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  • Heat-No-Service: Reproductive lifetime performance of gilts inseminated on first versus second observed estrus in commercial piglet producing herds
    77-80
    Views:
    253

    Heat No Service (HNS) is an increasing managerial decision made in commercial piglet producing herds. Performance of gilts has been shown to be influenced by initial decisions made on them at their introduction in the breeding herds. Lifetime Reproductive performance comprising of parity total born piglets and lifetime total born piglets of gilts initially bred on first observed estrus (0HNS) was compared with that of gilts bred on second observed estrus (1HNS). Stored data from Porcitec database consisted of 2.072 gilts bred on first observed estrus (0HNS) and 2.453 gilts bred on second observed estrus (1HNS) totaling to 4.525 gilts. Data was statistically analyzed using the GLM procedure of IBM SPSS version 25. The results showed a significance difference (p<0.001) in lifetime total born performance of gilts bred at 0HNS (mean 93.9) and 1HNS (mean 95.7). There was also a significant difference (p<0.001) of total born piglets in parity 1, 5 and 6 in the 2 groups. There was an observed increased parity total born and lifetime total born when first time insemination of gilts was delayed to second estrus. The findings in this study favor the 1HNS breeding with an overall increased lifetime total born. Gilts inseminated at 1HNS produce 1.57 more pigs for lifetime as compared with those inseminated at 0HNS when observation is made up to P6. Producers in piglet producing herds could re examine their decisions for increased productivity by promoting many gilts into 1HNS but still maintaining the balance between breed targets and production schedules to remain competitive and profitable in the current global swine industry.

  • Heat stress of cattle from embryonic phase until culling
    11-22
    Views:
    246

    Heat stress becomes a serious problem in the livestock sector as it affects cows' performance negatively. The objective of this paper review is to investigate the effects of heat stress during the different phases of the life cycle of cows; embryos, calves, heifers, and cows. Heat stress during early maternal gestation affects the ability of embryos to develop increasing the risk of abortion and early embryonic death. Heat stress during late maternal gestation affects the performance of calves and heifers later in their life, as it reduces growth performance, conducts physiological changes, impaired immunity, changes the behavior, and reduces the length and intensity of the estrus in heifers with decreasing in milk production in the first lactation. On the level of cows, milk quality and production, meat quality, and the final body weight decrease under hot temperatures. Heat stress decreases the conception rate, alters follicle growth, and estrous symptoms. Hormones secretion and physiological changes because of the heat stress conduct to impair the immunity system, and in oxidative stress and death in some cases. Same as for calves and heifers a change in the behavior of cows was detected in order to decrease their temperature.

  • Changing of yeaning rates using estrus synchronization and cervico-uterinal artificial insemination in goats
    43-47
    Views:
    102

    Breeding aims can be more efficiently and faster achieved by using AI. AI allows higher selection intensities for male selection, adequate genetic evaluation with efficient buck using and profitable farming. Moreover, the AI has very important advantages in animal health, especially in goats. By using our AI technology, these benefits can help the farmers in the practical life.

  • Studying the reproduction-biological effect of the GPR54 receptor gene in sheep
    48-51
    Views:
    81

    One of the main economical problems of sheep breeding is that continual production is not possible due to the seasonality of animals. Today, genes, mutations that may develop aseasonality in sheep are extensively researched in order to make the establishment of populations capable of aseasonal estrus possible.
    According to the current knowledge, the GPR54 gene participates in the GnRH release from the hypothalamus, and thus in the alteration of the reproduction state of the organism. Our research is aimed to determine whether the GPR54 gene has allele variations that influence the proneness to aseasonal estrus in sheep in a different extent. Therefore, the GPR54 gene sequence of sheep is first examined.