The effect of different weaning strategies on piglet growth, feed intake and gut health.

The present study evaluated the effects of weaning strategy on piglet growth performance, onset of feed intake, and intestinal health. A total of 254 crossbred piglets were used and the experimental period lasted 45 days. The piglets were assigned to the fallowing treatments: early strategic weaning (ESW, n = 85), piglets weaned at 16 days of age and transferred to the pre-nursery unit; strategic segregated weaning (SSW, n = 85), piglets weaned at 21 days of age and kept in the farrowing crate until 24 days of age; and conventional weaning (CW, n = 84), piglet weaned at 24 days of age and transferred directly to the nursery unity; this experimental group was used as a control. Piglets from all treatments were transferred to the nursery unit at 24 days of age. For the nursery phase three periods of evaluation was considered: nursery phase I (0-7 d), nursery phase II (7-14 d), and nursery phase III (14-21 days). Piglets from the ESW and CW had greater (P < 0.001) ADG in the lactation period 16-21 days. The BW at 24 day of age was higher (P < 0.001) for piglets in the ESW and CW groups. In the nursery phase I, the ESW group had higher (P = 0.003) daily feed intake. Piglets from the ESW group had higher (P = 0.004) BW at the end of the experimental period. The ESW and SSW groups had a higher percentage of piglets (88% and 92%, respectively; P < 0,001) consuming feed in the first 24 h after transference to the nursery facility. When the total experimental period is considered, a reduction (P < 0.001) in the incidence of diarrhea was observed for ESW piglets. Overall, there was no effect of weaning strategy on intestinal permeability. In conclusion, the results of our study showed that the Segregated Strategic Weaning management can be used to mitigate the deleterious effects of early weaning.

Evolução e premissas dos protocolos hormonais de inseminação artificial em tempo fixo na pecuária / Evolution and premises of hormonal protocols of fixed time artificial insemination in livestock

O Brasil historicamente tornou-se um dos principais produtores na pecuária de leite e corte. No entanto, para que o país continue com alta eficácia na produção, deve-se realizar a reposição de animais produtivos. Tal fator é proporcionado pela reprodução animal, através de novas biotecnologias criadas, sendo uma delas a Inseminação Artificial em Tempo Fixo (IATF), a qual atribui um determinado protocolo hormonal e permite saber o dia específico para a inseminação da fêmea, sem a necessidade da observação do estro. O objetivo da atual revisão é sintetizar a evolução dos protocolos hormonais de IATF e apresentar as estratégias atuais para o aumento da fertilidade do rebanho.(AU)

Brazil has historically become one of the main producers of dairy and beef cattle. However, for the country to continue with high efficiency in production, it is necessary to perform the replacement productive animals. Such factor is provided by animal reproduction, through new biotechnologies created, one of which is Artificial Insemination in Fixed Time (IATF), which assigns a certain hormonal protocol and it is possible to know the specific day for the insemination of the female without the need of oestrus observation. The objective of the current review is to synthesize the evolution of hormonal protocols of IATF and present the current strategies for increasing herd fertility.(AU)

Evolução e premissas dos protocolos hormonais de inseminação artificial em tempo fixo na pecuária / Evolution and premises of hormonal protocols of fixed time artificial insemination in livestock

O Brasil historicamente tornou-se um dos principais produtores na pecuária de leite e corte. No entanto, para que o país continue com alta eficácia na produção, deve-se realizar a reposição de animais produtivos. Tal fator é proporcionado pela reprodução animal, através de novas biotecnologias criadas, sendo uma delas a Inseminação Artificial em Tempo Fixo (IATF), a qual atribui um determinado protocolo hormonal e permite saber o dia específico para a inseminação da fêmea, sem a necessidade da observação do estro. O objetivo da atual revisão é sintetizar a evolução dos protocolos hormonais de IATF e apresentar as estratégias atuais para o aumento da fertilidade do rebanho.

Brazil has historically become one of the main producers of dairy and beef cattle. However, for the country to continue with high efficiency in production, it is necessary to perform the replacement productive animals. Such factor is provided by animal reproduction, through new biotechnologies created, one of which is Artificial Insemination in Fixed Time (IATF), which assigns a certain hormonal protocol and it is possible to know the specific day for the insemination of the female without the need of oestrus observation. The objective of the current review is to synthesize the evolution of hormonal protocols of IATF and present the current strategies for increasing herd fertility.