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Santana M.C.A.,São Paulo State University | Fiorentini G.,São Paulo State University | Messana J.D.,São Paulo State University | DIan P.H.M.,São Paulo State University | And 5 more authors.
Animal Production Science | Year: 2017

Over the productive cycle, the performance of cattle in grazing systems may be compromised, and feed supplementation is a strategy to establish nutritional balance and maximise the performance of grazing animals. The objective of this study was to evaluate the effect of different supplementation frequencies (i.e. daily supplementation (DS) versus Monday, Wednesday and Friday (MWF)) with different forms of soybean oil (i.e. soybean grain (SG), soybean oil (SO) and rumen-protected fat (RPF)) on the nutrient digestion and rumen fermentation of heifers grazing Brachiaria brizantha cv. Marandu pastures. Twelve crossbred heifers (1/4 Nellore × 1/4 Santa Gertrudis × 1/2 Braunvieh) with an initial bodyweight of 236.3 ± 27.6 kg were distributed in a completely randomised design with a factorial arrangement 3 × 2 (three diets and two supplementation frequencies). There was no interaction among the SO form or supplementation frequency on dry matter intake and dry matter digestibility (P > 0.05). The animals supplemented with SG exhibited lower nitrogen intake and absorption compared with animals that were fed SO (P < 0.05). The efficiency of microbial synthesis was not influenced by the diet or supplementation frequency (P > 0.05). Forms of SO affected the rumen pH; animals fed SO showed pH values similar to those of animals receiving SG but lower values than animals fed RPF (P < 0.05). Animals supplemented with DS exhibited higher levels of rumen ammonia nitrogen relative to those supplemented MWF. The reduction of supplementation frequency (from DS to MWF k) in our experimental conditions can be used to increase the efficiency of pasture utilisation without effects in fermentation activity of the rumen microbial population. Supplementation with SO is a strategy to increase propionic acid concentration and reduce A:P ratio, which is an indicator of improvement of the efficiency of the ruminal energy utilisation.

Gonzalez-Herrera L.G.,São Paulo State University | Gonzalez-Herrera L.G.,National University of Colombia | El Faro L.,Institute Zootecnia | Bignardi A.B.,Federal University of Mato Grosso | And 4 more authors.
Genetics and Molecular Research | Year: 2015

The objective of the present study was to estimate the genetic parameters for test-day milk yields (TDMY) in the first and second lactations using random regression models (RRM) in order to contribute to the application of these models in genetic evaluation of milk yield in Gyr cattle. A total of 53,328 TDMY records from 7118 lactations of 5853 Gyr cows were analyzed. The model included the direct additive, permanent environmental, and residual random effects. In addition, contemporary group and linear and quadratic effects of the age of cows at calving were included as fixed effects. A random regression model fitting fourth-order Legendre polynomials for additive genetic and permanent environmental effects, with five classes of residual variance, was applied. In the first lactation, the heritabilities increased from early lactation (0.26) until TDMY3 (0.38), followed by a decrease until the end of lactation. In the second lactation, the estimates increased from the first (0.29) to the fifth test day (0.36), with a slight decrease thereafter, and again increased on the last two test days (0.34 and 0.41). There were positive and high genetic correlations estimated between first-lactation TDMY and the remaining TDMY of the two lactations. The moderate heritability estimates, as well as the high genetic correlations between half the first-lactation TDMY and all TDMY of the two lactations, suggest that the selection based only on first lactation TDMY is the best selection strategy to increase milk production across first and second lactations of Gyr cows. © FUNPEC-RP.

Santana M.C.A.,Empresa de Assistencia Tecnica e Extensao Rural | Vieira B.R.,São Paulo State University | Costa D.F.,Funda Cao de Ensino Octavio Bastos | Costa D.F.,University of Sao Paulo | And 8 more authors.
Animal Production Science | Year: 2015

The objective of this study was to evaluate the effects of sources of soybean oil [ground soybean (GS), soybean oil (SO) and calcium salts of soybean oil (CS)] on DM intake (DMI), ingestive behaviour and average daily gain (ADG) of heifers grazing marandu palisadegrass (Brachiaria brizantha cv. Marandu) supplemented in two frequencies [daily and 3 days a week (Monday, Wednesday and Friday - MWF)]. The experiment was conducted from July until November of 2007. Forty-two crossbred heifers (1/4 Nellore × 1/4 Santa Gertrudis × 1/2 Braunvieh), 17-months old and 297.1 kg ± 30.5 BW ± s.e.m., were used. Supplements were offered at 0.75% BW.day. Treatments were allocated in a completely randomised design and distributed in a factorial arrangement (3 × 2 - SO from three different sources and two supplementation frequencies). Total DMI was greater in August and October (2.2 kg DM/kg BW) than in November (1.5 kg DM/kg BW). There was an effect of SO source on total DM, herbage and nutrients intake, but no effects of supplementation frequency. The animals supplemented with SO had greater DMI (P < 0.05) than the ones fed GS and CS. Average daily gain (0.580 g) was not affected by supplement sources or feeding frequency. Therefore, GS and CS are more efficient supplements. Supplementation frequency altered grazing time differently according to source. The MWF treatment resulted in a decreased grazing time when GS and SO were fed. However, in days when supplements were not offered, grazing time was increased for GS and CS. It was concluded that a decreased frequency of supplementation may be implemented without effect on weight gain and will reduce labour and machinery costs. © 2015 CSIRO.

Borquis R.R.A.,São Paulo State University | Neto F.R.D.A.,São Paulo State University | Baldi F.,São Paulo State University | Hurtado-Lugo N.,São Paulo State University | And 4 more authors.
Journal of Dairy Science | Year: 2013

In this study, genetic parameters for test-day milk, fat, and protein yield were estimated for the first lactation. The data analyzed consisted of 1,433 first lactations of Murrah buffaloes, daughters of 113 sires from 12 herds in the state of São Paulo, Brazil, with calvings from 1985 to 2007. Ten-month classes of lactation days were considered for the test-day yields. The (co)variance components for the 3 traits were estimated using the regression analyses by Bayesian inference applying an animal model by Gibbs sampling. The contemporary groups were defined as herd-year-month of the test day. In the model, the random effects were additive genetic, permanent environment, and residual. The fixed effects were contemporary group and number of milkings (1 or 2), the linear and quadratic effects of the covariable age of the buffalo at calving, as well as the mean lactation curve of the population, which was modeled by orthogonal Legendre polynomials of fourth order. The random effects for the traits studied were modeled by Legendre polynomials of third and fourth order for additive genetic and permanent environment, respectively, the residual variances were modeled considering 4 residual classes. The heritability estimates for the traits were moderate (from 0.21-0.38), with higher estimates in the intermediate lactation phase. The genetic correlation estimates within and among the traits varied from 0.05 to 0.99. The results indicate that the selection for any trait test day will result in an indirect genetic gain for milk, fat, and protein yield in all periods of the lactation curve. The accuracy associated with estimated breeding values obtained using multi-trait random regression was slightly higher (around 8%) compared with single-trait random regression. This difference may be because to the greater amount of information available per animal. © 2013 American Dairy Science Association.

Irano N.,São Paulo State University | Bignardi A.B.,São Paulo State University | Bignardi A.B.,Federal University of Mato Grosso | Baldi F.,São Paulo State University | And 6 more authors.
Genetics and Molecular Research | Year: 2015

The objective of this study was to estimate genetic parameters for 305-day cumulative milk yield (MY305) and its association with test-day milk yield (TDMY) in Saanen and Alpine goats in order to provide information that allows the use of TDMY as selection criteria. This was done using standard multi-trait and reduced rank models. Data from 1157 lactations, including the first three kiddings, and 5435 test-day records from 683 Saanen and 449 Alpine goats were used. MY305 was analyzed together with TDMY by multi-trait analysis, from the first to tenth test-day, using records of the first three lactations as repeated measures. Three multi-trait models were used: a standard (SM) and two reduced rank models that fitted the first two (PC2) and three (PC3) genetic principal components. Akaike and Schwarz Bayesian information criteria were used to compare models. Heritability for TDMY estimated with the SM ranged from 0.20 to 0.66, whereas the range calculated from the PC2 model was 0.16 to 0.63. Genetic correlations between TDMY and MY305 were positive and moderate to high, ranging from 0.56 to 0.98 when estimated with the SM, and 0.91 to 1.00 when estimated with the PC2. The standard multi-trait model produced estimates that were more accurate than the reduced rank models. Although the SM provided the worst fit according to the two model selection criteria, it was the best in this dataset. © FUNPEC-RP.

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