Sidnei Tavares dos Reis

Variability in reproductive traits in Jatropha curcas L. accessions during early developmental stages under warm subtropical conditions

Variability in floral, fruit, and seed characteristics, and oil content of 15 accession of Jatropha curcas during early development were assessed during two flowering periods in south Florida subtropical climate. The two flowering periods had leaf flushing in March. Field evaluation using 18 quantitative traits showed significant variation among accessions. The number of female flowers and female : male flower ratio ranged from 1 to 15 and 1 : 8.8 to 1 : 67.8, respectively. Fruit set by natural pollination was 89 and 66% during the first (1st) and second (2nd) flowering periods, respectively. A higher number of female‐type inflorescences were observed during summer. There were significant differences in seed traits, except for number of seeds per fruit. Accession TREC 31 had the highest individual seed dry weight and 100‐seed weight (0.83 g and 79.7 g, respectively). The oil content varied from 19.30% to 35.62%. Seed dry weight had positive correlation with seed fresh weight, seed length, seed thickness, seed width, and 100‐seed weight, but negative correlation with oil content. Based on the cluster analysis using 15 morphological traits, jatropha accessions were grouped into five main clusters and accessions from different geographic regions grouped together in a cluster. Principal component analyses (PCA) revealed morphological variation. The first three components explained 73.5% of the total variation and seed dry weight, 100‐seed weight, total flowers per inflorescence, male flowers per inflorescence and fruit set can be used to distinguish accessions. The PCA also indicated that flowering traits were more influenced by seed origin while seed traits were affected by flowering spans. Although evaluations were performed in plants during the juvenile phase, accessions TREC 31 and TREC 55 had superior averages for almost all characters evaluated. These results provide a preliminary assessment of the high variability in jatropha accessions evaluated and their potential for use in breeding and genetic improvement programs.

Viabilidade dos grãos de pólen de flores de pinheira (Annona squamosa) em diferentes horários

No manejo do cultivo da pinha (Annona squamosa), a polinizacao artificial e uma pratica preconizada para, obter maior pegamento dos frutos bem como uniformizacao do formato dos mesmos. Nesse sentido, conduziu-se este trabalho, com o objetivo de avaliar a viabilidade dos graos de polen de flores de pinheira em diferentes horarios de coleta. O polen foi obtido a partir de flores no estadio funcionalmente estaminada. Foram avaliados oito horarios de coleta de polen: zero hora, 1 hora, 2 horas, 3 horas, 4 horas, 5 horas, 6 horas e 7 horas da manha. Foi utilizado meio de cultura padrao para germinacao de polen, com concentracao de 10% de sacarose. As flores foram coletadas nos horarios estabelecidos e os graos de polen foram retirados das anteras com auxilio de um pincel numero 2 e em seguida inoculados em placas de Petri contendo o meio de cultura. O delineamento experimental foi inteiramente casualizado com quatro repeticoes, sendo cada parcela experimental constituida por duas placas Petri. Foram contados 100 graos de polen por placa. Apos 6 horas de inoculacao, os graos de polen foram visualizados sob lupa. Foram considerados germinados os graos de polen que possuiam tubo polinico com tamanho igual ou superior ao diâmetro do proprio polen. Nao foram observadas diferencas significativas entre o horario de coleta dos graos de polen. A percentagem media da germinacao variou de 46,75% a 53,62% dos graos de polen germinados.

Perfil de fermentação e perdas na ensilagem de diferentes frações da parte aérea de quatro variedades de mandioca

Objetivou-se com este trabalho determinar o perfil fermentativo das silagens de quatro variedades de mandioca. No estudo do pH, do nitrogenio amoniacal, dos acidos orgânicos, do indice de recuperacao de materia seca (MS) e da densidade das silagens, utilizou-se delineamento em blocos casualizados com esquema fatorial 4 × 3, com quatro repeticoes, sendo quatro variedades de mandioca (Amarelinha, Olho Roxo, Periquita e Sabara) e tres fracoes da parte aerea (planta inteira, sobras do plantio e terco superior). No estudo da perda de materia seca por gases e efluentes, o esquema fatorial utilizado foi 4 × 3 × 7, com quatro repeticoes, composto de quatro variedades de mandioca, tres fracoes da parte aerea e sete datas de abertura dos silos (1, 3, 5, 7, 14, 28 e 56 dias apos a ensilagem). A ensilagem foi realizada em silos de laboratorio confeccionados em tubos de PVC. Os dados obtidos foram submetidos a analise de variância e, para comparacao das medias, foi realizado o teste de Scott-Knott a 5% de significância. Nao houve diferenca significativa entre os valores de pH, acidos orgânicos e densidade das silagens das diferentes variedades, entretanto, o pH, o nitrogenio amoniacal e a densidade das silagens das fracoes da parte aerea diferiram entre as variedades. O nitrogenio amoniacal das silagens tambem diferiu entre as variedades. Embora a forragem fresca tenha apresentado valores de materia seca inferiores a 30%, os valores de pH foram satisfatorios. As silagens das fracoes terco superior e sobras do plantio tem otima qualidade fermentativa. As silagens deste estudo apresentam baixa perda de materia seca.

Caracterísiticas fermentativas de silagens de cana-de-açúcar com aditivos

Objetivou-se por meio deste trabalho avaliar as caracteristicas fermentativas de silagens de duas variedades de cana-de-acucar com diferentes aditivos. O experimento foi conduzido no Departamento de Ciencias Agrarias da UNIMONTES, Campus de Janauba-MG. Utilizou-se um delineamento inteiramente casualizado com esquema fatorial 2 x 5 + 2, sendo duas variedades de cana-de-acucar (RB 86 7515 e IAC 86 2480) e cinco aditivos (ureia, NaOH, CaO, milho e Lactobacillus buchneri) com tres repeticoes e um tratamento sem aditivo por variedade, com a abertura dos silos sendo feita aos 60 dias da ensilagem. Os aditivos NaOH e CaO propiciaram reducoes nas perdas por gases e efluentes das silagens de cana-de-acucar. A variedade IAC 86 2480 apresentou melhor indice de recuperacao de materia seca. Os aditivos NaOH e L. buchneri reduziram a atividade de agua na variedade IAC 86 2480. O milho e L. buchneri propiciaram menores valores de pH. A adicao de ureia elevou significativamente os valores de nitrogenio amoniacal. As silagens aditivadas com NaOH e CaO apresentaram elevados teores de acido latico e baixos teores de etanol. Os teores de acido acetico em porcentagem da materia seca foram elevados em todos os tratamentos. Ja o acido propionico e o butirico encontram-se dentro da faixa ideal, para o processo fermentativo. A utilizacao dos aditivos NaOH e CaO resultou em uma silagem com boas caracteristicas fermentativas e a melhor variedade para o processo de ensilagem foi a IAC 86 2480.

Degradabilidade in situ das silagens de variedades de cana-de açúcar com aditivos

The aim of this work was to evaluate the in situ degradability of the dry matter, crude protein and neutral detergent fiber of two sugarcane varieties ensiled with additives. The evaluation of the degradability was carried out according to a random blocks design, in factorial scheme 2 x 6, being two cane varieties (IAC 86-2480 and RB 86-7515), and five additives (urea, NaOH, CaO, corn and Lactobacillus buchneri), plus the control silage, with 3 blocks (animals). The NaOH and the CaO increased the values of soluble fraction and the effective degradability of dry matter. The soluble fraction and the effective degradability of the crude protein were higher with urea. The effective degradability of the neutral detergent fiber of the two varieties was higher in the silages with NaOH and CaO. The silages treated with NaOH and CaO are the best in nutritional value, because of the highest effective degradability of dry matter and neutral detergent fiber. The IAC 86-2480 variety presents better nutritional value than RB 86-7515, due to the highest effective degradability of dry matter.

Componentes principais das características de carcaças de bovinos anelorados e fontes de variação em lesões

This study was made in order to evaluate the principal components of carcass characteristics in Zebu cattle and variation factors for injuries. We used a database with information from 15,002 carcasses of Zebu cattle. The variables studied were hot carcass weight, carcass conformation, fat thickness score, sexual condition, number of teeth, injuries and distance from the farm to the slaughterhouse. We also raised the finishing system of cattle through information obtained from the technician responsible for the herd. To understand the relationship of the variables, we used the correlation of the principal components and original variables, the factorial plans, the unit circle, cluster analysis and non-parametric tests. The fat thickness score, sexual condition, hot carcass weight, the number of teeth, and farm comprised 68.26% of the total variability. The carcasses conformation and the finishing system explained a low proportion of the variability. Variables as farm, number of teeth, finishing system and fat thickness score influenced the number of injuried carcasses. The sexual condition, hot carcass weight and carcass conformation did not change the proportion of injuried carcasses.

Kinetics of "in vitro" fermentation of the silage shoots of cassava

The objective of this work to determine Kinetics of ruminal fermentation of silages of different fractions of the aerial parts of cassava varieties by technical semiautomatic gas production. The experiment was conducted in a completely randomized design with four replications, arranged in a 4x3 factorial design, four varieties of cassava (Amarelinha, Sabara, Olho Roxo e Periquita) and three fraction of shoots (upper, left over planting and whole plant). The material was ensiled in mini-silos of PVC, being opened after 56 days of fermentation. Silage samples were collected and submitted to pre-dried, ground and then proceeded to test gas production in vitro. The pressure readings of the gases produced during fermentations were performed at 2; 4; 6; 8; 10; 12; 15; 18; 21; 24; 30; 36; 48; 72 and 96 hours after the start of incubations. Pressure readings were made of gases through pressure transducer and subsequently adjusted to the volume of gases. The major ruminal DM disappearance occurred in times between zero and 24 hours. The highest yields of gas per hour were obtained at approximately 48 hours of fermentation for variety in Shiner fraction entire plant. The silages of different varieties and fractions of cassava shoots have the same potential for gas production. However, silage variety of Hopscotch fractions in the upper third of shoot and leftover planting have better effective degradability and potential.

Cinética de fermentação in vitro de fenos da parte aérea de mandioca

The objective of this work to determine Kinetics of ruminal fermentation of silages of different fractions of the aerial parts of cassava varieties by technical semiautomatic gas production. The experiment was conducted in a completely randomized design with four replications, arranged in a 4x3 factorial design, four varieties of cassava (Amarelinha, Sabara, Olho Roxo e Periquita) and three fraction of shoots (upper, left over planting and whole plant). The material was ensiled in mini-silos of PVC, being opened after 56 days of fermentation. Silage samples were collected and submitted to pre-dried, ground and then proceeded to test gas production in vitro. The pressure readings of the gases produced during fermentations were performed at 2; 4; 6; 8; 10; 12; 15; 18; 21; 24; 30; 36; 48; 72 and 96 hours after the start of incubations. Pressure readings were made of gases through pressure transducer and subsequently adjusted to the volume of gases. The major ruminal DM disappearance occurred in times between zero and 24 hours. The highest yields of gas per hour were obtained at approximately 48 hours of fermentation for variety in Shiner fraction entire plant. The silages of different varieties and fractions of cassava shoots have the same potential for gas production. However, silage variety of Hopscotch fractions in the upper third of shoot and leftover planting have better effective degradability and potential.

Rendimento, composição e análise sensorial do queijo minas frescal fabricado com leite de vacas mestiças alimentadas com diferentes volumosos

The objective of this study was to evaluate the physical-chemical and sensory quality and fatty acid profile of Minas cheese produced from milk from crossbred cows fed diets with four roughages (sugar cane, sorghum silage, sunflower silage and pasture of Panicum maximum cv. Tanzania). Yield, physical-chemical composition, fatty acid profile and sensory analysis of Minas cheese, as well as the physical-chemical composition of milk were analyzed. For the experiment, eight 1/2 Holstein/Gir crossbred cows, with lactation period of 180 ± 12 days were distributed in two 4 × 4 latin squares (four animals, four diets and four periods). The experimental periods had a duration of 18 days: 15 days of adaptation and three days of data collection. After cheese processing microbiological, physical-chemical and sensory analysis were done. Cheese samples were frozen and analyzed for fatty acid profile. The fat content of cheese was higher for diets with sugar cane and sunflower silage compared with sorghum silage and pasture of Panicum maximum cv. Tanzania. Cheese produced from milk from cows fed sunflower silage had superior fatty acid composition and nutritional quality indexes, and better profile and higher proportion of unsaturated fatty acids. Cheese yield did not differ between diets containing different roughages. Cheese produced from milk from cows fed a diet with sunflower silage presents higher preference at the sensory analysis test, especially regarding the attribute appearance.

Performance and carcass characteristics of lambs fed a solution of crude glycerin during feedlot and pre-slaughter lairage

The objective of this study was to evaluate performance and carcass and meat characteristics of lambs fed a solution of cheese whey plus water (100 g kg−1 dry matter) (CW) during feedlot and pre-slaughter lairage. Data were analyzed as a 2 × 2 factorial (place – feedlot and slaughterhouse, food – water or CW). We evaluated the following treatments (feedlot/slaughterhouse): CW/CW, CW/water, water/CW, and control (water/water). The lambs were given a balanced diet for 70 days in the feedlot. Slaughter started 12 h after the animals arrived at the slaughterhouse. Dry matter intake, gain-to-feed ratio, average daily gain, and body weight of lambs fed CW were similar to those of control lambs. The water/CW group consumed less of this solution than the CW/CW group in the slaughterhouse. The CW supplied as a pre-slaughter supplement reduces the drip losses of lamb carcasses provided that the animals also consume it during the feedlot period. The other carcass characteristics (carcass weight, pH, subcutaneous fat thickness, and ribeye area) were similar among treatments. The meat characteristics (color, water holding capacity, cooking losses, and shear force) were similar among treatments. Whey cheese added to water can be used as an ingredient of the diet for lambs and as pre-slaughter supplement, since it does not change performance and improves carcass characteristics.