Pregnancy Related Sequential Changes of the Foetal Fluids And Foetal Positioning in Sahel Goats

A study on pregnancy related, and sequential, changes in the Sahel goat foetal fluid and foetal disposition at various stages of pregnancy wasundertaken to provide basic data in these aspects of gestation in goats. Twenty five pregnant Sahel goats of known pregnancy stages, and managed under controlled conditions were used for this study. Thirtythree foetuses were obtained from these pregnancies of which 18 (54.5%) were females and 15 (45.5%) were males; 17 (68%) had single foetus,8(32%) twin foetuses. Transuterine migration was 23.53% in single and 37.5% in twin pregnancies. The foetal fluid changes showed that the volume of the amniotic fluid increased from day 28 (21.0 ± 0.33 ml)of gestation to day 112 (500 ± 15.81 ml) and then dropped onwards up to day 140 (220 ± 10.80 ml). Conversely, the allantoic fluid (25.5 ± 2.00 ml at 28d to 735.0 ± 17.08 ml at 140d) continued to increase in volume throughout pregnancy. The volume, colour, consistency and pH changed with increase in gestation period. The specific gravity of the amnioticfluid increased with advancing pregnancy. The results of this study suggest that urine enters first into amniotic cavity and then into the allantoic cavityby 112d pregnancy in goats. The present study also provided a guide to be used in assessing the volume and consistencies of foetal fluids in goats and the intrauterine positioning of foetuses as a measure to monitor and manage pregnant Sahel does.KEY WORDS: fluids, foetal, position, Sahel goat,sequential

Time-related and sequential developmental horizons of Sahel goat foetuses

The aim of the present study was to follow the time related developmental changes of caprine foetuses to aid in their age determination. Certain gross external features along with body size changes were studied. Twenty five pregnant Sahel does of known gestational age managed under controlled conditions were used for the study. Absolute changes in the body weight, crown-rump length and height at withers and their relative growth changes compared to body size had similar and significant growth relationships. All the parameters showed high positive significant correlation with the foetal age and with each other with r- values ranging from 0.975 to 0.998. A chronological guide on age estimation of caprine foetuses at 28 day gestational interval, evolved from observations based on developmental horizons. The present study has provided a baseline data which could be applied for age estimation of Sahel goat foetuses. It has also indicated that, it is necessary to employ many criteria involving physiological horizons to estimate the age of a foetus age within narrow limits

Understanding the trade-off between the environment and fertility in cows and ewes.

The environment contributes to production diseases that in turn badly affect cow performance, fertility and culling. Oestrus intensity is lower in lame cows, and in all cows 26% potential oestrus events are not expressed (to avoid getting pregnant). To understand these trade-offs, we need to know how animals react to their environment and how the environment influences hypothalamus-pituitary-adrenal axis (HPA) interactions with the hypothalamus-pituitary-ovarian axis (HPO). Neurotransmitters control secretion of GnRH into hypophyseal portal blood. GnRH/LH pulse amplitude and frequency drive oestradiol production, culminating in oestrus behaviour and a precisely-timed GnRH/LH surge, all of which are disrupted by poor environments. Responses to peripheral neuronal agents give clues about mechanisms, but do these drugs alter perception of stimuli, or suppress consequent responses? In vitro studies confirm some neuronal interactions between the HPA and HPO; and immuno-histochemistry clarifies the location and sequence of inter-neurone activity within the brain. In both species, exogenous corticoids, ACTH and/or CRH act at the pituitary (reduce LH release by GnRH), and hypothalamus (lower GnRH pulse frequency and delay surge release). This requires inter-neurones as GnRH cells do not have receptors for HPA compounds. There are two (simultaneous, therefore fail-safe?) pathways for CRH suppression of GnRH release via CRH-Receptors: one being the regulation of kisspeptin/dynorphin and other cell types in the hypothalamus, and the other being the direct contact between CRH and GnRH cell terminals in the median eminence. When we domesticate animals, we must provide the best possible environment otherwise animals trade-off with lower production, less intense oestrus behaviour, and impaired fertility. Avoiding life-time peri-parturient problems by managing persistent lactations in cows may be a worthy trade-off on both welfare and economic terms - better than the camouflage use of drugs/hormones/feed additives/intricate technologies? In the long term, getting animals and environment in a more harmonious balance is the ultimate strategy