Feeding effects of cottonseed and its co-products on the meat proteome from ram lambs

Gossypol easily pairs with lysine side chains and enzymes involved in the cellular growth process. The effect of gossypol (a compound present in cotton co-products) in ruminant metabolism and meat quality is not yet clear. This study was undertaken in order to evaluate the effects of cotton co-products in lamb muscle proteome. Twenty-four Santa Inês ram lambs, 5-months old (20.6 ± 1.9 kg), were randomly assigned to four treatments: control (without cottonseed), whole cottonseed, cottonseed meal and high oil cottonseed meal. At 95 days into the experiment, lambs were slaughtered and samples from Longissimus dorsi were collected. Proteins were extracted and analyzed by 2-D electrophoresis. Spots showing a significant effect from the treatment (the “treatment effect”) and present in more than 90 % of the samples were identified using mass spectrometry. Cotton co-products decreased the abundance of aldehyde and malate dehydrogenases, creatine kinase M-type and Adenosine triphosphate (ATP) synthase. They also increased four proteins related to muscle contraction. Thus, feeding cotton co-products to lambs changed the abundance of important muscle proteins. A cotton co-product diet induced a negative impact on the energy supply of muscle cells and, consequently, the abundance of ATP dependent proteins (contractile apparatus) increased, probably in order to offset and maintain muscle function. These proteomic changes can promote our understanding of alterations in the sensorial properties of meat due to cotton co-product diets in further investigations.

Feeding effects of cottonseed and its co-products on the meat proteome from ram lambs

Gossypol easily pairs with lysine side chains and enzymes involved in the cellular growth process. The effect of gossypol (a compound present in cotton co-products) in ruminant metabolism and meat quality is not yet clear. This study was undertaken in order to evaluate the effects of cotton co-products in lamb muscle proteome. Twenty-four Santa Inês ram lambs, 5-months old (20.6 ± 1.9 kg), were randomly assigned to four treatments: control (without cottonseed), whole cottonseed, cottonseed meal and high oil cottonseed meal. At 95 days into the experiment, lambs were slaughtered and samples from Longissimus dorsi were collected. Proteins were extracted and analyzed by 2-D electrophoresis. Spots showing a significant effect from the treatment (the “treatment effect”) and present in more than 90 % of the samples were identified using mass spectrometry. Cotton co-products decreased the abundance of aldehyde and malate dehydrogenases, creatine kinase M-type and Adenosine triphosphate (ATP) synthase. They also increased four proteins related to muscle contraction. Thus, feeding cotton co-products to lambs changed the abundance of important muscle proteins. A cotton co-product diet induced a negative impact on the energy supply of muscle cells and, consequently, the abundance of ATP dependent proteins (contractile apparatus) increased, probably in order to offset and maintain muscle function. These proteomic changes can promote our understanding of alterations in the sensorial properties of meat due to cotton co-product diets in further investigations.(AU)

Behaviors of beef cattle fed crude glycerol as a replacement for sorghum grain

The study of the animal behavior is a useful tool to comprehend the performance of beef animals finished in feedlots. Twenty-eight non-castrated Nellore males with initial body weight of 441 kg and 21.5 months of age were randomly assigned to receive a diet containing either sorghum grain orcrude glycerol as energy sources, and housed in individual (twelve animals) or collective pens (16 animals in four pens) at the School-Farm of IF Goiano (Iporá Campus). The experiment lasted 98 days (14 for adaptation and 84 for data collection). Feeding behaviors (eating, rumination, and resting) were determined every 14 days for one-hour intervals in four times post-feeding (0, 1, 5, and 9 hours). Feed sorting was evaluated every 14 days in three times post-feeding (4, 10, and 24 hours). Time spent eating was reduced (P<0.05) by crude glycerol in comparison with the sorghum grain diet (18.19 vs. 12.29 minutes/hour, sorghum vs. glycerol, respectively), while animals fed crude glycerol increased (P<0.05) the time spent resting compared with sorghum grain-fed animals (26.23 vs. 32.85 minutes/hour, sorghum vs. glycerol, respectively). Substituting sorghum grain with crude glycerol increased (P<0.05) the preference for long (44.77 vs. 106.66%, sorghum vs. glycerol, respectively), medium (64.95 vs. 105.78%, sorghum vs. glycerol, respectively), and short (88.57 vs. 101.29%, sorghum vs. glycerol, respectively) particles, whereas sorghum grain increased (P<0.05) the preference for fine particles of the diet (112.36 vs. 100.03%, sorghum vs. glycerol, respectively). Crude glycerol can be recommended as a replacement for sorghum grain in rations fed to beef cattle.(AU)

Behaviors of beef cattle fed crude glycerol as a replacement for sorghum grain

The study of the animal behavior is a useful tool to comprehend the performance of beef animals finished in feedlots. Twenty-eight non-castrated Nellore males with initial body weight of 441 kg and 21.5 months of age were randomly assigned to receive a diet containing either sorghum grain orcrude glycerol as energy sources, and housed in individual (twelve animals) or collective pens (16 animals in four pens) at the School-Farm of IF Goiano (Iporá Campus). The experiment lasted 98 days (14 for adaptation and 84 for data collection). Feeding behaviors (eating, rumination, and resting) were determined every 14 days for one-hour intervals in four times post-feeding (0, 1, 5, and 9 hours). Feed sorting was evaluated every 14 days in three times post-feeding (4, 10, and 24 hours). Time spent eating was reduced (P<0.05) by crude glycerol in comparison with the sorghum grain diet (18.19 vs. 12.29 minutes/hour, sorghum vs. glycerol, respectively), while animals fed crude glycerol increased (P<0.05) the time spent resting compared with sorghum grain-fed animals (26.23 vs. 32.85 minutes/hour, sorghum vs. glycerol, respectively). Substituting sorghum grain with crude glycerol increased (P<0.05) the preference for long (44.77 vs. 106.66%, sorghum vs. glycerol, respectively), medium (64.95 vs. 105.78%, sorghum vs. glycerol, respectively), and short (88.57 vs. 101.29%, sorghum vs. glycerol, respectively) particles, whereas sorghum grain increased (P<0.05) the preference for fine particles of the diet (112.36 vs. 100.03%, sorghum vs. glycerol, respectively). Crude glycerol can be recommended as a replacement for sorghum grain in rations fed to beef cattle.

Feed sorting of beef cattle in a feedlot fed different forages and housed in individual or collective pens / Seleção de partículas da dieta de bovinos de corte em confinamento alimentados com diferentes forragens e alojados em baias individuais ou coletivas

Feed sorting is a natural behavior of cattle that can result in inconsistencies in the nutritive value of the diet. Twenty-four non-castrated F1 Red Norte × Nelore males with an average initial body weight of 439.8 ± 59.6 kg and 21.7± 2.7 months of age were distributed in three experimental groups, and housed either in individual (12 animals) or collective pens (12 animals in three collective pens) at the Cattle Research and Education Center of the Instituto Federal de Educação, Ciência e Tecnologia Goiano (Campus Iporá). The experiment lasted 84 days (14 days of adaptation and 70 days for data collection). Animals were fed diets containing sugar cane in natura (CI), sugar cane silage (SC) or corn silage (CS) as sources of forage. Feed sorting was determined every 14 days at 4, 10, and 24 hours post-feeding using a three-screen and a bottom pan (Penn State Particle Separator) to yield long (>19 mm), medium ( 19, >8 mm), short ( 8, >1.18 mm) and fine ( 1.18 mm) particles. There was no effect (P>0.05) of source of forage on feed sorting for long, medium, and short particles. CS increased (P 0.05) sorting against fine particles compared with CI and SC. There was no response (P>0.05) of type of housing on feed sorting. The sources of forage evaluated in this study resulted in preferential consumption for long and medium particles, which may be beneficial for rumen health.(AU)

O consumo seletivo de partículas da ração é um hábito natural dos bovinos que pode resultar em inconsistências no valor nutricional da dieta. Vinte e quatro machos não castrados F1 Red Norte × Nelore com peso vivo médio inicial de 439,8 ± 59,6 kg e 21,7 ± 2,7 meses de idade foram distribuídos em três grupos experimentas e alojados em baias individuais (12 animais) ou coletivas (12 animais em três baias) no Setor de Bovinocultura do Instituto Federal de Educação, Ciência e Tecnologia Goiano (Campus Iporá). O experimento teve duração de 84 dias (14 dias para adaptação e 70 para coleta de dados). Os animais receberam dietas contendo cana-de-açúcar in natura (CI), silagem de cana (SC) ou silagem de milho (SM) como fontes de forragem. Avaliou-se o consumo seletivo de partículas da ração a cada 14 dias às 4, 10 e 24 horas pós-alimentação, utilizando-se um conjunto com três peneiras e um fundo liso (“Penn State Particle Separator”) para determinar partículas longas (>19 mm), médias (<19, >8 mm), curtas (<8, >1,18 mm) e muito curtas (<1,18 mm). Não houve efeito (P>0,05) de fonte de forragem sobre o consumo seletivo de partículas longas, médias e curtas. A SM aumentou (P<0,05) a rejeição pelas partículas muito curtas, em comparação com a CI e a SC. Não houve resposta (P>0,05) de alojamento sobre a seleção de partículas. As fontes de forragem avaliadas nesse estudo determinaram consumo preferencial das partículas longas (>19 mm) e médias (<19, >8 mm), o que pode ser benéfico para a saúde do rúmen.(AU)

Feed sorting of beef cattle in a feedlot fed different forages and housed in individual or collective pens / Seleção de partículas da dieta de bovinos de corte em confinamento alimentados com diferentes forragens e alojados em baias individuais ou coletivas

Feed sorting is a natural behavior of cattle that can result in inconsistencies in the nutritive value of the diet. Twenty-four non-castrated F1 Red Norte × Nelore males with an average initial body weight of 439.8 ± 59.6 kg and 21.7± 2.7 months of age were distributed in three experimental groups, and housed either in individual (12 animals) or collective pens (12 animals in three collective pens) at the Cattle Research and Education Center of the Instituto Federal de Educação, Ciência e Tecnologia Goiano (Campus Iporá). The experiment lasted 84 days (14 days of adaptation and 70 days for data collection). Animals were fed diets containing sugar cane in natura (CI), sugar cane silage (SC) or corn silage (CS) as sources of forage. Feed sorting was determined every 14 days at 4, 10, and 24 hours post-feeding using a three-screen and a bottom pan (Penn State Particle Separator) to yield long (>19 mm), medium ( 19, >8 mm), short ( 8, >1.18 mm) and fine ( 1.18 mm) particles. There was no effect (P>0.05) of source of forage on feed sorting for long, medium, and short particles. CS increased (P 0.05) sorting against fine particles compared with CI and SC. There was no response (P>0.05) of type of housing on feed sorting. The sources of forage evaluated in this study resulted in preferential consumption for long and medium particles, which may be beneficial for rumen health.

O consumo seletivo de partículas da ração é um hábito natural dos bovinos que pode resultar em inconsistências no valor nutricional da dieta. Vinte e quatro machos não castrados F1 Red Norte × Nelore com peso vivo médio inicial de 439,8 ± 59,6 kg e 21,7 ± 2,7 meses de idade foram distribuídos em três grupos experimentas e alojados em baias individuais (12 animais) ou coletivas (12 animais em três baias) no Setor de Bovinocultura do Instituto Federal de Educação, Ciência e Tecnologia Goiano (Campus Iporá). O experimento teve duração de 84 dias (14 dias para adaptação e 70 para coleta de dados). Os animais receberam dietas contendo cana-de-açúcar in natura (CI), silagem de cana (SC) ou silagem de milho (SM) como fontes de forragem. Avaliou-se o consumo seletivo de partículas da ração a cada 14 dias às 4, 10 e 24 horas pós-alimentação, utilizando-se um conjunto com três peneiras e um fundo liso (“Penn State Particle Separator”) para determinar partículas longas (>19 mm), médias (8 mm), curtas (1,18 mm) e muito curtas (0,05) de fonte de forragem sobre o consumo seletivo de partículas longas, médias e curtas. A SM aumentou (P0,05) de alojamento sobre a seleção de partículas. As fontes de forragem avaliadas nesse estudo determinaram consumo preferencial das partículas longas (>19 mm) e médias (8 mm), o que pode ser benéfico para a saúde do rúmen.

Impact of feeding cottonseed coproducts on reproductive system of male sheep during peripubertal period

Cottonseed coproducts contain gossypol which can have specific effects upon the male reproductive system. We evaluated the reproductive development of male lambs close to puberty fed on three cotton coproducts. Twenty-four 5-month old male lambs received four diets: 20 % of dry matter intake of whole cottonseed (WCS), high oil cottonseed meal (CSC), cottonseed meal (CSM), and a control group (CTL) without any cottonseed coproducts. Free gossypol intake was 16.32, 6.98, 5.47 and 0 mg kg1 BW1 d1 for WCS, CSC, CSM and CTL, respectively. Every 15 days, the animals were weighted and serum and semen samples were collected. After 95 days, testis samples were collected for analysis under light and transmission electron microscopes. The CTL group had higher testosterone concentrations than CSC at the end of the trial and lower total sperm defects, higher mass movement and higher scores for seminiferous epithelium than other treatments. The WCS and CSC groups showed higher levels of segmental aplasia lesion in sperm than other diets, which showed that high levels of gossypol led to higher occurrence of this lesion. Cottonseed coproducts had a negative impact on the reproductive system of pubertal lambs regardless of gossypol concentration. Therefore, the use of cottonseed coproducts to feed lambs earmarked for reproduction is not safe.

Impact of feeding cottonseed coproducts on reproductive system of male sheep during peripubertal period

Cottonseed coproducts contain gossypol which can have specific effects upon the male reproductive system. We evaluated the reproductive development of male lambs close to puberty fed on three cotton coproducts. Twenty-four 5-month old male lambs received four diets: 20 % of dry matter intake of whole cottonseed (WCS), high oil cottonseed meal (CSC), cottonseed meal (CSM), and a control group (CTL) without any cottonseed coproducts. Free gossypol intake was 16.32, 6.98, 5.47 and 0 mg kg1 BW1 d1 for WCS, CSC, CSM and CTL, respectively. Every 15 days, the animals were weighted and serum and semen samples were collected. After 95 days, testis samples were collected for analysis under light and transmission electron microscopes. The CTL group had higher testosterone concentrations than CSC at the end of the trial and lower total sperm defects, higher mass movement and higher scores for seminiferous epithelium than other treatments. The WCS and CSC groups showed higher levels of segmental aplasia lesion in sperm than other diets, which showed that high levels of gossypol led to higher occurrence of this lesion. Cottonseed coproducts had a negative impact on the reproductive system of pubertal lambs regardless of gossypol concentration. Therefore, the use of cottonseed coproducts to feed lambs earmarked for reproduction is not safe.(AU)

Thermal comfort index and infrared temperatures for lambs subjected to different environmental conditions

There is an abundance of thermal indices with different input parameters and applicabilities. Infrared thermography is a promising technique for evaluating the response of animals to the environment and differentiating between genetic groups. Thus, the aim of this study was to evaluate superficial body temperatures of lambs from three genetic groups under different environmental conditions, correlating these with thermal comfort indices. Forty lambs (18 males and 22 females) from three genetic groups (Santa Inês, Ile de France × Santa Inês and Dorper × Santa Inês) were exposed to three climatic conditions: open air, housed and artificial heating. Infrared thermal images were taken weekly at 6h, 12h and 21h at the neck, front flank, rear flank, rump, nose, skull, trunk and eye. Four thermal comfort indices were calculated using environmental measurements including black globe temperature, air humidity and wind speed. Artificial warming, provided by infrared lamps and wind protection, conserved and increased the superficial body temperature of the lambs, thus providing lower daily thermal ranges. Artificial warming did not influence daily weight gain or mortality. Skin temperatures increased along with increases in climatic indices. Again, infrared thermography is a promising technique for evaluating thermal stress conditions and differentiating environments. However, the use of thermal imaging for understanding animal responses to environmental conditions requires further study.

Thermal comfort index and infrared temperatures for lambs subjected to different environmental conditions

There is an abundance of thermal indices with different input parameters and applicabilities. Infrared thermography is a promising technique for evaluating the response of animals to the environment and differentiating between genetic groups. Thus, the aim of this study was to evaluate superficial body temperatures of lambs from three genetic groups under different environmental conditions, correlating these with thermal comfort indices. Forty lambs (18 males and 22 females) from three genetic groups (Santa Inês, Ile de France × Santa Inês and Dorper × Santa Inês) were exposed to three climatic conditions: open air, housed and artificial heating. Infrared thermal images were taken weekly at 6h, 12h and 21h at the neck, front flank, rear flank, rump, nose, skull, trunk and eye. Four thermal comfort indices were calculated using environmental measurements including black globe temperature, air humidity and wind speed. Artificial warming, provided by infrared lamps and wind protection, conserved and increased the superficial body temperature of the lambs, thus providing lower daily thermal ranges. Artificial warming did not influence daily weight gain or mortality. Skin temperatures increased along with increases in climatic indices. Again, infrared thermography is a promising technique for evaluating thermal stress conditions and differentiating environments. However, the use of thermal imaging for understanding animal responses to environmental conditions requires further study.(AU)

Avaliação ultrasonográfica da qualidade de carcaça de ovinos Santa Inês / Ultrassonography evaluation of sheep carcass quality of Santa Inês breed

A ultrassonografia pode ser uma importante ferramenta para a avaliação da composição da carcaça por ser uma técnica não invasiva que permite quantificar diferentes tecidos em animais vivos. O objetivo deste trabalho foi estimar as correlações entre medidas tomadas in vivo, por meio do ultrassom e do adipômetro, e na carcaça de ovinos da raça Santa Inês. Utilizaram-se 81 machos, entre 8 e 18 meses de idade, com peso médio de 31 kg. As medidas in vivo obtidas por ultrassonografia foram medida diagonal longitudinal, área de olho de lombo longitudinal, medida diagonal transversal e área de olho de lombo transversal. Determinou-se o peso de carcaça quente, rendimento da carcaça, gordura de cobertura da carcaça, comprimento de carcaça, área de olho de lombo da carcaça e peso dos cortes comerciais: pernil, lombo, paleta, costela e pescoço. As análises de variância, componentes principais, regressão polinomial e correlação foram realizadas utilizando-se programa estatístico SAS®. Não houve diferença entre animais castrados e inteiros para qualidade e componentes de carcaça, indicando, portanto, que a castração não proporciona uma carcaça de melhor qualidade. Os animais com os pesos de pernil, paleta e costela maiores apresentam menores peso de pele, altura de cernelha e peso dos órgãos abdominais, caracterizando um biotipo de animal que seria mais desejável a ser selecionado. Peso vivo, comprimento corporal e área de olho de lombo por ultrassom (in vivo) podem ser usados para predizer a área do olho de lombo da carcaça, peso do pernil, comprimento da carcaça, peso da carcaça quente e da meia carcaça. No entanto, o peso do lombo, pescoço, costela, rendimento de carcaça e peso dos órgãos abdominais não podem ser preditos por estas medidas in vivo. As medidas realizadas com adipômetro não apresentaram correlações significativas com medidas da carcaça, o que indica que não são eficientes para esta predição e, portanto, não devem ser utilizadas.

Ultrassonography is an important option to evaluate carcass composition and quality, as it is a non-invasive technique which quantifies different tissues in live animals. The objective of this study was to estimate the correlation between measurements taken in vivo, using ultrasound and skinfold thickness, in sheep carcasses from Santa Inês breed. Eighty-one males, aging 8 to 18 months, and weighting on average 31 kg live weight were used. The measures taken in vivo by ultrassonography were longitudinal diagonal length, longitudinal rib eye area, transversal diagonal length, transversal rib eye area. Hot carcass weight, carcass yield, carcass fat thickness, carcass length, carcass rib eye area and commercial retail cut weight (leg, loin, shoulder, ribs and neck) were determined. The analyses of variance, main components, polynomial regression and correlation were carried out using SAS® statistical program. There was no difference between castrated and intact animals for carcass quality and components, indicating that castration does not provide better carcass quality. Animals with higher leg, shoulder and rib weights had lower skin weight, wither height and weight of abdominal organs, indicating a more desirable body type for selection. Body weight, body length and rib eye area by ultrasound (in vivo) can predict the rib eye area, leg weight, carcass length, hot and half carcass weight. However, loin, neck and rib weights, carcass yield and weight of abdominal organs cannot be predicted by these in vivo measurements. The measurements taken with skinfold showed no significant correlations with carcass measures, which indicates that they are not efficient for prediction of carcass components and therefore should not be used.

Avaliação ultrasonográfica da qualidade de carcaça de ovinos Santa Inês / Ultrassonography evaluation of sheep carcass quality of Santa Inês breed

A ultrassonografia pode ser uma importante ferramenta para a avaliação da composição da carcaça por ser uma técnica não invasiva que permite quantificar diferentes tecidos em animais vivos. O objetivo deste trabalho foi estimar as correlações entre medidas tomadas in vivo, por meio do ultrassom e do adipômetro, e na carcaça de ovinos da raça Santa Inês. Utilizaram-se 81 machos, entre 8 e 18 meses de idade, com peso médio de 31 kg. As medidas in vivo obtidas por ultrassonografia foram medida diagonal longitudinal, área de olho de lombo longitudinal, medida diagonal transversal e área de olho de lombo transversal. Determinou-se o peso de carcaça quente, rendimento da carcaça, gordura de cobertura da carcaça, comprimento de carcaça, área de olho de lombo da carcaça e peso dos cortes comerciais: pernil, lombo, paleta, costela e pescoço. As análises de variância, componentes principais, regressão polinomial e correlação foram realizadas utilizando-se programa estatístico SAS®. Não houve diferença entre animais castrados e inteiros para qualidade e componentes de carcaça, indicando, portanto, que a castração não proporciona uma carcaça de melhor qualidade. Os animais com os pesos de pernil, paleta e costela maiores apresentam menores peso de pele, altura de cernelha e peso dos órgãos abdominais, caracterizando um biotipo de animal que seria mais desejável a ser selecionado. Peso vivo, comprimento corporal e área de olho de lombo por ultrassom (in vivo) podem ser usados para predizer a área do olho de lombo da carcaça, peso do pernil, comprimento da carcaça, peso da carcaça quente e da meia carcaça. No entanto, o peso do lombo, pescoço, costela, rendimento de carcaça e peso dos órgãos abdominais não podem ser preditos por estas medidas in vivo. As medidas realizadas com adipômetro não apresentaram correlações significativas com medidas da carcaça, o que indica que não são eficientes para esta predição e, portanto, não devem ser utilizadas.(AU)

Ultrassonography is an important option to evaluate carcass composition and quality, as it is a non-invasive technique which quantifies different tissues in live animals. The objective of this study was to estimate the correlation between measurements taken in vivo, using ultrasound and skinfold thickness, in sheep carcasses from Santa Inês breed. Eighty-one males, aging 8 to 18 months, and weighting on average 31 kg live weight were used. The measures taken in vivo by ultrassonography were longitudinal diagonal length, longitudinal rib eye area, transversal diagonal length, transversal rib eye area. Hot carcass weight, carcass yield, carcass fat thickness, carcass length, carcass rib eye area and commercial retail cut weight (leg, loin, shoulder, ribs and neck) were determined. The analyses of variance, main components, polynomial regression and correlation were carried out using SAS® statistical program. There was no difference between castrated and intact animals for carcass quality and components, indicating that castration does not provide better carcass quality. Animals with higher leg, shoulder and rib weights had lower skin weight, wither height and weight of abdominal organs, indicating a more desirable body type for selection. Body weight, body length and rib eye area by ultrasound (in vivo) can predict the rib eye area, leg weight, carcass length, hot and half carcass weight. However, loin, neck and rib weights, carcass yield and weight of abdominal organs cannot be predicted by these in vivo measurements. The measurements taken with skinfold showed no significant correlations with carcass measures, which indicates that they are not efficient for prediction of carcass components and therefore should not be used.(AU)

Uso de subprodutos do algodão na nutrição de ruminantes / Use of cotton byproducts in ruminant nutrition

O caroço, o farelo e a torta de algodão destacam-se como fonte alternativa de proteina e energia, que pode diminuir o custo da dieta dos animais. Estes produtos apresentam elevada quantidade de ácidos graxos, o que pode propiciar maior deposição de gordura na carcaça e maior ganho em peso, além de uma carne de melhor qualidade. Uma das grandes limitações para o uso desses produtos na nutrição animal é a presença de quantidades elevadas de gossipol (Gp). Esta substância é tóxica para os animais, sendo bastante conhecidos os seus efeitos deletérios no sistema reprodutivo de machos, principalmente em animais jovens. Esta caracteristica tem criado alguma resistência ao uso desses produtos na nutrição de ruminantes. Entretanto, apesar do potencial tóxico do Gp e de fatores de risco associados com a diminuição da fertilidade, os subprodutos de algodão oferecem uma alternativa que pode ser segura para a alimentação de ruminantes quando o teor desta substância no alimento é conhecido e utilizado em níveis recomendados. Dessa forma, realizou-se a presente revisão objetivando esclarecer dúvidas quanto ao uso dos subprodutos do algodão na alimentação de ruminantes, evidenciando resultados de efeitos no sistema reprodutivo e de desempenho dos animais.

The whole cotton seed, the bran and pie stands out as an alternative source of protein and energy, which can decrease the cost of the animal diet. These products feature high amounts of fatty acids, which may provide greater deposition of carcass fat and increased weight gain, and better meat quality. A major limitation for using these products in animal nutrition is the presence of high amounts of gossypol. This substance is toxic to animals and their harmful effects are well known on the reproductive system of males, especially in young animals. This feature has created some resistance in using these products in ruminant nutrition. Despite the potential toxic effects of Gp and risk factors associated with declining fertility, the byproducts of cotton offer an alternative that can be safely fed to ruminants if the level of Gp in the food is known and used at recommended levels. Thus, we carried out this review aiming to clarify the doubts regarding the use of cotton byproducts in ruminant feeding, presenting results of effects on the reproductive system and in the performance of animals.