Ninety-four pregnant Yankasa ewes were divided into 3 groups and fed;(1) 0, (2) 200 or (3) 400 g/head/day of a concentrate supplement in addition to 6 h grazing daily, from 35.9±2.0 days before, 98. 122.0 after lambing the dry season between 2 Jan vary 15 May 1984 Zaria, Northern Nigeria. There no significant differences (P>0.05) bet den litter size adjusted birth weight initial experiment a...

Difficulty in observing oestrus is a problem for many dairy farmers performing AI. Finding ways to synchronize oestrous cycles or strengthen display of oestrus without hormonal treatments would be of great interest because many consumers object to the use of exogenous hormones on healthy animals. Modification of reproductive cycles through chemical communication has been reported in several spe...

This paper suggests a method for automatic detection of sows returning to 1 oestrus in the gestation department. The detection is based on monitoring of 2 sows’ visits to a boar, where the duration and frequency of visits are modelled 3 separately and subsequently combined. The hypothesis is that it is possible 4 to reduce the response time and the number of false alarms compared to 5 previousl...

The success and efficiency of pig farming mainly depends on the reproductive performance of pigs. An experiment was conducted to study the effect of presence of the boar on the reproductive performance of sows, the feasibility and economics of rearing pigs of either sex together. Sixteen weaned Large White Yorkshire gilts, twelve weaned sows and two boars were randomly assigned to five groups a...

Optimal management of gilt reproduction requires oestrus synchronization. Hormonal treatments are used for this purpose, but there is a growing demand non-hormonal alternatives, especially in organic farms. The boar effect an important alternative opportunity to induce and synchronize without hormones. Before puberty, gilts exhibit ‘waiting period’ during which exposure could the first ovulatio...

This paper is concerned with the problem of synchronization for complex dynamic networks with state and coupling time-delays. Therefore, larger class and more complicated complex dynamic networks can be considered for the synchronization problem. Based on the Lyapunov-Krasovskii functional, a delay-independent criterion is obtained and formulated in the form of linear matrix inequalities (LMIs)...

The response of Meishan conceptuses to an exogenous precursor for oestradiol-17beta biosynthesis was investigated in vitro, to determine whether gestational age or morphological stage of development elicit changes in hormone metabolism. Conceptuses were recovered on days 11, 12, 13 or 15 after the onset of oestrus and cultured for 6 hours at 37 degrees C, in the presence or absence of testoster...

This trial evaluated the reproductive performance in an early routine oestrus induction programme using two different PGF2α preparations in dairy cattle. D-cloprostenol sodium (n = 192; Group A) or dinoprost (n = 187; Group B) was administered between days 35 and 42 post partum. Also, a group of non-treated cows (n = 135; Group C) was included as control. Pedometers were used to detect oestrus,...