Effect of a Combination of Propionic-Acetic Acid on Body Weight, Relative Weight of Some Organs, Lactic Acid Bacteria and Intestinal pH of Neonatal Broilers

This study was designed to determine the effect of a combination of propionic-acetic acid on body weight, the relative weight of some organs, lactic acid bacteria, and intestinal pH of neonatal broilers. A total of 60 1-day-old Ross 308® broiler chickens were randomly placed in metabolic cages to two treatments, three replicates, and ten birds per replicates. The treatments consisted of a control diet (CD) and CD + 0.03% of propionic acid and acetic acid in the drinking water at a rate of 4 ml/L of water. The combination of organic acids depressed the body weight in neonatal broilers (p 0.05) and increased the relative weight (p 0.05) of gizzard, proventriculus, small intestine, and liver; also acidified the cecum with a significant decrease (p 0.05) of the pH. Also, these organic acids increased (p 0.05) the count of green bacilli with a white halo in the small intestine and decreased (p 0.05) the proliferation of irregular flat green bacilli in the cecum, although for both intestinal portions, the total lactic acid bacteria count was not different (p>0.05) between treatments. The combined use in the diet and drinking water of the propionic and acetic organic acids, respectively, reduced the bodyweight of neonatal broilers (10 days) and the cecal pH, as well as modified the relative weights of some digestive organs and the growth of some morphological groups of lactic acid bacteria.(AU)

Effect of a Combination of Propionic-Acetic Acid on Body Weight, Relative Weight of Some Organs, Lactic Acid Bacteria and Intestinal pH of Neonatal Broilers

This study was designed to determine the effect of a combination of propionic-acetic acid on body weight, the relative weight of some organs, lactic acid bacteria, and intestinal pH of neonatal broilers. A total of 60 1-day-old Ross 308® broiler chickens were randomly placed in metabolic cages to two treatments, three replicates, and ten birds per replicates. The treatments consisted of a control diet (CD) and CD + 0.03% of propionic acid and acetic acid in the drinking water at a rate of 4 ml/L of water. The combination of organic acids depressed the body weight in neonatal broilers (p 0.05) and increased the relative weight (p 0.05) of gizzard, proventriculus, small intestine, and liver; also acidified the cecum with a significant decrease (p 0.05) of the pH. Also, these organic acids increased (p 0.05) the count of green bacilli with a white halo in the small intestine and decreased (p 0.05) the proliferation of irregular flat green bacilli in the cecum, although for both intestinal portions, the total lactic acid bacteria count was not different (p>0.05) between treatments. The combined use in the diet and drinking water of the propionic and acetic organic acids, respectively, reduced the bodyweight of neonatal broilers (10 days) and the cecal pH, as well as modified the relative weights of some digestive organs and the growth of some morphological groups of lactic acid bacteria.

Mycelial growth of strains of Pleurotus ostreatus developed on agar and its correlation with the productivity in pilot production farm

Radial growth rate, intracellular laccases and proteases activities, and protein content were evaluated in five strains of Pleurotus ostreatus, grown on starch-based and glucose-based agar media containing different concentrations of the glucose analogue 2-deoxyglucose (2-DG). Productivity of the strains in pilot scale cultivation was also determined. The mycelium of four strains had approximately between 0.6- to 3-fold higher protein content when grown on glucose medium containing 0.01 g/L of 2-DG than when grown on glucose medium. The radial growth rate and intracellular laccases activity of some strains showed a positive and a negative correlation with the productivity, respectively. These results suggest that the strains with high radial growth rate and low intracellular laccases activity on glucose without 2-DG, on starch without 2-DG or on glucose containing 0.01 g/L of 2-DG are highly productive in pilot production farm.

Avaliou-se o crescimento radial, as atividades de proteases e lacases e o conteúdo protéico de cinco cepas de Pleurotus ostreatus cultivado em agar à base de amido e à base de glicose contendo diferentes concentrações de 2-deoxiglicose (2-DG), um análogo da glicose. A produtividade das cepas em cultivo em escala piloto foi também determinada. Em quatro cepas o conteúdo protéico do micélio foi aproximadamente 0,6 a 3 vezes maior quando foram cultivadas em meio à base de glicose contendo 0,01g/L de 2-DG. O crescimento radial e a atividade de lacases apresentaram correlação positiva e negativa, respectivamente, com a produtividade. Esses resultados sugerem que as cepas com elevada taxa de crescimento radial e baixa atividade de lacases em glicose sem 2-DG, ou em amido sem 2-DG, ou em glicose com 0,01 g/L de 2-DG, são altamente produtivas em cultivo em escala piloto.

Spiders of soybean crops in Santa Fe province, Argentina: influence of surrounding spontaneous vegetation on lot colonization

Trials during two consecutive soybean cycles were performed in central Santa Fe in order to determine the main spider families present in the crop and to determine the influence of spontaneous margin flora on colonization towards the lot. Samplings were done by sweeping net and pitfall traps. It was concluded that:1. Oxyopidae was the most frequent family in the herbaceous layer of both the margins and the soybean crop, and Lycosidae in the lower layer; 2. Margin strips in a soybean lot contribute to the colonization of the crop by spiders of aerial habits and also promote re-colonization following pesticide applications, since they act as shelters. The influence on spiders of terrestrial habits was somewhat lower; 3. The distribution of the populations of spiders of terrestrial habits was homogeneous in a soybean crop seeded directly and these predators had a greater capacity to control pests at all points of the lot.

Com o objetivo de determinar as principais famílias de aranhas presentes em cultivos de soja na zona central de Santa Fé e de determinar a influência da flora espontânea das bordas, na colonização, para o lote, realizaram-se, durante dois ciclos de cultivo de soja, amostragens mediante rede de arraste e armadilhas de queda. Concluiu-se que: 1) a família de aranhas mais freqüente no estrato herbáceo das bordas e do cultivo de soja foi Oxyopidae, enquanto no estrato inferior foi Lycosidae; 2) as faixas marginais do cultivo em um lote de soja contribuem na colonização das aranhas de hábitos aéreos, sendo também promotoras da recolonização posterior às aplicações de pesticidas, ao atuar como zona de refúgio. Uma menor incidência, foi encontrada na colonização das aranhas de hábitos terrestres e sua distribuição populacional foi homogênea em um cultivo de soja de semeadura direta, proporcionando maior capacidade para controlar as pragas em todos os pontos do lote.