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In many bird species juvenile inexperience drastically reduces their survival, and parents must provide for them. I tested whether time budget and habitat use in adult wintering Common Cranes (Grus grus) in dehesas (pastoral woodland) of western Spain were affected by the presence of juveniles. Juvenile cranes devote less time to vigilance and spend more time feeding than adults in dehesas. Likewise, juveniles are involved in fewer aggressive encounters than adult cranes. Contrary to expectation, adults accompanied by juveniles devoted the same amount of time to vigilance and feeding and had the same intake rate than adults without juveniles in attendance. However, adult cranes with offspring in attendance were involved in more aggressive encounters than adults without juveniles in attendance when both adult groups were involved in large flocks. In contrast, when adults accompanied by juveniles were in small flocks they were involved in fewer aggressive encounters than adults without juveniles. I also detected a differential use of dehesas by adult cranes that was linked to juvenile presence and explained by the vulnerability of juvenile cranes in intraspecific social relationships. Adults with juveniles in attendance preferred dehesas with livestock where flock sizes were smaller than those in dehesas without livestock, and therefore where they might reduce the number of aggressive encounters with other cranes.

Free-choice supplements provide protein, trace minerals, vitamins, salt and chemotherapeutic agents to cattle. For optimal benefit, a supplement should be consumed on a regular basis and at levels that do not vary significantly on a day-to-day basis. Many factors affect variability in supplement intake such as palatability of the supplement, competition between animals and the ease with which the supplement may be consumed. The aim of this study was to evaluate the differences between a solid molasses-block supplement and a liquid-molasses supplement with respect to intake and the associated behaviors (attendance, duration, and intake rate). Using a cross-over design, 34 pregnant cows weighing 720 ± 11kg were randomly allocated to two separate groups (n = 17 for each group) and evaluated for two 3-wk periods (24 February to 16 March 1999 and 25 March to 14 April 1999), using both forms of the supplement. The individual intake was recorded by way of an electronic feeding system, which made use of an electromagnetic field around the feeder in conjunction with electronic identification (EID) tags, which registered each animal’s unique eight-digit number. Cows fed the liquid supplement visited the feeder more often (P < 0.05) when compared to those fed the block supplement. The mean dry matter intake did not differ between the supplements (349 g head-1 for the block and 330 g head-1 for the liquid), but there were significantly larger deviations in intake for the block supplement than the liquid (P < 0.05) indicating more uniformity in daily intake with the liquid supplement. In almost all cases the liquid supplement was consumed at a faster rate (P < 0.05) and significantly less time (P < 0.05) was spent at the feeder. Free-choice administration of additives in liquid supplements, as compared to blocks, may result in a more frequent and less variable intake. Key words: Protein, intake, supplement, cattle, behavior

We tested the hypothesis that rumen function is adaptive to diet quality and intake rate using ruminally fistulated elk and mule deer. In experiment 1 we measured rumen particle-size distribution, rumen fill, and particle and liquid passage rates of animals fed three diets varying in quality (chopped pea, alfalfa, and wheat hays). In experiment 2, similar measurements were obtained on elk fed alfalfa hay ad libitum or at restricted intake levels. Rumen characteristics and passage rates of particles and liquids were similar for animals consuming alfalfa and pea hays. Intake, rumen dry-matter concentration and fill, and liquid passage rate were significantly lower when animals consumed wheat hay. Few significant differences in rumen characteristics or passage rates were found between animals fed alfalfa ad libitum or at restricted levels. Rumen liquid volume and dry-matter fill were related linearly to intake (r2 = 0.98 for both) in deer and elk fed alfalfa and pea hays. However, liquid volume and dry-matter fill of elk fed wheat hay and alfalfa at restricted levels were higher than the deer–elk interspecific regression, indicating an adaptive ruminal response. We concluded that rumen function was adaptive to both diet quality and availability, but that the response likely was subject to the limitations imposed by food characteristics and the inherent limitations of rumen structure and function.

The effects of enforced exercise on performance and carcass composition of growing pigs were studied on eight crossbred gilts. Four animals were exercised periodically on a treadmill from a liveweight of 12 to 60 kg; the remaining four animals acted as a control group. Pigs were exercised three afternoons a week for a period of 60 min at a speed of 2 km/h. Animals were slaughtered at a liveweight of 60 kg and the left side of each carcass dissected into individual muscles, fat and bone. Proximate analyses were conducted on two selected muscles. There were no significant differences between the groups overall (0 to 9 wk) in feed intake, weight gain or efficiency of feed conversion. From 7 to 9 wk the exercised group grew at a significantly faster rate and consumed significantly less feed per kg liveweight than the control group. The enhanced rate of gain of the exercised group during this period occurred even though feed intakes of the two groups were similar. It is suggested that this improved gain may have been due to a compensatory growth effect associated with a relative decrease in the severity of the exercise treatment as the pigs increased in size. Exercise treatment had no significant effects on carcass weight or on the weight of the following organs: blood, heart, liver, kidneys, spleen, alimentary tract tissue and alimentary tract fat. Similarly, enforced exercise had no significant effects on either the proportion of carcass muscle, fat and bone or on muscle distribution. Chemical analysis of M. psoas major from exercised animals showed a significantly higher protein and lower moisture content, respectively, than those from control animals. Composition of M. biceps brachii in exercised and control animals was similar.