Nilton Rodrigues Paim

Análise de trilha para rendimento de sementes em trevo vermelho (Trifolium pratense L.)

Red clover is a temperate legume species that shows good dry matter yield potential and forage quality, being indicated to supplement livestock animals during the cool season in the Southern part of Brazil. The objective of this experiment was to study seed yield in red clover through the use of path analysis, aiming to generate basic information to be used on breeding program or in management strategies, which lead to an increase on seed yield, natural reseeding and thus to a greater pasture persistence. The following variables were analyzed: seed yield, number of stems per plant, number of seed head per plant, number of seed head per stem and weight of one thousand seeds. The number of seed head per plant was the variable with the greatest correlation with seed yield (r = .710), basically through its direct effect on seed yield. The other variables showed smaller correlation coefficients with seed yield (r values from .175 to .578) as well as presented negative or small direct effects on it. Therefore, the number of seed head per plant showed to be the main characteristic to be considered when an increase in the red clover seed yield is required.

Composição do leite de vacas Holandesas em pastejo de azevém com a utilização do trevo branco como fonte proteica

Was evaluated the composition of milk from animals grazing annual ryegrass (Lolium multiflorum Lam.) fed with white clover (Trifolium repens L.), as a replacement for the protein component of the ration (soybean meal), in percentages of protein, lactose, total solids and somatic cell counts. Were used two groups with eight Holstein cows, grouped by production, lactation period and body weight, in a randomized block design. One group received 3kg of energetic supplement subtracted of soybean meal daily and had access to the white clover pasture for approximately 2.5 hours (TB); the other received the same supplement, added of a quantity of protein equivalent to daily intake in previous treatment via white clover, in the form of soybean meal (FS). Significant differences were observed for protein and lactose content, with the highest values found for protein on TB (3.02%) and lactose on FS (4.64%). For the other variables there was no difference, with values from 10.40 and 10.39% of total solids and 182.88 and 153.53 (x1000) somatic cells on TB and FS respectively, showing that the use of this alternative source of protein was efficient.

Milk quality of Jersey cows kept on winter pasture supplemented or not with concentrate

Este trabalho foi realizado com o objetivo de avaliar o efeito do uso de suplementacao em pastagem cultivada constituida por Avena strigosa (aveia-preta), Lolium multiflorum (azevem-anual) e Vicia sativa L. (ervilhaca) sobre a composicao e a contagem de celulas somaticas (CCS) do leite de vacas Jersey. Foram utilizadas oito vacas da raca Jersey, distribuidas ao acaso, apos estratificacao por producao de leite, periodo de lactacao e peso corporal, em dois grupos homogeneos (um com suplementacao e outro apenas em pastagem), em delineamento experimental completamente casualizado. Os dois grupos foram mantidos na pastagem por aproximadamente 7 horas por dia em um sistema de pastejo rotativo em faixas, com periodo de ocupacao de um dia. O grupo sob suplementacao recebeu diariamente 8 kg de suplemento constituido de farelo de soja, casca de soja, calcario calcitico e sal mineral. Os resultados evidenciaram diferencas significativas entre os dois grupos, uma vez que os percentuais de solidos totais, proteina e gordura do leite foram maiores nas vacas sob suplementacao. O percentual de lactose nao foi influenciado pelo consumo de suplemento. A contagem de celulas somaticas, embora com diferenca estatistica menor para o grupo em pastagem, apresentou pequena oscilacao numerica entre os grupos, a qual nao pode ser considerada efeito da suplementacao. O fornecimento de suplemento a vacas Jersey em lactacao promove aumento do percentual de solidos totais do leite, uma vez que eleva suas concentracoes de gordura e proteina.

Tolerância ao frio e caracterização de híbridos entre leucaena leucocephala e L. diversifolia

The objective of this experiment was to identify material to be used as an alternative forage in the conditions of Southern Brazil. A population of hybrids between L. leucocephala and L. diversifolia (both tetraploid species, with 2n=104 chromosomes) in advanced generations was evaluated. The rate of growth in height, duration of flowering and frutification, number of flowers and legumes per inflorescence, seeds per legume, cold tolerance (expressed as foliage retention during winter) and regrowth ability in early spring were evaluated. A great intrapopulational variability was detected for all evaluated characteristics. Some individuals allying cold tolerance and desirable characteristics were identified to be used for further selection and breeding, which confirms the potentiality of Leucaena as a forage for Southern Brazil.

A model for floral color inheritance in Leucaena (Leguminosae)

A population of 513 hybrids of Leucaena leucocephala (4x) and L. diversifolia ssp. diversifolia (4x), that is being analyzed for several morphological and agronomical characteristics, aiming at selecting cold tolerant plants, was also analyzed for floral color. A model of additive dominant inheritance (pink color dominant over white color, or presence versus absence of pigment, and the number of dominant alleles present determining the intensity of the pink color) is proposed. The action of two independent locus sets is also suggested, one for the male (with two main structural genes) and another for the female floral organs (one main structural gene). It is suggested that an undetermined number of regulatory genes affect color expression.

Comportamento ingestivo de vacas leiteiras em pastagem de azevém alimentadas com diferentes fontes proteicas

The effect of the replacement of soybean meal in the ration with controlled grazing of white clover (Trifolium repens L.) on the ingestive behavior of cows of the holstein breed grazing on annual ryegrass (Lolium multiflorum Lam.) was studied. Two groups of animals with an average of 20 cows grouped by production, lactation period and body weight were used in a randomized block experimental design. One group received 3kg from energy supplement daily and had controlled access to the white clover pasture for approximately 2.5 hours (TB); the other received the same supplement, added of a quantity of protein equivalent to daily intake in previous treatment via white clover, in the form of soybean meal (FS). For behavior assessment the observation and recording of the rhythm of activity of the animals, during the grazing period in ryegrass for two consecutive days, fortnightly was done. The longest grazing time in minutes (min), 212.00 versus 194.24min day-1, and bite frequency (bite), 67.78 versus 64.09 bite min-1, between the animals from treatment FS, when compared to TB was observed. There was no difference in the intake of ryegrass between the treatments, with values of 3.65 and 4.11kg cow-1 day-1 of dry matter for TB and FS, respectively, suggesting adequate adaptation of the animals in the two situations studied.

Variabilidade intra e intergenotípica em uma população de híbridos entre Leucaena leucocephala e L. diversifolia

n†This work aimed to estimate the variability of some morphological characteristics in hy- brids of Leucaena. Twenty genotypes, with 30 individuals each, of hybrids between L.†leucocephala and L.†diversifolia were established in a randomized blocks design with six repetitions. Leaf length, number of pinnae and leaflet pairs, number of extrafloral nectaries, legume length and width and num- ber of seeds per legume were analyzed. Leaf length average values ranged from 8.6†cm to 30.6†cm. Number of leaflets per pinna ranged from 10.7 to 53.4 and the number of pinnae per leaf ranged from 5.6 to 20.3. Most of the individuals presented an average of 1.0 extrafloral nectary per leaf. The highest average value of number of seeds per legume was 24.1 and the lowest 5.0. Five genotypes were the most uniform considering the characteristics analyzed.