Abstract The objective of this work was to evaluate the food intake, nutrient digestibility, and weight gain of female suckling goat kids fed with goat and cow milk with different levels of fat. Thirty-two crossbred goats in the suckling phase were distributed in a 2×2 factorial arrangement, in a completely randomized design. Two sources of fat (goat and cow milk) and two levels of fat addition to milk (3.5 and 7.0%) were evaluated for 97 days in eight replicates. Dry matter intake was affected by milk source and fat levels. The highest nutrient intake was observed with goat milk with 7.0% fat. Crude protein intake was affected only by fat source due to the greater presence of protein in goat milk, whereas crude fat intake was affected only by fat levels. The average daily gain was higher for goat kids that ingested milk with 7.0% fat. The source of fat did not affect nutrient digestibility, but the levels of fat influenced dry matter digestibility. The inclusion of 7.0% fat in milk increases the weight gain of suckling goat kids without affecting fat digestibility. Fat from goat milk increases weight at weaning possibly due to a higher energy intake. digestibility Thirtytwo Thirty 22 2 2× arrangement design 3.5 35 3 5 (3. 70 7 0 9 replicates 7.0 3. (3 7. (

Resumo O objetivo deste trabalho foi avaliar o consumo, a digestibilidade dos nutrientes e o ganho de peso de cabritas lactentes alimentadas com leite de cabra e de vaca com diferentes níveis de gordura. Trinta e duas cabras mestiças lactentes foram distribuídas em arranjo fatorial 2×2, em delineamento inteiramente casualizado. Foram avaliadas duas fontes de gordura (leite de cabra e vaca) e dois níveis de adição de gordura no leite (3,5 e 7,0%) durante 97 dias, em oito repetições. O consumo de matéria seca foi influenciado pela fonte e pelo teor de gordura do leite. A maior ingestão de nutrientes foi observada com leite de cabra com 7,0% de gordura. O consumo de proteína bruta foi afetado apenas pela fonte de gordura devido à maior presença de proteína no leite de cabra, enquanto o consumo de gordura bruta foi afetado apenas pelos níveis de gordura. O ganho de peso médio diário foi maior para as cabritas que ingeriram leite com 7,0% de gordura. A fonte de gordura não afetou a digestibilidade dos nutrientes, mas os níveis de gordura influenciaram a digestibilidade da matéria seca. A inclusão do nível de 7,0% de gordura no leite aumenta o ganho de peso das cabritas sem afetar a digestibilidade da gordura. A gordura de leite de cabra aumenta o peso ao desmame possivelmente devido à maior ingestão de calorias. 22 2 2×2 casualizado 3,5 35 3 5 (3, 70 7 0 9 dias repetições 7,0 calorias 2× 3, (3 7, (

ABSTRACT Lactation records from cows of the southwestern Paraná state, Brazil, form the dataset of this study. We applied the information-theoretic approach to evaluate the ability of the nonlinear Wood, Brody, Dijkstra, and Gamma functions to fit to these data by employing a two-step technique based on nonlinear mixed-effects models and generalized linear mixed-effects models. Wood's equation was fitted with the combination of a first-order autoregressive correlation structure and a variance function to account for heteroscedasticity. This version was the best choice to mimic lactation records. Some geometric attributes of Wood's model were deduced, mainly the ascending specific rate from parturition to peak milk yield and the descending specific rate as a measure of the lactation persistence of the milk yield at peak production. Breed and parity order of the cows were assumed as fixed effects to obtain a reliable model fitting process. Regardless of breed, first-order parity cows had greater persistency than their older counterparts, and the greater the ascending rate of milk yield from the parturition to the peak, the sharper the decrease in milk yield post-peak; therefore, the rates (absolute values) of ascending and descending phases correlated positively. Nonetheless, the actual estimated values of the descending phase rates are negative. Wood's equation was flexible enough to mimic either concave- and convex-shaped lactation profiles. The correlations between both peak milk yield and random estimates for β with total milk yield per lactation were positive. However, peak milk yield might not be the only variable used for ranking cows; the total milk yield integrates all information of the lactation profile through the estimated parameters of Wood's equation.

ABSTRACT. The purpose of this study was to evaluate the effect of interaction between increasing neutral detergent fiber content and particle sizes on ingestive behavior of dairy goats. Forty-eight lactating, multiparous Saanen and Alpine goats, with average milk production of 1.4 ±0.57 kg d-1, around 60th ±12 day of lactation were distributed in a 3 x 4 factorial completely randomized design. The diets consisted: three particles sizes (02, 05 or 15 cm) and four levels of neutral detergent fiber (34, 41, 49 or 57% NDFf) from forage (Tifton 85 hay). The ingestive behavior was monitored during 24 hours. A regression and a multivariate time series cluster analysis were performed. No interaction was found (p > 0.05) between treatments. Feeding time was different according to the particle size, having an increasing linear effect. Rumination and idle times were not affected (p > 0.05). The temporal feeding behavior was clustered into two groups according to the profile of particle size of the diet. Rumination peaks were randomly distributed with more intense activity before morning and afternoon meals. The increase in NDFf content in the diet did not change the ingestive behavior. The multivariate cluster analysis in a time series data is useful to interpret animal feeding behavior.

Objetivou-se mensurar a movimentação das massas de gordura e proteína corporal, além de quantificar as massas dos órgãos e vísceras de cabras Alpinas ao longo das oito semanas de lactação. Foram utilizadas 51 cabras multíparas da raça Alpina, alocadas em baias metabólicas individuais. As cabras foram distribuídas em um delineamento inteiramente casualizado, com oito tratamentos e seis repetições, sendo os tratamentos constituídos pelas semanas de lactação. Foram realizados abates sequenciais de seis cabras por semanas de lactação para mensuração das massas de gordura e proteína, e também o peso dos órgãos e vísceras. Ocorreu redução significativa na massa dos tecidos proteico e adiposo, porém de forma adversa, sendo que o tecido proteico foi mobilizado com maior intensidade nas primeiras duas semanas pós-parto, já a o tecido adiposo uma queda de forma constante. Não houve efeito sobre peso do fígado, rúmen, omaso, abomaso e intestino grosso, mas ocorreu redução nos pesos do intestino delgado, útero e glândula mamária. As cabras Alpinas nas três semanas pós-parto mobilizam não apenas gordura, mas também proteína corporal para atender a demanda de produção de leite. Somente o intestino delgado, útero e glândula mamária tiveram seus pesos afetados com as oito semanas de lactação.

This study aimed to measure the changes of masses of body fat and protein, and also quantify the masses of organs and viscera of Alpine goats throughout the eight weeks of lactation. We used 51 multiparous Alpine goats, allocated in individual metabolic pens. The goats were distributed in a completely randomized design with six replications and eight treatments, and the treatments by weeks of lactation. Slaughters were carried sequential six goats per week of lactation to measure the mass of fat and protein, as well as the weight of the organs and viscera. Significant reduction in mass and adipose tissue protein, but adversely, and the tissue protein was mobilized with greater intensity in the first two weeks postpartum, since the fat falling steadily. There was no effect on liver weight, rumen, omasum, abomasum and large intestine, but there was a reduction in the weights of the small intestine, uterus and mammary gland. The Alpine goats within three weeks postpartum mobilize not just fat, but also body protein to meet the demand of milk production. Only the small intestine, uterus and mammary gland shown weight affected with eight weeks of lactation.

Objetivou-se avaliar o efeito do manejo para crescimento compensatório e da suplementação com ionóforo sobre o perfil metabólico e o crescimento da glândula mamária de novilhas leiteiras. Foram utilizadas 20 novilhas Pardo-Suíças puras, com peso inicial de 200 kg e 5 meses de idade. Os tratamentos foram arranjados em esquema fatorial 2 × 2 e os animais foram alocados aleatoriamente em cada uma das combinações. O fator 1 consistiu dos sistemas de alimentação (convencional e crescimento compensatório) e o fator 2, da utilização ou não de ionóforo (200 mg de monensina/animal/dia). Os animais do sistema convencional receberam alimentação ad libitum, enquanto os do sistema para crescimento compensatório foram submetidos a um manejo nutricional com dois períodos distintos: período de restrição energética (90 dias, P1) e período de realimentação (60 dias, P2). Novilhas submetidas ao sistema crescimento compensatório apresentaram maior concentração de nitrogênio ureico (N-ureico) plasmático e menor razão DNA:RNA no tecido mamário. Quando analisados dentro de período, os níveis de lipoproteínas de alta densidade (HDL) aumentaram no período de realimentação, enquanto os de N-ureico diminuíram. Além da alteração nos níveis de N-ureico, o balanço energético ao qual as novilhas em crescimento compensatório foram submetidas ocasionou aumento no teor dos ácidos graxos não-esterificados. Houve redução nos níveis de glicose sanguínea dos animais em crescimento compensatório no período de realimentação. A suplementação com ionóforo proporciona menor concentração de ácidos graxos não-esterificados durante o período de realimentação.

The objective of this trial was to compare the effect of compensatory growth regime on the metabolic profile and mammary gland development of dairy heifers. Twenty Brown-Swiss heifers averaging 200 kg of body weight and five months of age were used in a completely randomized design with a 2 × 2 factorial arrangement. The treatments were arranged in a factorial arrangement (2 × 2) and the animals were randomly allocated in each one of the combinations. The factor 1 consisted of the feeding regime (conventional and compensatory growth) and the factor 2, of the use or not of ionophore (200 mg of monensin/animal/day). The animals in the conventional regime received ad libitum feeding, while those in the compensatory growth regime were submitted to a nutritional management with two different periods: period of energy restriction (90 days) and realimentation period (60 days). Heifers submitted to the compensatory growth regime showed larger concentration of plasma urea nitrogen and lower DNA:RNA ratio in the mammary gland. When period was analyzed, the levels of high density lipoprotein (HDL) increased in the realimentation period, while the urea N decreased. In addition to the alteration in the levels of urea N, the energy balance to which the heifers in compensatory growth were submitted increased the non-esterified fatty acids. Blood glucose levels reduced in the animals in compensatory growth during the realimentation period. Supplementation with ionophore results in lower concentration of non-esterified fatty acids during the realimentation period.

The study was conducted to determine the kinetic parameters of in situ DM and NDF and the passage of particles of forages produced from the intercropping of brachiaria grass with corn and soybean crops. Three experiments were performed, as follows: Experiment 1 - Brachiaria grass intercropped with corn at different plant ages; Experiment 2 - Cultivation of brachiaria grass intercropped with corn set in different sowing arrangements; and Experiment 3 - Intercropping of brachiaria grass and soybean. Passage kinetic of particles was determined by the recovery of markers in feces. In order to obtain the ruminal degradation of DM and NDF, nylon bags were used at zero time, 3, 6, 9, 12, 24, 48, 72, 96, 120 and 144 hours. The particles' passage kinetic of corn with brachiaria grass silage and brachiaria grass silage presented 3%/h and 2.3%/h, respectively; and for soybean and brachiaria grass silage, it was 1.8%/h, which can be explained in part by the mixture of materials ensiled. The materials originated from the intercropping caused rumen fill. Degradation rates were lower when compared with literature data. The brachiaria grass silage obtained from corn and/or soybean crop-pasture integrated system is a feed with low nutritive value due to its low NDF degradation rate and low passage rate, causing rumen fill and, thus, possibly resulting in low intake and poor animal performance.

Objetivou-se com este trabalho apresentar uma metodologia de identificação e modelagem da autocorrelação residual considerando ajustes individuais do modelo de Wood às lactações de cabras leiteiras e também avaliar a influência de tal modelagem na qualidade do ajuste. O modelo de Wood foi ajustado individualmente às lactações, considerando três estruturas residuais. Na primeira, assumiu-se independência dos erros (EI) para todas as lactações, na segunda, assumiu-se a estrutura de erros autoregressivos de primeira ordem (AR1) para todas as lactações e, na terceira, nomeada por EI-AR1, foi utilizada a estrutura de erros AR1 somente para as lactações que apresentaram autocorrelação residual, segundo o teste de Durbin-Watson, e de EI para as demais. As três situações de ajuste foram comparadas pelos percentuais de convergência e pelas médias dos quadrados médios dos erros (QME) e dos coeficientes de determinação ajustados (R²aj). As médias dos QME e dos R²aj apresentaram valores semelhantes nas três situações de estrutura residual. No entanto, o modelo com estrutura EI-AR1 apresentou maior convergência, o que consiste em uma vantagem, já que permite que um maior número de animais seja avaliado quanto à sua curva de lactação. Portanto, em função da maior convergência obtida, o ajuste do modelo de Wood com a estrutura EI-AR1 consiste na opção mais indicada para grandes conjuntos de dados.

The objective of this research was to present a methodology for identification and modeling of residual autocorrelation considering individual adjustments of the Wood's model to lactation dairy goats and evaluate the influence of such modeling in the quality of adjustment. The Wood's model was adjusted individually for lactations in three different ways, the first have assumed independence of errors (IE) for all lactations, the second have assumed autoregressives first order errors (AR1) for all lactations and the third, named (IE-AR1), was used the AR1 errors structure only for lactations that showed residual autocorrelation according to Durbin-Watson test, and the IE errors structure for the other lactations. The three ways of adjustment were compared by the percentage of convergence and the average of the mean square errors (MSE) and coefficients of determination adjusted (R²adj). The average of MSE and R²aj were very similar in the three cases of residual structure. However, the model with IE-AR1 residual structure showed a higher rate of convergence, which is an advantage, as it allows a greater number of animals are evaluated for their lactation curve. Therefore, due to the increasing convergence obtained, the fit of the Wood's model with IE-AR1 residual structure is the option most suitable for large data sets.

Diets formulated with protein sources presenting different resistance to ruminal degradation were compared by evaluating ruminal parameters, production and microbial efficiency and nutrients flow to the omasum in goats. Eight rumen cannulated non-lactating, non-pregnant goats were distributed in a 4 × 4 Latin square design with two replicates. Treatments consisted of four diets where different sources of plant protein accounted for the major protein source named soybean meal, source of higher ruminal degradability, and three other sources of higher resistance of degradation: roasted soybean, corn gluten meal, and cottonseed cake. Amounts of rumen protein were similar among rations; however, flows of dry matter, protein and non-fiber carbohydrate to omasum were higher for diets with protein source with reduced rumen degradation rate. Higher values of rumen ammonia were obtained by using ration with soybean meal as major source of protein. Higher values of pH were obtained for rations with roasted soybean e cottonseed cake. Regarding kinetic of transit, similar values were found among rations. Diets with protein sources presenting reduced ruminal degradation increase nutrients flow to the omasum in goats and alter digestive parameters such as pH and ammonia without compromising bacteria growth and efficiency, which grants their use for dairy goats with similar efficiency to rations using more degradable sources of protein.

Foram utilizados 10.238 registros semanais de produção de leite no dia do controle leiteiro provenientes de 388 primeiras lactações de cabras da raça Saanen visando comparar diferentes modelos de regressão aleatória (MRA). Primeiramente, foram comparados cinco modelos, cujos termos exponenciais da função de Wilmink assumiram os seguintes valores -0,0350; -0,0500; -0,0565; -0,0680 e -0,1000 (W0350, W0500, W0565, W0680 e W1000, respectivamente), considerando-se homogeneidade de variância residual ao longo da lactação. No modelo W0500, o valor -0,0500 foi mantido, enquanto nos modelos W0350, W0565, W0680 e W1000 foram usados os valores -0,0350; -0,0565; -0,0680; e -0,1000, respectivamente, em substituição ao valor -0,0500, proposto no modelo original utilizado para bovinos de leite. Escolhido o melhor modelo, segundo o ln L, foram avaliadas, pelos critérios AIC, BIC e ln L, a homogeneidade e heterogeneidade da variância residual: homogeneidade, duas, três, quatro, cinco e seis classes ao longo da lactação. De acordo com o critério usado, o modelo W0350 apresenta o melhor ajuste dentre os avaliados. Com relação à variância residual, a utilização de seis classes ao longo da lactação é indicada pelos critérios AIC, BIC, ln L e teste de razão de verossimilhança. As estimativas de herdabilidade ao longo da lactação, para o melhor modelo, variam de 0,07 (2ª semana de lactação) a 0,25 (20ª semana de lactação).

It was used 10,238 weekly test day records from 388 first lactations of Saanen goats with the objective of comparing random regression models (RRM). Firstly, it was compared five models, whose exponential terms of Wilmink function assumed the following values: -0.0350; -0.0500; -0.0565; -0.0680 and -0.1000 (W0350, W0500, W0565, W0680 and W1000, respectively) by considering homogeneity of residual variance over the lactation period. The value -0.0500 was kept in the model W0500 whereas models W0350, W0565, W0680 and W1000 used values -0.0350; -0.0565; -0.0680 and -0.1000, respectively, replacing the value -0.0500, proposed by the original model used in dairy cattle. After choosing the best model according to ln L, homogeneity and heterogeneity for residual variance: homogeneity, two classes, three classes, four classes, five classes and six classes along the lactation were evaluated by using AIC, BIC and ln L criteria. According to criterion used, W0350 presents the best fit among the evaluated models. With regard to residual variance, the use of six classes over lactation is indicated by AIC, BIC, ln L and likelihood ratio test. Heritability estimates over lactation, for the best model, ranges from 0.07 (2nd lactation week) to 0.25 (20th lactation week).

To evaluate the effect of using urea in the diet on ovarian follicular dynamics and plasma urea and progesterone concentration, an experiment was carried out with 29 Alpine goats randomly distributed into four diets, each one containing 0%; 0.73%; 1.46% or 2.24% of urea on total dry matter. The follicular dynamics was monitored daily by ultrasonography. The estrous cycles were characterized by occurrence of two, three, four or five follicular waves. The emergence day of the first follicular wave in cycles with two waves, the length of the third wave and the maximum diameter of the largest follicle of the third wave in cycles with three waves presented a quadratic behavior according to the percentage of urea in the diets. In cycles with four waves, the urea intake did not influence the follicular dynamics. The interestrus and interovulatory periods and the luteal and follicular phases length did not differ among treatments. The plasma urea concentration did not differ among diets neither among collection weeks. Plasma progesterone concentration on the estrus day and on the 11th day after estrus presented quadratic behavior, and on the 15th day after estrus, it linearly reduced acording to the percentage of urea in the diets. The supply of urea in diets at levels up to 2.24% in dietary dry matter did not influence the dry matter intake and the urea plasma concentration. For goats, the emergence day and the length of the waves, the follicular diameter and the plasma progesterone concentration on the estrus day and in the latter stages of diestrus were altered when there was supply of urea in the diet.

Objetivou-se com este trabalho avaliar o efeito de diferentes teores de fibra em detergente neutro oriunda da forragem com maturidade avançada sobre o consumo, a digestibilidade da matéria seca e de nutrientes, o balanço de nitrogênio, a produção de leite, a eficiência de utilização da energia metabolizável e o comportamento ingestivo de cabras em lactação. Foram distribuídas cinco cabras em delineamento em quadrado latino 5 × 5 utilizando-se teores crescentes de fibra em detergente neutro oriunda da forragem como variável independente. As concentrações de fibra em detergente neutro oriunda da foragem utilizadas foram 20, 28, 35, 43 e 49%. Os consumos de matéria seca, de nutrientes e de energia líquida reduziram com o aumento de fibra na ração. No entanto, o consumo de fibra em detergente foi crescente, indicando capacidade de acomodação desse componente nutritivo pelos animais. O teor de fibra influenciou os coeficientes de digestibilidade da matéria seca, matéria orgânica, proteína bruta e dos carboidratos não-fibrosos, contudo, a digestibilidade da fibra em detergente neutro não foi influenciada pelas dietas. O nível de fibra em detergente neutro oriunda da forragem não influenciou os constituintes do leite (gordura, proteína e lactose). O teor de fibra oriunda da forragem teve efeito quadrático sobre a produção de leite (corrigida e não corrigida para 4% de gordura), em kg/dia, com maiores produções obtidas com o teor de 28% de fibra. A eficiência de utilização da energia metabolizável não foi influenciada pelas variações nas dietas. O teor de fibra em detergente neutro oriunda da forragem influencia o comportamento ingestivo de cabras em lactação, aumentando os tempos de ruminação e mastigação e diminuindo o tempo em ócio dos animais.

The objective of this study was to evaluate the different contents of neutral detergent fiber from forage at advanced maturity on intake, digestibility of the dry matter and of nutrients, nitrogen balance, milk production, efficiency metabolizable energy use and the ingestive behavior of lactating goats. Five dairy goats were distributed in 5 × 5 Latin square by using increasing contents of neutral detergent fiber from forage as independent variable. Concentrations of neutral detergent fiber from forage used were 20, 28, 35, 43 and 49%. The intakes of dry matter, of nutrients and of net energy were reduced with the increase of fiber to the ration. However the intake of neutral detergent fiber was increasing, indicating the capacity of accommodation of this nutrient by the animals. Fiber content influenced digestibility coefficients of dry matter, organic matter, crude protein and non-fibrous carbohydrates but digestibility of neutral detergent fiber was not influenced by the diets. Level of neutral detergent fiber from forage did not influence milk constituents (fat, protein and lactose). Content of fiber from the forage had a quadratic effect on milk production (corrected and not corrected for 4% of fat) in kg.day-1, with greater productions obtained with the content of 28% of fiber. Efficiency of use of the metabolizable energy was not influenced by the variations of the diets. Content of neutral detergent fiber from forage influences ingestive behavior of goats in lactation, increasing the time of rumination and chewing and reducing iddle time of the animals.

Objetivou-se com este trabalho avaliar o efeito dos níveis de fibra em detergente neutro oriunda da forragem (FDNf) em dietas para cabras em lactação. Foram distribuídas cinco cabras em um delineamento quadrado latino 5 × 5, utilizando-se cinco níveis de FDNf (19, 27, 35, 42 e 48%) como variável independente. Os consumos de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE), carboidratos não fibrosos (CNF), nutrientes digestíveis totais (NDT) e energia líquida (EL3x) reduziram linearmente com o aumento dos níveis de FDNF. O consumo de FDN não foi influenciado pelo aumento no nível de FDN e manteve-se próximo a 1,2% do PV. As variações nas concentrações de fibra das dietas não influenciaram os coeficientes de digestibilidade da MS, MO, FDN, PB e CNF. De forma semelhante, as concentrações dos constituintes do leite (gordura, proteína e lactose) não se alteraram entre os níveis de fibra das dietas. O nível de FDNf da dieta teve efeito linear decrescente sobre a produção de leite corrigida e não-corrigida para gordura. A melhor eficiência líquida de utilização da energia metabolizável consumida para produção de leite é atingida com dietas contendo 35% de FDNf.

This work aimed to evaluate the effect of neutral detergent fiber levels from forage (NDFf) in diets for lactating goats. Five goats were distributed in a 5 × 5 Latin square design, using five NDFf levels (19, 27, 35, 42 and 48%) as independent variable. Intakes of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), nonfibrous carbohydrates (NFC), total digestible nutrients (TDN) and net energy (NE) linearly decreased as NDFf levels increased. NDF intake was not influenced by increase in NDF level and it was maintained close to 1.2% of BW. The variations in the concentrations of fiber in the diets did not affect the digestibility coefficients of DM, OM, NDF, CP and NFC. Similarly, the concentrations of milk constituents (fat, protein and lactose) were not altered with the fiber levels of the diets. Level of NDFf had a decreasing linear effect on correct and not corrected milk production for fat. The best net efficiency of use of the metabolizable energy consumed for production of milk is reached with diets containing 35% of NDFf.

Utilizaram-se 10.238 registros semanais de produção de leite no dia do controle, provenientes de 388 primeiras lactações de cabras da raça Saanen, na avaliação de seis medidas da persistência da lactação, a fim de verificar qual a mais adequada para o uso em avaliações genéticas para a característica. As seis medidas avaliadas são adaptações de medidas utilizadas em bovinos de leite, obtidas por substituir, nas fórmulas, os valores de referência de bovinos pelos de caprinos. Os valores usados nos cálculos foram obtidos de modelos de regressão aleatória. As estimativas de herdabilidade para as medidas de persistência variaram entre 0,03 e 0,09. As correlações genéticas entre medidas de persistência e produção de leite até 268 dias variaram entre -0,64 e 0,67. Por apresentar a menor correlação genética com produção aos 268 dias (0,14), a medida de persistência PS4, obtida pelo somatório dos valores do 41º ao 240º dia de lactação como desvios da produção aos 40 dias de lactação, é a mais indicada em avaliações genéticas para persistência da lactação em cabras da raça Saanen. Assim, a seleção de cabras de melhor persistência da lactação não altera a produção aos 268 dias. Em razão da baixa herdabilidade dessa medida (0,03), pequenas respostas à seleção são esperadas neste rebanho.

It was used 10,238 weekly milk production records on the control day from the first 388 lactations of Saanen goats on the evalution of six lactation persistency measures in order to find out which was the best fitted for using in genetic evaluations on this trait. These six evaluated measures are adaptations from those used on dairy cattle, obtained by replacing, in the formula, bovine reference values by the goat ones. The values used in the calculations were obtained from random regression models. Heritability estimates for persistency measures ranged from 0.03 to 0.09. Genetic correlations between persistency measures and milk production until 268 days ranged from -0.64 to 0.67. Because it presented the lowest genetic correlation with production at 268 days (0.14), the persistency measure PS4 obtained by the sum of the genetic values from the 41st to the 240th day of lactation as deviations of production at 40 days of lactation, is the best recommended for genetic evaluations of lactation persistence on Saanen goats. Thus, the selection of the goats with the best persistency of lactation does not change the production at 268 days. Due to the low heritability of this measure (0.03), few responses to selection are expected on this herd.

Um total de 292 animais de três raças (leiteiras Alpina e Saanen e a raça brasileira naturalizada Moxotó) foram genotipados, compreendendo 276 casos de paternidade. As análises estatísticas foram realizadas nos programas TFPGA e CERVUS. A heterozigosidade esperada variou de 0,542 (ILSTS005) a 0,825 (INRA006), com média de 0,717 para todos os loci. O conteúdo de informação polimórfica (Polymorphic information content, PIC) para todos os loci, foi de 0,676 e 0,542 e a probabilidade de exclusão (EP), de 0,999591 e 0,988375 para casos em que o genótipo materno era conhecido e desconhecido, respectivamente. A taxa de erro de identificação de paternidade é de 10% nos registros avaliados.

A total of 292 animals from three breeds (Alpine and Saanen dairy breeds, and the Brazilian naturalized breed Moxotó) were genotyped, comprising 276 paternity cases. Statistical analyses were carried out by using TFPGA and CERVUS programs. Heterozygosis ranged from 0.542 (ILSTS005) to 0.825 (INRA006), with an average of 0.717 for all loci. Polymorphic information content (PIC) was 0.676 and 0.542, and combined exclusion probabilities (EP) were 0.999591 and 0.988375 for known and unknown maternal genotypes, respectively. The microsatellite system reveals 10% of paternity misidentification in evaluated registers.

Objetivou-se com este trabalho avaliar o efeito de dietas com diferentes concentrações de fibra em detergente neutro oriunda da forragem (FDNf) sobre os parâmetros ruminais (pH e amônia) em cabras leiteiras. Foram utilizados cinco cabras não-lactantes fistuladas no rúmen arranjadas em delineamento quadrado latino 5 × 5, utilizando-se os níveis de FDNf (19, 27, 35, 42 e 48%) como variável independente. O aumento dos níveis de FDNf das rações reduziu linearmente os coeficientes de digestibilidade aparente da MS, MO, EE e CNF e afetou de forma quadrática o coeficiente de digestibilidade da FDN. Os coeficientes de digestibilidade ruminal da MS, MO e FDN aumentaram linearmente com a variação dos níveis de FDNf. De forma contrária, observou-se redução no coeficiente de digestibilidade intestinal da MS, MO, PB e FDN. O aumento no teor de FDNf e os tempos de coleta influenciaram o pH ruminal, contudo a amônia ruminal foi afetada apenas pelos tempos de coleta. A eficiência de síntese de proteína microbiana, quando expressa em g/kg NDT, foi influenciada pela elevação dos níveis de FDNf, e foi melhor no nível de 29,57% de FDNf.

The objective of this study was to evaluate the effect of diets with different neutral detergent fiber levels derived from the forage (NDFf), on ruminal parameters (pH and ammonia) in dairy goats. Five non-lactating goats were used, with fistulae in the rumen. The animals were arranged in a 5 × 5 Latin square using the NDFf levels (19, 27, 35, 42 and 18%), as independent variables. The increase in the NDFf levels of the rations reduced linearly the coefficients of apparent digestibility of DM, OM, EE and NSC and affected the NDF digestibility coefficient quadratically. The coefficients of ruminal digestibility of DM, OM and NDF increased linearly with the variation in the NDFf levels. However, reduction was observed in the coefficient of intestinal digestibility of DM, OM, CP and NDF. The increase in the NDFf contents and the collection times influenced the ruminal pH, but the ruminal ammonia only affected by the collection times. The efficiency of microbial protein synthesis, when expressed in g/kg TDN, was influenced by the increase in NDFf levels, was best at the 29.57% NDFf level.