Data from 1279 lactations of 783 Alpine and Saanen goats of the herd of our university in Minas Gerais, Brazil, were used to study environmental effects on and to estimate genetic parameters for milk production until 270 days of lactation (MP270) and for production and percentages of fat (PFAT and %FAT), protein (PPROT and %PROT), lactose (PLACT and %LACT), and total dry extract (PEXTR and %EXTR). Environmental effects were estimated by a statistical model that included contemporary group effect, type of kidding, genetic grouping, and kidding order. A multi-trait animal model with animal and permanent environment random effects was used to estimate genetic parameters and the significant environmental effects (fixed). Contemporary group influenced all traits; genetic grouping did not influence %LACT; type of kidding did not influence PFAT, %PROT or %LACT, and kidding order did not influence %FAT or %EXTR. Heritability and repeatability estimates were, respectively, 0.19 and 0.37 (MP270); 0.10 and 0.20 (PFAT); 0.12 and 0.24 (PPROT); 0.15 and 0.27 (PLACT); 0.13 and 0.24 (PEXTR); 0.21 and 0.34 (%FAT); 0.39 and 0.44 (%PROT); 0.17 and 0.29 (%LACT); 0.31 and 0.47 (%EXTR). Estimates of genetic correlations among MP270 and production of milk constituents were positive and high, but correlations between MP270 and %FAT, MP270 and %PROT, MP270 and %ESTR were moderate and negative. These heritability estimates show that satisfactory genetic gains can be obtained by selection, especially for milk constituents.
The objective of this work was to evaluate the effect of using multiple supplements with different levels of cottonseed meal 38% on intake, total apparent digestibility of dietary components, efficiency of microbial synthesis and productive performance of beef heifers in Brachiaria decumbens pasture during the rainy season. It was used 25 Nellore heifers and 10 crossbred heifers with predominance of Zebu breed at 16 months of age and with 249.8 ± 0.6 kg of body weight. It was used a complete random experimental design with five treatments and seven replicates. Supplements contained approximately 30% of crude protein (CP) and soybean meal replaced by cottonseed meal 38% at the levels 0; 33; 67 and 100%, (CS0, CS33, CS67 and CS100, respectively) evaluated in relation to a control group, which received only mineral mixture (MM) ad libitum. Daily weight gain was 397, 546, 570, 525 and 542 g, respectively, for the groups MM, CS0, CS33, CS67 and CS100. There was no effect of the levels of cottonseed meal 38% on daily weight gain, which differed among animals fed supplement and control group, however. Intakes of crude protein and non-fibrous carbohydrates (NFC) in kg/day were greater in groups under supplementation. Coefficients of total apparent digestibility of CP and NFC were greater in animals fed supplements in relation to the control group. Increase on the replacement level of soybean meal by cottonseed meal had a positive linear effect on coefficients of total apparent digestibility of DM, organic matter and CP. There was no difference on microbial efficiency, expressed as g of crude protein per kg of TDN consumed by the animals under supplements and the ones of the control group, neither it was observed difference among levels of replacement of soybean meal by cottonseed meal. The use of cottonseed meal 38% replacing soybean meal in the diet does not harm performance of grazing beef heifers.
1 October 2017 in Animal Feed Science and Technology
Avaliou-se neste trabalho as características histomorfométricas da mucosa intestinal de tambaqui após uso de probiótico a base de Bacillus spp., veiculado na ração e dissolvido na água durante transporte. Foi utilizado um delineamento inteiramente casualizado com três tratamentos e sete repetições, sendo comparado um tratamento controle (peixes alimentados com ração comercial sem probiótico) a dois outros tratamentos envolvendo o uso de probiótico comercial, veiculado na ração ou na água de transporte. Um total de 510 juvenis de tambaqui (peso e comprimento total médio inicial de 83,26±28,14g e 17,39±1,90cm, respectivamente) foi distribuído em três tanques de alvenaria. Durante 60 dias, os peixes de dois tanques foram alimentados com ração comercial e os do terceiro tanque com ração comercial suplementada com probiótico. Após este período, os peixes de cada tanque foram divididos em sacos plásticos e transportados por 4 horas de acordo com os seguintes tratamentos: T1 = alimentação com ração comercial (controle); T2 = alimentação com ração comercial e probiótico adicionado na água durante o transporte (20mg/L); T3 = alimentação com ração comercial suplementada com probiótico (1,0g/kg de ração). Antes do transporte (basal), 24 e 96 horas após o transporte, oito peixes de cada tratamento foram submetidos a eutanásia e o intestino retirado para pesagem e mensuração do comprimento para estabelecimento da relação comprimento corporal/ intestino. Em seguida, foi realizada coleta da porção anterior e posterior do intestino, para avaliação das características morfo-histológicas da mucosa intestinal. O uso de probiótico durante o transporte não afetou o peso do intestino de juvenis de tambaqui. O comprimento do intestino do tambaqui não foi alterado pelo tratamento, sendo observada somente relação linear entre o comprimento intestinal e o comprimento corporal (CC) dos peixes. A suplementação com probiótico (Bacillus spp.) não exerceu nenhum efeito na altura e comprimento das vilosidades do intestino do tambaqui desafiados com o transporte.
The objective of this study was to identify the best random regression model using Legendre orthogonal polynomials to evaluate Alpine goats genetically and to estimate the parameters for test day milk yield. On the test day, we analyzed 20,710 records of milk yield of 667 goats from the Goat Sector of the Universidade Federal de Viçosa. The evaluated models had combinations of distinct fitting orders for polynomials (2-5), random genetic (1-7), and permanent environmental (1-7) fixed curves and a number of classes for residual variance (2, 4, 5, and 6). WOMBAT software was used for all genetic analyses. A random regression model using the best Legendre orthogonal polynomial for genetic evaluation of milk yield on the test day of Alpine goats considered a fixed curve of order 4, curve of genetic additive effects of order 2, curve of permanent environmental effects of order 7, and a minimum of 5 classes of residual variance because it was the most economical model among those that were equivalent to the complete model by the likelihood ratio test. Phenotypic variance and heritability were higher at the end of the lactation period, indicating that the length of lactation has more genetic components in relation to the production peak and persistence. It is very important that the evaluation utilizes the best combination of fixed, genetic additive and permanent environmental regressions, and number of classes of heterogeneous residual variance for genetic evaluation using random regression models, thereby enhancing the precision and accuracy of the estimates of parameters and prediction of genetic values.