Seroprevalence of reproductive and infectious diseases in cattle: the case of Madre de Dios in the Peruvian southeastern tropics.

OBJECTIVE: The objective of this study was to determine the seroprevalence of reproductive and infectious diseases in tropical cattle in the Tambopata and Tahuamanu Provinces in the department of Madre de Dios, Peru. SAMPLE: 156 bovines from 7 cattle farms were sampled. These farms used exclusive grazing for food and natural mating for reproduction and did not have sanitary or vaccination programs. METHODS: The serum of blood samples was subjected to ELISA with commercial kits for the detection of antibodies against Neospora caninum, Mycobacterium avium subsp paratuberculosis (MAP), Leptospira interrogans, pestivirus bovine viral diarrhea virus-1, retrovirus bovine leukemia virus (BLV), orbivirus bluetongue virus (BTV), and herpesvirus bovine herpes virus-1 (BHV). The data were analyzed by means of association tests with χ2 (P < .05) and Spearman rank correlation (P < .05) in the SPSS v.15.0 software (IBM Corp). RESULTS: A low prevalence of antibodies to L interrogans, N caninum, M avium subsp paratuberculosis, bovine viral diarrhea virus-1 was found, but it was high to BTV, BLV, and BHV (100%, 53.85%, and 72.44%, respectively). The presence of BLV and BHV was higher in the Las Piedras District, bovines less than 5 years old, and cattle with breed characteristics of zebu and crossbred (P < .01). In addition, there was a significant correlation between both infections, showing 83.3% of BLV positivity that were also BHV positive (P < .01). CLINICAL RELEVANCE: The high prevalence of antibodies to BTV, BHV, and BLV could be due to livestock management practices, direct contact with infected animals, and variation of the presence of vectors and natural reservoirs in the context of climate change in the tropics.

Influence of eCG and reproductive management in the resynchronization of ovulation in dairy goats.

Resynchronization protocols have been proposed as a way of shortening females' unproductive time in the flock, with good results in cattle and sheep. In goats, initial studies have shown that a second progestogen device inserted before luteolysis and pregnancy diagnosis does not interfere with the corpus luteum lifespan or functionality. This study aimed to evaluate the follicular growth, ovulation pattern and pregnancy rate after insertion of a second and new progestogen device for resynchronizing, with or without equine Chorionic Gonadotrophin (eCG), submitted to natural mating (NM) or artificial insemination (AI) to propose a viable resynchronization protocol for dairy goats. A total of 38 multiparous Saanen goats underwent a short-term progesterone protocol [six days exposed to medroxyprogesterone acetate (MAP) intravaginal sponges + 200 IU eCG and 0.12 mg of cloprostenol sodium on the 5th day + 0.025 mg of lecirelin 34 hours after sponge withdrawal] and, on day 16th after the ovulation, received a new MAP device which was retained until day 21. At this moment females were split into four groups: GeCG+NM - 100 IU eCG with NM; GSal+NM - saline solution with NM; GeCG+AI - 100 IU eCG with AI; and GSal+AI - saline solution with AI. Ultrasound scans were performed every 12 h from sponge withdrawal (day 21) until 108 h after sponge withdrawal (day 25) for follicular dynamics evaluation, at 240 h (day 31) for assessing the presence of active corpus luteum, and on day 60 for pregnancy diagnosis. No differences were found regarding ovulation time, synchronization and follicle size. However, GeCG+NM presented a greater estrus manifestation rate (100%) and pregnancy rate (62.5%) when compared to GSal+AI. In conclusion, resynchronization protocols in dairy goats may present satisfactory results.

Influence of eCG and reproductive management in the resynchronization of ovulation in dairy goats

Resynchronization protocols have been proposed as a way of shortening females' unproductive time in the flock, with good results in cattle and sheep. In goats, initial studies have shown that a second progestogen device inserted before luteolysis and pregnancy diagnosis does not interfere with the corpus luteum lifespan or functionality. This study aimed to evaluate the follicular growth, ovulation pattern and pregnancy rate after insertion of a second and new progestogen device for resynchronizing, with or without equine Chorionic Gonadotrophin (eCG), submitted to natural mating (NM) or artificial insemination (AI) to propose a viable resynchronization protocol for dairy goats. A total of 38 multiparous Saanen goats underwent a short-term progesterone protocol [six days exposed to medroxyprogesterone acetate (MAP) intravaginal sponges + 200 IU eCG and 0.12 mg of cloprostenol sodium on the 5th day + 0.025 mg of lecirelin 34 hours after sponge withdrawal] and, on day 16th after the ovulation, received a new MAP device which was retained until day 21. At this moment females were split into four groups: GeCG+NM ­ 100 IU eCG with NM; GSal+NM ­ saline solution with NM; GeCG+AI ­ 100 IU eCG with AI; and GSal+AI ­ saline solution with AI. Ultrasound scans were performed every 12 h from sponge withdrawal (day 21) until 108 h after sponge withdrawal (day 25) for follicular dynamics evaluation, at 240 h (day 31) for assessing the presence of active corpus luteum, and on day 60 for pregnancy diagnosis. No differences were found regarding ovulation time, synchronization and follicle size. However, GeCG+NM presented a greater estrus manifestation rate (100%) and pregnancy rate (62.5%) when compared to GSal+AI. In conclusion, resynchronization protocols in dairy goats may present satisfactory results.(AU)

Effect of temperature - humidity index on the onset of post- partum ovarian activity and reproductive behavior in Bos indicus cows.

The effect of climatic factors on ovarian activity and reproductive behavior (RB) was evaluated in 46 Bos indicus cows kept under grazing conditions. Temperature-humidity index (THI) was used as an indicator of stress and divided in alert, damage and emergency levels. Fat thickness (FAT) was taken during the last trimester of gestation (LTG) to approximately 90d postpartum (PP). At 30d PP animals received a progesterone (P4)-releasing device (CIDR) which was withdrawn 9d later. Ovarian activity was assessed by blood progesterone on days 21, 24, 27, 30, 49, 51, and 54 PP. Animals were divided into three groups, higher, and moderate RB and non-behavior. Sixty percent presented a THI >74 increasing dramatically from June to September up to >78. During LTG, animals lost 27% of their body reserves contrasting to PP where an increase of 2.6% (P=0.002) was observed. The percentages of cyclic and non-cyclic animals were 57 and 43%, respectively (P> 0.05). Seventy-two percent displayed RB and 28% were non-behavior (P<0.05). A negative correlation (r = -0.307; P = 0.038) between THI and RB, and a positive correlation (r = 0.427; P = 0.003) between the onset of ovarian activity and RB were observed. Differences in THI during the LTG (P<0.01) were observed between cyclic and non-cyclic animals. Non-behavior cows in the LTG had a higher THI (P <0.05). High levels of THI have a negative effect on the resumption of ovarian activity and RB in Bos indicus especially if high THI occurs during the last trimester of gestation.

Artificial insemination in rabbits: factors that interfere in assessing itsresults

Understanding the rabbit's sexual behavior andreproduction process is very important when using artificial insemination (AI) instead of natural mating in intensive rearing systems. Ovulation in rabbit females not occur spontaneously/ induced ovulatory animals, but it has to be induced through a neuro-hormonal reflex, which is stimulated during mating. The mating effect of satiety on specific measures of rabbit female sexual behavior has not beeninvestigated. When applying AI, in the absence of a male, ovulation has to be induced by exogenous hormonal analogs. Bio-stimulation techniques are suggested as a substitute for hormones in that respect. One of the most effective approachesto distribute ejaculates from bucks of superior quality or genetic value is the systematic use of AI in intensive rabbit production. Rabbit's sexual receptivity has a significant influence on fertility at insemination. In addition, a limitationfactor for rabbit AI spread is related to their semen preservation. Fresh diluted semen has been used but its quality can be maintained only for a short period. However, there are few articles available have indicated the negativity of AI usage on rabbit, and the factors that can influence the AIprocess including the sexual desire behavior. Therefore, the objective of this review is to identify the important factors that directly or indirectly affect AI process success, meanwhileinterfering with and/or relying on AI assessment.(AU)

Artificial insemination in rabbits: factors that interfere in assessing itsresults

Understanding the rabbit's sexual behavior andreproduction process is very important when using artificial insemination (AI) instead of natural mating in intensive rearing systems. Ovulation in rabbit females not occur spontaneously/ induced ovulatory animals, but it has to be induced through a neuro-hormonal reflex, which is stimulated during mating. The mating effect of satiety on specific measures of rabbit female sexual behavior has not beeninvestigated. When applying AI, in the absence of a male, ovulation has to be induced by exogenous hormonal analogs. Bio-stimulation techniques are suggested as a substitute for hormones in that respect. One of the most effective approachesto distribute ejaculates from bucks of superior quality or genetic value is the systematic use of AI in intensive rabbit production. Rabbit's sexual receptivity has a significant influence on fertility at insemination. In addition, a limitationfactor for rabbit AI spread is related to their semen preservation. Fresh diluted semen has been used but its quality can be maintained only for a short period. However, there are few articles available have indicated the negativity of AI usage on rabbit, and the factors that can influence the AIprocess including the sexual desire behavior. Therefore, the objective of this review is to identify the important factors that directly or indirectly affect AI process success, meanwhileinterfering with and/or relying on AI assessment.

Effect of temperature humidity index on the onset of post- partum ovarian activity and reproductive behavior in Bos indicus cows

The effect of climatic factors on ovarian activity and reproductive behavior (RB) was evaluated in 46 Bos indicus cows kept under grazing conditions. Temperature-humidity index (THI) was used as an indicator of stress and divided in alert, damage and emergency levels. Fat thickness (FAT) was taken during the last trimester of gestation (LTG) to approximately 90d postpartum (PP). At 30d PP animals received a progesterone (P4)-releasing device (CIDR) which was withdrawn 9d later. Ovarian activity was assessed by blood progesterone on days 21, 24, 27, 30, 49, 51, and 54 PP. Animals were divided into three groups, higher, and moderate RB and non-behavior. Sixty percent presented a THI >74 increasing dramatically from June to September up to >78. During LTG, animals lost 27% of their body reserves contrasting to PP where an increase of 2.6% (P=0.002) was observed. The percentages of cyclic and non-cyclic animals were 57 and 43%, respectively (P> 0.05). Seventy-two percent displayed RB and 28% were non-behavior (P<0.05). A negative correlation (r = -0.307; P = 0.038) between THI and RB, and a positive correlation (r = 0.427; P = 0.003) between the onset of ovarian activity and RB were observed. Differences in THI during the LTG (P<0.01) were observed between cyclic and non-cyclic animals. Non-behavior cows in the LTG had a higher THI (P <0.05). High levels of THI have a negative effect on the resumption of ovarian activity and RB in Bos indicus especially if high THI occurs during the last trimester of gestation.(AU)

Effect of temperature – humidity index on the onset of post- partum ovarian activity and reproductive behavior in Bos indicus cows

The effect of climatic factors on ovarian activity and reproductive behavior (RB) was evaluated in 46 Bos indicus cows kept under grazing conditions. Temperature-humidity index (THI) was used as an indicator of stress and divided in alert, damage and emergency levels. Fat thickness (FAT) was taken during the last trimester of gestation (LTG) to approximately 90d postpartum (PP). At 30d PP animals received a progesterone (P4)-releasing device (CIDR) which was withdrawn 9d later. Ovarian activity was assessed by blood progesterone on days 21, 24, 27, 30, 49, 51, and 54 PP. Animals were divided into three groups, higher, and moderate RB and non-behavior. Sixty percent presented a THI >74 increasing dramatically from June to September up to >78. During LTG, animals lost 27% of their body reserves contrasting to PP where an increase of 2.6% (P=0.002) was observed. The percentages of cyclic and non-cyclic animals were 57 and 43%, respectively (P> 0.05). Seventy-two percent displayed RB and 28% were non-behavior (P<0.05). A negative correlation (r = -0.307; P = 0.038) between THI and RB, and a positive correlation (r = 0.427; P = 0.003) between the onset of ovarian activity and RB were observed. Differences in THI during the LTG (P<0.01) were observed between cyclic and non-cyclic animals. Non-behavior cows in the LTG had a higher THI (P <0.05). High levels of THI have a negative effect on the resumption of ovarian activity and RB in Bos indicus especially if high THI occurs during the last trimester of gestation.

Effect of reproductive methods and GnRH administration on long-term protocol in Santa Ines ewes.

This study aimed to determine whether reproductive performance of ewes submitted to laparoscopic timed artificial insemination (TAI) would be similar to ante meridiem (AM)/post meridiem (PM) rule and assisted natural mating (NM), and whether GnRH may enhance the pregnancy rate in TAI. In experiment I, 191 non-lactating ewes were synchronized, then TAI was performed either 48 h after progesterone (P4) removal (TAI-48 h) or 12 h after estrus detection (AM/PM); moreover, some ewes were submitted to NM (NM) as control treatment. In experiment II, 247 non-lactating ewes were allocated in five treatments, a control (no-GnRH on protocol) and four treatments arranged in a factorial design 2 × 2. The factors were time and dose of GnRH: ewes that received either 10 µg (TAI-10 µg-36 h) or 25 µg of GnRH (TAI-25 µg-36 h) 36 h after P4 removal and ewes that received either 10 µg (TAI-10 µg-48 h) or 25 µg of GnRH (TAI-25 µg-48 h) at time of insemination, 48 h after P4 removal. In experiment I, pregnancy rate in TAI-48 h was lower (P = 0.03) than AM/PM and NM. Moreover, the probability of pregnancy in TAI-48 h was higher (P = 0.06) in ewes detected in estrus early. In experiment II, the use of GnRH in TAI protocols increased (P < 0.01) pregnancy rate at synchronization, and TAI-25 µ-48 h and TAI-10 µg-36 h treatments increased (P = 0.02) pregnancy rate compered to TAI-10 µg-48 h. We conclude that TAI decreased pregnancy rate compered to NM and AM/PM, which may be improved by GnRH use in TAI to synchronize ovulation.

Effects of different regimens of PGF2α treatment during postpartum on reproductive performance in dairy cows / Efeito de diferentes regimes de tratamento pós-parto com PGF2α sobre o desempenho reprodutivo de vacas leiteiras

The aim of this study was to evaluate the effects of early postpartum PGF2α treatment on reproductive performance in dairy cows synchronized with targeted breeding and natural mating after voluntary waiting period. In this experiment ,120 cows were assigned to three groups irrespective of presence or absence of luteal tissue. Cows in PG- 14 group were treated with PGF2α from day 14 postpartum, cows in PG-28 group were treated with PGF2α from day 28 postpartum and cows in PG-42 group were not treated with PGF2α until the end of voluntary waiting period (d 42). After day 42 postpartum, cows in three groups were treated with PGF2α within 14-day intervals until natural mating after voluntary waiting period. Recorded reproductive parameters included days to first heat, days to first mating, days open, service per conception, conception rate, percentage of repeat breeder animals and pregnancy loss. Early PGF2α treatment from day 14 postpartum significantly decreased days to first estrus (34.9 ± 0.74, P < 0.003), days to first mating (62.35 ± 1.53, P < 0.04), days open (117.23 ± 3.1, P < 0.001) and service per conception (1.9 ± 0.09, P < 0.02); and PG-14 group presented increased conception rate (52.5%, P < 0.05). The proportion of repeat breeder syndrome tended to be affected by treatment with PGF2α from day 14 postpartum. In conclusion, treatment of cows with PGF2α from day 14 postpartum improved reproductive performance.(AU)

O objetivo do presente trabalho foi avaliar os efeitos do tratamento pós-parto precoce com PGF2α sobre o desempenho reprodutivo de vacas leiteiras sincronizadas para reprodução controlada por monta natural após o período de espera voluntário. Neste experimento, 120 vacas foram distribuídas em três grupos independentes da presença ou ausência de corpo lúteo. Vacas no grupo PG-14 foram tratadas com PGF2α a partir do 14o dia pósparto, vacas do grupo PG-28 foram tratadas com PGF2α a partir do 28o dia pós-parto e as vacas do grupo PG-42 não foram tratadas com PGF2α até o final do período de espera voluntário (d42). Após o 42o dia pós-parto as vacas dos três grupos foram tratadas com PGF2α com intervalos de 14 dias até a monta natural após o período de espera voluntário. Os registros dos parâmetros reprodutivos incluíram: dias para o primeiro estro, dias para a primeira cobertura, dias em aberto, serviços por concepção, taxa de concepção, percentagem de animais repetidores de cios e as perdas de gestações. O tratamento precoce com PGF2α, a partir do 14o dia pós-parto reduziu significativamente os dias para o primeiro estro (34,9 ± 0,74, P < 0,003), dias para a primeira cobertura (62,35 ± 1,53, P < 0,04), dias em aberto (117,23 ± 3,1, P< 0,02); e o grupo PG-14 apresentou um acréscimo na taxa de concepção (52,5%, P < 0,05). A proporção da síndrome de vacas repetidoras de cios tendeu a ser afetada pelo tratamento com PGF2α a partir do 14o dia pós-parto. A conclusão obtida foi que o tratamento das vacas com PGF2α a partir do 14o dia pós-parto melhorou o desempenho reprodutivo dos animais.(AU)

Effects of different regimens of PGF2α treatment during postpartum on reproductive performance in dairy cows / Efeito de diferentes regimes de tratamento pós-parto com PGF2α sobre o desempenho reprodutivo de vacas leiteiras

The aim of this study was to evaluate the effects of early postpartum PGF2α treatment on reproductive performance in dairy cows synchronized with targeted breeding and natural mating after voluntary waiting period. In this experiment ,120 cows were assigned to three groups irrespective of presence or absence of luteal tissue. Cows in PG- 14 group were treated with PGF2α from day 14 postpartum, cows in PG-28 group were treated with PGF2α from day 28 postpartum and cows in PG-42 group were not treated with PGF2α until the end of voluntary waiting period (d 42). After day 42 postpartum, cows in three groups were treated with PGF2α within 14-day intervals until natural mating after voluntary waiting period. Recorded reproductive parameters included days to first heat, days to first mating, days open, service per conception, conception rate, percentage of repeat breeder animals and pregnancy loss. Early PGF2α treatment from day 14 postpartum significantly decreased days to first estrus (34.9 ± 0.74, P < 0.003), days to first mating (62.35 ± 1.53, P < 0.04), days open (117.23 ± 3.1, P < 0.001) and service per conception (1.9 ± 0.09, P < 0.02); and PG-14 group presented increased conception rate (52.5%, P < 0.05). The proportion of repeat breeder syndrome tended to be affected by treatment with PGF2α from day 14 postpartum. In conclusion, treatment of cows with PGF2α from day 14 postpartum improved reproductive performance.(AU)

O objetivo do presente trabalho foi avaliar os efeitos do tratamento pós-parto precoce com PGF2α sobre o desempenho reprodutivo de vacas leiteiras sincronizadas para reprodução controlada por monta natural após o período de espera voluntário. Neste experimento, 120 vacas foram distribuídas em três grupos independentes da presença ou ausência de corpo lúteo. Vacas no grupo PG-14 foram tratadas com PGF2α a partir do 14o dia pósparto, vacas do grupo PG-28 foram tratadas com PGF2α a partir do 28o dia pós-parto e as vacas do grupo PG-42 não foram tratadas com PGF2α até o final do período de espera voluntário (d42). Após o 42o dia pós-parto as vacas dos três grupos foram tratadas com PGF2α com intervalos de 14 dias até a monta natural após o período de espera voluntário. Os registros dos parâmetros reprodutivos incluíram: dias para o primeiro estro, dias para a primeira cobertura, dias em aberto, serviços por concepção, taxa de concepção, percentagem de animais repetidores de cios e as perdas de gestações. O tratamento precoce com PGF2α, a partir do 14o dia pós-parto reduziu significativamente os dias para o primeiro estro (34,9 ± 0,74, P < 0,003), dias para a primeira cobertura (62,35 ± 1,53, P < 0,04), dias em aberto (117,23 ± 3,1, P< 0,02); e o grupo PG-14 apresentou um acréscimo na taxa de concepção (52,5%, P < 0,05). A proporção da síndrome de vacas repetidoras de cios tendeu a ser afetada pelo tratamento com PGF2α a partir do 14o dia pós-parto. A conclusão obtida foi que o tratamento das vacas com PGF2α a partir do 14o dia pós-parto melhorou o desempenho reprodutivo dos animais.(AU)

Effects of different regimens of PGF2α treatment during postpartum on reproductive performance in dairy cows / Efeito de diferentes regimes de tratamento pós-parto com PGF2α sobre o desempenho reprodutivo de vacas leiteiras

The aim of this study was to evaluate the effects of early postpartum PGF2α treatment on reproductive performance in dairy cows synchronized with targeted breeding and natural mating after voluntary waiting period. In this experiment ,120 cows were assigned to three groups irrespective of presence or absence of luteal tissue. Cows in PG- 14 group were treated with PGF2α from day 14 postpartum, cows in PG-28 group were treated with PGF2α from day 28 postpartum and cows in PG-42 group were not treated with PGF2α until the end of voluntary waiting period (d 42). After day 42 postpartum, cows in three groups were treated with PGF2α within 14-day intervals until natural mating after voluntary waiting period. Recorded reproductive parameters included days to first heat, days to first mating, days open, service per conception, conception rate, percentage of repeat breeder animals and pregnancy loss. Early PGF2α treatment from day 14 postpartum significantly decreased days to first estrus (34.9 ± 0.74, P < 0.003), days to first mating (62.35 ± 1.53, P < 0.04), days open (117.23 ± 3.1, P < 0.001) and service per conception (1.9 ± 0.09, P < 0.02); and PG-14 group presented increased conception rate (52.5%, P < 0.05). The proportion of repeat breeder syndrome tended to be affected by treatment with PGF2α from day 14 postpartum. In conclusion, treatment of cows with PGF2α from day 14 postpartum improved reproductive performance.

O objetivo do presente trabalho foi avaliar os efeitos do tratamento pós-parto precoce com PGF2α sobre o desempenho reprodutivo de vacas leiteiras sincronizadas para reprodução controlada por monta natural após o período de espera voluntário. Neste experimento, 120 vacas foram distribuídas em três grupos independentes da presença ou ausência de corpo lúteo. Vacas no grupo PG-14 foram tratadas com PGF2α a partir do 14o dia pósparto, vacas do grupo PG-28 foram tratadas com PGF2α a partir do 28o dia pós-parto e as vacas do grupo PG-42 não foram tratadas com PGF2α até o final do período de espera voluntário (d42). Após o 42o dia pós-parto as vacas dos três grupos foram tratadas com PGF2α com intervalos de 14 dias até a monta natural após o período de espera voluntário. Os registros dos parâmetros reprodutivos incluíram: dias para o primeiro estro, dias para a primeira cobertura, dias em aberto, serviços por concepção, taxa de concepção, percentagem de animais repetidores de cios e as perdas de gestações. O tratamento precoce com PGF2α, a partir do 14o dia pós-parto reduziu significativamente os dias para o primeiro estro (34,9 ± 0,74, P < 0,003), dias para a primeira cobertura (62,35 ± 1,53, P < 0,04), dias em aberto (117,23 ± 3,1, P< 0,02); e o grupo PG-14 apresentou um acréscimo na taxa de concepção (52,5%, P < 0,05). A proporção da síndrome de vacas repetidoras de cios tendeu a ser afetada pelo tratamento com PGF2α a partir do 14o dia pós-parto. A conclusão obtida foi que o tratamento das vacas com PGF2α a partir do 14o dia pós-parto melhorou o desempenho reprodutivo dos animais.

Diagnosis of bovine brucellosis in bulls by seroagglutination and seminal plasma agglutination tests / Diagnóstico da brucelose bovina em reprodutores através da soroaglutinação e sêmen plasma aglutinação

Brucellosis is a zoonotic disease with common agent is Brucella abortus in bovine specie. The disease in bulls is usually asymptomatic and could have absence of anti-B. abortus antibody in serum. It was investigated of the occurrence of bovine brucellosis in bulls, which involved testing blood serum and seminal plasma from 177 bulls used for natural mating or as semen donors. Blood was collected from all the animals by venipuncture of the jugular vein to obtain the serum samples, while seminal plasma was obtained from the animals by electroejaculation. Samples were tested in a screening test (rose Bengal test). In the second stage, the samples testing positive in the RBT were subjected to the confirmatory test (2-mercaptoethanol). None of the animals tested positive when blood serum was used. However, 5.06% of the bulls were considered reagent positive when seminal plasma was tested. It also sought to determine whether there was an association between the kind of production and the destination of animals with positive results. The calculated odds ratio indicated that bulls of the kind of production dairy/both (beef and dairy) had a higher risk of brucellosis infection. It is recommended that seminal plasma agglutination and seroagglutination techniques are applied concomitantly.(AU)

Brucelose é uma zoonose que nos bovinos tem como principal agente a bactéria Brucella abortus. A doença nos touros é geralmente assintomática e pode haver ausência de anticorpos anti- B. abortus no soro sanguíneo. O presente estudo teve como objetivo principal avaliar a ocorrência da brucelose bovina em reprodutores para isso foram empregados testes oficiais tendo como material o soro sanguíneo e o plasma seminal. Foram utilizados 177 machos bovinos destinados à monta natural ou doação de sêmen. O soro sanguíneo foi obtido através de venopunção da jugular e o plasma seminal através da eletroejaculação. As amostras foram submetidas ao teste de triagem (Antígeno acidificado tamponado) e na segunda etapa, apenas as amostras positivas na triagem foram submetidas ao exame confirmatório (2-mercaptoetanol). Não houveram animais positivos quando utilizado o soro sanguíneo. Para plasma seminal houve 5,06% de touros reagentes. Avaliou-se também se sistema produtivo ou a destinação do animal possuíam associação com resultados positivos. O cálculo de odds ratio demonstrou que os reprodutores bovinos do sistema produtivo misto/leite tem maior risco de infecção para brucelose. Recomenda-se que a técnica de sêmen plasma aglutinação seja feita em conjunto com a soroaglutinação.(AU)

Diagnosis of bovine brucellosis in bulls by seroagglutination and seminal plasma agglutination tests / Diagnóstico da brucelose bovina em reprodutores através da soroaglutinação e sêmen plasma aglutinação

Brucellosis is a zoonotic disease with common agent is Brucella abortus in bovine specie. The disease in bulls is usually asymptomatic and could have absence of anti-B. abortus antibody in serum. It was investigated of the occurrence of bovine brucellosis in bulls, which involved testing blood serum and seminal plasma from 177 bulls used for natural mating or as semen donors. Blood was collected from all the animals by venipuncture of the jugular vein to obtain the serum samples, while seminal plasma was obtained from the animals by electroejaculation. Samples were tested in a screening test (rose Bengal test). In the second stage, the samples testing positive in the RBT were subjected to the confirmatory test (2-mercaptoethanol). None of the animals tested positive when blood serum was used. However, 5.06% of the bulls were considered reagent positive when seminal plasma was tested. It also sought to determine whether there was an association between the kind of production and the destination of animals with positive results. The calculated odds ratio indicated that bulls of the kind of production dairy/both (beef and dairy) had a higher risk of brucellosis infection. It is recommended that seminal plasma agglutination and seroagglutination techniques are applied concomitantly.

Brucelose é uma zoonose que nos bovinos tem como principal agente a bactéria Brucella abortus. A doença nos touros é geralmente assintomática e pode haver ausência de anticorpos anti- B. abortus no soro sanguíneo. O presente estudo teve como objetivo principal avaliar a ocorrência da brucelose bovina em reprodutores para isso foram empregados testes oficiais tendo como material o soro sanguíneo e o plasma seminal. Foram utilizados 177 machos bovinos destinados à monta natural ou doação de sêmen. O soro sanguíneo foi obtido através de venopunção da jugular e o plasma seminal através da eletroejaculação. As amostras foram submetidas ao teste de triagem (Antígeno acidificado tamponado) e na segunda etapa, apenas as amostras positivas na triagem foram submetidas ao exame confirmatório (2-mercaptoetanol). Não houveram animais positivos quando utilizado o soro sanguíneo. Para plasma seminal houve 5,06% de touros reagentes. Avaliou-se também se sistema produtivo ou a destinação do animal possuíam associação com resultados positivos. O cálculo de odds ratio demonstrou que os reprodutores bovinos do sistema produtivo misto/leite tem maior risco de infecção para brucelose. Recomenda-se que a técnica de sêmen plasma aglutinação seja feita em conjunto com a soroaglutinação.

Prediction of breeding values in beef cattle using different definitions of additive genetic groups / Definição de grupos genéticos aditivos visando melhor predição de valores genéticos em bovinos de corte

The paper aims to analyze the structure of additive genetic groups as an alternative to include animals with unknown parentage in genetic evaluation. Several traits were studied: weaning weight; yearling weight; post-weaning weight gain in 345 days; scrotal circumference at 18 months of age; and visual muscling scores at 18 months of age. As a control group it was used a database where all animals had known paternity. Thus, three scenarios were defined where 30%; 50% or 70% of the observations were randomly taken as animals with unknown parentage. For these three simulated databases, the strategies considered to define additive genetic groups were: effect of year at birth; effect of farm at birth; effect of year and farm at birth; and a negative control group, which considered animals with unknown paternity. The most appropriate strategy for additive genetic group was chosen as the one that resulted in a higher regression coefficient and additive genetic value closest to the predicted for those animals in the control group. The results considering the strategy of additive genetic show large agreement with the control group. Among the strategies proposed, farm of birth and year of birth of the animal with unknown parentage achieved the best results.(AU)

O objetivo do estudo foi avaliar a estrutura de grupos genéticos aditivos como alternativa para incluir animais com paternidade desconhecida nas avaliações genéticas. As características estudadas foram: peso a desmama; peso ao sobreano; ganho de peso pós-desmama em 345 dias; perímetro escrotal ao sobreano e o escore visual de musculosidade ao sobreano. Um banco em que todos os animais tinham paternidade conhecida foi utilizado como grupo controle. A partir deste, três cenários foram criados em que 30; 50 ou 70% dos indivíduos foram aleatoriamente assumidos como animais com paternidade desconhecida. As estratégias consideradas de grupos genéticos aditivos foram: safra de nascimento do animal com paternidade desconhecida; fazenda de nascimento do animal com paternidade desconhecida; ano de nascimento e fazenda de nascimento do animal e um grupo controle negativo que manteve os animais com pais desconhecidos. A estratégia adequada de grupo genético aditivo foi escolhida como sendo aquela que resultou em um maior coeficiente de regressão e com valor genético aditivo mais próximos ao predito para os animais do grupo controle. Os resultados que incluíram a estratégia de grupo genético aditivo nos modelos de predição dos valores genéticos mostraram maior coerência com o grupo controle, frente a não inclusão destes nas análises. Dentre as estratégias propostas, ano de nascimento e fazenda de nascimento do animal e apenas ano de nascimento do animal com paternidade desconhecida obtiveram os melhores resultados.(AU)

Prediction of breeding values in beef cattle using different definitions of additive genetic groups / Definição de grupos genéticos aditivos visando melhor predição de valores genéticos em bovinos de corte

The paper aims to analyze the structure of additive genetic groups as an alternative to include animals with unknown parentage in genetic evaluation. Several traits were studied: weaning weight; yearling weight; post-weaning weight gain in 345 days; scrotal circumference at 18 months of age; and visual muscling scores at 18 months of age. As a control group it was used a database where all animals had known paternity. Thus, three scenarios were defined where 30%; 50% or 70% of the observations were randomly taken as animals with unknown parentage. For these three simulated databases, the strategies considered to define additive genetic groups were: effect of year at birth; effect of farm at birth; effect of year and farm at birth; and a negative control group, which considered animals with unknown paternity. The most appropriate strategy for additive genetic group was chosen as the one that resulted in a higher regression coefficient and additive genetic value closest to the predicted for those animals in the control group. The results considering the strategy of additive genetic show large agreement with the control group. Among the strategies proposed, farm of birth and year of birth of the animal with unknown parentage achieved the best results.

O objetivo do estudo foi avaliar a estrutura de grupos genéticos aditivos como alternativa para incluir animais com paternidade desconhecida nas avaliações genéticas. As características estudadas foram: peso a desmama; peso ao sobreano; ganho de peso pós-desmama em 345 dias; perímetro escrotal ao sobreano e o escore visual de musculosidade ao sobreano. Um banco em que todos os animais tinham paternidade conhecida foi utilizado como grupo controle. A partir deste, três cenários foram criados em que 30; 50 ou 70% dos indivíduos foram aleatoriamente assumidos como animais com paternidade desconhecida. As estratégias consideradas de grupos genéticos aditivos foram: safra de nascimento do animal com paternidade desconhecida; fazenda de nascimento do animal com paternidade desconhecida; ano de nascimento e fazenda de nascimento do animal e um grupo controle negativo que manteve os animais com pais desconhecidos. A estratégia adequada de grupo genético aditivo foi escolhida como sendo aquela que resultou em um maior coeficiente de regressão e com valor genético aditivo mais próximos ao predito para os animais do grupo controle. Os resultados que incluíram a estratégia de grupo genético aditivo nos modelos de predição dos valores genéticos mostraram maior coerência com o grupo controle, frente a não inclusão destes nas análises. Dentre as estratégias propostas, ano de nascimento e fazenda de nascimento do animal e apenas ano de nascimento do animal com paternidade desconhecida obtiveram os melhores resultados.

Definição de grupos genéticos aditivos visando melhor predição de valores genéticos em bovinos de corte

The paper aims to analyze the structure of additive genetic groups as an alternative to include animals with unknown parentage in genetic evaluation. Several traits were studied: weaning weight; yearling weight; post-weaning weight gain in 345 days; scrotal circumference at 18 months of age; and visual muscling scores at 18 months of age. As a control group it was used a database where all animals had known paternity. Thus, three scenarios were defined where 30%; 50% or 70% of the observations were randomly taken as animals with unknown parentage. For these three simulated databases, the strategies considered to define additive genetic groups were: effect of year at birth; effect of farm at birth; effect of year and farm at birth; and a negative control group, which considered animals with unknown paternity. The most appropriate strategy for additive genetic group was chosen as the one that resulted in a higher regression coefficient and additive genetic value closest to the predicted for those animals in the control group. The results considering the strategy of additive genetic show large agreement with the control group. Among the strategies proposed, farm of birth and year of birth of the animal with unknown parentage achieved the best results.

O objetivo do estudo foi avaliar a estrutura de grupos genéticos aditivos como uma alternativa para melhor ajuste de animais com paternidade desconhecida nas avaliações genéticas. As características estudadas foram: peso a desmama; peso ao sobreano; ganho de peso pós-desmama em 345 dias; perímetro escrotal ao sobreano e o escore visual de musculosidade ao sobreano. Um banco em que todos os animais tinham paternidade conhecida foi utilizado como grupo controle. A partir deste, três cenários foram criados em que 30; 50 ou 70% dos indivíduos foram aleatoriamente assumidos como animais com paternidade desconhecida. As estratégias consideradas de grupos genéticos aditivos foram: ano de nascimento do animal com paternidade desconhecida; fazenda de nascimento do animal com paternidade desconhecida; ano de nascimento e fazenda de nascimento do animal e um grupo controle negativo que manteve os animais com pais desconhecidos. A estratégia adequada de grupo genético aditivo foi escolhida como sendo aquela que resultou em um maior coeficiente de regressão e com valor genético aditivo mais próximos ao predito para os animais do grupo controle. Os resultados que incluíram a estratégia de grupo genético aditivo nos modelos de predição dos valores genéticos mostraram maior coerência com o grupo controle, frente a não inclusão destes nas análises. Dentre as estratégias propostas, ano de nascimento e fazenda de nascimento do animal e apenas ano de nascimento do animal com paternidade desconhecida obtiveram os melhores resultados.

Reproductive characteristics of Awassi ewes mated artificially or naturally to Jordanian or Syrian Awassi rams en

A total of 586 Awassi ewes of varying ages were mated to 11 Jordanian and 11 Syrian Awassi rams either naturally or artificially during the normal breeding season to evaluate reproductive performance of Awassi sheep and compare the local Awassi rams toSyrian rams. The length of the estrous cycle was longer (P < 0.01) during June to July (28.6 + 0.9 d) than August to September (17.8 + 0.7 d). Syrian-sired matings resulted in a greater lambing rate to the first mating within breeding season than Jordanian-sired matings (P < 0.05), but not for the second, third, or fourth mating. The cumulative lambing rate after the fourth mating tended to be greater (P < 0.1) using Jordanian compared to Syrian sires. The number of single lambs per ewe lambing was significantly (P < 0.001) greater than multiple births. Birth, weaning, and marketing weights and average daily gain before weaning were significantly greater in single (P < 0.001) and male-lamb (P < 0.05) pregnancies than in twins and females. An increase (P < 0.01) in the average daily gain during the lambing season was observed in November and December compared to January, February, or March. The overall mortality rate was 21%, and there was a decrease (P < 0.001) from 1 to 3 yr of age and an increase (P < 0.01) from November to March. Jordanian and Syrian rams yielded similar reproductive characteristics except for the lambing rate of first mating. Lambs born early in the season had better (P < 0.01) average daily gain and lower (P < 0.001) mortality than those born later.(AU)

Reproductive characteristics of Awassi ewes mated artificially or naturally to Jordanian or Syrian Awassi rams

A total of 586 Awassi ewes of varying ages were mated to 11 Jordanian and 11 Syrian Awassi rams either naturally or artificially during the normal breeding season to evaluate reproductive performance of Awassi sheep and compare the local Awassi rams toSyrian rams. The length of the estrous cycle was longer (P < 0.01) during June to July (28.6 + 0.9 d) than August to September (17.8 + 0.7 d). Syrian-sired matings resulted in a greater lambing rate to the first mating within breeding season than Jordanian-sired matings (P < 0.05), but not for the second, third, or fourth mating. The cumulative lambing rate after the fourth mating tended to be greater (P < 0.1) using Jordanian compared to Syrian sires. The number of single lambs per ewe lambing was significantly (P < 0.001) greater than multiple births. Birth, weaning, and marketing weights and average daily gain before weaning were significantly greater in single (P < 0.001) and male-lamb (P < 0.05) pregnancies than in twins and females. An increase (P < 0.01) in the average daily gain during the lambing season was observed in November and December compared to January, February, or March. The overall mortality rate was 21%, and there was a decrease (P < 0.001) from 1 to 3 yr of age and an increase (P < 0.01) from November to March. Jordanian and Syrian rams yielded similar reproductive characteristics except for the lambing rate of first mating. Lambs born early in the season had better (P < 0.01) average daily gain and lower (P < 0.001) mortality than those born later.