Palma forrageira na alimentação de cabras leiteiras

Objetivou-se avaliar o uso da palma e dos níveis de substituição da palma miúda (Nopalea cochenilifera Salm-Dyck) pela palma Orelha de Elefante Mexicana (Opuntia strica [Haw]. Haw) sobre consumo e digestibilidade dos nutrientes, comportamento ingestivo, consumo de água, síntese de proteína microbiana, produção a produção e qualidade do leite e queijo coalho de cabras Saanen em lactação. Foram utilizadas 10 cabras da raça Saanen em lactação (5010,09 kg de peso corporal), divididas em primíparas e multíparas, com médias de produção de leite de 3,5 kg/dia, distribuídas em um duplo quadrado latino 5 x 5. O período experimental teve duração de 95 dias divididos em cinco períodos de 19 dias cada, com os 14 primeiros para adaptação dos animais, seguidos de cinco dias para coleta de dados e amostras. As dietas experimentas foram compostas dos seguintes tratamentos: Controle (Base de feno de tifton e concentrado); 0; 11,5; 23,5 e 35% de palma Opuntia em substituição à Nopalea, na base da matéria seca. O consumo de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB) e nutrientes digestíveis totais (NDT) não sofreram efeito (p>0,05) da substituição da palma Nopalea pela palma Opuntia, todavia, o consumo de fibra em detergente neutro corrigida para cinza e proteína (FDNcp) e carboidratos não fibrosos (CNF) foram afetados (p0,05) pelos tratamentos. Ocorreu variação nos teores de sólidos totais do leite, as dietas com Nopalea apresentaram menor teor (9,91) em relação à dieta controle (10,12). Os teores de proteína, lactose e caseína sofreram efeito quadrático (p 0.05) from the replacement of the Nopalea cactus by the Opuntia cactus, however, the intake of neutral detergent fiber corrected for ash and protein (NDFcp) and non-fibrous carbohydrates (CNF) were affected (p 0.05) due to the replacement of the Nopalea cactus by Opuntia. There was variation in the content of total milk solids, the diets with Nopalea showed lower content (9.91) compared to the control diet (10.12). The protein, lactose and casein contents underwent a quadratic effect (p <0.05). There was variation in the physical-chemical composition of the cheese for the levels of fat, protein, pH and yield, the diets with cactus decreased the levels of fat concerning to the control diet whose average values were 20.21% (Opuntia), 21.30% (Nopalea) and 22.70% (control). However, protein contents were higher for diets with Opuntia cactus (20.82%) compared to the control diet (16.92%). The control diet promoted greater cheese yield compared to diets with cactus. Goat rennet cheese fed with Opuntia cactus according to the scores for appearance, flavor, texture and overall evaluation represented good acceptance by the tasters. In the purchase intention test there was acceptance for Saanen goats' milk rennet cheeses fed with Opuntia and Nopalea cactus.Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNP

Productive performance of cows in zebu characteristics of importance to milk production

In dairy cattle, the economic performance of the production system is closely related to the productive performance of the herd. Thus, in the first chapter of this work, the objective was to verify the influence of body condition score (ECC) on productive traits of zebu cows. Data from 98 zebu cows of Gir and Guzerá breeds, belonging to the Agricultural Research Center of Rio Grande do Norte (EMPARN). For the statistical analysis, cows were previously grouped into classes of physiological stage, lactation period, somatic cell counting (CCS) and ECC, included in the model as fixed effects. Analyses were performed using the procedures available in SAS® computational package (SAS, 2009). ECC influenced (P <0.05) the milk fat content, with an increase of 0.25 percentage units in fat content for each increase of 0.5 in the ECC. The average milk constituents were higher in the first class (I) of days in milk (P <0.05). The second chapter aimed at determining the genetic and phenotypic trends of Gir and Guzerá herds belonging to that research center. For this, estimates of DEP (predicted transmitting ability) for milk production traits and components (fat and protein) obtained in the genetic evaluations of the National Breeding Program for the Improvement of Guzerá Dairy Cattle, using data of monthly milk records. Descriptive analyzes and regressions of different characteristics were performed using the statistical procedures available in the computational package SAS® (Statistical Analysis System). Positive genetic and phenotypic trends for milk production and constituents were observed in the Gir and Guzerá herds, except for the phenotypic trend for fat and protein in that of Guzerá breed.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Na bovinocultura leiteira, o desempenho econômico de um sistema de produção está diretamente relacionado ao desempenho zootécnico do rebanho. Assim, no primeiro capítulo deste trabalho, o objetivo foi verificar a influência do escore de condição corporal (ECC) sobre as características produtivas de vacas zebuínas. Para tanto, foram utilizados dados de 98 vacas das raças zebuínas Gir e Guzerá, pertencentes à Empresa de Pesquisa Agropecuária do Rio Grande do Norte (EMPARN). Para as análises estatísticas, as vacas foram previamente agrupadas em classes para o estagio fisiológico, período de lactação, contagem de células somáticas (CCS) e ECC, incluídas como efeitos fixos no modelo. As análises foram realizadas utilizando-se os procedimentos disponíveis no pacote computacional SAS® (SAS, 2009). O ECC influenciou (P<0,05) o teor de gordura do leite, com um aumento 0,25 unidades percentuais no teor de gordura a cada aumento de 0,5 no ECC. As médias dos constituintes do leite foram maiores na primeira classe (I) de dias em lactação (P<0,05). O segundo capítulo teve como objetivo verificar as tendências genética e fenotípica dos animais Gir e Guzerá pertencentes à Empresa de Pesquisa Agropecuária do Rio Grande do Norte. Para isso, foram utilizadas as estimativas de DEP (diferença esperada na progênie) para as características de produção e constituintes do leite (gordura e proteína) dos animais avaliados pelo Programa Nacional de Melhoramento do Guzerá para Leite, a partir dos dados de controles leiteiros mensais. As análises descritivas e as regressões das diferentes características foram realizadas empregando os procedimentos estatísticos disponíveis no pacote computacional SAS® (Statistical Analysis System). Observou-se tendência genética e fenotípica positiva para a produção de leite e constituintes nos rebanhos Gir e Guzerá avaliados, à exceção da tendência fenotípica para gordura e proteína na raça Guzerá

CONCENTRATION OF UREA NITROGEN IN BUFFALO MILK DURING DIFFERENT SEASONS OF THE YEAR IN NORTHEASTERN BRAZIL

This study aimed at assessing the influence of different seasons of the year (dry and rainy) on urea nitrogen (MUN) concentration of buffalo milk in a commercial herd from Rio Grande do Norte state. The region is characterized by a rainy tropical climate with a dry and wet season from August to January and February to July, respectively. Samples were collected monthly from the cooling tank between February 2010 and February 2011, in the morning. Next, they were homogenized and packed in 40-mL plastic flasks, containing the preservative Bronopol® and later sent to the laboratory for urea nitrogen analysis. Although March 2010 exhibited greater ureanitrogen concentration (25.4 ± 4.4 mg/dL) and November the lowest mean (12 ± 0.4 mg/ dL), there was no significant variation in milk urea nitrogen in samples collected from cooling tanks during the rainy and dry seasons

Gir and Guzerat cow milk production and composition according to lactation stage, somatic cell count, physiological state and body condition

 This work was realized to evaluate lactation stage, physiological state, somatic cell count (SCC) and body condition score (BCS) on production and composition of cow's milk from Gir and Guzerat breeds were studied. Ninety-eight cows were analyzed and classified according to their physiological state, lactation stage, SCC and BCS. Milk production was weighed monthly to obtain production data. Composed samples were collected in vials containing preservatives and sent to the laboratory for analysis. Data were used for statistic descriptive analysis and analysis of variance. Higher milk production in the first 60 days of lactation was observed. Fat, protein and total solids concentration increased according to the increase of days in milk; while lactose concentration decreased. Higher levels of fat, protein and total solids in milk of non-pregnant cows were observed; while pregnant cows had higher daily production and higher lactose content in their milk. Higher lactose levels in milk were observed in animals with lower SCC. The BCS had no effect on milk composition or on somatic cell count. Zebu cow milk production and composition are influenced by lactation stage, physiological state and SCC.

Estimation of genetic and phenotypic trends for dairy traits of Gyr and Guzerá breeds

<div><p>ABSTRACT. Milk production has high economic importance in dairy cattle production systems, which justifies its inclusion in genetic breeding programs. The objective of this study was to evaluate the genetic and phenotypic trends of dairy traits in Gyr (167 lactations) and Guzerá (148 lactations) breeds in the State of Rio Grande do Norte (RN). Milk, fat and protein production obtained from monthly dairy controls were the traits evaluated. The expected differences in progeny (DEPs) for these traits were estimated using an animal model. From the means of phenotypic values and DEPs, we estimated the genetic and phenotypic trends in linear regressions as a function of the year of calving of the animal. Positive genetic and phenotypic trends were observed for Gyr (26.8 and 88.7 kg year-1) and Guzerá (8.44 and 37.68 kg year-1). Gyr breed presented positive genetic trends for fat (1.08 kg year-1) and protein (0.45 kg year-1) production and the Guzerá breed showed positive genetic trends for fat (0.36 kg year-1) and protein (0.25 kg year-1) production. The selection applied in the evaluated herds has produced satisfactory genetic and phenotypic progress for milk, fat and protein production.</p></div