Impact of climatic variability on growth performance of Fogera cattle in Northwestern Ethiopia

This study aimed to assess the impact of climatic variability on the growth performance of the Fogera cattle at Metekel Ranch. About 15-years of meteorological data were collected from National Meteorological Agency. Then, the heat stress (HS) condition of the ranch location was calculated by the temperature-humidity index (THI). Moreover, all animals born and calves that were weaned from 2005 to 2019 were included in this study. Seasons and years of birth were fitted as predictors, while growth parameters were fitted as response variables. Data were analyzed by least-squares means analysis of variance using R software version 3.5.2 program. Moreover, a multiple linear regression model was also used. The trends in BW and WW of calves were significantly decreasing along the study period. The result also indicated that the relative humidity and ambient temperature regression coefficient was negative for BW and WW. The Pearson correlation coefficient also indicated there was a negative relationship between growth parameters and climatic variables. When THI increases from 67 to 72, the BW and WW of the calves were decreased by 3.5 and 25 kg, respectively. However, the optimum THI for higher BW and WW was less than or equal to 67. The lower BW and WW of calves observed in this study is due to the cumulative effect of the climate conditions of the study area and herd management practices. Therefore, in any improvement to be made in the ranch, environmental factors should be considered along with necessary amelioration activities.(AU)

Nellore cloned calf viability during the postnatal period / Viabilidade de bezerros nelores clonados durante o período pós natal imediato

This study evaluated the viability of Nellore cloned calves derived from somatic cell nuclear transfer (SCNT) and compare their viability with animals of the same breed derived from in vitro fertilization (IVF). Thus, two groups were formed. Group I (GI) consisted of 10 calves derived from SCNT and group II (GII) consisted of 10 calves derived from IVF. The differences detected between the groups were in the physical examination of the respiratory tract in GI, which represented the most common clinical-pathological disturbances. The Apgar index score indicated that 80% of GI animals were depressed and all had pale mucous membranes. Thus, anemia was reported in GI. In GII, this started at 12 h of life and was probably caused by an iron deficiency. Moreover, total calcium and ionized calcium levels were higher in GI immediately after birth. These alterations probably resulted in a high incidence of mortality in GI, reaching 90% of the calves, whereas mortality was only 20% for the calves in GII. In conclusion, cloned calves, which were derived from SCNT, had physiological and metabolic alterations after delivery, leading to a higher mortality rate during the perinatal period.(AU)

O objetivo deste trabalho foi avaliar a viabilidade de bezerros da raça Nelore oriundos da técnica da transferência nuclear de células somáticas (TNCS), no período pós natal imediato, comparando-a com animais desta mesma raça, oriundos de fertilização in vitro (FIV). Para tanto, os animais foram alocados em dois grupos, a saber: Grupo I (GI) - 10 animais frutos de TNCS; e, Grupo II (GII) - 10 animais oriundos de FIV. Nos respectivos bezerros, todos obtidos por cesariana, foram realizadas as avaliações físicas, escore de APGAR, bem como coleta de amostras de sangue nos momentos 0 (ao nascimento), às 2, 4, 6 e 12 horas de vida, a fim de avaliar os resultados de eritrograma, análises bioquímicas e hormonais, comparando-os entre os grupos e momentos. Nos animais que vieram a óbito foi realizada a necropsia para investigar a causa mortis. As diferenças observadas foram em relação aos achados clínico-patológicos, envolvendo, principalmente, o sistema respiratório caracterizado por bradpneia associada à dispneia, e a presença de edema e atelectasia pulmonar observadas no GI. Ademais, após a colostragem notou-se que 80% dos animais avaliados não foram capazes de manter a glicemia sendo mais evidentes nos animais do GII, possivelmente devido à hiperinsulinemia que se manifestou neste grupo ao longo de todo o período experimental. ...(AU)

Avaliação de amostras de sangue de gado zebuíno nelore usando o analisador hematológico CELL-DYN 3500 / Evaluation of zebu Nellore cattle blood samples using the Cell-Dyn 3500 hematology analyzer

The Cell-dyn 3500 is a multiparameter flow cytometer, which may analyze samples from several species performing several simultaneous analyses. It is able to perform white blood cells, red blood cells and platelet counts, besides differential leukocyte counts, packed cell volume and hemoglobin determination. Cell-Dyn 3500 performs total leukocyte count both optically and by impedance. The equipment may choose one or other method, based on the reliability of the results. Erythrocyte and platelet counts are determined by impedance. Leukocyte differentiation is based on an optical principle, using separation in multiangular polarized light. The objective of this study was to compare the results of complete blood count of Zebu Nellore heifers from Cell-dyn 3500, with those obtained from a semi-automated cell counter (Celm CC 510) and the manual technique. Blood samples were collected from the jugular vein in 5 mL EDTA vacuum tubes from 58 Nellore heifers, at 24 months of age. Samples were processed in parallel in the three different techniques. Results were analyzed using paired t test, Pearsons correlation and the Bland-Altmann method. There was a strong correlation for all parameters analyzed by Cell-Dyn 3500, manual method and semi-automated cell counter, except for basophils and monocytes counts. These results confirm that this analyzeris reliable for blood samples analysis of zebu cattle.

O Cell-Dyn 3500 é um citômetro de fluxo multi-parâmetros que realiza várias análises simultâneas em diversas espécies de animais. Ele realiza a contagem total de leucócitos, de hemácias e de plaquetas, além do diferencial de leucócitos, o volume globular e a determinação de hemoglobina. O Cell-Dyn 3500 realiza a contagem total de leucócitos, tanto pelo método óptico quanto pela impedância. O equipamento pode escolher um ou outro método, baseado na confiabilidade dos resultados. A contagem de hemáceas e plaquetas é determinada pelo método de impedância. A diferenciação de leucócitos é baseada em um princípio óptico de análise, utilizando-se separação em luz polarizada multiangular. O objetivo deste trabalho foi comparar os resultados de hemogramas, realizados pelo Cell-Dyn 3500, com aqueles realizados por um contador celular semi-automático (Celm CC-510) e pela técnica manual. Amostras de sangue foram colhidas da veia jugular, em tubos de 5,0 ml à vácuo com EDTA, de 58 novilhas Nelore de 24 meses de idade. As amostras foram processadas paralelamente nas três técnicas. Os resultados foram analisados pelo teste t pareado, correlação de Pearson e pelo método de Bland-Altmann. Houve forte correlação entre os resultados hematológicos obtidos pelo Cell-Dyn 3500, pelo método manual e pelo contador celular semi-automático (Celm CC-510), exceto para a contagem de basófilos e monócitos. Esses resultados confirmam que o equipamento é confiável para a análise de amostras de sangue de gado zebuíno.

Avaliação de amostras de sangue de gado zebuíno nelore usando o analisador hematológico CELL-DYN 3500 / Evaluation of zebu Nellore cattle blood samples using the Cell-Dyn 3500 hematology analyzer

The Cell-dyn 3500 is a multiparameter flow cytometer, which may analyze samples from several species performing several simultaneous analyses. It is able to perform white blood cells, red blood cells and platelet counts, besides differential leukocyte counts, packed cell volume and hemoglobin determination. Cell-Dyn 3500 performs total leukocyte count both optically and by impedance. The equipment may choose one or other method, based on the reliability of the results. Erythrocyte and platelet counts are determined by impedance. Leukocyte differentiation is based on an optical principle, using separation in multiangular polarized light. The objective of this study was to compare the results of complete blood count of Zebu Nellore heifers from Cell-dyn 3500, with those obtained from a semi-automated cell counter (Celm CC 510) and the manual technique. Blood samples were collected from the jugular vein in 5 mL EDTA vacuum tubes from 58 Nellore heifers, at 24 months of age. Samples were processed in parallel in the three different techniques. Results were analyzed using paired t test, Pearsons correlation and the Bland-Altmann method. There was a strong correlation for all parameters analyzed by Cell-Dyn 3500, manual method and semi-automated cell counter, except for basophils and monocytes counts. These results confirm that this analyzeris reliable for blood samples analysis of zebu cattle.(AU)

O Cell-Dyn 3500 é um citômetro de fluxo multi-parâmetros que realiza várias análises simultâneas em diversas espécies de animais. Ele realiza a contagem total de leucócitos, de hemácias e de plaquetas, além do diferencial de leucócitos, o volume globular e a determinação de hemoglobina. O Cell-Dyn 3500 realiza a contagem total de leucócitos, tanto pelo método óptico quanto pela impedância. O equipamento pode escolher um ou outro método, baseado na confiabilidade dos resultados. A contagem de hemáceas e plaquetas é determinada pelo método de impedância. A diferenciação de leucócitos é baseada em um princípio óptico de análise, utilizando-se separação em luz polarizada multiangular. O objetivo deste trabalho foi comparar os resultados de hemogramas, realizados pelo Cell-Dyn 3500, com aqueles realizados por um contador celular semi-automático (Celm CC-510) e pela técnica manual. Amostras de sangue foram colhidas da veia jugular, em tubos de 5,0 ml à vácuo com EDTA, de 58 novilhas Nelore de 24 meses de idade. As amostras foram processadas paralelamente nas três técnicas. Os resultados foram analisados pelo teste t pareado, correlação de Pearson e pelo método de Bland-Altmann. Houve forte correlação entre os resultados hematológicos obtidos pelo Cell-Dyn 3500, pelo método manual e pelo contador celular semi-automático (Celm CC-510), exceto para a contagem de basófilos e monócitos. Esses resultados confirmam que o equipamento é confiável para a análise de amostras de sangue de gado zebuíno. (AU)

Increasing the dose of GnRH at a synchronized timed AI increases pregnancy rates in Bos indicus influenced cattle

Compared to Bos taurus cattle, Bos indicus influenced cattle have a history of decreased pregnancy rates following artificial insemination (AI). These decreased pregnancy rates among Bos indicus influenced cattle may be attributed to their higher excitability response to stressful situations, which can result in increased circulating cortisol that can delay or suppress ovulation. This experiment was designed to evaluate the effect of an increased GnRH dose at a synchronized timed artificial insemination (TAI) on pregnancy rates in Bos indicus influenced cattle. Over two years, Bos indicus influenced heifers (n = 50) from four locations, Bos taurus heifers (n = 123) and lactating Bos indicus influenced cows (n = 83) were inseminated with conventional semen using the CO-Synch+CIDR protocol. Heifers were inseminated between 48 to 56 h and mature cows between 56 to 66 h of last PGF2 α administration. Non-lactating Brahman cows (n = 32) were also synchronized in the above manner and inseminated between 56 to 66 h with sexed Bos indicus influenced semen. All cows were randomly selected to receive either 100 μg (n = 144) or 200 μg (n = 144) of GnRH at insemination and examined via ultrasonography for pregnancy ~30 days post-TAI. The administration of 200 μg of GnRH at the time of AI to Bos indicus influenced cattle significantly (P < 0.004) increased pregnancy rates (0.43 ± 0.05) compared with 100 μg of GnRH (0.21 ± 0.04). This pattern of increased pregnancy rates in the 200 μg GnRH group occurred at all locations and in all cow types. Among Bos taurus heifers , the increased dose of GnRH at the time of AI did not affect pregnancy rates; 200 μg (0.49 ± 0.06) compared with a 100 μg dose (0.55 ± 0.06). These results indicate that increasing the dose of GnRH at the time of AI can increase synchronized pregnancy rates in Bos indicus influenced cattle, but not among Bos taurus heifers.

Increasing the dose of GnRH at a synchronized timed AI increases pregnancy rates in Bos indicus influenced cattle

Compared to Bos taurus cattle, Bos indicus influenced cattle have a history of decreased pregnancy rates following artificial insemination (AI). These decreased pregnancy rates among Bos indicus influenced cattle may be attributed to their higher excitability response to stressful situations, which can result in increased circulating cortisol that can delay or suppress ovulation. This experiment was designed to evaluate the effect of an increased GnRH dose at a synchronized timed artificial insemination (TAI) on pregnancy rates in Bos indicus influenced cattle. Over two years, Bos indicus influenced heifers (n = 50) from four locations, Bos taurus heifers (n = 123) and lactating Bos indicus influenced cows (n = 83) were inseminated with conventional semen using the CO-Synch+CIDR protocol. Heifers were inseminated between 48 to 56 h and mature cows between 56 to 66 h of last PGF2 α administration. Non-lactating Brahman cows (n = 32) were also synchronized in the above manner and inseminated between 56 to 66 h with sexed Bos indicus influenced semen. All cows were randomly selected to receive either 100 μg (n = 144) or 200 μg (n = 144) of GnRH at insemination and examined via ultrasonography for pregnancy ~30 days post-TAI. The administration of 200 μg of GnRH at the time of AI to Bos indicus influenced cattle significantly (P < 0.004) increased pregnancy rates (0.43 ± 0.05) compared with 100 μg of GnRH (0.21 ± 0.04). This pattern of increased pregnancy rates in the 200 μg GnRH group occurred at all locations and in all cow types. Among Bos taurus heifers , the increased dose of GnRH at the time of AI did not affect pregnancy rates; 200 μg (0.49 ± 0.06) compared with a 100 μg dose (0.55 ± 0.06). These results indicate that increasing the dose of GnRH at the time of AI can increase synchronized pregnancy rates in Bos indicus influenced cattle, but not among Bos taurus heifers.(AU)