Search PubMed⌕ Search

Biomedical subjects

J A Cherry

Publications and source records attributed to J A Cherry.

At least 55 records · Page 3Linked to original sources
PubMed1986

Sexual dimorphism and gonadal control of ultrasonic vocalizations in adult pine voles, Microtus pinetorum.

We investigated the vocalizations produced by adult pine voles during various social interactions by presenting an experimental animal with either an anesthetized or awake (unanesthetized) conspecific. Ultrasonic vocalizations (USVs) occurred frequently during tests in which an awake male was present, but were rarely detected in tests involving only awake females, or when a female was presented with an anesthetized conspecific. Higher rates of USVs were produced when males were tested with a familiar female than when tested with an unfamiliar male or female. Equivalent rates were produced when males were presented with either anesthetized or awake animals, but female-soiled bedding failed to elicit USVs from males. Sonic vocalizations (SVs) were produced by both sexes and were associated with aggressive behavior, but occurred only in tests between awake, unfamiliar animals. Castration greatly reduced and testosterone therapy restored USVs emitted by males in response to anesthetized conspecifics. Our results suggest that (i) USVs are emitted predominantly by males; (ii) familiarity enhances USV response; (iii) SVs are produced during aggressive interactions; and (iv) androgens regulate the production of USVs by males. Possible roles for pine vole vocalizations are discussed.

Animals↗
PubMed1986

Lipocyte hyperplasia and sexual maturation of Japanese quail (Coturnix coturnix japonica).

1. Hyperplastic growth of adipose tissue in Japanese quail (Coturnix coturnix japonica) was examined in relation to sexual maturity to determine whether fat cell number is fixed in mature individuals of this species. 2. Total DNA concentrations in the lipid (lipocyte) and non-lipid (stroma) fractions of collagenase (EC 3.4.24.3)-digested abdominal (retroperitoneal) fat depots were determined on a chronological-age basis from 28 to 240 d of age. The in vivo incorporation of [methyl-3H]thymidine into DNA of both the lipocyte and stroma fractions of abdominal fat from both ad lib. and restricted-fed (75% of ad lib.) females was also examined at ages before and subsequent to sexual maturity. 3. In both males and females, significant increases in abdominal fat weights at ages beyond sexual maturity were associated with increased lipocyte DNA. Regardless of the feeding regimen and stage of maturity, substantial radioactivity was recovered from both the stromal and lipocyte fractions of abdominal fat when female quail were examined 24 h after the administration of tritiated thymidine. When examined 5 d post-injection, the majority of the radioactivity was contained in the lipid fraction of collagenase-digested adipose tissue. 4. Both the total DNA content of adipose tissue and the incorporation of tritiated thymidine into adipose tissue indicated that lipocyte hyperplasia contributes to postmaturational increases in fat deposition.

Abdomen↗
PubMed1986

Inheritance of traits associated with sexual maturity when populations of chickens reach 50% lay.

In order to study the mode of inheritance of traits associated with the onset of sexual maturity, data from stocks differing greatly in genetic background were analyzed when populations achieved 50% lay. Chickens used in this experiment consisted of three parental lines and five crosses. Parental lines were White Plymouth Rocks bidirectionally selected for high (HH) and low (LL) 56-day body weight, and a closed population of Jersey Black Giants (JJ). Crosses were produced from reciprocal matings of the White Rock lines (HL and LH), their F2 (HL X HL), and Jersey males mated to weight-line females (JH, JL). When 50% of the pullets within a population had laid, various traits were measured for each individual in that population. Retrospective analyses showed that sexually mature pullets were heavier at 91 and 126 days of age than those which had not commenced lay. Body weight dimorphism between layers and nonlayers was disproportionately greater in LL and F2 pullets than in those of other populations, resulting in a population by physiological stage interaction. Fat depots were heavier and percentages of fat were higher in laying than nonlaying pullets. Evidence was obtained suggesting that an absolute quantity of breast tissue was necessary before lean tissue percentage became meaningful as a threshold trait for the onset of egg production. Modes of inheritance for body weight and compositional characteristics were different in sexually immature and mature pullets, suggesting that muscle functioned as a nutrient reserve in laying pullets and a nutrient store in those that had not reached this physiological stage.

Aging↗
PubMed1985

Lipogenesis and lipolysis in fed and fasted chicks from high and low body weight lines.

Lipogenic and lipolytic capacities were examined in fasted and nonfasted 28-day-old chicks from high-weight (HW) and low-weight (LW) selected lines. Lipogenesis was assessed in liver and bone (sternum) tissues through the activities of malic enzyme (EC 1.1.1.40), citrate cleavage enzyme (EC 4.1.3.8), and acetyl coenzyme A carboxylase (EC 6.4.1.2), as well as through the in vitro incorporation of acetate-1-14C into liver and bone lipid fractions. Lipolysis was estimated through the in vitro release of free fatty acids (FFA) from abdominal adipose tissue and through plasma FFA. Fasting depressed lipogenesis and increased lipolysis. Regardless of the feeding state, LW chicks exhibited higher lipogenic and lipolytic capacities than their HW counterparts, suggesting that lipid degradation may be relatively more important than synthesis in determining net fat deposition. In addition, the incorporation of radioactive acetate into bone lipid was associated with detectable activity of lipogenic enzymes, providing further evidence that the skeleton is an important site of lipogenesis in the chicken.

Acetyl-CoA Carboxylase↗
PubMed1985

Breaking strength and composition of the skin of broiler chicks: response to dietary calorie-protein ratios.

Skin breaking strength and protein, fat moisture, and total collagen concentrations of skin from the breast, thigh, and back of male and female commercial broilers were measured in response to diets containing relatively wide or narrow ratios of calories to protein (C:P). Comparisons were made at 28, 42, and 56 days of age. Chicks fed diets containing relatively wide C:P ratios had weaker skin than those fed diets with narrower C:P ratios, with differences being greater at 56 days than at younger ages. Regardless of diet, males had stronger skin than females. Although the magnitude of the differences varied with age, breast skin was stronger than thigh skin, with skin from the back being intermediate in strength. The observed differences in breaking strength were not consistently associated with fat, protein, moisture, or collagen concentrations of the skin.

Animals↗
PubMed1984

Age, body weight and body composition requirements for the onset of sexual maturity of dwarf and normal chickens.

Comparisons of age, food intake, body weight and body composition at the onset of sexual maturity were made between dwarf and normal chickens from lines selected for high or low juvenile body weight. At the same age birds which had started to lay were significantly heavier and contained significantly more abdominal and carcass fat than those which were not laying. Differences between normal and dwarf pullets within lines varied with genetic background, indicating differences between lines in meeting a body weight or a body composition requirement, or both, for the onset of sexual maturity.

Adipose Tissue↗
PubMed1984

Selection for body weight at eight weeks of age. 17. Overfeeding.

Female chicks from lines selected for high and low body weight and their reciprocal F1 crosses were overfed via force feeding to crop capacity from hatching to 21 days of age. Low-weight line chicks could be overfed at an earlier age to a greater extent than those from the high-weight line and F1 progeny. The degree of overfeeding appeared to be associated with the relative size of certain gastrointestinal components. Differences among lines in their capacity to be overfed were reflected in concomitant changes in body weight and carcass fat. Relationships among feed consumption and growth are discussed within the context of selection for body weight and heterosis under various feeding regimens.

Animals↗
PubMed1984

Effects of light and feeding space on leg abnormalities in broilers.

The influence of two management factors on the incidence and severity of leg abnormalities was studied in three experiments utilizing a total of 7200 male broiler chickens. Birds provided intermittent illumination (IL) had significantly fewer and less severe leg abnormalities than birds under continuous illumination. Broilers given 2.94 cm of feeding space per bird had more but less severe leg defects than birds given 1.47 cm of feeding space. Bird activity was greater under IL and is deemed to be at least partially responsible for the stronger legs recorded among broilers under this management practice.

Animal Husbandry↗
PubMed1984

Phenotypic profiles of broiler stocks fed two levels of methionine and lysine.

A phenotypic profile was compiled for eight commercial broiler stocks fed diets containing two levels of methionine and lysine. Stock by diet interactions were unimportant for most traits, although differences among stocks were somewhat magnified when they were fed the lower levels of methionine and lysine. Feed efficiency (body weight/feed consumption) to a fixed age was negatively associated with body weight, feed intake, frequency of leg disorders, and size of the abdominal fat pad. Its association with immunological and physiological traits varied with the environment. Apparent improvements in performance may be partially attributed to increases in growth rate, which have enabled broilers to reach market age at earlier ages.

Animals↗
PubMed1984

Fertility and behavioral responses of roosters to diets differing in protein and calcium.

Diets differing in calcium (approximately 3.2 and .9%) and protein (15 and 12%) were fed to assess their effects on fertility, behavior, and physiological traits of White Leghorn males from lines selected for high (HA) and low (LA) antibody titers in response to the administration of sheep erythrocytes. Two trials, terminated when the males were 721 and 380 days of age, respectively, were conducted. In Trial 1, the HA males consumed significantly more feed than the LA males and those fed the low protein diets consumed more feed than those fed the high protein diets. No significant differences in feed intake were observed in Trial 2. Neither line, calcium level, nor protein level had a consistent effect on body weight in either trial. There were no significant first or second order interactions between main effects. Comparisons within ages and trials for percentage and duration of fertility revealed no significant differences between lines, protein level, or calcium level. Although the HA males produced significantly more antibodies to canine erythrocytes, dietary effects on antibody titers, heterophil: lymphocyte ratios, and plasma corticosterone were not significant. Thus, there was no indication that dietary treatments were inducing physiological adaptation. Behavioral adaptations, however, were observed; differences were significant for fear, territoriality, air pecking, and head shaking. It was concluded that behavioral responses symptomatic of nutrient deficiencies occur when no overt deficiency is present; this infers that an animal's well-being cannot be assessed strictly on the basis of behavioral consequences.

Animals↗
PubMed1984

Skin breaking strength in chickens: comparisons among genetic combinations.

Skin breaking strength was measured in lines of chickens divergently selected for high (H) and low (L) juvenile body weight, their F1 reciprocal crosses (HL and LH), and an F2 generation derived from HL X HL matings. In both lines, skin covering the breast had higher breaking strength than that covering the thigh. Skin of chicks from the LL line had the lowest breaking strength, that from HH and LH matings the greatest, and that from HL and F2 matings was intermediate. Percentage heterosis for breaking strength was significantly positive while percentage recombination was not significant.

Animals↗
PubMed1984

Responses to dietary self selection and calories in liquid form by weight selected lines of chickens.

Feed intake of adult White Plymouth Rock male chickens from lines selected for high (HW) and low (LW) juvenile body weight was examined as a function of dietary self selection, glucose solutions in lieu of water, and environmental temperature. More energy was consumed by LW males allowed to select between high protein and high energy diets and when glucose solutions were provided in lieu of water, than on complete diets. In contrast, these regimens had relatively little influence on caloric intake in the HW line. On split diets, protein consumption was reduced in both the HW and LW lines, indicating that both populations overconsumed protein when fed complete diets.

Animals↗
PubMed1984

Modified step-up protein feeding regimens for egg-type chickens. 1. Growth and production performance.

Effects of sequential changes in dietary protein on growth from 0 to 20 weeks of age and on egg production from 20 to 72 weeks of age were evaluated with White Leghorn chickens. Four dietary treatments were compared. They consisted of three dietary regimens wherein an 18% crude protein (CP) diet was fed to 1, 2, or 3 weeks of age (Treatments 1, 2, and 3, respectively) and then common 12, 15, and 18% CP diets to 8, 14, and 20 weeks, respectively. These three regimens were compared with a control regimen (Treatment 4) that consisted of feeding 18, 15, and 12% CP diets to 6, 14, and 20 weeks of age, respectively. At 20 weeks of age, 144 birds from each treatment were moved into laying cages for the subsequent 52 weeks of egg production. In comparison with birds on the control feeding regimen, those reared under Treatments 1, 2, and 3 consumed significantly less feed during the 20-week growing period. Birds of Treatments 2 and 3 consumed significantly more protein than those of Treatments 1 and 4. By feeding a 12% CP diet from 1, 2, and 3 to 8 weeks of age, body weights were significantly lower than the average body weight of the control birds, approximately 20, 17, and 13%, respectively, by 6 weeks of age, but only 2 to 4% at 16 weeks of age, and by nonsignificant amounts at 28 weeks of age. Treatment 1 birds consumed 1.8% (significantly) less feed per unit body weight and were 2.6% (significantly) lighter at 20 weeks of age compared with the control birds.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1984

Body weight and composition of Japanese quail (Coturnix coturnix japonica) at sexual maturity.

The influence of dietary protein (26%, 24%, 20%, 16%, and 14%) and restricted feeding (100%, 80%, and 60% of ad libitum) on body weight and body composition of Japanese quail (Coturnix coturnix japonica) at sexual maturity was examined in two similar experiments. Although less variable than chronological age, body weight at sexual maturity also differed significantly. In Experiment 1, there were no significant differences in breast weight, tibia length or carcass fat due to diet. In Experiment 2, differences in body composition were apparent as age at the onset of lay was increased by dietary manipulation. Early maturing quail tended to enter lay when a minimum chronological age or critical body lipid level was reached; late maturing quail entered lay when a critical lean body weight or skeletal size was reached. It is proposed that multiple threshold traits associated with growth and body composition are critical for the onset of sexual maturity.

Aging↗
PubMed1983

Lipogenesis and lipolysis in normal and dwarf chickens from lines selected for high and low body weight.

Lipogenic and lipolytic comparisons were made among normal and dwarf adult males from both high-weight (HW) and low-weight (LW) selected lines. Six nonfasted birds from each of the four populations were sacrificed, and in vitro lipogenesis and lipolysis were measured in liver, adipose, and bone tissue. Also determined were activities of acetyl CoA carboxylase (E.C.6.4.1.2), NADP-malate dehydrogenase (E.C.1.1.1.40), ATP-citrate lyase (E.C.4.1.3.8), and plasma-free fatty acids (FFA). In comparison with the HW chickens, the LW males tended to exhibit higher activities of lipogenic enzymes, a greater capacity to incorporate acetate-1-14C into liver slices, an increased mobilization of FFA from adipose tissue, and high concentrations of FFA in plasma. The results indicated that the maintenance of increased postmaturational body fat associated with selection for high body weight was primarily the result of decreased lipolysis rather than enhanced lipogenesis. Effects of the dwarf allele on lipogenesis and lipolysis were not clear. Acetate incorporation into bone tissue was substantially higher than for adipose tissue, suggesting that bone may be an important site of lipogenesis in the fowl.

ATP Citrate (pro-S)-Lyase↗
PubMed1983

Selection for body weight at eight weeks of age. 16. Restriction of feed and water.

The consumption of feed or water of chickens selected for high body weight was restricted to that of a line selected for low body weight. In addition, reciprocal crosses of the two lines underwent feed or water restriction to that of the low body weight parental line. Restriction of water depressed feed intake to a greater degree in the high line than in the crosses but depressed body weight by approximately 10% in all groups through 28 days of age. Feed restriction caused a greater depression in body weight in the high line than in the crosses at 28 days of age. The effect of feed or water restriction on the feed:water ratio was dependent upon mating type, suggesting the absence of a simple relationship among growth, body composition, and feed efficiency.

Animals↗
PubMed1983

Overfeeding and restriction effects on food and glucose preference in weight selected lines of chickens.

Adult males from lines of chickens selected for high (HW) and low (LW) body weights were subjected to either ad libitum, forced, or restricted feeding for 21 consecutive days. Males from the HW line could be force fed to a greater extent than could those from the LW line. A preference for glucose solution versus water was tested in the groups fed diets ad libitum and restricted and in birds compensating from force feeding. Regardless of line, ad libitum-fed birds preferred the glucose solution to water and the restricted-fed birds preferred water to glucose. The HW birds compensating from forced feeding preferred glucose to water, whereas birds treated similarly from the LW line preferred water to glucose. After the assays were completed for preference for glucose solution versus water, each bird was provided continuous access to both a high protein and a high energy diet. Under ad libitum feeding, the HW males consumed more of the high-protein diet than of the high energy diet, while those from the LW line voluntarily consumed more of the high energy than of the high protein diet. The preference of the LW birds for the high energy diet was enhanced by both restricted and forced feeding. The preference of the HW males for the high protein diet was changed by both force and restricted feeding; more of the high energy diet than of the high protein diet was consumed by these birds.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗