203 research outputs found
Linkage disequilibrium in Brazilian Santa Inês breed, \u3ci\u3eOvis aries\u3c/i\u3e
For genomic selection to be successful, there must be sufficient linkage disequilibrium between the markers and the causal mutations. The objectives of this study were to evaluate the extent of LD in ovine using the Santa Inês breed and to infer the minimum number of markers required to reach reasonable prediction accuracy. In total, 38,168 SNPs and 395 samples were used. The mean LD between adjacent marker pairs measured by r2 and |D′| were 0.166 and 0.617, respectively. LD values between adjacent marker pairs ranged from 0.135 to 0.194 and from 0.568 to 0.650 for r2 for |D′| across all chromosomes. The average r2 between all pairwise SNPs on each chromosome was 0.018. SNPs separated by between 0.10 to 0.20 Mb had an estimated average r2 equal to 0.1033. The identified haplotype blocks consisted of 2 to 21 markers. Moreover, estimates of average coefficients of inbreeding and effective population size were 0.04 and 96, respectively. LD estimated in this study was lower than that reported in other species and was characterized by short haplotype blocks. Our results suggest that the use of a higher density SNP panel is recommended for the implementation of genomic selection in the Santa Inês breed
Long-term Bias of Internal Markers in Sheep and Goat Digestion Trials
Two digestion trials, one with sheep and another with goats, were conducted to evaluate the long-term bias (LTB) of the indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) internal markers. The study used eight Santa Inês castrated male sheep (average body weight of 16.6 kg) distributed in two 4×4 Latin squares and eight Saanen castrated male goats (average body weight of 22.6 kg) distributed in two 4×4 Latin squares. The experiments were conducted simultaneously, and the animals were housed in 1.2 m2 individual pens with wood-battened floors equipped with individual feeders and drinkers. The animals received isonitrogenous diets that were offered ad libitum and contained 14% crude protein and 70% sugar cane (with 0, 0.75, 1.5 or 2.25% CaO, in natural matter percentage), corrected with 1% urea and 30% concentrate. The experiment consisted of four experimental periods of 14 d each, with the feed, leftovers and feces sampled on the last four days of each period. The marker concentrations in the feed, leftovers and fecal samples were estimated by an in situ ruminal incubation procedure with a duration 240 h. The relationship between the intake and excretion of the markers was obtained by adjusting a simple linear regression model, independently from the treatment (diets) fixed effects and Latin squares. For both the sheep and goats, a complete recovery of the iDM and iNDF markers was observed (p>0.05), indicating the absence of LTB for these markers. However, the iADF was not completely recovered, exhibiting an LTB of −9.12% (p<0.05) in the sheep evaluation and −3.02% (p<0.05) in the goat evaluation
Parâmetros qualitativos da silagem de milheto amonizada com ureia, a diferentes densidades de compactação
The objective of this work was to evaluate the effects of urea ammoniation of pearl millet silage, at different compaction densities, on chemical composition, losses in the ensilage process, fermentation profile, microbial population count, and aerobic stability. The experimental design was completely randomized, in a 2×4 factorial arrangement, with two compaction densities (600 and 800 kg m-3) and four urea levels (0, 2, 4, and 6% on a dry matter basis), with five replicates. For the aerobic stability assay, the experimental design was completely randomized, in a 2×4 factorial arrangement, with two times (0 and 72 hours) and four urea levels (0, 2, 4, and 6%, on dry matter basis), with five replicates. The urea levels interacted significantly with density as to the contents of organic matter, crude protein, neutral detergent insoluble protein, and as to dry matter recovery; and with exposure hours as to the contents of acid detergent fiber and lignin. Molds and yeasts were not observed in the ammoniated silages. The 800 kg m-3 density reduced losses in the fermentation process of pearl millet silage, and promoted better nutritive value than the compaction at 600 kg m-3. The use of urea does not reduce losses and does not improve the aerobic stability of silages; however, it controls mold growth after silage exposure to air.O objetivo deste trabalho foi avaliar a amonização com ureia em silagens de milheto com diferentes densidades de compactação, quanto aos seus efeitos sobre a composição químico-bromatológica, as perdas no processo de ensilagem, o perfil fermentativo, a contagem de populações microbianas e a estabilidade aeróbia. Utilizou-se o delineamento inteiramente casualizado, em arranjo fatorial 2×4, com duas densidades de compactação (600 e 800 kg m-3) e quatro níveis de ureia (0, 2, 4 e 6% com base na matéria seca), com cinco repetições. Na avaliação da estabilidade aeróbia, utilizou-se o delineamento experimental inteiramente casualizado, em arranjo fatorial 2×4, com dois tempos (0 e 72 horas) e quatro níveis de ureia (0, 2, 4 e 6%, com base na matéria seca), com cinco repetições. Os níveis de ureia interagiram significativamente com a densidade, quanto aos teores de matéria orgânica, proteína bruta, proteína insolúvel em detergente neutro e quanto à recuperação de matéria seca; e com o tempo de exposição, quanto aos teores de fibra em detergente ácido e de lignina. Não se observaram mofos e leveduras nas silagens amonizadas. A densidade de compactação de 800 kg m-3 reduziu as perdas no processo de ensilagem do milheto e proporcionou silagem de maior valor nutritivo do que a compactação a 600 kg m-3. O uso de ureia não reduz as perdas e não melhora a estabilidade aeróbia das silagens; no entanto, controla o crescimento de mofos após a exposição da silagem ao ar
Desempenho de bijupirá criado em águas salobras e alimentado com diferentes níveis de arraçoamento
The objective of this work was to evaluate different feeding rates on the productive performance of cobia (Rachycentron canadum) grown in brackish waters. For the experiment, 1,600 juveniles were distributed in 16 enclosures installed in an estuarine pond. Four different feeding rates were evaluated: 1, 3, 5, and 7% live weight (LW) per day. The following performance parameters were assessed: survival, final biomass, specific growth rate, daily weight gain, apparent feed conversion, protein efficiency rate, lipid efficiency rate, and hepatosomatic index. Survival was greater than 80% at all feeding rates. The most efficient feed conversion rate was obtained with the feeding rate of 5% LW per day, which also resulted in better values for the hepatosomatic index. The rate of 5% LW per day provides a better productive performance for cobia in brackish waters.O objetivo deste trabalho foi avaliar diferentes taxas de arraçoamento no desempenho produtivo de bijupirá (Rachycentron canadum) criado em águas salobras. Para o experimento, 1.600 juvenis foram distribuídos em 16 cercados instalados em viveiro, em área estuarina. Foram avaliados quatro diferentes níveis de arraçoamento: 1, 3, 5 e 7% do peso vivo (PV) por dia. Avaliaram-se os seguintes parâmetros de desempenho: sobrevivência, biomassa final, taxa de crescimento específico, ganho de peso diário, conversão alimentar aparente, taxa de eficiência proteica, taxa de eficiência lipídica e índice hepatossomático. A sobrevivência foi superior a 80% em todos os níveis de arraçoamento. A conversão alimentar aparente mais eficiente foi obtida com a taxa de arraçoamento de 5% do PV por dia, que também resultou em melhores valores para o índice hepatossomático. A taxa de 5% do PV por dia proporciona melhor desempenho produtivo para o bijupirá em águas salobras
Nutritive value of sugarcane bagasse ammoniated with four urea doses
O objetivo deste trabalho foi avaliar a composição químico-bromatológica e a digestibilidade in vitro do bagaço de cana-de-açúcar, submetido à amonização com uréia. Os tratamentos constaram de quatro doses de uréia, adicionadas ao bagaço de cana-de-açúcar, e adição de 1,2% de soja como fonte de urease. O delineamento experimental utilizado foi o inteiramente casualizado. O bagaço foi armazenado em silos de PVC com capacidade para 5,3 L, que foram abertos depois de 110 dias de amonização. Com a adição das doses de uréia ao bagaço, houve aumento linear nos teores de proteína bruta. Os teores de fibra em detergente neutro, fibra em detergente ácido, hemicelulose, celulose, lignina e carboidratos totais diminuíram, enquanto os teores de nitrogênio insolúvel em detergente ácido, nitrogênio insolúvel em detergente neutro, carboidratos não fibrosos, nitrogênio amoniacal e pH aumentaram, significativamente, com a adição de uréia. Nas doses avaliadas, a uréia adicionada ao bagaço promove aumento no conteúdo dos compostos nitrogenados, diminuição dos componentes fibrosos e aumenta a digestibilidade in vitro da matéria seca. Estimada pela equação de regressão, a adição de 2,62% de uréia ao bagaço de cana fornece o teor mínimo de proteína bruta para o bom funcionamento do rúmen.The objective this experiment was to evaluate chemical-bromatologic composition and in vitro dry matter digestibility of sugarcane bagasse submitted to ammonization with urea. The treatments were four urea dose added to the sugarcane bagasse and addition of 1.2% (DM basis) of soybean as urease source. The experimental design utilized was a completely randomized. The bagasse was stored in PVC silos with 5.3 L capacity, which were opened after 110 days of ammonization. With the urea dose addition to the bagasse, crude protein levels increased linearly. The neutral detergent fiber, acid detergent fiber, hemicelluloses, cellulose, lignin and total carbohydrates levels decreased, while the acid detergent insoluble nitrogen, neutral detergent insoluble nitrogen, nonfibrous carbohydrates, ammonia nitrogen levels and pH increased significantly with urea addition. At evaluated dose, the urea added to bagasse provides increase in nitrogen compounds content, decrease of fiber compounds, and increases the in vitro dry matter digestibility. Estimated by regression equation, the addition of 2.62% urea to sugarcane bagasse provides the minimum crude protein level to good functioning of the rumen
Apparent digestibility of diets containing cocoa meal and palm kernel cake in lactating goats
O objetivo deste trabalho foi avaliar a digestibilidade aparente dos nutrientes de dietas, contendo farelo de cacau (Theobroma cacao L.) ou torta de dendê (Elaeis guineensis Jacq.), em substituição parcial ao concentrado à base de milho e farelo de soja, na alimentação de cabras lactantes. Foram utilizadas cinco cabras da raça Saanen, aos 60 dias de lactação, em experimento delineado em quadrado latino 5x5, com duração de 14 dias, dos quais 10 dias de adaptação e quatro para coleta dos dados. As dietas, formuladas para possibilitar produção de 2 kg de leite por dia, constituíram-se de 36% de volumoso e 64% de concentrado. Utilizou-se, como volumoso, a silagem de milho e concentrado padrão, com substituição de 0%, 15% e 30% pelo farelo de cacau ou torta de dendê. Houve redução na digestibilidade real da proteína bruta, com a inclusão do farelo de cacau, a 15% e 30%. O coeficiente de digestibilidade aparente, do extrato etéreo das dietas com 30% de torta de dendê, foi maior que o de 15% de farelo de cacau. Os subprodutos, em razão da digestibilidade aparente, apresentam viabilidade de uso, como alternativa na dieta de cabras em lactação.The objective of this work was to evaluate nutrients apparent digestibility of diets containing cocoa (Theobroma cacao L.) meal or palm kernel (Elaeis guineensis Jacq.) cake, which partially replaced corn and soybean meal concentrate in lactating goats feeding. Five Saanen goats, in 60 days of lactation, were used in a 5x5 latin square experimental design, during 14 days, comprehending an adaptation period of 10 days and four days for data collection. Diets formulated to allow milk production of 2 kg day-1 consisted of 36% roughage and 64% concentrate. The roughage used was corn silage and 0%, 15% and 30% of cocoa meal or palm kernel cake substituted the standard concentrate. There was reduction of crude protein real digestibility with inclusion of cocoa meal (15% and 30%). The ether extract apparent digestibility coefficient of diets, with 30% palm kernel cake, was greater than that of 15% cocoa meal. The by-products have potential as alternative feed for lactating goats, based on their apparent digestibility
Forage availability in Xaraés grass pastures subjected to nitrogen sources of the slow and fast release
La N-(n-butil) triamida tiofosfórica (NBPT) es un inhibidor de la ureasa usado en los sistemas agrícolas para reducir las pérdidas por volatilización de NH3 y maximizar el uso del nitrógeno ureico (N). Se realizó un estudio de campo para evaluar el efecto de la urea tratada con NBPT sobre la densidad volumétrica y la masa de forraje en el pasto Brachiaria brizantha cv. Xaraés. El periodo experimental fue de un año (septiembre 2017 a septiembre 2018). El diseño experimental fue de bloques completamente aleatorios con un arreglo factorial de 3×2×4: tres estaciones del año (lluvia, sequía y transición), dos fuentes de urea (convencional y tratada con NBPT), y cuatro tasas de N (0, 80, 160 y 240 kg N ha-1 año-1). Se hicieron tres réplicas. Ambas fuentes de nitrógeno tuvieron un efecto positivo (P<0.0001) sobre la densidad aparente, la masa de forraje y el estrato de pastoreo durante la estación de lluvia y la de transición. También produjeron aumentos de N en los pastos. La relación hoja:tallo disminuyó linealmente (P<0.0045) a medida que aumentaron las tasas de N; la relación mayor fue durante la estación de lluvia y la menor en la estación de sequía. A la tasa de 80 kg N ha-1 año-1, hubo una diferencia (P=0.0042) entre las fuentes de N. A esta tasa la urea convencional produjo una mayor (P=0.0006) masa de forraje total, masa de forraje pospastoreo (P= 0.0042) y densidad volumétrica del forraje (P=0.0006). En las estaciones de lluvia y de transición, la aplicación de N, cual sea la fuente, resultó en un aumento en la masa y la densidad volumétrica del forraje en praderas de pasto Xaraés hasta la tasa de 240 kg N ha-1 año-1.The N-(n-butyl) thiophosphoric triamide (NBPT), a urease inhibitor, has been reported as one of the most promising compounds to reduce losses by volatilization, and to maximize the use of urea nitrogen (N) in agricultural systems. A field study was carried out to examine urease inhibitors' potential about volumetric density and forage mass grass (Brachiaria brizantha cv. Xaraés) to N application. The experiment was carried out from September 2017 to September 2018. The experimental design used was complete randomized blocks in the 3×2×4 factorial array, considering: three periods of the year (wet season, dry season, and the transition), two sources of urea (conventional urea and NBPT–treated urea), and four N rates (0, 80, 160 and 240 kg N ha-1 yr-1), replicated three times. Nitrogen sources promoted a positive effect (P<0.0001) on bulk density, forage mass, and in the grazing stratum during the wet season and the transition season, with increasing N rates in pastures. The leaf: stem ratio decreased linearly (P<0.0045) as increased N rates, and the higher ratio during the wet season and lower in the dry season of the year. For the rates of 80 kg N ha-1 yr-1, there was a significant difference (P=0.0042) between sources, with greater (P=0.0006) forage mass of 0–30 cm, post-grazing forage mass (P=0.0042) and forage volumetric density (P=0.0006), when utilized the conventional urea. The application of N, regardless of the source, provides an increase in forage mass and volumetric density in Xaraés grass pastures up to a dose of 240 kg N ha-1 yr-1, in the transition season and wet season
Qualitative parameters of pearl millet silage ammoniated with urea, at different compaction densities
Pic Maurice. Note sur le genre Rhipidius Thunb. [Col.]. In: Bulletin de la Société entomologique de France, volume 10 (18),1905. p. 252
Forages dry matter, fibrous fraction and crude protein ruminal degradability
O objetivo deste trabalho foi avaliar a degradabilidade ruminal da matéria seca, da fibra em detergente neutro, da fibra em detergente ácido e da proteína bruta da alfafa (Medicago sativa), aveia-preta (Avena strigosa), leucena (Leucaena leucocephala) e guandu (Cajanus cajan). Amostras de 3 g das forragens foram incubadas no rúmen de três novilhos por períodos de 0, 6, 12, 24, 36, 48 e 72 horas. As degradabilidades efetivas da matéria seca da alfafa e da aveia, para a taxa de passagem de 5% por hora, foram elevadas (acima de 60%). A leucena e o guandu apresentaram valores inferiores, 50,9 e 56,0%, respectivamente. A partir de 24 horas de incubação, a aveia se destacou com maior desaparecimento da fibra em detergente neutro e da fibra em detergente ácido, e ainda apresentou as mais elevadas taxas de degradação efetiva destas frações. A aveia foi a forragem que apresentou maior degradabilidade da matéria seca, da fibra em detergente neutro, da fibra em detergente ácido e da proteína bruta no rúmen. O guandu, entretanto, foi a forragem com as piores taxas de degradação.The objective of this work was to evaluate ruminal degradability of dry matter, neutral detergent fiber, acid detergent fiber and crude protein of alfalfa (Medicago sativa), black oat (Avena strigosa), leucaena (Leucaena leucocephala) and pigeon pea (Cajanus cajan). Samples of 3 g of forages were incubated in the rumen of three steers for 0, 6, 12, 24, 36, 48 and 72 hours periods. The dry matter effective degradabilities of alfalfa and oat, for a passage rate of 5%/hour, were high (over 60%). However, leucaena and pigeon pea showed lower values, 50.9 and 56.0%, respectively. From 24-hour incubation period on, the oat presented the highest neutral detergent fiber and acid detergent fiber disappearance and showed the greatest effective degradation rates of these fractions. The oat was the forage with the highest dry matter, neutral detergent fiber, acid detergent fiber and crude protein ruminal degradability. Pigeon pea, however, was the forage that showed the worst degradation rates
Methodology for studying the behavior of calves in confinement during the post-weaning phase
Twelve 60-day old, 120 kg mean initial age and weight, post-weaning Holstein calves were randomly distributed between two treatments (concentrates in meal or pellet form). The diet consisted of hay ad libitum and 2 kg daily of concentrates. Each animal was observed at six different time intervals: 5, 10, 15, 20, 25, and 30 minutes. A repeated measure of experimental units design, in a 2 x 6 factorial arrangement was used. The objective was to identify the most adequate time intervals to study ingestive behavior compared to the standard 5-minute observation interval scale. Treatments had no effect on the variables studied. Feeding, ruminating and idle activities duration times did no differ (P>0.05) among time interval scales. However, only in the 5- and 10-minute scales were the number of discrete periods of feeding, ruminating and idleness and their duration, statistically the same (P>0.05). Use of scales of up to 10-minute intervals between observations is recommended for this type of experiment (Pt
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