Groups of gilts of similar age, weight and breeding were allocated at 165 days of age to four treatments. One group of gilts was isolated from boars throughout the experiment. Fewer animals reached puberty during the experiment in this group than in the other groups where boars were introduced. Introduction of a boar to gilts at 165 or 190 days of age resulted in precipitation of oestrous activity. At 165 days, considerable synchrony of oestrus was obtained when there was a rotation of the boars used for testing, but the effect was much less marked when only one boar was used.

No abstract

The search for alternatives to in-feed antibiotics in animal nutrition has highlighted the role dietary modulation can play in improving gut health. Current antibiotic replacement strategies have involved the use of microbes beneficial to health (probiotics) or fermentable carbohydrates (prebiotics) or both (synbiotics). The present review recognises the contribution of fermented feeds and fermentable carbohydrates in improving the gut environment in non-ruminants. It proposes the screening of probiotic bacteria for the production of fermented feeds and supplementation of these feeds with fermentable carbohydrates prior to feeding animals. It is suggested that the term 'fermbiotics' should be used to describe this intervention strategy.

Forty eight and ninety six pigs weaned at 22.6 f 2.6 days, were allocated to two trials to study the effect of feeding post-weaning diets ad libitum, either as dry pellets (DF) or as meal mixed with water in the ratio 2.5 : 1 (LF). The trials, lasting 28 days, differed only in the type of trough used to present the liquid feed to the pigs. In both trials the daily gain of LF pigs over the 4 weeks of the trial was significantly ( P < 0.001) better than that of the D F pigs. Daily gains for the two treatment groups were respectively 428 and 343 15 g day-' in Trial 1 and 454 and 397 k 10 g day-' in Trial 2. The feed conversion ratio (FCR) (corrected to fresh weight of dry feed) of LF pigs was significantly poorer ( P < 0.01) than that of D F pigs in both trials primarily as a result of feed wastage by the LF pigs. FCR for the D F and LF pigs was, respectively, 1.31 and 1.89 & 0-05 in Trial 1. In Trial 2 improvements in the trough design reduced the difference in FCR. FCR for the D F and LF treatments was 1.37 and 1.44 f 0.02 respectively. In Trials 1 and 2 LF pigs used on average 76% and 35% more water than D F pigs. LF pig produced 12% (Trial 1) and 5.7% (Trial 2) more effluent per unit of liveweight gain than D F pigs. Microbiological examination of the liquid feed system demonstrated that the system acted as a fermenter. Lactobacillus spp proliferated rapidly and became the dominant organism within 5 days and the populations remained relatively constant thereafter. The proliferation of lactobacilli reduced the pH of the liquid feed from approximately 6.0 to between 3.5 and 4.0. At the lower levels of pH the number of coliforms in the feed was significantly reduced.

No abstract