Neonatal Milestones,Behavior and Growth Rate of Sumatran Rhinoceros (Dicerorhinus sumatrensis) Calves Born and Bred in Captivity

The birth of Sumatran rhino calves at the Cincinnati Zoo and Botanical Garden offered a unique opportunity to study early development and cow–calf behavior in this elusive, critically endangered species. Study goals were to: (1) record developmental milestones of newborn calves; (2) characterize cow and calf behavior during the first year following birth; (3) compare trends in the behavioral development of a male vs. female calf; and (4) record weight gain and footprint size throughout the first year. In addition to recording eight neonatal milestones, more than 450 hr of behavioral data were collected on each of the two calves (one male and one female) and their dam during the first 12 months of life. Neonatal milestones were achieved within 24 hr of birth with the exception of first defecation, which occurred at 16–18 days. Although nursing bouts decreased slightly in the second half of the year (from once every 90 min to once every 2 hr), they continued to occur frequently throughout the day and night. Therefore, calves grew rapidly from approximately 33 kg at birth to 400 kg at 12 months. Average daily weight gain for the first week was approximately 2.0 kg, whereas average daily weight gain for the remaining 12 months was slight (<1 kg) and did not differ between calves. Eating and resting occupied 70–80% of the Sumatran rhino cow and calves' time and no gender biases in either maternal investment or developmental parameters were noted. Finally, footprint measurements proved valuable for estimating calf age. Zoo Biol 31:546‐560, 2012. © 2011 Wiley Periodicals, Inc.     

Occurrence of bifidobacteria in faeces of calves fed milk or a combined diet

The development of faecal bacteria composition in calves fed milk or a combined diet was investigated from 4 to 21 days of age. On day 7, bifidobacteria in faeces of milk-fed calves already increased from about 7.6 to 9.2 log CFU/g and did not change until the end of the study, whereas in calves fed the combined diet bifidobacteria only moderately increased to 7.9 log CFU/g and decreased slowly until day 21. The counts of bifidobacteria in calves on a combined diet were significantly (p < 0.01) lower compared to those in milk-fed calves. Bifidobacterial counts determined by cultivation or by fluorescence in situ hybridisation (FISH) did not differ significantly. Our results showed that the occurrence of bifidobacteria in calf faeces is highly dependent on the diet composition. Faecal bacteria flora of calves fed exclusively by milk is rich in bifidobacteria, but in calves on a combined diet coliforms dominated.     

Comparison of bacterial flora and enzymatic activity in faeces of infants and calves

Sixty-four breast-fed infants and 23 calves were investigated for bacteria and enzymatic activity in their faecal samples. The bacteria were measured using cultivation and fluorescence in situ hybridization. Enzymatic activity was also examined. Forty-seven (64%) infants and all the calves had high numbers of bifidobacteria (usually >9 log CFU g-1) in their faeces, but 17 infants (36%) did not have a detectable amount of the bacteria. Most of the bifidobacteria-negative infants had significant quantities of clostridia in their faecal flora. While the infants did not have significantly higher counts of bifidobacteria, the samples from calves contained significantly (P<0.05) more coliform bacteria and lactobacilli. There were also significant differences in their enzymatic activities. Bifidobacteria-positive samples had a greater alpha-glucosidase activity, while bifidobacteria-negative samples had a lower activity of alpha-galactosidase, and calf samples had the highest beta-glucuronidase activity. A significant increase in bifidobacteria in calf faeces between days 3 and 7 was accompanied by a decrease in Escherichia coli. Our results show that the faecal flora of calves is similar to that of infants with regard to the occurrence of bifidobacteria as a dominant bacterial group.     

The effect of confinement on motivation to exercise in young dairy calves

The objective of this research was to determine if confinement of 8-day-old calves for varying lengths of time is associated with an increase in motivation to perform locomotor behaviors. Holstein heifer and bull calves (N=48) were used in a factorial arrangement with two crossed factors. Factor A was housing with two levels (individual confinement versus group pens) and factor B was hours in confinement with four levels (6, 12, 24, and 48h). Individual confinement was in 1.06mx1.06m pens, while group pens had a 3.68mx6.09m outside run and a 3.68mx6.09m covered area that also contained a 3.68mx2.44m area bedded with wood shavings. The calves were placed on treatment when they were 8+/-2 days of age.At the end of the treatments, a blood sample was taken for plasma cortisol determination and lymphocyte counts and the calves were open-field tested for 5min.Walk, trot, distance traveled and behaviors performed while standing during the open-field test were higher in the calves kept in group pens (P=0.0003, 0.01, 0.04 and 0.04), but were not influenced by hours in treatment. Calves confined for 48h had greater incidences of kicking and falling (P=0.014 and 0.025). Lymphocyte count (P=0.029) was lower in the calves confined for 12h, but there was not a trend across hours in confinement that indicated a consistent effect. Housing or hours in treatment did not affect canter, buck, buck-kick, rear, stumble, vocalization and cortisol concentrations. The interaction between hours in treatment and housing was not significant for any of the variables tested.This study suggests that 2 days may not have been enough time for the effects of close confinement to influence motivation in young calves, or that calves averaging 8 days of age may be too young to display increased motivation for locomotor activity. Confinement of such young calves actually inhibits locomotor activity in open-field tests.     

Vasoactive intestinal peptide antagonist retards the development of neonatal behaviors in the rat

Based on the demonstrated neurotrophic activity of VIP in vitro, a recently designed VIP antagonist was used to assess the role of this neuropeptide in the behavioral development of rats. Rats received daily subcutaneous injections from birth to day 14. Observations of developmental milestones/behaviors were made daily for 21 days. Of the measures of behavioral development tested, the time to surface right on day 4 and the day of onset for forelimb placing, hindlimb placing, forelimb grasping and air righting were significantly retarded by the antagonist. Cotreatment with VIP prevented the antagonist-induced delay. These results suggest that VIP activity is important in the development of select complex motor behaviors.     

Delay in motor development of twins in Africa: a prospective cohort study.

Twins are prone to developmental delay due to prematurity and low birthweight. However it is unknown if twinning is an independent risk factor for developmental delay. The objective of this study was to compare the attainment of a set of gross motor milestones in a cohort of twins and singletons in The Gambia. Eighty-four pairs of twins and 72 singletons were enrolled at birth and followed up until 18 months of age. The mean age at achieving milestones was higher in twins for each development outcome and the difference between twins and singletons was significant after adjustment for confounders for maintaining head, sitting without support and walking. In twins, we found a highly significant correlation within pairs for most milestones. When monozygotic and dizygotic twins were compared, a significant heritability was observed for crawling, sitting, standing and walking, with over 90% of population variance observed due to genetic factors rather than environmental factors. There was little evidence for a genetic contribution towards very early milestones. In conclusion, our data suggest that twinning is an independent risk factor for developmental delay in early life in The Gambia, and that genetic factors contribute strongly to certain motor development outcomes.     

The presence of the dam during handling prevents the socialization of young calves to humans

The effect of handling and hand-feeding of calves with or without their dams present on the calves’ subsequent response to humans was investigated using 5 groups of 10 Danish Friesian calves, each of which received a different treatment. The treatments were: calf separated from its dam immediately after birth, housed in a single pen and handled (group SH) or not handled (group S) calf adjacent to cow and handled (group CH) or not handled (C) for the first 4 days after calving. The fifth group was housed together with their dams for the first 4 days of life and then moved to single pens and handled there for the next 4 days (group C-SH). The handling treatment was carried out three times daily for 4 days and consisted of 6 min of hand-feeding with milk from a teat-bucket and patting, stroking and talking to the calf. After separation, all calves were housed in single pens. Human contact was minimised except during the treatment periods.

The approach behaviour of each calf to an unknown person was tested at days 20, 40 and 55 in their home pen. Flight distance was determined at day 55. The test at day 55 was carried out in a large single pen where the calves had been housed for 24 h prior to the test. The latency to interact (in seconds) with the person was significantly shorter (P<0.001) in all three tests for SH (13±5, 29±7 and 44±8, at days 20, 40 and 55, respectively) and C-SH (28±6, 47±17 and 70±17) compared to S (240±25, 238±33 and 173±5), C (240±28, 202±36 and 167±13) and CH (233±36, 271±29 and 128±19). The results of the latter three groups did not differ significantly. Treatment also affected the position and the orientation of the calf in the pen during the tests. Calves in SH and C-SH stood at the front of the pen and faced the person more often than calves in S, C and CH. Again, there were no significant differences between the results of the latter three groups.

The results indicate that the presence of the dam limits the effect of the handling treatment on young calves’ motivation to interact with humans. It is likely that primary socialization occurs with the dam, preventing a secondary socialization developing with humans, until the calf is isolated from the dam.     

猫气味重复暴露对青春期布氏田鼠反捕食和焦虑样行为的影响

捕食者气味对猎物的行为和生理有重要的影响。本研究主要确定猫气味重复暴露对青春期布氏田鼠（Lasiopodomys brandtii）的反捕食行为、焦虑样行为和内分泌水平的影响,以探讨青春期布氏田鼠对猫气味的反应对策。研究结果表明,猫气味暴露1 d,青春期布氏田鼠隐藏行为显著增加,而移动行为、跳跃行为、修饰行为和接触行为均显著减少;随着暴露时间延长至18 d,其反捕食行为与对照组间无显著差异,青春期布氏田鼠对猫气味产生了行为适应。旷场实验结果表明,猫气味重复暴露后,青春期布氏田鼠在旷场中的移动总距离和总平均速度显著减少,但其在旷场中的静止时间显著增加。明暗箱实验结果表明,猫气味组雌性布氏田鼠进入明箱次数显著高于雄性个体,不同性别与处理之间的布氏田鼠在明箱中停留时间比例没有显著差异。长期猫气味重复暴露对青春期布氏田鼠血浆中促肾上腺皮质激素（ACTH）和皮质酮（CORT）浓度无显著影响。以上结果表明,初次猫气味暴露对青春期布氏田鼠的反捕食行为有显著的影响,随着暴露时间的延长,其影响程度逐渐降低,存在明显的适应性。     

Nursing behavior and early development of impala at San Diego Wild Animal Park

Because impala are commonly exhibited and handreared in zoos and their natural nursing behavior had not previously been studied, we examined nursing and early development in five impala calves housed in a large, naturalistic enclosure. Calves were observed for the first 5 weeks of life during 12-hr continuous watches and 20-min focal animal samples. Total daily suckling time decreased while time grazing and feeding on concentrates increased from 1–5 weeks of age. An increasing proportion of nursing bouts were terminated by the dam as calves matured, with dams terminating almost 70% of bouts during the first week. Suckling success and maternal grooming also decreased after week I, suggesting that impala mothers cut back early on nursing and grooming of offspring. Rapid decline in mother-young spatial proximity and a concomitant increase in calf association with age-mates over time suggests that the mother-young bond is weak and ephemeral in impala. An example of the implications of our results for improving handrearing programs would be that newborn calves should be started on a daylight feeding schedule of one bottle-feeding every three hours, and that they not be allowed to gorge themselves at any one of these feedings.     

Growth variation in common marmoset monkeys (Callithrix jacchus) fed a purified diet: relation to care-giving and weaning behaviors

Significant relations were observed between select infant-care and weaning behaviors and growth in body weight in common marmoset monkeys (Callithrix jacchus). The patterns of these relations suggest that earlier occurrence of developmental milestones, such as cessation of transport (being off carriers) and weaning to solid food, were associated with slower growth during the subsequent period. In contrast, more frequent nursing bouts during the period in which weaning was initiated were associated with higher growth rates. In the case of being off carriers, these effects did not carry over to older ages, suggesting that any deficits in growth were temporary. In the case of earlier, more frequent consumption of solid food, there was some suggestion that there were longer-term effects, followed by catch-up growth. The knee-to-heel length of subjects was not related to the measured behaviors. There was no relation between early weaning to solid food and leanness at day 75, suggesting that, although this behavior was affecting overall weight, it did not affect relative gains of fat versus lean mass. There were, however, significant correlations between cessation of transport or frequency of nursing bouts during the weaning period and leanness, with earlier cessation of transport and less frequent nursing associated with leaner infants, after weaning. Our results differed from those of a previous study that found a relation between linear growth and abuse in this species, with abuse defined as physical injury by other members of the group. We found no differences in growth between abused and nonabused infants. However, abused infants had lower birth weight.     

Effect of starvation and refeeding on digestive enzyme activities in juvenile roach, Rutilus rutilus caspicus

We evaluated the effects of starvation and refeeding on digestive enzyme activities in juvenile roach, Rutilus rutilus caspicus. Fish were divided into four feeding groups (mean mass 1.68 ± 0.12 g). The control group was fed to satiation twice a day throughout the experiment with formulated diet (SFK). The other three groups were deprived of feed for 1(S1), 2(S2), and 3(S3) weeks, respectively, and then fed to satiation during the refeeding period. The results showed that trypsin specific activity was not affected significantly either by starvation or refeeding, in all experimental groups. Chymotrypsin specific activity did not change significantly in S1 fish during the experimental period. In S2 and S3 fish no significant changes were observed during the starvation period. Upon refeeding, the activity increased in S2 fish, while it decreased in S3 fish. Amylase specific activity decreased significantly during the starvation period in all experimental groups. Upon refeeding, the activity increased. Alkaline phosphatase specific activity did not change significantly during the experiment period in S3 fish, while it showed significant changes during the starvation and refeeding period in the S1 and S2 fish. Starvation also had a significant effect on the structure of the intestine.     

Responses of Neurons of the Extrastriate Area 21b of the Cat Brain Cortex to Changes in Orientation of Moving Visual Stimuli

We studied the responses of neurons of the extrastriate cortical area 21b of the cat to changes in orientation of the movements of visual stimuli within the receptive field (RF) of the neuron under study. Our experiments demonstrated that 24 of 108 cells (22%) responded differentially to a certain extent to orientation of the movements of visual stimuli. As a whole, neurons of the area 21b did not demonstrate fine tuning on the optimum angle of orientation. In many cases, neuronal responses to different orientations of the movement of visual stimulus depended significantly on specific parameters of this stimulus (its shape, dimensions, and contrast). Some directionally sensitive neurons responded to a change in orientation of the movement of visual stimuli by modification of the index of directionality. We also studied spatial organization of the RF of neurons with the presentation of stationary visual stimuli. Comparison of the neuronal responses to a change in orientation of the movements of stimuli and to presentation of stationary stimuli showed that the correlation between the orientation sensitivity of the neuron under study and the stationary functional organization of its RF was insignificant. We hypothesize that inhibitory processes and subthreshold influences from a space surrounding the RF play a special role in the formation of the neuronal responses generated in the associative visual cortical regions to visual stimulation.     

BIOCHEMICAL CHANGES IN THE BRAIN IN RATS POISONED WITH AN ALKYLMERCURY COMPOUND, WITH SPECIAL REFERENCE TO THE INHIBITION OF PROTEIN SYNTHESIS IN BRAIN CORTEX SLICES

The incorporation of [U-¹⁴C]leucine into the protein of brain cortex slices from rats poisoned with methylmercury thioacetamide was markedly inhibited before the development of neurological symptoms and when the oxygen consumption, aerobic and anaerobic glycolysis and sulphydryl enzyme activities were unchanged. After the appearance of neurological symptoms, the oxygen consumption decreased significantly, while lactic acid formation did not change under anaerobic conditions, but slightly decreased under aerobic conditions. The activities of the three sulphydryl enzymes (Mg-activated ATPase, fructose- diphosphate aldolase and succinate dehydrogenase) were almost the same in visual cortex, motor cortex, cerebellum and caudate nucleus, while the activities of Mg-activated ATPase and succinate dehydrogenase in the white matter were lower than that in the grey matter. There was no difference in the activity of fructosediphosphate aldolase in grey and white matter. The activities of all three enzymes did not show any change in the earlier stage of poisoning when the animal remained free from neurological symptoms. At the more advanced stage, when neurological symptoms were present, only the activity of the succinate dehydrogenase decreased significantly, while the activities of the other two enzymes remained unchanged. The selective inhibition of protein synthesis may have a direct bearing on the poisoning by the alkylmercury compound.     

Early Neurodevelopment and Self-Reported Adolescent Symptoms of Depression and Anxiety in a National Canadian Cohort Study

Objective

Little is known about the mental health outcomes of young children who experience developmental delay. The objective of this study was to assess whether delay in attaining developmental milestones was related to depressive and anxious symptoms in adolescence.

Method

The sample included 3508 Canadian children who participated in a nationally representative prospective cohort study. The person most knowledgeable about the child reported on attainment of developmental milestones spanning several developmental domains at ages 2–3. The children were followed into adolescence and self-reported depressive and anxious symptoms were used from adolescents ages 12–13. An overall assessment of developmental milestones as well as a supplementary analysis of specific categories of developmental milestones was conducted.

Results

Cohort members who displayed delayed developmental milestones in early childhood were more likely to experience higher levels of depressive and anxious symptoms as adolescents. However, there was no interaction between delayed developmental milestones and stressful life events. In the supplementary analysis, two developmental domains (self-care and speech/communication) were associated with higher levels of depressive and anxious symptoms in adolescence.

Conclusion

Delay in attainment of early developmental milestones is significantly associated with adolescent depressive and anxious symptoms.     

Developmental changes in the activity of membrane-bound gamma-glutamyl transpeptidase and in the sialylation of synaptosomal membranes from the chick embryonic brain.

gamma-Glutamyl transpeptidase (GGT) is a membrane-bound sialoglycoprotein. The developmental changes in GGT activity and in sialic acid content were determined in a crude synaptosomal membrane fraction from the cerebral hemispheres of the chick embryo between days 11 and 19 of incubation. The GGT activity increased almost eightfold during the examined developmental period, while sialic acid content rose significantly only between days 11 and 15. Cortical administered on day 13 significantly increased GGT activity. On the other hand, the content of membrane bound sialic acid was not substantially affected. The value of the GGT apparent Michaelis constant (Kmapp) for gamma-glutamyl-p-nitroanilide in the presence of 20 mmol.l-1 glycylglycine was 1.5 mmol.l-1 and cortisol did not influence it. However, Vmax was increased by this hormone. The affinity of GGT to concanavalin A (ConA) did not change during development. Neither the administration of cortisol nor neuroaminidase treatment had any effect on the interaction of GGT with ConA. Desialylation of crude synaptosomal fraction did not change GGT activity. The results presented here suggest no developmental nor functional relationship between the activity of GGT and the level of sialylation in synaptosomal membranes from the cerebral hemispheres of the chick embryo.     

Effects of parity and periconceptional metabolic state of Holstein–Friesian dams on the glucose metabolism and conformation in their newborn calves

The metabolic state of pregnant mammals influences the offspring’s development and risk of metabolic disease in postnatal life. The metabolic state in a lactating dairy cow differs immensely from that in a non-lactating heifer around the time of conception, but consequences for their calves are poorly understood. The hypothesis of this study was that differences in metabolic state between non-lactating heifers and lactating cows during early pregnancy would affect insulin-dependent glucose metabolism and development in their neonatal calves. Using a mixed linear model, concentrations of glucose, IGF-I and non-esterified fatty acids (NEFAs) were compared between 13 non-lactating heifers and 16 high-yielding dairy cows in repeated blood samples obtained during the 1st month after successful insemination. Calves born from these dams were weighed and measured at birth, and subjected to intravenous glucose and insulin challenges between 7 and 14 days of age. Eight estimators of insulin-dependent glucose metabolism were determined: glucose and insulin peak concentration, area under the curve and elimination rate after glucose challenge, glucose reduction rate after insulin challenge, and quantitative insulin sensitivity check index. Effects of dam parity and calf sex on the metabolic and developmental traits were analysed in a two-way ANOVA. Compared with heifers, cows displayed lower glucose and IGF-I and higher NEFA concentrations during the 1st month after conception. However, these differences did not affect developmental traits and glucose homeostasis in their calves: birth weight, withers height, heart girth, and responses to glucose and insulin challenges in the calves were unaffected by their dam’s parity. In conclusion, differences in the metabolic state of heifers and cows during early gestation under field conditions could not be related to their offspring’s development and glucose homeostasis.     

Kindling during early postnatal development: the effects on the maturation of the hippocampal electrophysiological characteristics

The effect of repeated pentylentetrazole (PTZ) administration on the postnatal development of hippocampal electrophysiological indices has been studied. Contrary to adult rats, repeated PTZ injections did not intensify convulsive activity in rat pups (from postnatal day 14). We did not observe any between-group differences in population spike amplitudes and paired pulse facilitation (PPF) ratio at 70 ms interpulse interval during early period of postnatal development, PPF suppression at short interlulse interval (15 ms) only was significantly less in PTZ group as compared with saline-injected controls, but the effect of saline injections has developed in the same directio However PTZ resulted in the modification of developmental profile. Besides the change of paired-pulse inhibition (15 ms), in the slices of young rats (27-48 postnatal days) the input-output curve was specifically modified and the intensity-dependent increase in population spike amplitudes was less expressed than in the slices of young control rats repeatedly subjected to saline injection, while PPF ratio of both groups was significantly decreased in a similar way, as compared with passive controls. In addition, LTP magnitude in the slices of PTZ group was also suppressed. These modifications did not correlate with convulsive activity. A significant correlation with convulsive activity was found only for population spike amplitudes evoked by low, near-threshold stimuli.     

Behavioral development of a polar bear cub (Ursus maritimus) in captivity

The difficulty of observing polar bears (Ursus maritimus) in the wild has prohibited the gathering of behavioral data necessary to develop a baseline set of milestones for monitoring cub development. This study describes and quantifies previously undocumented trends in behavior observed in a captive cub–information that will be useful both in future comparative studies and in the implementation of husbandry improvements. Nearly 400 hr of behavioral data were collected, 100 hr of which were video recordings from the maternity den during the first 3 months of life. Den videos were scored to determine activity budgets and levels of maternal contact. For the remainder of the first year, mother and cub were observed in the outdoor enclosure. The onset and relative frequency of 40 discrete cub behaviors were tracked, as were patterns of mother–cub contact, including nursing and weaning. This study revealed that environmental conditions, habitat enrichment, and conditioning procedures influenced the patterns of developmental behavior exhibited by a polar bear cub. Both climatic and developmental factors had significant effects on the time the bears spent swimming. Management practices, such as environmental enrichment, and a conditioning procedure involving separation of mother and cub caused transient changes in several tracked behaviors. As the cub aged, the longest time between consecutive maternal contacts increased. Nursing bouts recorded per hour of observation decreased, and the duration of individual nursing bouts and pre‐nurse begging periods increased. Zoo Biol 22:507–514, 2003. © 2003 Wiley‐Liss, Inc.     

The incorporation of solubilized wheat proteins in milk replacers for veal calves: effects on growth performance and muscle oxidative capacity

Replacement of skim milk proteins by solubilized wheat protein (SWP) in milk replacers for veal calves would contribute to the reduction in feeding costs. The occurrence of metabolic disorders has, however, been reported. Forty-two male calves received one of three treatments over 140 days: a control diet, a diet containing SWP without or with branched-chain amino acid supplementation. Liveweight gain, carcass yield, color and conformation did not show any significant differences. No metabolic disorders were noted. Supplementation with branched-chain amino acids reduced the marginal Val deficiency but did not modify the growth performances. With the SWP containing diets, the plasma metabolite profile was characteristic of those observed with non-clotting diets. It was statistically correlated to the changes in the orientation of the Semitendinosus muscle energy metabolism towards a more oxidative type and to indications of a lower efficiency of amino acid utilisation for protein deposition. At the present levels of inclusion, SWP proved to be an interesting alternative to the sole use of whey as the protein source in milk replacers for veal calves.