Mixotrophic cultivation of microalgae provides a very promising alternative for producing carbohydrate-rich biomass to convert into bioethanol and value-added biocompounds, such as vitamins, pigments, proteins, lipids and antioxidant compounds. Spirulina platensis may present high yields of biomass and carbohydrates when it is grown under mixotrophic conditions using cheese whey. However, there are no previous studies evaluating the influence of this culture system on the profile of fatty acids or antioxidant compounds of this species, which are extremely important for food and pharmaceutical applications and would add value to the cultivation process. S. platensis presented higher specific growth rates, biomass productivity and carbohydrate content under mixotrophic conditions; however, the antioxidant capacity and the protein and lipid content were lower than that of the autotrophic culture. The maximum biomass yield was 2.98 ±0.07 g/L in growth medium with 5.0% whey. The phenolic compound concentration was the same for the biomass obtained under autotrophic and mixotrophic conditions with 2.5% and 5.0% whey. The phenolic compound concentrations showed no significant differences except for that in the growth medium with 10.0% whey, which presented an average value of 22.37±0.14 mg gallic acid/g. Mixotrophic cultivation of S. platensis using whey can be considered a viable alternative to reduce the costs of producing S. platensis biomass and carbohydrates, shorten cultivation time and produce carbohydrates, as it does not require adding expensive chemical nutrients to the growth medium and also takes advantage of cheese whey, an adverse dairy industry byproduct.

The objective of this study was to characterize the chemical composition and lipid profile of colostrum and milk of purebred Quarter Horse mares. Thirty-four (34) purebred mares were selected, which were then separated into groups according to age, birth order and lactation stage. Colostrum samples were collected in the first six hours after delivery and milk samples from the 7 th postpartum day, with intervals of 14 days until the end of lactation. The samples were refrigerated and sent to the Milk Laboratory of the University ( Laboleite — UFRN ), where they were analyzed for chemical composition. Colostrum was assessed by refractometry. The lipid profile was determined by gas chromatography through a separation of methyl esters. The data were tabulated and subjected to descriptive statistics and analysis of variance by the F-Test, and the groups were compared by the Tukey test using a significance level of 5%. There was high protein content and reduced lactose content for the colostrum of the Quarter Horse mares, differing from other breeds. The milk composition was not influenced by the mares’ age. However, variations in the lactation stage and in the birth order of the Quarter Horse mares altered the milk’s chemical composition. There is variation in the lipid composition of milk according to the lactation stage, without changing the characteristic profile of the mares’ milk or diminishing the nutritional quality of the lipid fraction.

ABSTRACT. Several human health problems have been related to the allergenic constitution of bovine milk due to the body's immune reaction to milk proteins. It is necessary find solutions to minimize the occurrence of such reactions, given the importance of milk as a source of animal protein. The aim of this study was to evaluate the allelic frequency of the CSN2 gene and to evaluate differences in the characteristics of Gir and Guzerá bovine milk. One hundred and fifty-six cows were used (68 Gir and 88 Guzerá) from the Felipe Camarão Experimental Station herd of the Agricultural Research Corporation of RN (EMPARN). DNA extractions were carried out from hair follicles of the animals; the gene was then amplified and sequenced in an ABI 3100 automatic sequencer. The obtained sequences were submitted to analysis using the Geneious 5.6.5 ® program. Data were submitted to analysis of variance and to the Tukey- Kramer test at 5% probability and cluster analyses by main components were performed. Allele frequencies were 98 and 97% for the A2 allele and 0.96 and 0.93% for the genotype A2A2 for Gir and Guzerá, respectively. Gir and Guzerá animals showed differences in protein, lactose, and nonfat dry extract levels. Although correlations between milk yield and the production and some milk components are moderate, increases in milk yield are always greater than the increase in constituent yield. In addition, even though Guzerá animals have a higher percentage of protein, lactose, and non-fat dry extract, milk from Zebu breeds is an alternative for individuals sensitive to β-casein protein.

RESUMODevido aos prejuízos causados pela mastite subclínica na perda de produção e qualidade do leite, o presente estudo teve como objetivo verificar a correlação existente entre a contagem de células somáticas (CCS) e a composição química do leite cru resfriado coletado na região agreste do estado do Rio Grande do Norte nos períodos de seca e chuva. As amostras foram coletadas em sete propriedades leiteiras no período da manhã, entre janeiro de 2010 e março de 2012, e encaminhadas ao Laboratório da Rede Brasileira de Qualidade do Leite (ESALQ/USP). Foram determinados os teores de proteína, gordura, lactose, caseína, sólidos totais, extrato seco desengordurado e nitrogênio ureico, além da CCS e bacteriana total. Os dados foram submetidos à análise de variância, análise de correlação e teste de comparação de médias (Tukey a 5%). A CCS média foi de 604 mil células/mL, com variação significativa para o período seco (558 mil células/mL) e chuvoso (650 mil células/mL). A CCS correlacionou-se positivamente com os teores de gordura e sólidos totais e negativamente com os teores de lactose do leite bovino armazenado em tanque de resfriamento, independente do período, no agreste do Rio Grande do Norte.Palavras-chave: lactose; proteína do leite; qualidade do leite; sistema de produção; mastite.

Resumo -O objetivo deste trabalho foi estimar parâmetros genéticos para idades ao primeiro (IPP) e segundo partos (ISP), idades ao primeiro (IPP PEN ) e segundo partos penalizadas (ISP PEN ), e a ocorrência de parto até os 38 meses de idade (PP 38 ), em bovinos da raça Canchim, bem como estimar as relações genéticas entre essas características e o peso (PE 420 ) de machos e femêas e a circunferência escrotal (CE 420 ) de novilhos, medidos aos 420 dias de idade. Foram estimados parâmetros genéticos em análises bicaracterísticas, por meio de inferência bayesiana. As análises foram realizadas entre CE 420 e PE 420 e as características reprodutivas medidas em fêmeas. As características reprodutivas das fêmeas devem apresentar baixa resposta à seleção, e mudanças no manejo e nas condições ambientais melhoram tais características. A seleção quanto ao maior peso aos 420 dias de idade não deve provocar mudanças nas características reprodutivas em fêmeas, enquanto a seleção para o aumento da circunferência escrotal, na mesma idade, contribui para melhorar tais características.Termo para indexação: bovinos de corte, circunferência escrotal, idade ao parto, ocorrência de parição, peso. Genetic parameters for growth and reproductive traits of Canchim breedAbstract -The objective of this work was to estimate genetic parameters for age at first (AFC) and at second (ASC) calvings, penalized age at first (AFC PEN ) and at second (ASC PEN ) calvings, and occurrence of calving until 38 months of age (PP 38 ) in Canchim breed, as well as to estimate the genetic correlations between these traits with weight (PE 420 ) of males and females, and scrotal circumference (CE 420 ) measured at 420 days of age. Genetic parameters were estimated by two-trait analyses using the Bayesian inference. The analyses were performed between CE 420 and PE 420 , and the reproductive traits measured in the females. The female reproductive traits should show low response to selection, and changes in the management and environmental conditions improve these traits. Selection for the higher weight at 420 days of age does not change female reproductive traits, while selection to increase scrotal circumference, at the same age, contributes to improve such traits.

Our aim was to identify the relationship between mozzarella cheese yield and buffalo milk composition, processing factors, and recovery of whey constituents. A production of 30 batches of mozzarella cheese at a dairy industry in northeast Brazil (Rio Grande do Norte) was monitored between March and November 2015. Mozzarella yield and 32 other variables were observed for each batch, and divided into 3 groups: milk composition variables (12); variables involved in the cheesemaking process (14); and variables for recovery of whey constituents (6). Data were analyzed using descriptive statistics, Pearson correlation, and principal component analysis. Most of the correlations between milk composition variables and between the variables of the manufacturing processes were not significant. Significant correlations were mostly observed between variables for recovery of whey constituents. Yield only showed significant correlation with time elapsed between curd cuttings and age of the starter culture, and it showed greater association with age of the starter culture, time elapsed between curd cuttings, and during stretching, as well as with milk pH and density. Thus, processing factors and milk characteristics are closely related to dairy efficiency in mozzarella manufacturing.

The objective was to evaluate the physico-chemical composition, somatic cell count and electrical conductivity of the milk from lactating Zebu cows. For this, monthly milk samples were collected on the official milk control day intended for analysis of electrical conductivity of milk (ECM), somatic cell count (SCC) and milk composition. We used monthly data from 680 controls, from 10 Gyr and 17 Guzerat cows from a herd located in the city of São Gonçalo do Amarante/RN, from August to November 2013. Analyses of variance, mean test and Pearson correlation analysis were conducted. The levels of fat (% F), protein (% P), lactose (% L), total solids (% TS) and non-fat dry extract (% NFDE) were dependent variables for the ECM and SCC. The milk of Gyr cows for ECM, SCC, GOR, PROT, LACT, TS and NFDE were respectively, 3.88±1.18 mS/cm, 1629±2195 thousands cells/mL, 4.71±1.77%, 3.29±0.31%, 4.5±0.33%, 13.5±1.78%, 8.79±0.37%, and for the Guzerat breed 3.59±0.88 mS/cm 1356±1793 thousands cells/mL, 4.47±0.98%, 3.43±0.32%, 4.52±0.24%, 13.5±1.19%, 9.02±0.48%. No significant correlations between SCC and ECM characteristics were observed. However, when the correlation of each of these parameters and milk composition in different classes for each breed was analyzed, a significant correlation of the SCC was observed with the protein and lactose in Gyr, of the ECM with the lactose and SCC with total solids and fat for the Guzerat cows.

Research was conducted in eight commercial herds located in the state of Rio Grande do Norte, Brazil. Properties were classified according to the production system, the seasons were divided into four and the genetic groups into six. Milk samples from morning milking were collected monthly, directly from a cooling tank. Protein, fat, lactose, total solids, casein, urea nitrogen concentrations/levels, somatic cell count (SCC) and total bacterial count (TBC) were determined. For milk composition, the detected results were satisfactory and met the requirements of Normative Ruling 62, but the averages for SCC and TBC were above the recommended limit. All variables, with the exception of casein from total protein were influenced (P <0.05) by the production system used in the production unit. A lower fat content was recorded in 2010 compared to 2011. For the seasons, all the constituents of milk had lower values in drier season (seasons 3 and 4), with the exception of casein; SCC and TBC had higher values in periods 1 and 2, which are considered rainy periods. There was variation in the chemical composition of milk according to the genotypes. Milk chemical composition met the legal and market requirements, with a positive emphasis on specialized production systems. The variations over the year and according to the genetic group of the herd are also significant and should be taken into account in the search for improvements. As for the hygiene and health aspects of milk, the results portray the need for a greater focus by the entities involved in the sector, as well as the producers, on the viability of an adequacy program and monitoring of management practices related to this criterion. Campos, P. P. L. da E. et al.do tanque de resfriamento, amostras de leite na ordenha da manhã. Foram determinados os teores de proteína, gordura, lactose, sólidos totais, caseína, as concentrações de nitrogênio ureico, a contagem de células somáticas (CCS) e a contagem bacteriana total (CBT). Para a composição do leite, os resultados detectados foram satisfatórios e atenderam às exigências previstas na Instrução Normativa 62, mas as médias obtidas para CCS e CBT estão acima do limite recomendado. Todas as variáveis analisadas, com exceção da caseína da proteína total, foram influenciadas (P<0,05) pelo sistema de produção utilizado na unidade produtiva. Verificou-se menor teor de gordura em 2010, quando comparado a 2011. Para as estações do ano, com exceção da caseína, todos os constituintes do leite apresentaram menores valores na época mais seca (estações 3 e 4), já a CCS e CBT apresentaram maiores valores nas épocas 1 e 2, que são considerados períodos de chuva. Verificou-se variação na composição química do leite de acordo com os genótipos estudados. A composição química do leite atende às exigências legais e de mercado, com destaque positivo para os sistemas de produção especializados. As variações ao longo do ano e de acordo com o grupo genético do rebanho são também significantes, devendo ser levadas em consideração na bus...