Desempenho reprodutivo pós-parto de vacas de corte submetidas a indução/sincronização de cio

Brauner, Cássio Cassal; Pimentel, Marcelo Alves; Lemes, Jaqueline Schneider; Pimentel, Cláudio Alves; Moraes, J. C. F.

doi:10.1590/s1516-35982009000100013

Cited by 3 publications

(3 citation statements)

References 17 publications

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“…Cows were subjected to an estrus synchronization protocol [8] 60 ± 15 days after calving. On day 0 cows received an intravaginal device impregnated with 250 mg of medroxi-progesterone acetate (MAP) 2 and were given a estradiol benzoate injection (EB) (5 mg, Gonadiol®, im) 3 .…”

Section: Methodsmentioning

confidence: 99%

Performance Efficiency of Pasture-raised Primiparous Beef Cows of Three Different Biotypes and Two Milk Production Levels

Lemes

Pimentel

Vaz

et al. 2017

Acta Scientiae. Vet.

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Background: Productivity and efficiency of beef production systems should be estimated based on cow size, calf growth rate and cow reproduction rate, which are critical factors for the evaluation of production characteristics of beef cattle of different biological types. One of the ways to measure beef cow productivity is based on the ratio of calf weaning weight to cow weight. The purpose of this study was to evaluate the performance and reproductive efficiency of primiparous beef cows of three different biotypes and two milk production levels, from calving to weaning, in pasture-raised beef systems. Materials, Methods & Results: Forty-two primiparous Angus cows were classified according to body weight at calving, as follows: Heavy (431 kg); Medium (388 kg); and Light (348 kg). Cow efficiency as a function of biotype was evaluated at two different moments: calving and weaning, based on the ratio of calf weight to cow weight*100 (in kilograms). Calf production efficiency was determined based on the ratio of calf weaning weight (CWW) to cow pregnancy rate (PR), resulting in the calf production index = kg of weaning calves per cow (CWW*PR/100). The experimental design was a completely randomized factorial 3 x 2 x 2 design (three biotypes x two calf sexes x two milk production levels). The results were subjected to ANOVA and F-test. The Light and Medium cow groups produced more (P < 0.05) kilograms of calf per kilogram of cow (16.0 and 15.1 kg, respectively) than the Heavy group (14.0 kg). Light cows showed lower (P < 0.05) milk production and, as a result, lighter (P < 0.05) calves at weaning (151.9 ± 4.3 kg) than Medium and Heavy groups, 166.0 ± 3.7; 166.5 ± 4.0 kg, respectively. At beginning of the breeding season, cows of the Lower milk production group were on average 27.49 kg heavier than cows in the Higher milk production group. There was an interaction (P < 0.05) between total milk production and calf sex on characteristics of performance in calves and performance efficiencies of the system. Light and Medium cows showed 51 and 25 kg total weight gain from calving to weaning, corresponding to 14.7 and 6.4% of body weight, respectively. The Heavy group, however, showed a 3 kg loss (0.5% of body weight) during the same period. Discussion: A higher growth rate was observed in the pre-weaning period of the calves of heavy cows; as a result, these calves were heavier at weaning. To achieve this result, heavier cows may compensate this higher nutritional requirement using body reserves. This biological adjustment may not be economically efficient, since the subsequent reproduction of these cows could be impaired by increases in milk production. Therefore, the target cow in a pasture-raised beef system is one whose low nutritional requirements enable her to produce milk, resulting in heavier calves, and whose physiological conditions enable her to conceive again during the breed season. Light cows can be considered an efficient group, since their pregnancy rate enabled them to create a positive difference for the group, notwithstanding their lower milk production and lighter calves (P < 0.05) at weaning. This tendency is expected, since increased growth rates are associated with a decrease in puberty and early finishing age. It is essential to select animals according to their efficiency in order to reduce the cow’s requirements, since this favors the increased productivity of cows of lower maintenance cost in relation to their body weight, leading to higher biological and economic efficiency in the beef production system. In conclusion, because of their lower nutritional requirements, cows of small and moderate biotypes and lower total milk production are more efficient than cows of larger biotypes and higher milk production in pasture-raised beef systems.

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Section: Methodsmentioning

confidence: 99%

Performance Efficiency of Pasture-raised Primiparous Beef Cows of Three Different Biotypes and Two Milk Production Levels

Lemes

Pimentel

Vaz

et al. 2017

Acta Scientiae. Vet.

Self Cite

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“…According to Peres et al (2009), obtaining a 50% pregnancy rate in B. indicus herds with cows subjected to TAI is an acceptable value, and studies which used different protocols demonstrated that this rate can become more accessible. Brauner et al (2009) evaluated the reproductive performance of postpartum beef cows and reported that anestrous animals respond positively to protocols of induction/ synchronization of estrus. In the present study, no effect of calf presence was detected since the protocol and the temporary removal of the calves were effective in inducing ovulation in the nursing cows.…”

Section: Discussionmentioning

confidence: 99%

Timed artificial insemination and early diagnosis of pregnancy to reduce breeding season in Nelore beef cows

Carneiro

Campos

Santos

2011

Trop Anim Health Prod

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The purpose of this study was conducted to evaluate the use of a system of timed artificial insemination (TAI) and early diagnosis of pregnancy in Nelore beef cows in order to reduce the breeding season (BS) from 150 to 90 days and analyze the factors affecting the conception rate of cows selected for TAI. The study included 110 Nelore cows belonging to the Experimental Farm Capim Branco, Brazil. The body condition scores (BCS) were evaluated, and those above 2.50 were included in the TAI protocol. Five groups of cows were formed at intervals of 21 days postpartum and then commenced a 9-day progesterone protocol. Progesterone devices were used three times. Statistical analysis of binary variables was performed by logistic regression in the program Proc Logistic of Sas. A 5% of significance (P < 0.05) was used to determine the presence of statistical differences and the effect of independent variables on conception rate. The TAI and early diagnosis of pregnancy reduces the BS from 150 to 90 days without changing the pregnancy rate. The conception rate was not affected by the presence of the calf (P > 0.05), the corpus luteum (P > 0.05), the BCS (P > 0.05), or the number of reuses of the intravaginal progesterone device (P > 0.05). Therefore, this technique is beneficial for breeding Nelore beef cattle and can be used in anestrous cows with a BCS above 2.50. Additionally, the progesterone devices can be reused to reduce the cost of the protocol without compromising the results.

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“…Porém, ocorre normalmente uma carência de controle de índices produtivos dos animais, como a determinação das densidades de lotação das pastagens, as quais, por muitas vezes são exacerbadas, provocando o exaurimento da diversidade florística pela alta carga animal, ocasionando baixos retornos produtivos (3,4) , podendo com a utilização estratégica de tecnologias impactar favoravelmente no sistema de cria (5,6,7) . Fagundes et al (8) ao avaliarem o desempenho produtivo e reprodutivo de vacas primíparas em duas cargas animais em campo nativo, verificaram maiores ganhos médios diários e taxa de prenhez, com carga média anual de 280 kg de peso corporal quando comparada carga animal de 360 kg de peso corporal.…”

Section: Introductionunclassified

Análise De Custos, Receitas E Ponto De Equilíbrio Dos Sistemas De Produção De Bezerros No Rio Grande Do Sul

Gonçalves

Vaz

et al. 2017

Ciênc. anim. bras.

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ResumoO objetivo deste trabalho foi realizar a avaliação da viabilidade econômica de um modelo tradicional de produção de bezerros de corte em sistema extensivo, desenvolvido nas condições de receitas obtidas e gastos de insumos recomendados para as condições de produção normais no estado do Rio Grande do Sul. Foram realizadas duas entrevistas em propriedade rurais para coleta de dados referentes aos gastos de recursos, estruturas disponíveis para o sistema de produção e taxas de ocupação das áreas de pastejo. Os resultados mostraram que os principais custos operacionais da atividade foram a mão de obra e a alimentação do rebanho. Nos custos de oportunidade a terra representou a maior proporção (52,0%) do custo total. Os custos fixos foram maiores do que os custos variáveis (61,7% vs 38,3%). As margens bruta e líquida indicaram que a atividade é sustentável, mas economicamente o ponto de equilíbrio de natalidade (85,0%) esteve acima dos índices médios relatados pela literatura, e valores negativos para rentabilidade (-19,0%) e lucratividade (-23,2%). Concluiu-se que a viabilidade dos sistemas de produção estudados nesta pesquisa podem ser obtidos a partir da otimização de tecnologias de produção ou a redução dos custos fixos sem alterar as receitas. Palavras-chave: bovinos de corte, custos de produção, natalidade, rentabilidade. AbstractThe aim of this study was the evaluation of the economic viability of a traditional model of beef calves production in extensive system, developed under the conditions of relevant receipts and input costs recommended for normal production conditions in the of Rio Grande do Sul state. There were two interviews in rural property for collection of data on the expenditure of resources, structures available for the system of production and occupancy rates of grazing areas. The results showed that

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Desempenho reprodutivo pós-parto de vacas de corte submetidas a indução/sincronização de cio

Cited by 3 publications

References 17 publications

Performance Efficiency of Pasture-raised Primiparous Beef Cows of Three Different Biotypes and Two Milk Production Levels

Performance Efficiency of Pasture-raised Primiparous Beef Cows of Three Different Biotypes and Two Milk Production Levels

Timed artificial insemination and early diagnosis of pregnancy to reduce breeding season in Nelore beef cows

Análise De Custos, Receitas E Ponto De Equilíbrio Dos Sistemas De Produção De Bezerros No Rio Grande Do Sul

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