, 3.150 and 3.200 kcal/kg of ME, with the inclusion of 0,125% of an emulsifying that has soy lecithin as its main component. The aim was to determinate the apparent metabolized energy (AME) and the apparent metabolized energy corrected by nitrogen (AMEn) in diets with three levels of metabolized energy (ME), as well as nitrogen balance (NB), digestibility coefficients of dry matter (DCDM), ether extract (DCEE), nitrogen (DCN), and crude energy (DCCE). It was verified that the inclusion of the emulsifying increased the DCDM, DCN, NB, and AMEn in diets with 2.950 and 3050 kcal/kg, while in the growth phase, the AME and AMEn in diets with lower levels of metabolized energy (3.100 kcal/kg), suggesting the inclusion of the emulsifying in broilers diet with lower levels of metabolized energy. The second experiment aimed to study the inclusion of the emulsifying in broilers diet with two different fat sources (soy oil and chicken fat), therefore forming a 2x2 factorial. It was used an emulsifying that has soy lecithin as its main component with 0,5% of inclusion (on top). The emulsifying (soy lecithin) improved the broilers body weight in 35 (120 g) and 42 (150 g) days old, regardless to the fat source used in the diet, as well as the productive efficiency ratio (416,69). There were no differences to the percentage of ether extract found in the excrete of 7 and 21 days old broilers. To assess the intestinal histomorphometry of 21 days of age, the emulsifying increased the villous height in the intestine of broilers fed with soy oil, not showing any differences to the chicken fat, while in the jejunum, the greatest villous height was found in diets with chicken fat and in the ileum, with soy oil, both of which used the emulsifying. There was no verification of the emulsifying effect and the type of fat for the livers histology, but it was verified that the fat source influenced the serum blood profile, which the total cholesterol and high density lipoprotein (HDL) were higher in diets with chicken fat for 7 days old chicks. The glutamic oxaloacetic transaminase (GOT) enzyme showed lower values for diets with soy oil and emulsifying, and the glutamic-pyruvic transaminase (GPT) was higher for the chicken fat, without any effect of the emulsifying for 7 days old chicks. For 21 days old broilers, the GPT was higher for broilers fed with chicken fat in the diet. There was no interaction, as well as emulsifying effect, for the relative liver weight, pancreas and small intestine on the evaluated ages (21 and 42 days), as well as the carcass yield. The inclusion of the emulsifying improved the body weight of 21 and 42 days old broilers, the productive efficiency ratio and the height of the villous, both in the duodenum and jejunum, being indicated its inclusion in the broilers diet.

Estudos sobre a qualidade da farinha e óleo de vísceras de frango para uso em Pet food

As farinhas de origem animal são ingredientes importantes para a fabricação de rações quanto aos aspectos econômico, saúde animal e nutricional. Seu uso na formulação de dietas é facilitado por conterem aminoácidos, energia, cálcio e fósforo em quantidades apreciáveis. Para que o controle da qualidade seja eficiente, a avaliação dos ingredientes deve ser feita por meio de análises físicas, químicas e biológicas. Dentre os fatores que influenciam a qualidade das farinhas de origem animal, os de maior importância são a umidade, alta temperatura, tempo em excesso no digestor, moagem, excesso de gordura, contaminações, tempo entre o sacrifício e processamento da farinha, proteína bruta, acidez, índice de peróxidos e contaminação microbiana. Para verificação de fatores que podem interferir na qualidade das farinhas de vísceras de aves foram realizados três experimentos; o primeiro experimento objetivou-se avaliar o tempo de espera para o processamento e diferentes tipos de antimicrobianos na qualidade da víscera de frango e, para isso, foi realizado o processamento de 30 bateladas sendo divididas em 6 tratamentos com 5 tempos de espera para o processamento 0 (T0), 12 (T12), 24 (T24), 36 (T36), 48 (T48) horas. Foi avaliado o rendimento de óleo de víscera de aves, a composição química dos óleos de víscera de aves, residuais de antioxidante sintético e perfil de ácido graxos. No T48 constatou um maior rendimento (15,1%) de óleo e maior nível de proteína no óleo, a maior umidade foi verificada no T0 e T12, o residual antioxidante reduziu conforme houve o aumento do tempo de espera para o processamento o perfil de ácidos graxos não sofreu alteração em relação ao tempo de espera para o processamento. O segundo experimento teve como objetivo avaliar o efeito de diferentes antioxidantes sintéticos e naturais sobre a estabilidade oxidativa utilizando reator de oxidação (Rancimat®). Os antioxidantes possuem sua origem de forma sintética como é o caso dos BHT, BHA, TBHQ, ou podem ter sua origem natural, normalmente representados pelo grupo dos tocoferóis. Com a crescente demanda por produtos naturais existe um grande interesse na utilização destes compostos naturais como o tocoferol exercendo o papel de antioxidante do material. O mix de Tocoferol, Lecitina de Soja, Extrato de Alecrim e Óleo Vegetal. O uso de 800mg/kg teve desempenho compatível com os antioxidantes sintéticos a base de Hidróxido de Anizola Butilado (B.H.A), Hidróxido de Tolueno Butilado (B.H.T.) e óleo vegetal. 500mg/kg, reforçando com isso os fatos de que os antioxidantes naturais podem ser empregados na conservação destes materiais com desempenho semelhante aos sintéticos, porem buscando um outro tipo de mercado que prioriza a ingredientes naturais. O terceiro experimento teve como objetivo a avaliação da temperatura de processamento sobre a qualidade do óleo de víscera de frango e a farinha de víscera de frango. A temperatura de processamento é colocada como um dos principais aspectos que influenciam na qualidade desse produto. Foram confeccionadas farinhas de vísceras de aves em três diferentes temperaturas 103º, 108º e 113º e não foi observado diferenças na composição química da farinha de víscera de frango, a temperatura de processamento também não teve influência sobre resultado da digestibilidade da matéria orgânica (DIVMO) da farinha, a estabilidade oxidativa medida pelo período de indução PI no reator de oxidação (Rancimat®) demonstra uma diferença na estabilidade do óleo resultante da menor temperatura de processamento 103º sendo o PI dele 50% dos óleos obtidos a 108 e 113º.

Flours of animal origin are important ingredients for the manufacture of feed in terms of economic, animal health and nutritional aspects. Its use in the formulation of diets is facilitated by containing amino acids, energy, calcium and phosphorus in appreciable quantities. For quality control to be efficient, the evaluation of ingredients must be done through physical, chemical and biological analyzes. Among the factors that influence the quality of animal meal, the most important are humidity, high temperature, excess time in the digester, grinding, excess fat, contamination, time between sacrifice and processing of flour, crude protein, acidity, peroxide index and microbial contamination. To verify factors that may interfere with the quality of poultry flours, three experiments were carried out. The first experiment aimed to evaluate the waiting time for processing and different types of antimicrobials in the quality of the chicken viscera. processing of 30 batches being divided into 6 treatments with 5 waiting times for processing 0 (T0), 12 (T12), 24 (T24), 36 (T36), 48 (T48) hours. The performance of poultry viscera oil, the chemical composition of poultry viscera oils, residual synthetic antioxidant and fatty acid profile were evaluated. At T48 it was found a higher yield (15.1%) of oil and a higher level of protein in the oil, the highest humidity was verified at T0 and T12, the antioxidant residual reduced as the waiting time for processing increased. fatty acids did not change in relation to the waiting time for processing. The second experiment aimed to evaluate the effect of different synthetic and natural antioxidants on oxidative stability using an oxidation reactor (Rancimat®). Antioxidants have their origin in a synthetic way as is the case of BHT, BHA, TBHQ, or they may have their natural origin, usually represented by the group of tocopherols. With the growing demand for natural products, there is great interest in the use of these natural compounds such as tocopherol, playing the role of antioxidant of the material. The mix of Tocopherol, Soy Lecithin, Rosemary Extract and Vegetable Oil. 800mg / kg had performance compatible with synthetic antioxidants based on Butylated Anizole Hydroxide (B.H.A), Butylated Toluene Hydroxide (B.H.T.), Vegetable Oil. 500mg / kg, thereby reinforcing the facts that natural antioxidants can be used in the conservation of these materials with performance similar to the synthetic ones, however looking for another type of market. The third experiment aimed to evaluate the processing temperature on the quality of chicken and viscera oil and chicken viscera flour. The processing temperature is placed as one of the main aspects that influence the quality of this product. Poultry flours were made at three different temperatures 103, 108 and 113º, no differences were observed in the chemical composition of chicken viscera flour, the processing temperature also had no influence on the result of the digestibility of organic matter (DIVMO). flour, the oxidative stability measured by PI in the oxidation reactor (Rancimat®) demonstrates a difference in the stability of the oil resulting from the lower processing temperature of 103º, with its PI 50% of the oils obtained at 108 and 113º.

Produção de leite e comportamento alimentar em vacas da raça Holandês recebendo somatotropina recombinante

A somatotropina recombinante bovina (rbST) vem sendo utilizada para a maximização da produção em rebanhos leiteiros. Como resposta ao seu uso há um aumento na exigência nutricional, e para suprir essa demanda, há um acréscimo no consumo de matéria seca. Sendo assim, existem duas formulações comerciais de rbST de liberação lenta no Brasil, que se diferenciam, principalmente, pelo veículo utilizado. O rbST-Fast (MSD Saúde Animal) que contém lecitina e vitamina E, o que torna a solução mais hidrossolúvel e de liberação mais rápida em comparação ao rbST-Slow (Agener União Saúde Animal), o qual contém óleo de gergelim e zinco, tornando sua liberação mais lenta e contínua, com isso o objetivo deste estudo foi avaliar o efeito da administração de duas formas comerciais (rbST-Slow, Agener União Saúde Animal; e rbST- Fast, MSD Saúde Animal) contendo 500 mg de rbST na produção de leite e comportamento alimentar de vacas da raça Holandês após o pico de produção. Foram utilizadas 18 vacas secundíparas da raça Holandês, entre 90 e 210 dias em lactação (DEL), distribuídas aleatoriamente em dois grupos. Grupo rbST-Fast (n=9) e o grupo rbST-Slow (n=9), nos quais receberam uma dose de 500 mg de rbST a cada 14 dias, concluindo 5 ciclos consecutivos de aplicação e 70 dias de período experimental. O escore de condição corporal (ECC) foi realizado através da escala de 1 a 5 e o peso foi estimado através de fita métrica. As produções de leite diárias foram medidas eletronicamente pelo software DelPro (DeLaval®) durante os 70 dias experimentais. A avaliação do consumo e comportamento alimentar dos animais foi obtida diariamente durante o período de 24 horas por dia, através de alimentadores inteligentes (Intergado®), de forma automática e individualizada. Nestes alimentadores foram mensurados o consumo dos animais, tempo de consumo (min/dia) e número de visitas com consumo (dia) ao comedouro. Os dados foram analisados pelo procedimento MIXED para medidas repetidas no programa estatístico SAS (SAS v9.4 Institute Inc., Cary, NC, USA). Quanto ao comportamento alimentar, o grupo rbST-Fast apresentou tendência de maior consumo de matéria seca (CMS) (P=0,07) e maior consumo de matéria verde (P=0,06) em relação ao grupo rbST-Slow, com mesma variabilidade no consumo alimentar entre os tratamentos (P=0,64). Além disso, os animais tratados com rbST-Fast apresentaram maior número de visitas aos comedouros com consumo (P<0,01), maior tempo em consumo (P<0,01) e maior CMS por porcentagem de peso vivo (P<0,01). Durante o período de tratamento, os animais do grupo rbST-Fast apresentaram maior produção média de leite em comparação ao grupo rbST-Slow (P=0,03). Quanto aos resultados de peso pode-se observar que os animais tratados com rbST-Fast apresentaram maior variação de peso, perdendo aproximadamente três vezes mais peso que os animais tratados com rbST-Slow (P<0,01). Quanto à variação no ECC, não houve diferença estatística entre os tratamentos (P=0,30). Concluímos que as vacas do grupo rbST-Fast produziram mais leite, tenderam a consumir mais com a mesma variabilidade de consumo quando comparadas às vacas do grupo rbST-Slow®.

Recombinant bovine somatotropin (rbST) has been used to maximize production in dairy herds. In response to its use, there is an increase in the nutritional requirement, and to supply this demand, there is an increase in the consumption of dry matter. Therefore, there are two commercial formulations of slow release rbST in Brazil, which differ, mainly, by the vehicle used. The rbST-Fast (MSD Animal Health) which contains lecithin and vitamin E, which makes the solution more water-soluble and quicker compared to the rbST-Slow (Agener União Saúde Animal), which contains sesame oil and zinc, making its release slower and more continuous, the objective of this study was to evaluate the effect of the administration of two commercial forms (rbST-Slow, Agener União Saúde Animal; and rbST- Fast, MSD Animal Health) containing 500 mg of rbST in the production of milk and feeding behavior of Holstein cows after peak production. Eighteen secondary Holstein cows were used, between 90 and 210 days in lactation (LED), randomly distributed in two groups. The rbST-Fast group (n = 9) and the rbST-Slow group (n = 9), in which they received a dose of 500 mg of rbST every 14 days, concluding 5 consecutive application cycles and 70 days of trial period. The body condition score (ECC) was performed using a scale from 1 to 5 and weight was estimated using a tape measure. Daily milk yields were measured electronically by the DelPro software (DeLaval®) during the 70 experimental days. The evaluation of the consumption and feeding behavior of the animals was obtained daily during the period of 24 hours a day, through intelligent feeders (Intergado®), in an automatic and individualized way. In these feeders, animal consumption, consumption time (min / day) and number of visits with consumption (day) to the feeder were measured. The data were analyzed using the MIXED procedure for repeated measures in the SAS statistical program (SAS v9.4 Institute Inc., Cary, NC, USA). As for eating behavior, the rbST-Fast group showed a trend towards higher consumption of dry matter (CMS) (P = 0.07) and higher consumption of green matter (P = 0.06) compared to the rbST-Slow group, with same variability in food consumption between treatments (P = 0.64). In addition, the animals treated with rbST-Fast showed a higher number of visits to feeders with consumption (P <0.01), longer time in consumption (P <0.01) and higher CMS by percentage of live weight (P <0, 01). During the treatment period, animals in the rbST-Fast group had a higher average milk production compared to the rbST-Slow group (P = 0.03). Regarding the weight results, it can be observed that the animals treated with rbST-Fast showed greater variation in weight, losing approximately three times more weight than the animals treated with rbST-Slow (P <0.01). As for the variation in ECC, there was no statistical difference between treatments (P = 0.30). We conclude that cows in the rbST-Fast group produced more milk, tended to consume more with the same variability in consumption when compared to cows in the rbST-Slow® group.