Prevalence of gastrointestinal parasitic infection in cows and buffaloes in Lower Dir, Khyber Pakhtunkhwa, Pakistan

Abstract Gastrointestinal (GI) Parasitic infection is a hot issue for cattle management. There is variation of GI parasites effects in sex, age of cattle, drinking water condition, nutrition, and severity of infection. Studies on prevalence of GI parasites among cattle population in Dir Lower are lacking. A total of 40 farms were selected randomly in six tehsil namely Tehsil Adenzai, Tehsil Timergara, Tehsil Balambat, Tehsil Munda ,Tehsil Lalqala, Tehsil Khall. Freshly cattle fecal samples were collected randomly from the selected farms during March 2018 till December 2018. Out of 314 buffaloes and cattle examined 58.59% (184/314) were positive for eggs, cyst/oocyst of one or more species of GI Parasites. The prevalence of parasitic infection was higher in Buffaloes 63.55% (75/118) as compared to Cow 55.61% (109/196) but the difference was not significant (p>0.05) Entamoeba,spp, Moniezia spp, Haemonchus spp and Coccidian spp were found in this study. The non-treated animals indicated the highest percentage of infection in cow 57.71% (101/175) and buffalo 68.13% (62/91).GI parasite prevalence in female animal were higher female cow 62.58% (87/139) and female buffalo 77.33% (58/75) as compared to male. But the difference is non-significant (p> 0.05) Yearling calves had the lower rate of GI parasitic infection than adults. Future investigations are necessary to evaluate the economic loss due to GI parasites in cattles.

Resumo A infecção gastrointestinal (GI) parasitária é um assunto importante para o manejo do gado. Existem variações nos efeitos dos parasitas GI quanto a sexo, idade do gado, condição da água potável, nutrição e gravidade da infecção. Faltam estudos sobre a prevalência de parasitas GI entre a população de gado em Lower Dir. Um total de 40 fazendas foi selecionado aleatoriamente em seis tehsil, nomeadamente Tehsil Adenzai, Tehsil Timergara, Tehsil Balambat, Tehsil Munda, Tehsil Lalqala, Tehsil Khall. Amostras fecais de gado fresco foram coletadas aleatoriamente das fazendas selecionadas de março de 2018 até dezembro de 2018. Dos 314 búfalos e bovinos examinados, 58,59% (184/314) foram positivos para ovos, cisto/oocisto de uma ou mais espécies de parasitas GI. A prevalência de infecção parasitária foi maior em Buffaloes 63,55% (75/118) em comparação com vaca 55,61% (109/196), mas a diferença não foi significativa (p > 0,05). Entamoeba spp, Moniezia spp, Haemonchus spp e Coccidian spp foram encontrados neste estudo. Os animais não tratados indicaram a maior porcentagem de infecção em vacas 57,71% (101/175) e búfalos 68,13% (62/91). A prevalência do parasita GI em fêmeas foi maior em vacas fêmeas 62,58% (87/139) e búfalas 77,33% (58/75) em comparação ao masculino. Mas a diferença não é significativa (p > 0,05). A modelagem linear geral mostrou que o tratamento do animal estava significativamente relacionado com a prevalência de parasitas GI. Bezerros de um ano tiveram a maior taxa de infecção parasitária gastrointestinal. Futuras investigações são necessárias para avaliar a perda econômica devido aos parasitas GI em bovinos.

Prevalence of gastrointestinal parasitic infection in cows and buffaloes in Lower Dir, Khyber Pakhtunkhwa, Pakistan / Prevalência de infecções parasitárias gastrointestinais em vacas e búfalos em Lower Dir, Khyber Pakhtunkhwa, Paquistão

Gastrointestinal (GI) Parasitic infection is a hot issue for cattle management. There is variation of GI parasites effects in sex, age of cattle, drinking water condition, nutrition, and severity of infection. Studies on prevalence of GI parasites among cattle population in Dir Lower are lacking. A total of 40 farms were selected randomly in six tehsil namely Tehsil Adenzai, Tehsil Timergara, Tehsil Balambat, Tehsil Munda ,Tehsil Lalqala, Tehsil Khall. Freshly cattle fecal samples were collected randomly from the selected farms during March 2018 till December 2018. Out of 314 buffaloes and cattle examined 58.59% (184/314) were positive for eggs, cyst/oocyst of one or more species of GI Parasites. The prevalence of parasitic infection was higher in Buffaloes 63.55% (75/118) as compared to Cow 55.61% (109/196) but the difference was not significant (p>0.05) Entamoeba,spp, Moniezia spp, Haemonchus spp and Coccidian spp were found in this study. The non-treated animals indicated the highest percentage of infection in cow 57.71% (101/175) and buffalo 68.13% (62/91).GI parasite prevalence in female animal were higher female cow 62.58% (87/139) and female buffalo 77.33% (58/75) as compared to male. But the difference is non-significant (p> 0.05) Yearling calves had the lower rate of GI parasitic infection than adults. Future investigations are necessary to evaluate the economic loss due to GI parasites in cattle's.

A infecção gastrointestinal (GI) parasitária é um assunto importante para o manejo do gado. Existem variações nos efeitos dos parasitas GI quanto a sexo, idade do gado, condição da água potável, nutrição e gravidade da infecção. Faltam estudos sobre a prevalência de parasitas GI entre a população de gado em Lower Dir. Um total de 40 fazendas foi selecionado aleatoriamente em seis tehsil, nomeadamente Tehsil Adenzai, Tehsil Timergara, Tehsil Balambat, Tehsil Munda, Tehsil Lalqala, Tehsil Khall. Amostras fecais de gado fresco foram coletadas aleatoriamente das fazendas selecionadas de março de 2018 até dezembro de 2018. Dos 314 búfalos e bovinos examinados, 58,59% (184/314) foram positivos para ovos, cisto/oocisto de uma ou mais espécies de parasitas GI. A prevalência de infecção parasitária foi maior em Buffaloes 63,55% (75/118) em comparação com vaca 55,61% (109/196), mas a diferença não foi significativa (p > 0,05). Entamoeba spp, Moniezia spp, Haemonchus spp e Coccidian spp foram encontrados neste estudo. Os animais não tratados indicaram a maior porcentagem de infecção em vacas 57,71% (101/175) e búfalos 68,13% (62/91). A prevalência do parasita GI em fêmeas foi maior em vacas fêmeas 62,58% (87/139) e búfalas 77,33% (58/75) em comparação ao masculino. Mas a diferença não é significativa (p > 0,05). A modelagem linear geral mostrou que o tratamento do animal estava significativamente relacionado com a prevalência de parasitas GI. Bezerros de um ano tiveram a maior taxa de infecção parasitária gastrointestinal. Futuras investigações são necessárias para avaliar a perda econômica devido aos parasitas GI em bovinos.

Estimation of genetic parameters for weaning and yearling weights in a composite population used to form the Purunã breed

We aimed to evaluate the effects of sex and the linear and quadratic components of age of dam at calving, as well as apply a mixed model including maternal effect for the genetic evaluation of weaning (WW) and yearling (YW) weights. The phenotypic database was composed by Charolais, Caracu, Aberdeen Angus, and Canchim purebred and crossbred animals. Single-trait analyses were performed using models that included the maternal effect for WW and YW traits, and a model ignoring this effect on YW (YWNM). The Deviance Information Criterion (DIC), model posterior probabilities (MPP), accuracy of breeding values (ACC), and Spearman's rank correlation were applied to compare the models including and ignoring the maternal effect on YW. Sex and age of dam at calving had significant effects on WW and YW. The direct heritability estimates were 0.21±0.03 and 0.05±0.02, and the maternal heritabilities were 0.11±0.02 and 0.02±0.01 for WW and YW, respectively. The heritabilities estimated for YW may have been influenced by the several genetic groups in the population and by used conventional animal model, which may not have been the better fit model to evaluate YW in this population. The DIC, MPP, and ACC values indicated that YW outperformed the YWNM model, but the rank correlation and percentages of individuals selected in common suggested that the best animals would be selected independently of the model chosen.

Adult and yearling pampas deer stags (Ozotoceros bezoarticus) display mild reproductive seasonal patterns with maximum values in autumn

The pampas deer is an endangered species, from which reproductive biology little is known. We aimed to describe and compare the reproductive seasonal patterns of adult and yearling pampas deer stags throughout the year, including morphological traits, testosterone concentration, sperm morphology and cryoresistance pattern changes. Six adult (AS) and five yearling (YS) stags were captured with anesthetic darts once in winter, spring, summer and autumn to study morphological variables, serum testosterone and semen. Adult males were heavier, their neck girth tended to be greater and their testosterone concentration was higher than in YS. Animals were heavier in summer and autumn. Neck girth and testosterone concentration were greater in autumn. Scrotal circumference, testicular volume and gonado-somatic index varied with seasons, decreasing from winter to spring, increasing in summer and remaining in greater values in autumn. Sperm quality had maximum values from summer to winter. However, the cryoresistance ratio of motility score was greater in spring. In conclusion, in the captivity conditions, pampas deer stags seems to present a light seasonal reproductive pattern, with maximum testis size, testosterone secretion and fresh semen quality in autumn. Nevertheless, sperm cryoresistance ratio seemed to remain stable along the year. Although YS were still growing, they achieved similar semen quality than AS.

Adult and yearling pampas deer stags (Ozotoceros bezoarticus) display mild reproductive seasonal patterns with maximum values in autumn

The pampas deer is an endangered species, from which reproductive biology little is known. We aimed to describe and compare the reproductive seasonal patterns of adult and yearling pampas deer stags throughout the year, including morphological traits, testosterone concentration, sperm morphology and cryoresistance pattern changes. Six adult (AS) and five yearling (YS) stags were captured with anesthetic darts once in winter, spring, summer and autumn to study morphological variables, serum testosterone and semen. Adult males were heavier, their neck girth tended to be greater and their testosterone concentration was higher than in YS. Animals were heavier in summer and autumn. Neck girth and testosterone concentration were greater in autumn. Scrotal circumference, testicular volume and gonado-somatic index varied with seasons, decreasing from winter to spring, increasing in summer and remaining in greater values in autumn. Sperm quality had maximum values from summer to winter. However, the cryoresistance ratio of motility score was greater in spring. In conclusion, in the captivity conditions, pampas deer stags seems to present a light seasonal reproductive pattern, with maximum testis size, testosterone secretion and fresh semen quality in autumn. Nevertheless, sperm cryoresistance ratio seemed to remain stable along the year. Although YS were still growing, they achieved similar semen quality than AS.(AU)

Influence of temperament-related genes on live weight traits of Charolais cows

We investigated whether a panel of molecular markers previously associated with temperament has an effect on live growth traits. Phenotypic data from 412 Charolais cows categorized according to their age in adult and young cows were used to determine Pearson's correlations between birth (BW), weaning (WW), and yearling live (YW) weight and temperament traits (measured as exit velocity [EV] and temperament score [TS]). For association analysis, selective genotyping of a group of 80 cows identified as the most docile and temperamental were genotyped with a 151-SNP (single-nucleotide polymorphisms) panel of molecular markers previously associated with temperament. Significant Pearson's correlations between birth weight and weaning weight and the two temperament measurements (EV and TS) were observed only in the young cow group. Significant effects of ten SNP on BW and WW were observed. Four markers located on candidate genes for temperament traits also had an effect on birth weight and weaning weight in Charolais cows, which indicates that both traits could be influenced by the same genes.(AU)

Alternative adjustment of scrotal circumference for growth traits in Nellore cattle

The objective of this study was to estimate adjustment factors of scrotal circumference for growth traits in Nellore cattle. Measurement at post-yearling of scrotal circumference from 100,107 Nellore was adjusted for six traits: age (A), body weight (BW), hip height (HH), conformation (C), precocity (P), musculature (M), and simultaneously for age and the other five traits (A-BW, A-HH, A-C, A-P, A-M), body weight and the other four traits (BW-HH, BW-C, BW-P, BW-M), and hip height and the other three traits (HH-C, HH-P, HH-M). Standard values were 500 days, 300 kg, 135 cm, and 3, for age, body weight, hip height, and visual scores, respectively. Amplitudes of adjustment factor of scrotal circumference for age, body weight, and hip height were 0.6028, 0.4869, and 0.1572, respectively. Scrotal circumference is expected to grow, on average, 8.71 cm per 100 days of age, 6.51 cm per 100 kg of body weight, and 4.81 cm per 10 cm of hip height. The results showed higher amplitude in the adjustment factor of scrotal circumference for age and body weight (0.3429) compared with age and hip height and body weight and hip height (0.1271 and 0.0443, respectively). The amplitude observed in adjustment factor of scrotal circumference for conformation, precocity, and musculature were 0.1328, 0.1175, and 0.1160, respectively. Considering different adjustment factors of scrotal circumference can be useful for identifying better selection criteria for growth and/or sexual precocity in Nellore.(AU)

Best linear model to explain variability in the growth in Blanco Orejinegro cattle and effect of the serological status for bovine viral diarrhea and bovine leukosis / Melhor modelo linear para explicar a variabilidade no crescimento de bovinos Blanco Orejinegro e efeito do status sorológico para diarreia viral bovina e leucose bovina

The cattle breed Blanco Orejinegro (BON) is an important animal genetic resource in Colombia that needs to be studied to identify its productive benefits for Colombian livestock. The aim of this work was to establish the best linear model that explains the variability for birth weight, weaning weight and yearling weight, and estimate the effect of the serological status for Bovine Viral Diarrhea (BVD) and Bovine Leukosis (BL) in BON cattle in Colombia. The information on animal weighings belonging to 14 BON cattle herds, was collected and cleansed. Using the least squares method, 12 linear models were evaluated including as fixed effects, factors such as herd, sex, weighing month, birth order, season (rainy or dry), birth year, and contemporary group (formed by the concatenation of the factors herd, sex, and birth year). The weighing age was included as a covariate for weaning and yearling weights. For the selection of a model that best describes each parameter, the criteria for choosing models, such as Akaike information criterion (AIC), Bayesian Information criterion (BIC), coefficient of determination (R2 ), and the sum of squares of the error (SSE), were considered. The model that included the contemporary group showed the best fit, being also the best to describe the three parameters evaluated, since, of the four criteria considered for its evaluation, AIC and SSE showed the lowest values and the highest R2 . With this model, weight predictions with higher precision were able to be performed. Employing indirect ELISA screening tests of blood plasma, the serological status of each animal was estimated for BVD and BL viral infections. The serological status of these two viral infections was included in the best-fit model. There was no significant effect of the serological status on the parameters evaluated, so there are indications that animals that came in contact with the virus were not affected during growth.(AU)

A raça bovina Blanco Orejinegro (BON) é um importante recurso genético animal da Colômbia que requer estudos que identifiquem seus benefícios produtivos para a bovinocultura colombiana. O objetivo deste trabalho foi identificar o melhor modelo linear que explique a variabilidade do peso ao nascimento, ao desmame e ao ano e estimar o efeito do status sorológico para diarréia viral (BVD) e leucose bovina (BL) em gado BON da Colômbia. As informações sobre a pesagem de animais pertencentes a 14 fazendas dedicadas à criação de BON foram coletadas e depuradas. Utilizando o método dos mínimos quadrados, foram avaliados 12 modelos lineares nos quais foram incluídos como efeitos fixos fatores de rebanho, sexo, mês de pesagem, ordem de parição, época de nascimento (chuvosa ou seca), ano de nascimento e grupo de contemporâneos; a idade no momento da pesagem foi incluída como covariável para as características peso ao desmame e peso ao ano. Para a escolha do modelo que melhor descreve cada característica, foram considerados os critérios para escolha dos modelos AIC, BIC, coeficiente de determinação (R2 ) e soma dos quadrados dos erros (SCE). Verificou-se que o modelo que incluía o grupo de contemporâneos apresentou o melhor ajuste, sendo o melhor para descrever as três características avaliadas, uma vez que, dentre os quatro critérios levados em consideração para a sua avaliação, o AIC e a SCE apresentaram os menores valores e os R2 mais altos. Com este modelo, foi possível fazer predições de peso com maior acurácia. Os testes ELISA de rastreamento indireto estimaram o status sorológico de cada animal para infecções virais por BVD e BL. O efeito do status sorológico nessas duas infecções virais foi incluído no modelo que apresentou melhor ajuste. Não houve efeito do status sorológico sobre as características avaliadas, portanto há indicações de que os animais que tiveram contato com o vírus não foram afetados durante o crescimento.(AU)

Estimação de parâmetros genéticos para características de pesos e pesos metabólicos na desmama e pós-desmama em bovinos Brahman / Estimation of genetic parameters for weaning weights and metabolic weights characteristics and post weaning in Brahman cattle

Objetivou-se estimar herdabilidades e correlações de características ponderais com 36.505 animais, da Associação Brasileira de Criadores Zebu. O modelo incluiu efeito genético direto, materno, ambiente permanente, residual - aleatórios e efeitos de grupos contemporâneos - fixos. Os parâmetros foram estimados pelo método de máxima verossimilhança restrita (REML), utilizando-se software Wombat. Os resultados das herdabilidades variaram de 0,20 a 0,25 peso à desmama e ao sobreano; 0,16 a 0,20 peso metabólico não ajustado e ajustado à desmama, 0,21 a 0,25 peso metabólico ajustado à desmama e metabólico ajustado ao sobreano. As correlações genéticas entre peso à desmama e peso metabólico não ajustado à desmama, peso à desmama e peso metabólico ajustado à desmama são, respectivamente 0,76 e 1,00. A correlação genética entre peso ao sobreano e metabólico ao sobreano não ajustado, peso ao sobreano com metabólico sobreano ajustado foram 0,97 e 1,00. Correlação genética entre peso à desmama e ao sobreano foi 0,72, peso metabólico não ajustado à desmama e metabólico não ajustado ao sobreano 0,54, peso metabólico ajustado à desmama e metabólico ajustado ao sobreano foi 0,71. Correlações genéticas entre peso à desmama e metabólico ajustado à desmama e peso ano com metabólico ano ajustado foram 1,00 e 1,00. Portanto, utilização de peso metabólico sem ajuste de idade pode viesar estimativas de parâmetros genéticos.(AU)

The objective of this study was to estimate heritability and correlations of 36,505 animals, belonging to the Brazilian Association of Zebu Breeders. They were estimated by Restricted Maximum Likelihood method (REML) using Wombat software. The model included the direct additive genetic effect, maternal, permanent maternal environment and residual as random and fixed effects of contemporary group. The results of heritability ranged from 0,20 to 0,25 for weaning weight and yearling; 0,16 to 0,20 for real metabolic weaning, 0,21 to 0,25 for metabolic adjusted weight at weaning and yearling metabolic adjusted. The genetic correlations between weaning weight with metabolic real, weaning weight adjusted with metabolic are respectively 0,76 and 1,00. The genetic correlation between yearling weight and metabolic real, yearling weight adjusted metabolic were 0,97 and 1,00. Genetic correlations between weaning weight and yearling was 0,72, real metabolic weight at weaning and yearling real metabolic was 0,54, adjusted metabolic weight at weaning and yearling metabolic adjusted was 0,71. Genetic correlations between weight at weaning and adjusted metabolic and weight-adjusted metabolic year were 1,00 and 1,00. Therefore, the use of metabolic weight without age adjustment can warn the estimates.(AU)

Estimação de parâmetros genéticos para características de pesos e pesos metabólicos na desmama e pós-desmama em bovinos Brahman / Estimation of genetic parameters for weaning weights and metabolic weights characteristics and post weaning in Brahman cattle

Objetivou-se estimar herdabilidades e correlações de características ponderais com 36.505 animais, da Associação Brasileira de Criadores Zebu. O modelo incluiu efeito genético direto, materno, ambiente permanente, residual - aleatórios e efeitos de grupos contemporâneos - fixos. Os parâmetros foram estimados pelo método de máxima verossimilhança restrita (REML), utilizando-se software Wombat. Os resultados das herdabilidades variaram de 0,20 a 0,25 peso à desmama e ao sobreano; 0,16 a 0,20 peso metabólico não ajustado e ajustado à desmama, 0,21 a 0,25 peso metabólico ajustado à desmama e metabólico ajustado ao sobreano. As correlações genéticas entre peso à desmama e peso metabólico não ajustado à desmama, peso à desmama e peso metabólico ajustado à desmama são, respectivamente 0,76 e 1,00. A correlação genética entre peso ao sobreano e metabólico ao sobreano não ajustado, peso ao sobreano com metabólico sobreano ajustado foram 0,97 e 1,00. Correlação genética entre peso à desmama e ao sobreano foi 0,72, peso metabólico não ajustado à desmama e metabólico não ajustado ao sobreano 0,54, peso metabólico ajustado à desmama e metabólico ajustado ao sobreano foi 0,71. Correlações genéticas entre peso à desmama e metabólico ajustado à desmama e peso ano com metabólico ano ajustado foram 1,00 e 1,00. Portanto, utilização de peso metabólico sem ajuste de idade pode viesar estimativas de parâmetros genéticos.(AU)

The objective of this study was to estimate heritability and correlations of 36,505 animals, belonging to the Brazilian Association of Zebu Breeders. They were estimated by Restricted Maximum Likelihood method (REML) using Wombat software. The model included the direct additive genetic effect, maternal, permanent maternal environment and residual as random and fixed effects of contemporary group. The results of heritability ranged from 0,20 to 0,25 for weaning weight and yearling; 0,16 to 0,20 for real metabolic weaning, 0,21 to 0,25 for metabolic adjusted weight at weaning and yearling metabolic adjusted. The genetic correlations between weaning weight with metabolic real, weaning weight adjusted with metabolic are respectively 0,76 and 1,00. The genetic correlation between yearling weight and metabolic real, yearling weight adjusted metabolic were 0,97 and 1,00. Genetic correlations between weaning weight and yearling was 0,72, real metabolic weight at weaning and yearling real metabolic was 0,54, adjusted metabolic weight at weaning and yearling metabolic adjusted was 0,71. Genetic correlations between weight at weaning and adjusted metabolic and weight-adjusted metabolic year were 1,00 and 1,00. Therefore, the use of metabolic weight without age adjustment can warn the estimates.(AU)

Direct and maternal annual genetic changes for selected traits at weaning and yearling in beef cattle

Heritability and direct and maternal genetic changes were estimated in Nellore cattle for the following traits: birth to weaning weight gain (BWG), weaning to yearling weight gain (YWG), weaning conformation (WC), weaning precocity (WP), weaning muscling (WM), yearling conformation (YC), yearling precocity (YP), yearling muscling (YM) and yearling scrotal circumference (SC). Direct and maternal heritability for weaning traits were 0.21±0.03 and 0.13±0.01 (BWG); 0.19±0.03 and 0.07±0.01 (WC); 0.22±0.03 and 0.07±0.01 (WP); 0.20±0.03 and 0.07±0.01 (WM), respectively. For yearling traits, direct heritability were 0.19±0.04 (YWG); 0.32±0.05 (YC); 0.37±0.05 (YP); 0.38±0.05 (YM) and 0.41±0.04 (SC). Positive and significant direct genetic changes (p < 0.05) were found for all traits, except for WC (p = 0.09), equal to 0.138 kg year-1 (BWG), 0.003 units year-1 (WC), 0.011 units year-1 (WP), 0.009 units year-1 (WM), 0.132 kg year-1 (YWG), 0.003 units year-1 (YC), 0.011 units year-1 (YP), 0.011 units year-1 (YM) and 0.020 cm year-1 (SC), indicating favorable genetic gains in the period. For weaning traits, we obtained negative and non-significant (p > 0.05) maternal genetic trends, with values of -0.084 kg year-1 (BWG), -0.004 units year-1 (WC), -0.004 units year-1 (WP) and -0.004 units year-1 (WM). Thus, greater emphasis should be given for maternal genetic merit of weaning traits in this population, if improvements in maternal ability were desirable.(AU)

Direct and maternal annual genetic changes for selected traits at weaning and yearling in beef cattle

Heritability and direct and maternal genetic changes were estimated in Nellore cattle for the following traits: birth to weaning weight gain (BWG), weaning to yearling weight gain (YWG), weaning conformation (WC), weaning precocity (WP), weaning muscling (WM), yearling conformation (YC), yearling precocity (YP), yearling muscling (YM) and yearling scrotal circumference (SC). Direct and maternal heritability for weaning traits were 0.21±0.03 and 0.13±0.01 (BWG); 0.19±0.03 and 0.07±0.01 (WC); 0.22±0.03 and 0.07±0.01 (WP); 0.20±0.03 and 0.07±0.01 (WM), respectively. For yearling traits, direct heritability were 0.19±0.04 (YWG); 0.32±0.05 (YC); 0.37±0.05 (YP); 0.38±0.05 (YM) and 0.41±0.04 (SC). Positive and significant direct genetic changes (p 0.05) maternal genetic trends, with values of -0.084 kg year-1 (BWG), -0.004 units year-1 (WC), -0.004 units year-1 (WP) and -0.004 units year-1 (WM). Thus, greater emphasis should be given for maternal genetic merit of weaning traits in this population, if improvements in maternal ability were desirable.

Environmental effects on performance of progeny from different Nellore sires in Brazilian semiarid region / Fatores ambientais sobre o desempenho de progênies de diferentes touros da raça Nelore no semiárido brasileiro

The aim of this study was to evaluate the influence of environmental factors on the performance of progeny from different Nellore sires in Brazilian semiarid region. Data on live weight, average daily gain and scrotal circumference of 741 animals categorized as OR (open registry) or PB (purebred) and born from 27 sires were collected from a commercial farm located in Varzelândia-MG. Evaluations were taken at 12 (yearling) and 18months of age. Data were analyzed using the least-squares method, considering the effect of pedigree (OR or PB), sire, year of birth, month of birth and calf sex in the model. There was a significant influence of the pedigree, sex, month of birth and sire on animal's performance until yearling age, whereas the performance traits at 18months were influenced only by the month of birth and sire (P<0.05). Therefore, environmental factors such as year, month of birth and calf sex are important sources of variation on calf performance from birth to18 months and it should be considered when comparing and selecting animals based on these traits.(AU)

O objetivo deste trabalho foi avaliar a influência dos fatores ambientais sobre o desempenho das progénies de diferentes touros da raça Nelore no semiárido brasileiro. Informações de 741 animais foram coletadas de uma fazenda comercial localizada no municipio de Varzelândia-MG. Os animais eram filhos de 27 touros da raça Nelore e eram categorizados como LA (livro aberto) ou PO (puros de origem). Foram avaliados os dados de peso, ganho de peso médio diário e perímetro escrotal. As avaliações foram realizadas aos 12 (ano) e 18 (sobreano) meses de idade. Os dados foram analisados pelo método dos quadrados mínimos, utilizando um modelo que considerou efeito de categoria (LA ou PO), touro, anos, mês de nascimento e sexo dos bezerros. Houve influência significativa da categoria, sexo, mês de nascimento e touro sobre o desempenho dos animais até o ano, enquanto as características de desempenho ao sobreano foram influenciadas somente pelo mês de nascimento e touro (P<0,05). Sendo assim, os fatores do meio como ano e mês de nascimento e sexo do bezerro são importantes fontes de variação sobre o desempenho dos bezerros do nascimento até o sobreano, devendo, portanto, ser consideradas na comparação e seleção de animais com base nestas características.(AU)

Season affects energy input/output ratio in beef cattle production

Purpose of the study was to assess the effect of season on cultural energy analysis of beef cattle production systems. For this purpose, a summer feeding trial involving 188 yearling steers, with a mean body weight of 299 kg which started on 28 April and finished on 3 October and a winter feeding trial involving 182 yearling steers, with a mean body weight of 327 kg which started on 8 November and finished on 12 April were compared. In each season, housing consisted of three outside lots with access to overhead shelter, three outside lots with no overhead shelter and a semi-enclosed (open-front) cold confinement building containing four lots. Ad libitum corn grain, 2.27 kg of 35% dry matter (DM) whole plant sorghum silage and 0.68 kg of a 61% protein-vitamin mineral supplement was offered. Cultural energy (CE) used for feed and other production inputs was derived from their corresponding lot feed consumption and their corresponding values from the literature. Transportation energy was also included in the analysis. Cattle fed in summer had higher total CE expenditure than those fed in winter (P<0.05). Feed energy constituted more than half of the total CE and was higher for summer fed cattle (P<0.05). Energy inputs/kg live weight and/kg carcass were lower for summer fed cattle (P<0.05). Cultural energy per Mcal protein energy was higher for winterfed cattle (P<0.05). The energy output ratio defined as the Mcal input/Mcal output was better for summer fed cattle (P<0.05). Results show that time of year feeding affects cattle performance and CE use and summer feeding is an effective way of increasing the sustainability of beef cattle production.(AU)

Season affects energy input/output ratio in beef cattle production

Purpose of the study was to assess the effect of season on cultural energy analysis of beef cattle production systems. For this purpose, a summer feeding trial involving 188 yearling steers, with a mean body weight of 299 kg which started on 28 April and finished on 3 October and a winter feeding trial involving 182 yearling steers, with a mean body weight of 327 kg which started on 8 November and finished on 12 April were compared. In each season, housing consisted of three outside lots with access to overhead shelter, three outside lots with no overhead shelter and a semi-enclosed (open-front) cold confinement building containing four lots. Ad libitum corn grain, 2.27 kg of 35% dry matter (DM) whole plant sorghum silage and 0.68 kg of a 61% protein-vitamin mineral supplement was offered. Cultural energy (CE) used for feed and other production inputs was derived from their corresponding lot feed consumption and their corresponding values from the literature. Transportation energy was also included in the analysis. Cattle fed in summer had higher total CE expenditure than those fed in winter (P<0.05). Feed energy constituted more than half of the total CE and was higher for summer fed cattle (P<0.05). Energy inputs/kg live weight and/kg carcass were lower for summer fed cattle (P<0.05). Cultural energy per Mcal protein energy was higher for winterfed cattle (P<0.05). The energy output ratio defined as the Mcal input/Mcal output was better for summer fed cattle (P<0.05). Results show that time of year feeding affects cattle performance and CE use and summer feeding is an effective way of increasing the sustainability of beef cattle production.

Environmental effects on performance of progeny from different Nellore sires in Brazilian semiarid region / Fatores ambientais sobre o desempenho de progênies de diferentes touros da raça Nelore no semiárido brasileiro

The aim of this study was to evaluate the influence of environmental factors on the performance of progeny from different Nellore sires in Brazilian semiarid region. Data on live weight, average daily gain and scrotal circumference of 741 animals categorized as OR (open registry) or PB (purebred) and born from 27 sires were collected from a commercial farm located in Varzelândia-MG. Evaluations were taken at 12 (yearling) and 18months of age. Data were analyzed using the least-squares method, considering the effect of pedigree (OR or PB), sire, year of birth, month of birth and calf sex in the model. There was a significant influence of the pedigree, sex, month of birth and sire on animal's performance until yearling age, whereas the performance traits at 18months were influenced only by the month of birth and sire (P<0.05). Therefore, environmental factors such as year, month of birth and calf sex are important sources of variation on calf performance from birth to18 months and it should be considered when comparing and selecting animals based on these traits.

O objetivo deste trabalho foi avaliar a influência dos fatores ambientais sobre o desempenho das progénies de diferentes touros da raça Nelore no semiárido brasileiro. Informações de 741 animais foram coletadas de uma fazenda comercial localizada no municipio de Varzelândia-MG. Os animais eram filhos de 27 touros da raça Nelore e eram categorizados como LA (livro aberto) ou PO (puros de origem). Foram avaliados os dados de peso, ganho de peso médio diário e perímetro escrotal. As avaliações foram realizadas aos 12 (ano) e 18 (sobreano) meses de idade. Os dados foram analisados pelo método dos quadrados mínimos, utilizando um modelo que considerou efeito de categoria (LA ou PO), touro, anos, mês de nascimento e sexo dos bezerros. Houve influência significativa da categoria, sexo, mês de nascimento e touro sobre o desempenho dos animais até o ano, enquanto as características de desempenho ao sobreano foram influenciadas somente pelo mês de nascimento e touro (P<0,05). Sendo assim, os fatores do meio como ano e mês de nascimento e sexo do bezerro são importantes fontes de variação sobre o desempenho dos bezerros do nascimento até o sobreano, devendo, portanto, ser consideradas na comparação e seleção de animais com base nestas características.

Bayesian analysis on the growth traits in nelore mocho cattle raised in cerrado biome / Análise bayesiana para características de crescimento em bovinos da raçanelore mocho criados em bioma cerrado

This paper aims to estimate the (co) variances components on the genetic parameters for growth traits in Nelore Mocho cattle, raised in Cerrado biome, using Bayesian statistics. The data has been obtained from 48,063 cattle, provenient of Nelore Mocho herd, born from 1987 to 2009, participant of Breeder and Research Nacional Association’s (ANCP) Nelore Brazil Program. It has been evaluated the standard weight in 120 (P120), 210 (P210), 365 (P365), 450 (P450) years old, the weight gain from the birth to the weaning (GPND), and the weight gain from weaning to yearling (GPDS). The estimates on (co) variances components and genetic parameters have employed univariate analyses considering the Bayesian statistics animal model by the MTGSAM (Multiple Trait using Gibbs Sampler under Animal Model). The estimated values for direct heritability ranged from medium to high magnitude in standard weights (with range of 0.23 to 0.33) and the weight gain (0.18 for GPND and 0.24 for GPDS), for the creates and recreates phase, respectively. These results indicate that there is genetic variability in Nelore Mocho herd for growth traits, showing effective genetic growth when using the direct selection of these features in genetic improvement programs

O objetivo deste estudo foi estimar os componentes de (co) variância e parâmetros genéticos para as características de crescimento de bovinos da raça Nelore Mocho criados em bioma Cerrado, utilizando a inferência bayesiana. As informações foram obtidas de 48.063 animais Nelore Mocho, nascidos entre 1987 a 2009, provenientes de rebanhos participantes do Programa Nelore Brasil da Associação Nacional de Criadores e Pesquisadores (ANCP). Foram avaliadas as características de pesos padronizados aos 120 (P120), 210 (P210), 365 (P365) e 450 (P450) dias de idade, além do ganho de peso do nascimento a desmama (GPND) e o ganho de peso da desmama ao sobreano (GPDS). Os componentes de (co)variância e parâmetros genéticos foram estimados por meio de análises uni-características considerando a estatística bayesiana sob modelo animal e utilizando o programa MTGSAM (Multiple Trait using Gibbs Sampler under Animal Model). Os valores estimados para as herdabilidades foram de média a alta magnitude para todas as características de pesos padronizados (variando de 0,23 a 0,33) e de média magnitude para as características de ganho em peso (0,18 para GPND e 0,24 para GPDS). As herdabilidades estimadas indicaram a existência de variabilidade genética para as características de crescimento na raça Nelore Mocho, portanto, a seleção direta para tais características trará progresso genético apreciável.

Correlação entre as características de escores visuais com o peso à desmama em bovinos da raça Brangus / Correlation between traits of visual scores with weaning weight in Brangus cattle

A seleção genética através de programas baseados em avaliação dos escores visuais, tanto no período de desmame quanto ao sobreano, é um modo de controle e melhoramento do rebanho de fácil aplicação e baixo custo, capaz de gerar ganhos genéticos ao longo dos anos de utilização. No presente estudo foram utilizados dados de 93 machos desmamados no ano de 2017 pertencentes a Estância GAP São Pedro. Também foi calculada através do programa BioEstat 5.3, a correlação pelo método de Spearmann dos escores de P, M, U entre si e dos mesmos com o peso à desmama. Os resultados demonstraram a associação positiva entre o peso corporal e os escores de precocidade e musculatura.

Genetic selection through programs based on visual score evaluation, both during weaning and yearling, is a low cost and easy to apply herd control and genetic selection method, capable of generating genetic results in over the years. In the present study, data gathered from 93 weaned males were used in 2017, belonging to the Estância GAP São Pedro. It was also calculated through the program BioEstat 5.3, a correlation by the Spearmann method of the scores of Precocity, Musculature, Prepuce and each other with weight on weaning. The results demonstrated the positive association between body weight and precocity and musculature scores.

Bayesian analysis on the growth traits in nelore mocho cattle raised in cerrado biome / Análise bayesiana para características de crescimento em bovinos da raçanelore mocho criados em bioma cerrado

This paper aims to estimate the (co) variances components on the genetic parameters for growth traits in Nelore Mocho cattle, raised in Cerrado biome, using Bayesian statistics. The data has been obtained from 48,063 cattle, provenient of Nelore Mocho herd, born from 1987 to 2009, participant of Breeder and Research Nacional Associations (ANCP) Nelore Brazil Program. It has been evaluated the standard weight in 120 (P120), 210 (P210), 365 (P365), 450 (P450) years old, the weight gain from the birth to the weaning (GPND), and the weight gain from weaning to yearling (GPDS). The estimates on (co) variances components and genetic parameters have employed univariate analyses considering the Bayesian statistics animal model by the MTGSAM (Multiple Trait using Gibbs Sampler under Animal Model). The estimated values for direct heritability ranged from medium to high magnitude in standard weights (with range of 0.23 to 0.33) and the weight gain (0.18 for GPND and 0.24 for GPDS), for the creates and recreates phase, respectively. These results indicate that there is genetic variability in Nelore Mocho herd for growth traits, showing effective genetic growth when using the direct selection of these features in genetic improvement programs(AU)

O objetivo deste estudo foi estimar os componentes de (co) variância e parâmetros genéticos para as características de crescimento de bovinos da raça Nelore Mocho criados em bioma Cerrado, utilizando a inferência bayesiana. As informações foram obtidas de 48.063 animais Nelore Mocho, nascidos entre 1987 a 2009, provenientes de rebanhos participantes do Programa Nelore Brasil da Associação Nacional de Criadores e Pesquisadores (ANCP). Foram avaliadas as características de pesos padronizados aos 120 (P120), 210 (P210), 365 (P365) e 450 (P450) dias de idade, além do ganho de peso do nascimento a desmama (GPND) e o ganho de peso da desmama ao sobreano (GPDS). Os componentes de (co)variância e parâmetros genéticos foram estimados por meio de análises uni-características considerando a estatística bayesiana sob modelo animal e utilizando o programa MTGSAM (Multiple Trait using Gibbs Sampler under Animal Model). Os valores estimados para as herdabilidades foram de média a alta magnitude para todas as características de pesos padronizados (variando de 0,23 a 0,33) e de média magnitude para as características de ganho em peso (0,18 para GPND e 0,24 para GPDS). As herdabilidades estimadas indicaram a existência de variabilidade genética para as características de crescimento na raça Nelore Mocho, portanto, a seleção direta para tais características trará progresso genético apreciável.(AU)

Correlação entre as características de escores visuais com o peso à desmama em bovinos da raça Brangus / Correlation between traits of visual scores with weaning weight in Brangus cattle

A seleção genética através de programas baseados em avaliação dos escores visuais, tanto no período de desmame quanto ao sobreano, é um modo de controle e melhoramento do rebanho de fácil aplicação e baixo custo, capaz de gerar ganhos genéticos ao longo dos anos de utilização. No presente estudo foram utilizados dados de 93 machos desmamados no ano de 2017 pertencentes a Estância GAP São Pedro. Também foi calculada através do programa BioEstat 5.3, a correlação pelo método de Spearmann dos escores de P, M, U entre si e dos mesmos com o peso à desmama. Os resultados demonstraram a associação positiva entre o peso corporal e os escores de precocidade e musculatura.(AU)

Genetic selection through programs based on visual score evaluation, both during weaning and yearling, is a low cost and easy to apply herd control and genetic selection method, capable of generating genetic results in over the years. In the present study, data gathered from 93 weaned males were used in 2017, belonging to the Estância GAP São Pedro. It was also calculated through the program BioEstat 5.3, a correlation by the Spearmann method of the scores of Precocity, Musculature, Prepuce and each other with weight on weaning. The results demonstrated the positive association between body weight and precocity and musculature scores.(AU)