SUMMARY This study aimed to investigate the relationship among somatic cell scores (SCS) and currently selected traits (milk yield, and fat, protein, lactose, total solids and no-fat-solids contents) in Holstein dairy cows in a semi-arid climate. The data were collected from available records of 272 Holstein cows from January 2007 to December 2016. Farms were located in Agreste region of Pernambuco whose climatic characteristics according to Instituto Nacional de Meteorologia-INMET were: average annual temperature of 25.21 °C; average annual precipitation 562.07 mm, and average annual relative humidity 75.61%.. A total of 4,586 records of somatic cell counts (SCC) in the milk, milk yield and milk components was analyzed. The SCC was transformed logarithmically into SCS SCS = log 2 ( SCC / 100 , 000 ) + 3 ) before statistical investigation. Ten SCS were obtained for determining their effects on milk yield and composition. Data were processed using PROC GLM and PROC CORR procedures in SAS. Results showed positive correlations among SCS and fat, protein, total solids and solids-non-fat contents, while the SCS and lactose content and milk yield were negatively correlated. The highest milk yield (34.43 kg/cow/day) was obtained for the lowest SCS (0; 0 to 24 cells x 1000/mL). The milk yield and lactose decreased while protein and fat contents increased when SCS increased mostly above score five (400 to 799 cells x 1000/mL). It was observed that the increase in SCS influenced negatively milk yield and composition in Holstein cows created in the semi-arid climate in Brazil.

Article history Due to the increasing importance of cryptosporidiosis in animal productivity, this study was carried out to investigate the occurrence of Cryptosporidium spp. and its association with animal weight development and fecal consistency in crossbred Nellore cattle. Thus, fecal samples of 30 cattle were collected biweekly, and their growth was accompanied by weighing animals from birth to 210 days of age (June 2014 to May 2015). The modified Ritchie and Ziehl-Neelsen techniques were used to screen for the presence of Cryptosporidium spp. oocysts. The chi-square, Fisher exact, Tukey and Spearman's correlation tests were used for statistical analysis. Oocysts of Cryptosporidium spp. were found in 69 (16.43%) of the 420 samples of cattle feces, and these parasitized animals presented a mean weight gain (4.76 kg) lower than that of non-parasitized individuals (10.58 kg) (p<0.05). The presence of this protozoan was detected in diarrhea and pasty stools (81.78%), indicating an association of the parasite with persistent diarrheal episodes (p<0.001). Among the bovines examined in this study, a higher occurrence of Cryptosporidium spp. was observed in lean diarrheic calves, which presented lower weight gain and poor productive performance.

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Agricultura -Economia -Brasil. 2. Agronomia -Pesquisa -Brasil. I. Pereira, Alexandre Igor de Azevedo. II. Série. CDD 630.981 Elaborado por Maurício Amormino Júnior -CRB6/2422 O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores.2019 Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais.

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Ocorrência de protozoários do gênero Cryptosporidium spp. em bovinos criados em propriedades da zona rural do município de Bom Jesus, Piauí] Ronaldo do

Highlights: Cows raised in the Agreste region produced an average of 32.46 kg milk per day. Primiparous cows presented higher levels of milk components. There was a significant increase in the SCS with the increase in the order of calving. The Wood model showed a good fit of lactation curve.