Decline In Food Intake Research Articles

Welfare of Male and Female Broiler Chickens in Relation to Stocking Density, as Indicated by Performance, Health and Behaviour

AbstractThe purpose of this experiment was to provide information relevant to the current debate concerning the optimisation of terminal stocking density for commercial broiler production. In a modern, controlled-environment house with 24 floor pens (each 11.4 m2), 4020 day-old broilers (Ross 308) were allocated to three terminal (42 days) stocking densities (28, 34 and 40 kg m-2) x two sexes x four replicates, according to a randomised block design. Group sizes varied from 130 to 208. Husbandry conditions were in accordance with normal commercial practice. Performance and behaviour were measured systematically during each of the six weeks of life, and additional measurements were made of leg health and litter condition. Data were analysed using ANOVA to determine the effects of stocking density, sex and age. The realised mean terminal stocking densities were 28.2, 33.5 and 38.5 kg m2. The main significant effects of stocking density treatment were a linear decline in food intake with increasing density during week six (the final week), and a reduced proportion of time spent panting deeply during weeks five and six at the lowest density. Increased (shallow and deep) panting shown by females in weeks two to five suggests that if thermal discomfort becomes a problem at higher stocking densities later in the growing period, it may do so earlier in females. There was no conclusive evidence from this study that broiler welfare is compromised any more at 40 than at 34 kg m−2. The fact that the proportion of time spent panting deeply in week six was considerably lower at 28 kg m2 than at 34 and 40 kg m−2 suggests that thermal comfort (and hence welfare) at this age may be improved at densities of less than 34 kg m−2. However, the significant effects of age, age x density, and age x sex on time spent panting deeply suggest that the age at slaughter and the sex of birds in single-sex flocks should be taken into account in future considerations of optimal maximum terminal stocking density.

Decreased Food Intake With Aging

There is a physiological decline in food intake with aging. The reasons for the decline in food intake are multifactorial and involve both peripheral and central mechanisms. Altered hedonic qualities of food occur due to alterations in taste and, more particularly, smell with aging. A decline in adaptive relaxation of the fundus of the stomach and an increased rate of antral filling appear to play a role in the early satiation seen in many older persons. Cholecystokinin levels are increased with aging and older persons are more sensitive to the satiating effects of this gut hormone. The decline in testosterone levels in older males leads to increased leptin levels and this may explain the greater decline in food intake with aging in the male. Within the hypothalamus, decreased activity of both the dynorphin (kappa opioid) and neuropeptide Y systems occurs in aging rodents. Cytokines are potent anorectic agents. Many older persons have mild inflammatory disorders that lead to anorexia. Exercise may increase food intake in older persons.

Anorexia, body composition, and ageing.

Over the lifespan there is a decline in food intake. This has been termed the physiological anorexia of aging. It has many causes, including alterations in the gastrointestinal satiating system, the effect of elevated leptin levels, especially in men, and a variety of changes in central nervous system neurotransmitters. Beyond the age of 70 years body mass declines. This includes both loss of adipose tissue and muscle mass. The loss of muscle mass in older individuals is termed sarcopenia. There is increasing evidence that this is caused, in men, partly by the decline in testosterone. Illness results in an increase of cytokines that produce both anorexia and cause protein wasting. Many of the causes of cachexia in older individuals are treatable. Depression is the most common cause of weight loss in older individuals. Dieting in older individuals is associated with a loss of skeletal tissue as well as fat mass. This can place older individuals at risk of becoming the 'fat frail'.

The role of leptin resistance in the lipid abnormalities of aging.

Leptin resistance has been implicated in the pathogenesis of obesity-related complications involving abnormalities of lipid metabolism that resemble those of old age. To determine whether development of leptin resistance in advancing age might account for such abnormalities, we compared the effects of hyperleptinemia (>40 ng/ml) induced in 2-month-old and 18-month-old lean wild-type (+/+) Zucker diabetic fatty rats by adenovirus gene transfer. The decline in food intake, body weight, and body fat in old rats was only 25%, 50%, and 16%, respectively, of the young rats. Whereas in young rats plasma free fatty acids fell 44% and triacylglycerol (TG) 94%, neither changed in the rats. In hyperleptinemic young rats, adipocyte expression of preadipocyte factor 1 increased dramatically and leptin mRNA virtually disappeared; there was increased expression of acyl CoA oxidase, carnitine palmitoyl transferase 1, and their transcription factor peroxisome proliferator-activated receptor alpha, accounting for the reduction in body fat. These hyperleptinemia-induced changes were profoundly reduced in the old rats. On a high-fat diet, old rats consumed 28% more calories than the young and gained 1.5x as much fat, despite greater endogenous hyperleptinemia. Expression of a candidate leptin resistance factor, suppressor of cytokine signaling 3 (SOCS-3), was compared in the hypothalamus and white adipocytes of young and old rats before and after induction of hyperleptinemia; hypothalamic SOCS-3 mRNA was approximately 3x higher in old rats before, whereas it was 3x higher in WAT after, hyperleptinemia. We conclude that the anorexic and antilipopenic actions of leptin decline with age, possibly through increased SOCS-3 expression, and that this could account for the associated abnormalities in lipid metabolism of the elderly.

Effects of Photoperiod on the Cessation of Growth during Autumn in Male Red Deer and Growth Hormone and Insulin-like Growth Factor-I Secretion

Male red deer undergo seasonal cycles of food intake and growth rate, which are high during spring and low during winter, despite high quality foodad libitum.Hormonal profiles during the cessation of growth in autumn and the potential role of photoperiod in the timing of the observed changes have been investigated. Whether this seasonal decrease in growth affected the response of GH and IGF-I to fasting was also examined. Two groups of six male 1-year-old red deer were exposed to different photoperiods after the summer solstice. One group (C) was given a simulated natural photoperiod while the other group (SS) was maintained on a summer solstice photoperiod (16L:8D). GH was measured in blood collected continuously and divided into pools every 5 min for 24 h in the fed state and after a 48-h fast on two occasions; the first was in November before photoperiod manipulation began and the second was in April approximately 16 weeks after initiating treatments. IGF-I, prolactin, and testosterone were measured in weekly samples. Individual live weight and group food intake were also measured each week. The normal growth pattern seen in the C group was delayed in the SS group. Thus, from 7 March until the second GH sampling on 11 April the live weight of deer in group C fell; in contrast, deer in group SS continued to grow (−43 vs 186 g/day s.e.d.=65.5,P<0.01). Food intake changes reflected the pattern of growth in both groups. Mean GH (P<0.05), GH pulse amplitude (P<0.01), and IGF-I (P<0.001) declined in both groups from November to April. This decline was more marked in group C and in April these parameters were all lower in group C than in group SS (GH,P<0.05; IGF-1,P<0.01). Prolactin levels in April were also lower in group C than in group SS (P<0.01); testosterone was not affected by treatment. Fasting increased mean GH and GH pulse amplitude in both groups in November (P<0.05). In April, the fasting response differed between the groups. In group C, mean GH, pulse amplitude, and pulse frequency were all greater in the fasted state than in the fed state (P<0.05), while in group SS there were no significant differences (P>0.05). IGF-I was lower in the fasted state than in the fed state at both sampling dates (P<0.001). The seasonal decline in food intake and growth is associated with decreased GH, IGF-I, and prolactin concentrations, and increased testosterone and the GH response associated with fasting. All these changes except those of testosterone were delayed or reduced by continued exposure to a summer solstice photoperiod in autumn. The decreased photoperiod in autumn may thus influence the normal timing of the seasonal growth cycle.

Meal patterns associated with the age-related decline in food intake in the Fischer 344 rat.

We previously reported that aging Fischer 344 (F344) rats display a spontaneous, rapid loss in body weight associated with decreased food intake near the end of life. Here, we describe the specific changes in feeding patterns underlying this reduced intake. Nine male F344 rats, aged 25 mo, were monitored continuously until 7 days after the onset of spontaneous rapid weight loss (i.e., senescence). Regardless of age at death (25.5-32.5 mo), all senescent rats demonstrated a similar pattern of decreased food intake. They ate significantly smaller meals (g/meal) of shorter duration during spontaneous rapid weight loss compared with their period of weight stability (presenescence). However, no differences occurred in the number of meals eaten per day. Rapid weight loss had no effect on the rats' selection of preferred diets. Serum levels of the hormone leptin were not higher in the senescent vs. age-matched presenescent rats, nor was the incidence of common disease different in senescent animals. Moreover, the area of the pituitary-hypothalamus interface, measured to identify possible hypothalamic compression, was similar in the senescent rats and an age-matched, presenescent control group despite significantly greater pituitary size in the former. Our data show that simultaneous with rapid spontaneous weight loss, aging rats demonstrate significant changes in feeding patterns suggestive of earlier satiation. These feeding alterations do not result from loss of ability to select for palatable food, elevated serum leptin levels, specific pathology, or hypothalamic compression.

The effects of work and two planes of nutrition on trypanotolerant draught cattle infected with Trypanosoma congolense

AbstractThirty-two N'Dama bulls aged 3 to 4 years were used to study the interactions between work, trypanosomosis and nutrition. The bulls were randomly allocated to two treatments, working (W) and non-working (N). Half in each treatment were placed on an andropogon hay basal diet (B), the other half on a better quality groundnut hay diet (H). Five days a week, four pairs of animals in the BW group and and four pairs in the HW group pulled weighted sledges four times around a 2056-m track. Loads were set to ensure energy expenditure was equivalent to 1·4 times maintenance. After 4 weeks all 32 bulls were injected intradermally with 104 Trypanosoma congolense organisms. The trial continued for a further 8 weeks.Trypanosome infection caused a significant (P &lt; 0·001) decline in packed cell volume (PCV), and the anaemia was more severe (P &lt; 0·05) in working animals; three pairs in the HW group and two pairs in the BW group were withdrawn because PCV fell below 17%. Diet had no effect on PCV or parasitaemia. Infection caused a decline in food intake (P &lt; 0·001) but with significant interactions between diet and work. Intake patterns were similar in the BN and BW groups whilst the HW animals consumed significantly more groundnut hay compared with the HN group (P &lt; 0·01). However, nutrition had no significant effect on lap times or the team's ability to work under trypanosomosis challenge. Post-infection, diet was the dominant factor determining weight change, HN and HW animals weighed significantly more than BN and BW animals (P &lt; 0·01) and the interaction between period, diet and work demonstrated that BWhad the lowest weights in the latter stages of the trial (P &lt; 0·05).The results suggest that supplementation with better quality forages confers no benefit to an animal infected with trypanosomes. Nor can trypanotolerant cattle sustain long periods of work if subiected to a primary challenge of trypanosomes.

Mechanisms Responsible for Adult Onset Decline in Food Intake and Body Weight gain due to Neonatal Neuropeptide Y Administration • 1582

Mechanisms Responsible for Adult Onset Decline in Food Intake and Body Weight gain due to Neonatal Neuropeptide Y Administration • 1582

Estradiol, progesterone, and prolactin regulate maternal nest-building in rabbits.

Maternal nest-building in rabbits, expressed across the last third of pregnancy, consists of: digging a burrow, collecting straw and shaping it into a nest inside the burrow, plucking body hair and lining the straw nest with it. The sequential expression of these activities is correlated with specific changes in the plasma concentration of estradiol, progesterone (P), and prolactin (PRL). To further substantiate the participation of these hormones in the control of maternal nest-building we explored in ovariectomized (ovx) New Zealand white rabbits the capacity of several combinations of such hormones to stimulate digging, straw-carrying, and hair-pulling. Does given estradiol benzoate (EB; 5 micrograms/day from days 3 to 21) plus P (2 or 10 mg/day from days 4 to 16) dug into a substrate from the fourth day of the P treatment until withdrawal of this hormone. The intensity of this effect was greater in the group treated with the high dose of P. Straw-carrying and hair-pulling occurred after P withdrawal in a dose-response way. Food intake, which declines in pregnant females shortly before parturition, decreased to the same extent in both groups of ovx EB-treated does after P withdrawal. A significant increase in PRL plasma levels was observed on day 9 in does given EB plus 2 mg P/day and at two days following P withdrawal in does given EB plus 10 mg P/day. When such ovx EB/P-treated does were given bromocriptine to block PRL release (1 or 3 mg/Kg/day, from days 11 to 21) the expression of digging was unmodified. By contrast, bromocriptine abolished the display of straw-carrying and hair-pulling, and also prevented the decline in food intake normally following P withdrawal. The addition of ovine PRL to ovx EB/P-treated does given bromocriptine reduced the expression of digging, did not restore straw-carrying or hair-pulling, and provoked a sharp decline in food intake. The possible mechanisms of interaction between PRL and steroid hormones for the regulation of specific aspects of the pregnant doe's physiology and behavior are discussed.

Reduction in circulating IGF-I and hepatic IGF-I mRNA levels after caecal ligation and puncture are associated with differential regulation of hepatic IGF-binding protein-1, -2 and -3 mRNA levels.

Sepsis is characterized by a severe shift in metabolism, characterized by low IGF-I levels. We have studied the influence of caecal ligation and puncture (CLP) on the levels of circulating IGF-I and hepatic IGF-I and IGF-binding protein (IGFBP)-1, -2 and -3 mRNA in adult male Wistar rats (n = 12) and compared it with sham-operated rats (n = 6). In order to exclude anorexia-induced changes we also studied animals pair-fed to both groups. IGF-I levels were measured by RIA. Steady-state hepatic IGF-I, IGFBP-1, IGFBP-2 and IGFBP-3 mRNA levels were measured by Northern blot analysis using specific rat cDNA probes. Food intake averaged 13.0 +/- 2.0 g/day in the sham-operated rats fed ad libitum during the study period, with a sharp decline in food intake in the CLP animals (2.3 +/- 1.3 g/day). After CLP, there was a significant reduction in circulating IGF-I levels (467.2 +/- 50.9 micrograms/l) compared with sham-operated animals (924.0 +/- 75.3 micrograms/l; P = 0.04) or those pair-fed to the CLP rats (612.5 +/- 52.9 micrograms/l; P = 0.04). Total hepatic IGF-I mRNA levels were significantly reduced (2.57 +/- 0.05 densitometric units (DU) after CLP compared with the sham-operated group (2.71 +/- 0.04); P = 0.04), or their pair-fed controls (2.75 +/- 0.08 DU; P < 0.05). Hepatic IGFBP-3 mRNA levels were lower after CLP (0.37 +/- 0.04 DU) than in the sham-operated animals (0.66 +/- 0.09 DU; P = 0.04) or their pair-fed controls (0.61 +/- 0.05 DU; P = 0.04). On the other hand, hepatic IGFBP-2 mRNA levels were increased after CLP (0.91 +/- 0.11 DU) compared with sham-operated animals (0.28 +/- 0.06 DU; P = 0.01) or with their pair-fed controls (0.22 +/- 0.02; P = 0.01), as were hepatic IGFBP-1 mRNA levels (CLP animals 0.95 +/- 0.11 DU; sham-operated 0.30 +/- 0.04 DU, P = 0.01; pair-fed 0.30 +/- 0.02 DU, P = 0.01). No significant difference between sham-operated animals and their pair-fed controls was observed in circulating IGF-I levels (888.0 +/- 109.3 micrograms/l; P = not significant (N.S.)), hepatic mRNA levels for IGF-I (2.72 +/- 0.06 DU; P = N.S), IGFBP-3 (0.71 +/- 0.07 DU; P = N.S.), IGFBP-2 (0.25 +/- 0.07 DU; P = N.S.) or IGFBP-1 (0.27 +/- 0.06 DU; P = N.S.). In summary, after CLP there was a reduction in both circulating and hepatic IGF-I mRNA levels associated with a specific and differential regulation of hepatic IGFBP-1, -2 and -3 mRNA levels. Although we cannot eliminate a possible effect of surgical stress combined with malnutrition, our results suggest that these changes are a specific effect of sepsis rather than simply a result of surgical stress or poor nutrition alone.

Manifestations of cancer cachexia induced by colon 26 adenocarcinoma are not fully ascribable to interleukin-6.

In order to further clarify the role of interleukin 6 (IL-6) in the pathogenesis of cachexia, recombinant human IL-6 (hIL-6) was administered s.c. by osmotic pump for 9 days at a dose of 1 or 10 micrograms/day into CDF1 mice inoculated with a non-cachexia-inducing subclone of colon 26 adenocarcinoma (clone 5), or with a cachexia-inducing subclone (clone 20) of this malignancy. The serum level of IL-6 in non-cachectic mice with clone-5 tumors was 35% lower than in cachectic mice bearing clone 20 of colon 26 adenocarcinoma on the 19th day after tumor inoculation. IL-6 administration induced anemia, thrombocytosis and visceral organ hypertrophy not only in mice with clone-5 tumors but also in control mice with no tumor burden. Lipolysis and proteolysis became conspicuous when a large dose (10 micrograms/day) of IL-6 was infused into mice with clone-5 tumors. However, IL-6 supplementation did not induce loss of body weight, a decline in food intake or lymphocytopenia, which were characteristically observed in cachectic mice with clone-20 tumors. In conclusion, IL-6 appears to be a permissive factor for the development of cachexia but, while it can induce some of the symptoms typical of cachexia, it cannot in itself induce the full cachectic syndrome.

Development of Altered Taste Preferences in Tumor-bearing Rats

Experimental tumors induce a decline in food intake that may derive from changes in taste or the development of taste aversions. The preferences of tumor-bearing (TB) and non-tumor-bearing (NTB) rats for five chemicals (three palatable and two aversive taste stimuli) were studied in an animal model of experimental cancer employing the methylcholanthrene (MCA) sarcoma. In protocol 1, five groups of Fischer 344 rats were given 23-h, two-bottle preference tests (taste solution vs. water) daily from day 3 after tumor implantation until spontaneous death occurred. Both NTB and TB rats avoided quinine hydrochloride and hydrochloric acid solutions throughout the experiment indicating that tumor growth produced no disruption in the animals' perception of these normally aversive tastes. In both groups, preference for sucrose (88% to 97%) and saccharin (75% to 93%) remained high until days 22 and 17 respectively, but tended to decline with advanced tumor growth. In both cases, a reduction in total calorie intake preceded the changes in sucrose or saccharin preference by several days. With or without a tumor, rats exhibited approximately 50% preference for NaCl at all times. In protocol 2, a four-bottle preference test (sucrose vs. saccharin vs. NaCl vs. water) was administered before tumor implantation and again 3 weeks later when a decline in food intake was evident. Both TB and NTB rats displayed a dominant preference for sucrose over saccharin, NaCl, and water at the pre- and posttests. However, a comparison of the difference scores (pre- minus postimplantation) of NTB and TB rats showed a small but significant suppression of TB animals' preference for sucrose. The altered preferences for sweet but not salt taste stimuli suggest that food-related taste cues may be more susceptible to the development of taste aversions during cancer. However the contribution of taste changes to the anorexia of cancer remains unclear and it is possible that the changes in taste preference may be secondary to the reduction in food intake.

Lactation in the sow during heat stress

Ambient temperatures above the evaporative critical temperature (ECT) of lactating sows lead to a reduction in food intake, milk yield, reproductive performance and growth rate of piglets. The fall in food intake of the lactating sow is closely associated with a rise in deep body temperature as is also observed in growing pigs. Evidence is presented indicating that the reduction in milk yield of sows exposed to high temperatures may be greater than would be expected from an equivalent decline in food intake for sows housed under thermoneutral conditions. It is suggested that the direct effect of high temperatures on milk yield may result from a redirection of blood flow to the skin and away from other tissues, including the mammary gland. Experimental observations showing that skin temperature is maintained while deep body temperature declines after initially rising rapidly in lactating sows exposed to 28°C for four days lends indirect support to this theory. Oxygen uptake of lactating sows was observed to decrease from 523 to 411 ml/min when ambient temperature was increased from 18 to 28°C. This decline of 20% in heat production was associated with a 25% decline in milk yield and a 40% reduction in food intake. The oxygen uptake of lactating sows was found to be similar to that of non-breeding animals with an equivalent food intake. Consequently, ECT for lactating and non-lactating animals was found to be similar. Performance of lactating sows exposed to high temperatures can be improved by reducing the animal's heat production through decreasing the fibre and increasing the fat content of the diet. However, increasing heat loss from the sow, particularly through increasing the area of wet skin, has a greater positive effect on animal performance than modifying the diet.

Skeletal muscle amino acid and myofibrillar protein mRNA response to thermal injury and infection.

This study investigates alterations in rat skeletal muscle after burn trauma (30% body surface area, full-thickness scald injury) with or without concomitant burn wound infection (immediate postburn inoculation with Pseudomonas aeruginosa), an injury model previously described by the authors.1 The study design allowed evaluation of sequential changes in skeletal muscle membrane integrity after burn or burn-infection injury and whether these occur coordinately with changes in muscle protein mass, specific protein transcription, intracellular amino acid and electrolyte concentrations, and indices of cellular energy status. Four groups of rats were compared: animals subjected to burn injury alone (Burn), burn injury plus wound infection (BI), freely fed, unburned control animals (FF), and unburned animals pair-fed to BI (PF: to control for anorexia in the BI group). Skeletal muscle myofibrillar protein transcription (relative abundance of messenger RNA for actin and myosin heavy chain); indices of muscle mas...

Intermittent acceleration as a countermeasure to soleus muscle atrophy.

The centrifuge proposed for the Space Station will most likely be used, in part, for countermeasure studies. At present, there is a paucity of information concerning the duration and frequency of acceleration necessary to counteract the atrophy process associated with microgravity. The present study was designed to investigate intermittent acceleration during non-weight bearing of the soleus muscle and its resultant effects on muscular atrophy. Each day rats were removed from hindlimbs suspension and accelerated to 1.2 g for four 15-min periods evenly spaced over a 12-h interval. The soleus muscle experienced non-weight bearing the remaining 23 h each day. This paradigm, when repeated for 7 days, did not completely maintain the mass of soleus muscle, which was 84% of control. Interestingly, the identical protocol utilizing ground support in lieu of acceleration successfully maintained the soleus muscle mass. The failure of the centrifugation protocol to adequately maintain soleus muscle mass might be due to an undefined stress placed on the animals inherent in centrifugation itself. This stress may also explain the transient decline in food intake of the intermittent acceleration group on the 2nd and 3rd days of treatment. Also, these data support the concept that the frequency of exposure, as opposed to the duration of exposure, to weight bearing during hindlimb unweighting seems to be the more important determinant of maintaining postural muscle mass.

Gluconeogenesis in the Tumor-Influenced Rat Hepatocyte: Importance of Tumor Burden, Lactate, Insulin, and Glucagon

In an attempt to define the relationship between tumor burden (cachexia) and host hepatocyte gluconeogenesis, the following experiments were performed with the use of an F344 male rat bearing a transplantable sarcoma. Food intake of tumor-bearing (TB) rats was constant until day 24 following implant and a tumor burden of 18 +/- 5.2% (mean +/- SD), at which time food intake progressively declined daily. Tumor burden was arbitrarily divided at 12.8% to determine if any measured changes occurred prior to or following the approximate time when a significant decline in food intake occurred. Plasma glucose levels decreased with tumor burden. Whole-blood lactate levels increased with tumor burden. Fasting plasma alanine levels decreased with tumor burden. Plasma 3-methylhistidine levels increased with tumor burden. Plasma glucagon levels increased with tumor burden, whereas plasma insulin levels decreased. Hormone changes were noted at small tumor burdens prior to a decline in food intake. Viable hepatocytes were isolated from 4 groups: non-tumor-bearing (NTB), small tumor burden [(STB) 3.5% total body weight (TBW)], moderate tumor burden [(MTB) 14% TBW], and large tumor burden [(LTB) 23% TBW]. As expected in NTB rats, hepatocytes produced significantly more glucose with 20 mM lactate than 20 mM alanine or than Hanks' balanced salt solution (HBSS) alone. Hepatocytes from STB rats demonstrated the same basic relationship for lactate, alanine, and HBSS, but they produced significantly more glucose from lactate and HBSS alone than NTB hepatocytes. With alanine as substrate, the rates of glucose production by hepatocytes were not affected by the presence or size of tumor. However, with lactate as substrate, hepatocytes from MTB and LTB rats produced progressively less glucose as tumor burden increased (r = -0.85, p less than .001), which may partly explain the reduction in blood glucose and elevation in blood lactate levels observed. Elevated gluconeogenesis in TB rats occurred early prior to a decline in food intake. The key precursor appeared to be lactate. The balance between glucagon and insulin appeared to promote the abnormal host carbohydrate metabolism observed.

Preoperative insulin reverses cachexia and decreases mortality in tumor-bearing rats

As a model of surgical stress in the cancer-bearing animal, we resected large flank sarcomas from cachectic rats under ether anesthesia and closed wounds primarily. The metabolic cost of tumor resection was measured using a long-term continuous indirect calorimeter. In the immediate postresection period energy balance decreased and host energy expenditure increased significantly ( P < 0.005). In animals with similar tumor weights, mortality following resection was determined by the degree of cachectic depletion. We then considered whether improvement of preoperative host nutritional status with insulin treatment might improve a subsequent surgical outcome. Insulin, when administered exogenously to cachectic tumor-bearing rats, has been shown to stimulate food intake and preserve host weight and does not stimulate tumor growth. When individual rats bearing a cachexia-producing flank sarcoma demonstrated a decline in food intake to <75% of predicted (approximately 25 days after tumor implantation), they were randomized to receive either daily injections of NPH insulin (2 units/100 g/day) for 5 days or no treatment for 5 days. Animals then underwent tumor resection and 14-day survival was measured. All resections were performed in an unbiased manner without the surgeon's knowledge of each rat's treatment status. In an experiment using 59 rats, insulin-treated rats had a threefold higher 5-day preoperative food intake and did not lose weight in the preoperative period, while untreated rats lost 17 g ( P < 0.001). Mortality in the insulin-treated group was 10% versus 28% in the untreated group. The experiment was repeated using 50 rats with deeper, more locally invasive tumors with similar results. Operative mortality was 20% in the insulin treated group versus 60% in the untreated group ( P < 0.001, χ 2 test). Preoperative insulin therapy of cachectic TB rats appeared to reverse host cachexia and improve survival following tumor resection.

The effects of artificially-induced fly-strike on food intake and liveweight gain in sheep

A single, artificially-induced fly-strike with Lucilia sericata larvae was associated with a rapid (decline in food intake in sheep, with a consequent reduction in liveweight. Loss of weight ranged from 0.5 to 5.5 kg over four to six days and recovery to pre-infestation liveweight took three to 36 days. Pair-fed, uninfested partners of these sheep also showed a reduction in liveweight, whereas uninfested sheep in some experiments fed ad libitum showed either little change or a gain in liveweight over the same period. In general, maggot infested sheep took less time to regain weight than did their pair-fed partners although the weight lost as a proportion of initial weight was similar in both groups. Loss of appetite alone would appear to account for these events.

Winter Weight Loss in Japanese Serow

To obtain winter weight loss patterns by sex and age, we examined whole weight data on 925 Japanese serows (Capricornis crispus) shot in Gifu and Nagano prefectures, Japan, during November-March in 1980-81 and 1981-82. Weight loss among yearling, juvenile, adult, and aged serows of both sexes ranged from 5 to 23%, whereas lambs did not lose much weight. Adults lost more weight during the severe winter than during the moderate winter. J. WILDL. MANAGE. 50(2):336-338 It is well documented that body weights of northern ungulates are heaviest in fall, decline over winter, and are lightest in early spring (Moen 1973, Anderson et al. 1974, Franzmann et al. 1978, Nichols 1978, Knaus and Schrider 1983). From winter until spring, metabolic rate and food intake decline, and these animals then are in a negative energy balance wherein they depend mainly on stored body fat for sustenance. Food availability and weather conditions during winter can directly affect mortality. A knowledge of seasonal changes in ungulate body weights is an important management consideration because such trends serve as an index of range nutritional status. As a part of a population study of Japanese serows we investigated their weight loss patterns by sex and age from late fall to early spring. These findings are reported here. We are deeply indebted to M. Sugimura of the Dep. Vet. Anat., Gifu Univ., for granting permission to report data collected by him and his staff. We thank K. Tokita, H. Saitoh, R. Higashi, and H. Higashi, Res. Cent. Jap. Wildl., and personnel of the Gifu and Nagano Gov. for their invaluable assistance. This work was supported in part by a Grant-in-Aid for Sci. Res. from the Minist. Educ., Sci., and Cult., Jap. STUDY AREA AND METHODS The collection area encompassed approximately 9,000 km2 along the Gifu-Nagano prefectural border which is located in the central part of Honshyu, Japan. Elevations range from 700 to 2,600 m. Topography in the area is dissected by rugged, steep drainages and mounta ns extending north and south. The vegetation is a mosaic of clearcut patch with dwarf bamboo (Sasa kurilensis); temperate deciduous forest with Siebold's beech (Fagus crenata); Erman's birch (Betula ermanii), and oak (Quercus spp.); and artificial forest dominated by Hinoki cypress (Chamaecyparis obtusa) and Japanese larch (Larix leptolepis). Serow density on some regions of the area estimated by a direct count of the number seen in 1981 varied from 1.2 to 6.5/km2 (K. Tokita, unpubl. data). Serows were shot by hunters during November March 1980-81 and 1981-82. Whole body weight of the 925 serows taken were obtained to the nearest 0.5 kg. The ages of all serows were determined from horn ring and cemenum annuli counts (Miura 1985) and by tooth replacement pattern (Miura and Yasui 1985). Because serows presumably are born from late May to early June (Sugimura et al. 1983), ages of study specimens were grouped into 5 classes: lamb (0.5-1.0), yearling (1.5-2.0), juvenile (2.53.0), adult (3.5-11.0), and aged (>11.5 years old). To obtain the seasonal weight change patterns by sex and age, we calculated mean weights by 10-day intervals during each month. Linear regressions and correlation coefficients were derived according to Moen (1973). This content downloaded from 157.55.39.144 on Wed, 07 Sep 2016 05:44:31 UTC All use subject to http://about.jstor.org/terms J. Wildl. Manage. 50(2):1986 SEROW WEIGHT Loss * Miura and Maruyama 337 RESULTS AND DISCUSSION Monthly records from 11 meterological stations in the study area indicated that the winter of 1980-81 was severe, with monthly maximum snow depth averaging 48.0 cm from December to March. The 1981-82 winter was more moderate, with monthly maximum snow depth averaging 9.6 cm. Differences in mean whole weights between the 2 years were found in females for 3 age classes. Female lamb, adult, and aged serows were heavier during the 2nd year than the 1st (P 0.05) between the slopes of regression lines for these age-sex classes. However, the intercept of the regression line for pregnant adult females differed from that of nonpregnant adults (P 0.05) in the slopes and intercepts of the equations, adult serows apparently lost more weight during the severe winter of 1980-81 (21.2% for males and 17.4% for females) than during the moderate winter of 1981-82 (13.6 and 13.8%, respectively). This might be due to food limitation because deep snow covered much of 70 MALES

Anorexia, serum zinc, and immunologic response in small cell lung cancer patients receiving chemotherapy and prophylactic cranial radiotherapy.

Anorexia is a major clinical problem for patients with certain types of cancer. The specific mechanisms that result in this spontaneous decline in food intake remain unknown. In noncancer populations, zinc has been shown to play a role in maintaining normal appetite, taste acuity, and immunocompetence. One purpose of this prospective, longitudinal study of cachexia in ten males with small cell lung carcinoma was to determine if anorexia (caloric intake), perceived taste changes, zinc intake, and impaired cellular immunity were associated with serum zinc concentrations. The average daily caloric intake declined 490 kcal from time of diagnosis to seven months after diagnosis (mean caloric intake = 72% of RDA). Daily zinc intake ranged from 6.5 to 25.4 mg over the seven months. During this period, the mean serum zinc concentrations, although low (71 micrograms/dl), remained within the normal range. The average weight declined from 81.7 to 74.1 kg. There was no identifiable pattern of perceived taste changes; most of the perceived changes were recorded during the period coinciding with prophylactic cranial radiation. At the initial testing, four of nine subjects were anergic to a battery of skin test antigens (mumps, candida, tuberculin purified protein derivative). The only subject who remained responsive to two antigens throughout the study remained alive at 12 months. Caloric intake was inadequate to maintain weight. While zinc intake was low, low normal serum zinc concentrations were maintained; thus in this sample, serum zinc does not appear to be the anorexigenic factor.