Endocrine Profile and Reproductive Performance in Heifers Induced to Lactation

Background: Low reproductive efficiency has been one of the main factors that lead to dairy herd culling in the reproductive age. In multiparous animals, such inefficiency and culling can occur because of various factors and may be associated with occasional endocrine failures. To avoid revenue losses that incur due to lack of lactation, lactation is artificially induced in the animals that are not pregnant, using a defined protocol. The aim of this study was, therefore, to evaluate and compare the reproductive performance of heifers submitted to the induction protocol with that of pregnant heifers during the transition period.Materials, Methods & Results: Sixty Holstein heifers, 32 ± 0.6 months of age, were divided into two groups: Control Group (Control, n = 30) comprising pregnant heifers that were accompanied since 21 days before the expected calving date until 224 days in milk (DIM) and an Induction Group (Induction, n = 30) comprising non-pregnant heifers submitted to a lactation induction protocol, accompanied from the beginning of the protocol until 224 DIM. For evaluation of the endocrine profile (progesterone and estradiol concentrations) of these animals, blood samples were collected at two periods: the pre-lactation (weeks -3, -2 and -1) and post-lactation (weeks 1 and 4). Heifers from both groups were submitted to weekly reproductive evaluations, from the beginning of lactation until 35 DIM. Uterine examinations were performed using ultrasonography and vaginoscopy to evaluate uterine content, cervical opening, and mucosal aspect. Females in good reproductive health were subjected to a hormonal protocol for timed artificial insemination (TAI). The pregnancy rate of heifers that could reproduce (Control, n = 13, and Induction, n = 20) were evaluated and inseminated until 49 DIM. Progesterone levels were similar (P > 0.05) in the two groups at both pre- and post-start of lactation. Estradiol concentrations were different (P < 0.01) among groups only in the pre-lactation period. Higher levels of progesterone (P = 0.06) were observed in the induced heifers (Induction Group = 1.07 ± 0.23 ng/mL and Control Group = 0.38 ± 0.28 ng/mL). Therefore, in the fourth week, induced heifers exhibited higher luteinic activity, the progesterone concentration was above 1 ng/mL in 42% of the animals, while just 12.5% of the Control heifers had it. The overall pregnancy rate was 47.75%. The pregnancy rate recorded for induced heifers and Control heifers was 40% and 55.55%, respectively.Discussion: Progesterone and estradiol evaluations were performed in the first week after the beginning of the lactation to evaluate the metabolism and physiological concentration of the hormones used during the protocol. The measurements were again performed in the fourth week to evaluate the return to cyclicity of the heifers in both groups. The high serum concentrations of estradiol attained during the induction, in the pre-lactation period, may have possible interfered with the uterine environment and follicular population of these animals. Furthermore, it is possible that the hormonal combination used has a central effect on the synthesis and release of gonadotrophins and/or an effect on the ovarian follicular population. Based on the hormonal profile evaluated, particularly the endocrine profile, and the reproductive performance of heifers, the results suggest that the protocol for induced lactation has a positive effect on fertility

Uso de insulina para aumento da fertilidade de vacas de corte pós-parto lactantes inseminadas

The objective of this work was to evaluate the effect of insulin alone or in association with equine chorionic gonadotropin (eCG) on the fertility of postpartum beef cows subjected to synchronization. A total of 340 cows was subjected to fixed time artificial insemination. In the trial 1, the cows were subjected to temporary weaning (TW), while in the trial 2 the same protocol was tested without TW. The addition of an insulin injection to a progesterone/eCG-based protocol without TW increased the pregnancy rate of beef cows with body condition score (BCS) equal to or lower than 2.5. Insulin had no effect on cows submitted to TW or with BCS equal to or higher than 3.0.O objetivo deste trabalho foi avaliar apenas o efeito da insulina ou dela em associação com gonadotrofina coriônica equina (eCG) na fertilidade de vacas em pós-parto submetidas à sincronização. Um total de 340 vacas foi submetido à inseminação artificial em tempo fixo. No experimento 1, as vacas foram submetidas ao desmame temporário (DT), enquanto no experimento 2, o mesmo protocolo foi testado sem DT. A adição de uma injeção de insulina a um protocolo baseado em progesterona/eCG sem DT aumentou a taxa de prenhez de vacas de corte com escore de condição corporal (ECC) igual ou menor que 2,5. A insulina não teve efeito em vacas submetidas a DT ou com ECC igual ou maior que 3,0

Preferência e caracterização química de doce tipo ambrosia com ovos de galinha e de codorna

Objetivou-se com este trabalho caracterizar a composição química, a preferência e a intenção de compra de doces de ambrosia elaborados com ovos de galinha ou de codorna. Foram realizadas análises bromatológicas (matéria seca, cinza, proteína bruta e extrato etéreo), análises sensoriais com 50 consumidores; análise de preferência (escala variando de 7 - gostei extremamente a 1 - desgostei extremamente) e análise de intenção de compra (variando de 1 - só compraria se fosse forçado a 5 - compraria muito frequentemente) das ambrosias testadas. A partir da avaliação bromatológica foi verificado que a ambrosia elaborada com ovos de codorna apresentou maior teor de gordura (p&lt;0,05) do que a elaborada com ovos de galinha. Na análise sensorial, no conjunto dos atributos avaliados, 68% dos consumidores preferiram ambrosia elaborada com ovos de codorna. De forma semelhante, 54% dos consumidores gostaram extremamente da ambrosia elaborada com ovos de codornas, enquanto que apenas 12% atribuíram este mesmo valor a ambrosia de ovos de galinha. Concluiu-se que ovos de codorna podem ser usados na elaboração de doce ambrosia, apresentando aceitação sensorial e potencial mercadológico. No entanto, ovos de codorna aumentam o teor de gordura da ambrosia em comparação com ovos de galinha

Escore de locomoção e condição corporal apresentam baixa contribuição relativa para a ocorrência de lesões podais em vacas leiteiras

This study aims to evaluate the occurrence and distribution of foot lesion and body condition scores to define which lesions are determinant for the manifestation of locomotion scores in dairy cows. A database from 482 Holstein cows was evaluated considering information on body condition scores (BCS), locomotion scores (LS), and cows with hoof lesions. Sole hemorrhage was the hoof lesion with the greatest occurrence (74.15%), followed by nail hypoplasia (11.35%). Most cows with LS 1 showed a 3 and 4 BCS, in contrast to most animals with 2.5 and 3.5 LS, which showed a 2 and 3 LS. Linear correlations indicate that a 0 LS is inversely associated with sole hemorrhage lesions (r = -0.19), and sole hemorrhage and digital dermatitis (r = -0.26), whereas LS 1 cows are inversely related to sole hemorrhage and digital dermatitis (r = 0.14). Regardless of the categorization between healthy and lame animals, most individuals in the system showed a BCS between 3.0 and 3.5. However, we found that locomotion and body condition scores showed a low relative contribution to the occurrence of foot disorders.O objetivo foi avaliar a ocorrência, distribuição de lesões podais e escore de condição corporal, para então definir quais lesões são determinantes para a manifestação do escore de locomoção em vacas leiteiras. Uma base de dados de 482 vacas da raça Holandês foi avaliado, utilizando informações de escore de condição corporal (ECC), escore de locomoção (EL) e animais com lesões podais. A lesão de maior ocorrência foi hemorragia de sola (74%), seguido por unha em saca-rolha (11%). A maior proporção de vacas com EL 1, apresentou ECC entre 3 e 4, em contraste, no EL 2 e 3, a maioria dos animais encontrava-se com escore 2.5 e 3.5. A correlação linear indicou que EL 0 é inversamente associado com lesões de hemorragia de sola (r = -0.19) e hemorragia de sola e dermatite digital (r= -0.26). Vacas com EL 1 relacionaram-se inversamente apenas com hemorragia de sola e dermatite digital (r = 0.14). Independentemente da categorização entre claudicantes e saudáveis, a maioria dos animais apresentou ECC 3.0 e 3.5. No entanto, com base nos animais avaliados neste sistema o escore de locomoção e de condição corporal apresentaram baixa contribuição relativa para a ocorrência de afecções podais

Effect of GnRH or Estradiol Benzoate on Reproductive Traits during a Heatsynch Protocol in Dairy Cows

Background: Milk production of cows is closely correlated with its reproductive efficiency. One of the several factors influencing the dairy efficiency is the decline in fertility of the cows/heifers. Use of hormonal protocol are often used to improve the fertility of the recipients. Several programs are available to inseminate dairy cows, with variation in the use of different types of hormones, time of use and range of duration period, as well as the time of AI. The objective of this study was to evaluate the efficiency of follicular wave emergence induction of estradiol benzoate in comparison to GnRH in a Heatsynch protocol and its influence on reproductive parameters.Materials, Methods & Results: In this study were used primiparous and multiparous Holstein cows (n = 325). Animals were divided randomly into two different treatments according with the hormone used to induce follicular wave emergence (D0). The GnRH group (n = 167), was given 25 mg, while in the EB group (n = 158) was used 2 mg. At same day, were inserted, a controlled internal drug-releasing containing 1.9 g of progesterone CIDR®. On day 7, CIDR was removed and cows were given 25 mg luteinizing hormone followed by an injection of 1 mg Inducer Ovulation at day 8. Cows were then observed for signs of estrus for at least two hours (twice daily at 7 am and 6 pm) for three days following CIDR® removal. Cows detected in estrus were inseminated 12 h later the estrus detection. Pregnancy status was determined by ultrasonography at 30 ± 5 d and 60 ± 5 d after AI. A single technician was responsible for the estrus detection and inseminations. A single technician was responsible for the estrus detection and inseminations. Ultrassonographic examinations with ultrasound, transrectal linear probe of 5 MHz, were performed for the diagnosis of pregnancy at 30 and 60 days after artificial insemination. Binomially distributed data, such as, estrous response, conception rate, pregnancy rate and pregnancy losses, were analyzed by Chi-square test. Pregnancy rates at 30-35 days and 60-65 days as well as pregnancy losses were considered in the model for the effect of parity (primiparous vs. multiparous) and the group of estrus behavior during the Heatsynch protocol. Conception rate was similar between GnRH (36.1%, 57/158) and EB (37.7%, 63/167) treatments. Cows showing estrus signs after CIDR removed were 71.9% in GnRH and 62% in EB group (P = 0.05). Embryonic losses were different (P = 0.03) according to groups of cows showing estrus signals or not.Discussion: Our results demonstrate that conception rates are not affected by using either EB or GnRH at the beginning of the Heatsynch protocol. Therefore, the EB can be an alternative choice to GnRH at Heatsynch beginning. Similar results were found by autor in dairy cows, once it was also observed that there is no difference in conception rate in two TAI protocols using either GnRH or EB. In Heatsynch protocols the increase in estrus detection are a key factor to increase fertility in lactating dairy cows. It can be explained once animals in regular estrous cycle have a palpable corpus luteum and circulating progesterone concentration higher than 1 ng/mL which leads than to enhance pregnancy ratios. The use of BE at the time of CIDR insertion in TAI protocols for dairy cattle proved to be an alternative to GnRH considering conception rates. Therefore, the use of BE at the time of CIDR insertion in a Heatsynch protocol in dairy cattle proved to be an alternative to GnRH which can be an important tool to increase the TAI utilization by farmers. Furthermore, in Heatsynch protocol cows showing estrus have pregnancy rates improved and lower pregnancy losses

Efeito da reutilização do CIDR na taxa de prenhez de vacas de corte primíparas pós-parto de acordo com o escore de condição corporal

O escore de condição corporal (ECC) e a concentração sérica de progesterona são pontos importantes para o sucesso dos programas de inseminação artificial em tempo fixo (IATF) em vacas de corte. Assim, o objetivo do presente estudo foi avaliar a taxa de prenhez de vacas de corte primíparas Bos taurus durante o pós-parto com ECC?3,0 ou >3,0, submetidas a protocolos de inseminação artificial com tempo fixo utilizando CIDR novo ou de 2º uso. Foram utilizadas vacas prímiparas (n=237), que receberam um CIDR novo (CIDR Novo, n=122) ou de 2º uso (CIDR Usado, n=115) e 2mg de benzoato de estradiol no dia 0. Todas as vacas receberam uma injeção de 12,5mg de dinoprost no dia 7 e 0,5mg de cipionato de estradiol no dia 9, quando o CIDR foi removido. Também no dia 9 os terneiros foram separados das vacas até o momento da IATF, realizada 48h após a remoção do CIDR. O diagnóstico de gestação foi realizado por ultrassonografia 35 dias após a IATF. A taxa de prenhez geral obtida neste experimento foi de 48,1% (114/237). Desconsiderando-se o ECC, a diferença de taxa de prenhez aproximou-se da significância (P=0,057) entre os grupos, sendo de 54% (66/122) para o grupo CIDR Novo e 41% (48/115) para o grupo CIDR Usado. Quando considerada a interação entre o tratamento e o ECC, observou-se que não houve diferença na taxa de prenhez entre os grupos. Porém, observa-se novamente uma tendência (P=0,087) de menor taxa de prenhez para o grupo CIDR Usado comparado ao CIDR Novo para vacas com ECC?3,0. Portanto, apesar de apenas uma tendência, observou-se que vacas com baixo ECC submetidas à sincronização com CIDR previamente usado apresentam redução da taxa de prenhez

Effects of different production systems on health, zootechnical and metabolic parameters in Holstein calves in the extreme south of Brazil

The aim of this study was to evaluate the incidence of diseases as well as metabolic and zootechnical parameters in Holstein calves maintained in individual or collective housing systems in the extreme south of Brazil. One hundred calves were included immediately after birth and monitored for 90 days. Animals were randomly divided into two groups: individual stalls group (ISG; n=50) and collective stalls group (CSG; n=50). ISG calves were individually housed in 1.2m² wood pens and received 6 L of milk/day and concentrate food and water ad libitum for 90 days. Calves in the CSG were housed in groups of up to 25 animals, in a total of two stalls containing one animal per 3 m2. CSG calves received up to 8 L of milk/day at 0-15 days, milk ad libitum at 15-40 days, 7.2 L of milk. /day at 40-60 days, and gradual weaning at 60-90 days with concentrate food and water ad libitum, using an automatic feeder. In both groups, Zootechnical  parameters (weight, thoracic perimeter, height at the withers, and rump width) were measured weekly during the first 28 days and once every 15 days until weaning. Blood samples were retrieved weekly during the first 28 days. Metabolic parameters evaluated in this study were total calcium, beta-hydroxybutyrate (BHBA), free fatty acids (FFA), and glucose. The animals were monitored daily for clinical signs of diseases diarrhea and respiratory symptoms. General morbidity was higher in CSG 92% compared to ISG 74% (p0.05). Glucose, FFA, and BHBA concentrations were higher in the ISG (p<0.05) and total calcium higher in CSG (p<0.05). Finally, the weight and thoracic perimeter were higher in the CSG than those in the ISG, whereas the height and, rump width, at the withers was higher in the ISG than that in the CSG (p<0.05). In conclusion, animals raised in a collective system with automatic feeders exhibited less diarrhea and increased serum calcium as well as improved zootechnical development, although they had a higher incidence of bronchopneumonia

Resumption of postpartum ovarian activity of Bos indicus cows in the presence or not of the calf

The objective of this work was to test the effect of the presence or absence of the calf in the activities of estrous, follicular dynamics and hormone secretion of Bos indicus cows. Forty and six cows were divided in 3 groups. In group with contact (CC), the calves were prevented from suckling by being confined into a pen, that allowed auditory, olfactory and visual contact of the cows with their own calves (n=17). In group without contact (SC), the calves were weaned and prevented from any contact. In control group (T), the calves weren t weaned, remaining with their mothers (n=12). The CC group showed greater ratio of cows in estrous (76.5%) when compared to T (16.7%), but no difference from SC (64.7%). The CC group showed greater ratio of ovulation (76.5%) when compared to T (33.3%) and an apparent difference (p=0.06) when compared to SC (64.7%). The duration of estrous was lesser (p = 0.04) in group CC (8.4 h + 4.4 h) than the SC (12.9 + 13.4 h), however the group T (11 + 1.4 h) was not different from the others. The average interval between weaning and onset of estrus (35 + 6.3 h), weaning and end of estrus (44.4 + 5.4 h), intensity of estrus behavior (26.6 + 24 mounts), weaning and time of ovulation (70 + 12.7 h), onset of estrus and time of ovulation (33.3 + 9.3 h) and the end of estrus and time of ovulation (23.3 + 10.3 h) were not observed differences.The T group achieved 48 + 8.4 h of interval between weaning and the LH peak while in the weaned groups (CC and SC) the average interval was of 45.3 + 10.4 h, showing no differences between the CC group (42.5 + 8.2 h) and the SC (47.5 + 11.8 h). The interval between the peak of LH and the time of the ovulation presented a general average of 24.8 + 7.7 h, showing no differences between the groups T (25.5 + 5.7 h), CC (24.9 + 8 h) and SC (24.5 + 8.6 h). It was found that the contact between cow and calf during weaning was not different from that of the cows without any contact and there was no advantage in restricting contact between cow and calf. It was confirmed that weaning has a beneficial effect on the percentage of estrous and ovulation when compared to cows not weaned.O objetivo deste trabalho foi estudar o efeito da presença ou ausência do terneiro nas atividades de estro, dinâmica folicular e níveis hormonais em vacas de origem Bos indicus. Quarenta e seis vacas foram divididas em 3 grupos. No grupo com contato (CC), os terneiros foram desmamados e impedidos de mamar, mas mantidos em um curral, o qual permitia contato auditivo, olfativo e visual das vacas com sua cria (n=17). No grupo sem contato (SC), os terneiros foram desmamados e impedidos de qualquer contato (n= 17). No grupo T (n=12), as crias não foram desmamadas, permanecendo juntas às suas mães, constituindo o grupo testemunha. O grupo CC (76,5%) apresentou maior proporção de vacas em estro quando comparado ao T (16,7%), mas não diferente do SC (64,7%). O grupo CC possui maior porcentagem de vacas ovuladas (76,5%) quando comparado ao T (33,3%) e uma diferença aparente (p=0,06) quando comparado ao SC (64,7%). A duração do estro foi menor (p = 0,04) no grupo CC (8,4 h + 4,4 h) quando comparado ao SC (12,9 + 13,4 h). O intervalo entre o desmame e o início do estro (35 + 6,3 h), o desmame e o final do estro (44,4 + 5,4 h), a intensidade do estro (26,6 + 24 montas), o desmame e a ovulação (70 + 12,7 h), o início do estro e a ovulação (33,3 + 9,3 h) e o final do estro e a ovulação (23,3 + 10,3 h) não foram diferentes entre os tratamentos. As vacas do grupo T obtiveram 48 + 8,4 h de intervalo entre o desmame e o pico de LH enquanto que nos grupos desmamados (CC e SC) o intervalo médio foi de 45,3 + 10,4 h, não havendo diferença entre as vacas do grupo CC (42,5 + 8,2 h) e SC (47,5 + 11,8 h). O intervalo entre o pico de LH e o momento da ovulação apresentou uma média geral de 24,8 + 7,7 h, não havendo diferença entre os grupos T (25,5 + 5,7 h), CC (24,9 + 8 h) e SC (24,5 + 8,6 h). Verificou-se que o contato da vaca com a cria durante o desmame não foi diferente das vacas sem contato algum e não houve vantagem em restringir o contato da mãe com sua cria. Ficou confirmado que o desmame exerce um efeito benéfico na porcentagem de estro e ovulação quando comparado a vacas não desmamadas

Serum Metabolic Markers Pre and Postpartum in Holstein Cows According to the Mastitis Occurrence

Background: Bovine mastitis causes major economic losses for milk producers by reducing the quantity and the quality of the milk or even leading to the complete loss of the mammary gland secretory capacity. During the transition period, dairy cows are susceptible to infectious diseases; therefore, markers that allow early identification of cows in higher risk of developing diseases are especially useful at this time. Therefore, the aim of this study was to evaluate serum markers in the pre and postpartum of multiparous dairy cows with clinical mastitis and with health condition in the postpartum period in a semi-extensive management system.Materials, Methods & Results: Thirty-Six Holstein cows were monitored daily during milking until 59 days postpartum and were categorized according to the pre-milking strip cup test into clinical mastitis (mastitis group (MG)) and absence of symptoms (control group (CG)) that were negative to the test, representing the health cows. All cows were reared as one group and maintained in a semi-extensive pasture-based system. Blood samples were collected weekly after morning milking via venipuncture of the coccinea vein into tubes without anticoagulant and grouped for prepartum (-21 to 0 days from calving), early postpartum (0 to 30 days from calving), and late postpartum (30 to 59 days from calving) periods. Milk production was recorded daily. The serum markers albumin, aspartate aminotransferase (AST), phosphorus, gammaglutamyltransferase (GGT) and non-esterified fatty acids (NEFA) were measured. Statistical analyses were performed using SAS®. The cases of clinical mastitis occurred on average at 37.2 ± 4.9 days postpartum. Health cows (CG) had higher milk production compared to the mastitis group (MG) only in the late postpartum period (P 0.05). In the early postpartum period the AST activity was higher in CG than in MG (P = 0.02). The GGT enzyme tended to be more concentrated in the CG than in the MG during the early (P = 0.06) and late (P = 0.08) postpartum periods. Late postpartum phosphorus concentration was lower for MG than CG (P = 0.04). In the prepartum and early postpartum periods, there was no difference among groups for phosphorus concentration (P > 0.05).Discussion: A decrease in milk production in MG compared to CG observed in late postpartum period was due to the incidence of mastitis observed around 37 days postpartum. Cows that presented clinical mastitis in the postpartum period did not differ in the blood concentration of NEFA in the prepartum period. In the late postpartum period higher concentration of phosphorus was observed in the CG than in MG, indicating that animals affected by mastitis may be in the weakest energy status. Regarding liver health, the concentration of AST was higher in the recent postpartum period for CG, in disagreement with previous studies that related AST to tissue injury caused by mastitis. The GGT enzyme tended to had higher concentrations in CG than MG during the whole postpartum period and may be related to increased hepatic metabolism due to higher production. There were no changes in albumin levels among healthy and mastitis cows, indicating that this marker can not be used to predict clinical mastitis. There were no metabolic alterations in the prepartum period related to the occurrence of postpartum mastitis in multiparous cows in a semi-extensive management system

Relationship between pre-partum body condition score changes, acute phase proteins and energy metabolism markers during the peripartum period in dairy cows

This study evaluated the relationship of pre-partum BCS variations on the acute phase response around parturition and milk production of dairy cows. The animals were divided into two groups: cows that gained BCS from the third to the first week pre-partum (GBC=n 11) and those that lost BCS (LBC=n 9) in the same period. Blood samples were collected pre and postpartum to determine serum concentrations of glucose (GLU), non-esterified fatty acids (NEFA), insulin (INS), albumin (ALB), paraoxonase (PON), haptoglobin (HP) and blood cell counts. The GBC group showed higher PON concentration in the postpartum (p\u3c.05) and higher ALB concentration both pre and postpartum periods (p\u3c.05), whereas the LBC animals showed a higher HP concentration in both periods (p\u3c.05). Milk yield increased 3 kg/cow/day in the group that increased their BCS (p\u3c.03). The LBC cows showed increased monocyte counts (p\u3c.03), in addition to having a greater number of animals with the neutrophil:lymphocyte ratio higher than 1 (p\u3c.03). The remaining parameters did not differ between groups. In conclusion, animals that lost BCS during the pre-partum period demonstrated to have a higher inflammatory status around parturition and lower milk production