Scielo RSS <![CDATA[Revista Brasileira de Zootecnia]]> vol. 44 num. 10 lang. es <![CDATA[SciELO Logo]]> <![CDATA[Replacement of fish meal by protein soybean concentrate in practical diets for Pacific white shrimp]]> ABSTRACTThe objective of this work was to evaluate the performance of Litopenaeus vannameifed different levels (0, 25, 50, 75, and 100%) of soybean protein concentrate (63.07% crude protein, CP) to replace fish meal-by product (61.24% CP). The study was conducted in clear water in fifteen 800 L tanks equipped with aeration systems, constant heating (29 ºC), and daily water exchange (30%). Each tank was stocked with 37.5 shrimp/m3 (3.03±0.14 g). Feed was supplied four times a day, at 6% of the initial biomass, adjusted daily. After 42 days, the weight gain of shrimp fed diets with 0 and 25% protein replacement was higher than that observed in shrimp fed 100% replacement, and there were no differences among those fed the other diets. Feed efficiency and survival did not differ among shrimp fed different protein replacements. There was a negative linear trend for growth parameters and feed intake as protein replacement with soybean protein concentrate increased. Fish meal by-product can be replaced by up to 75% of soybean protein concentrate, with no harm to the growth of Pacific white shrimp. <![CDATA[Protein and mRNA expression of estradiol receptors during estrus in yaks (Bos grunniens)]]> ABSTRACTThe objective of this study was to investigate mRNA by real-time PCR and protein expression by immunofluorescence of the estradiol receptors (ER) in the pineal gland, hypothalamus, pituitary gland, and gonads of yaks (Bos grunniens). The analysis showed that the level of expression of ER mRNA was greater in the pituitary gland tissue than in other glands during estrus. Immunofluorescence analyses showed that ER proteins were located in the pineal cells, synaptic ribbon, and synaptic spherules of the pineal gland. In the hypothalamus, ER proteins were located in the magnocellular and parvocellular neurons. The ER proteins were located in acidophilic cells and basophilic cells in the pituitary gland. In the ovary, ER proteins were present in the ovarian follicle, corpus luteum and Leydig cells. Estradiol exerts its main effects on the pituitary gland during estrus in yak. <![CDATA[Effect of plant extracts on growth performance and insulin-like growth factor 1 secretion in growing pigs]]> ABSTRACTThe objective of the present study is to evaluate the effects of plant extracts on growth performance, nutrient digestibility, and immune blood characteristics in growing pigs. A total of 80 [(Landrace × Yorkshire) × Duroc] pigs with an initial body weight (BW) of 27.31±2.15 kg were used in a 6-wk experiment. Pigs were allotted to one of four treatments (1 - Control (CON) (basal diet); 2 - PE1 (CON + 0.05% plant extracts); 3 - PE2 (CON + 0.10% plant extracts); and 4 - PE3 (CON + 0.15% plant extracts)) in a randomized complete block design according to sex and initial BW. The PE1 and PE2 treatments provided a greater average daily gain than the CON treatment. From weeks 0 to 6 the pigs fed diets PE2 and PE3 showed greater apparent total tract digestibility of dry matter than those fed the CON diet. Pigs fed the plant-extract treatments had a reduction in total mercaptan emission on day 3 compared with control treatment. On day 5, fecal acetic acid content was decreased with increased blood WBC (white blood cells) and lymphocyte counts and serum IGF-1concentration by plant extract supplementation compared with the control treatment. All the results showed a 95% significance level. Supplementation of plant extracts can improve growth performance and nutrient digestibility in growing pigs, decrease fecal gas emission, and increase immune components such as WBC and lymphocytes, and serum IGF-1 concentration in growing pigs. <![CDATA[A survey of dairy calf management practices in some producing regions in Brazil]]> ABSTRACTThis study aimed to characterize the Brazilian dairy calves raising systems through a survey of major aspects of animal husbandry. One hundred seventy-nine producers and/or technicians were interviewed. The questionnaire addressed issues related to the management of the dry cow and the newborn, nutritional management of the liquid-feeding phase, housing, and health management. A third of newborn calves stay with their mothers for more than 24 h after delivery, and only 56% of the calves receive colostrum within the first 8 h of life. Four out of ten producers allow the calf to suckle colostrum directly from the mother. Regarding the liquid diet, 44 and 35% of the farms provide marketable milk and discard milk for the calves, respectively. It was possible to identify several areas of improvement in the raising system; for instance, greater attention could be given to dry cows and the monitoring of births and to the establishment of adequate protocols to evaluate colostrum quality and feeding management. <![CDATA[Factors affecting beef consumption in the valley of Mexico]]> ABSTRACTThe objective of this study was to know the factors that determine the consumption of beef in the Metropolitan Area of the Valley of Mexico, using logit and probit modeling (nominal variable) with 400 surveys. The results showed that significant variables that determine the probability of purchasing beef are schooling, number of members per family, meat preference, family income, and presence of disease in the individual. The largest marginal effects on the purchase decision were provided by the income and the meat preference variables, while the price was not significant. The main factors that determine the consumption of beef are schooling and the number of members in the family, while the meat preference and income are dismissed.