Airton Manzano

Efeitos da implantação de técnicas agropecuárias na intensificação de sistemas de produção de leite em estabelecimentos familiares

The economic viability of milk production in small family farms (SFF) in Sao Carlos, SP, from 1998 to 2001, after implementation of several technical and management actions in order to increase production was studied. Six SFF with sizes varying from 4.2 to 27.2 hectares and milk production as the main economical activity were selected. The technical actions implemented in each SFF were: agricultural: a) feeding: cropping and feeding sugar-cane + urea in the dry-season, concentrate supplementation according to the cow milk production level and rotational grazing in the rainy-season, b) animal welfare: identification and improvement of animal welfare, c) reproduction: use of artificial insemination and/or bulls and reproductive control of the herd, d) disease control: control of ectoparasites and endoparasites as well as brucellosis and tuberculosis tests, and e) genetic breeding: use of selected bulls, environment: recovery and conservation of natural resources, improvement of water quality and recovery of soil fertility, and administration techniques: culling of low-production animals, herd productivity control, practice of partnership and economical analysis. For statistical analysis was used an ANOVA model that included effects of the six SFF and fixed effects of year and months within year. The year effect was confounded with the technical and management actions and was assessed by orthogonal polynomials in order to estimate the quantitative changes in the response variables related to the year of 1998. The estimated means of the six SFF for annual milk production, milk production/ha/year, milk production/cow, net income and assets increased by 24%, 36%, 38%, 70% and 27%, respectively comparing year 2001 with 1998. Operational and total costs reduced 24.1% and 15.8%, respectively, while profit increased 4%. Two out of six SFF were chosen as extension units and used as models of SFF. It was concluded that implementation of technologies were efficient in all SFF investigated in this study.

Eficiência de utilização de nutrientes em novilhas das raças Canchim e Nelore e cruzadas Canchim-Nelore

The objective of this work was to study the efficiency of nutrient utilization by Canchim (CA), Nellore (NE) and crossbreed 1/2 Canchim + 1/2 Nelore (CANE) growing heifers, in three diets: maintenance, forage:concentrate ratio (RFC) of 75:25 (test 1), diet for weight gains up to 700 g/animal/day, RFC of 60:40 (test 2) and diet for weight gains up to 1200 g/animal/day, RFC of 40:60 (test 3). Twenty-four heifers were used in each test, eight of each genetic group. Each test had by three phases: a) performance, of 90 days,where the dry matter intake and daily weight gains were determined; b) coefficients of apparent digestibility and nitrogen balance of animals; and c) liquid phase digesta passage rates. The heifers from CA, NE and CANE showed similar results, within each diet, for all analyzed variables.

Polpa de Citros Peletizada na Alimentação de Eqüinos

The objective of this research was to study three levels of pelleted citrus pulp (PCP) in substitution to corn in diets of growing fillies. Twenty-one purebred and crossbred Arabian fillies averaging 278+9.6 kg of initial live weight and 18 months of age were used. The animals were maintained in individual pens and were daily exercised. A completely randomized design with three treatments: basal diet (T1), 7.5% PCP (T2) and 15.0% PCP (T3) with seven replicates, and with the filly as the experimental unit. The experimental period was of 16 weeks. The diets were formulated with 40% of coast-cross (Cynodon dactylon Pers) hay and 60% of concentrate, 14.5% of crude protein (CP), 2.77 kcal/g of digestible energy, on the dry matter (DM) basis. Weight gain, voluntary feed intake (gDM/kg.75) and the hearth girth did not differ among the treatments. The average withers height for T1 (6.8+1.0 cm) was higher than T2 (3.4+1.0 cm) and T3 (4.6+1.0 cm). The DM apparent digestibility coefficient for T2 (68.7+1.2%) and T3 (67.5+1.2 %) were higher than T1 (58.6+1.2 %). The same result was obtained for the CP, T2 (77.1+ 1.5 %) and T3 (78.6+1.5 %) were higher than that for T1 (70.8+1.5 %). For the gross energy, T2 (59.8+0.4%) was lower than both T1 (62.0+0.4%) and T3 (61.2+0.4%). There were no differences among the treatments for neutral detergent fiber, acid detergent fiber and the solid and liquid passage rate of the digesta. The pelleted citrus pulp can be used up to 15,0% in the diets of growing fillies, without affecting the animal performance.

Estudo de parâmetros bioquímicos de éguas gestantes, Puro Sangue Árabe

Metabolic rates were determined during the first and last gestation periods in Arab mares raised on Coast-cross(Cynodon dactylon) pasture. For this study, blood, urine and stool samples were collected and body measures were taken. The mares had a weight gain, from the beginning till the end of the gestation, of 69,4 kg. Total protein values in the blood had shown a significant increase (P<0,05) from the first to the last gestation month, while the albumin values decreased. The ratio of albumin : protein was constant during the gestation, reflecting balance in the protein feeding. The levels of calcium, phosphorus, magnesium, copper and zinc in the blood serum did not suffer any alteration during pregnancy. The same could be observed with total protein, glucose, creatinin and urea in the urine. The calcium and magnesium levels in the urine had an increase (P<0,05) of the beginning to the end of gestation. Conversely, the phosphorus and potassium decreased (P<0,05) due to increased mobilization of these elements in the final period, as result of fetal growth. In the stools, the protein, calcium, phosphorus and potassium levels decreased (P<0,05) at the beginning and end of pregnancy, probably due to greater mobilization and an increase of nutritional needs. Analysis of the data allowed to conclude that most of the analyzed elements were eliminated in the urine, with the exception of the microminerals, which were eliminated in the stools. Considering the development of the animals during pregnancy the biochemical parameters obtained in this study can be considered as reference values for Arab pregnant mares raised exclusively on Coast-cross pasture.

Tamanho amostral envolvendo múltiplos caracteres: uma aplicação à digestibilidade em bovinos

The objective of this work was to estimate minimum sample size (n) for comparison of treatments in experiments of consumption and digestibility of cattle in a multitrait analysis. Data from digestibility of 72 heifers aging approximately 18 months and with 250 kg of live weight were used. A completely randomized experiment was conducted at Embrapa-Centro de Pesquisa de Pecuaria do Sudeste, Sao Carlos, SP, Brazil, from 1988 to 1989, considering the combination of nine treatments organized in a factorial 3 x 3 (three genetic groups: Canchim, Nellore and ½ Canchim + ½ Nellore, and three dietary levels of crude protein: 6, 10 and 13%, and eight heifers each). The end points analyzed were feed consumption (g/kg0.75), digestible energy, retained nitrogen (RN), RN (mg/kg0.75), and digestibilities of dry matter, crude protein, neutral detergent fiber and acid detergent fiber. The minimum sample size required to detect significant differences (D) between mean vectors was calculated by a SAS program considering a t-variate normal distribution with mean vector 0 and covariance matrix S, Hotellings T2 test, F-distribution with noncentrality parameter (d2D) and combinations of type I error (a) and power of the test (1 b) and D. The calculated n ranged from 6 to 47, and was affected more by variation in D than variation in a or power of the test.