Low Relative Weight Gain Research Articles

Association between severe retinopathy of prematurity and postnatal weight gain in very low-birthweight infants at Chiang Mai University Hospital, Thailand

ABSTRACTBackground: Poor postnatal weight gain has been associated with low serum IGF-1, a key factor in the pathogenesis of retinopathy of prematurity (ROP).Aim: To investigate an association between relative weight gain (RWG) and severe ROP in very low-birthweight (VLBW) Thai infants.Methods: The medical records of VLBW infants who were admitted to the neonatal intensive care unit in Chiang Mai University Hospital from June 2014 to December 2016 and screened for ROP were reviewed. RWG and total calorie intake (TCI) in the 2nd, 4rth and 6th week of age were calculated and those with no ROP/mild ROP and severe ROP requiring laser treatment were compared.Results: The study included 139 VLBW infants, 24 (17.3%) of whom had ROP requiring laser treatment. Infants with severe ROP requiring laser treatment had a lower median birthweight (840 vs 1,195 g, p < 0.001) and median gestational age (GA) (27 vs 30 wk, p < 0.001) than those with no ROP/mild ROP. When RWG and TCI were compared, the infants with severe ROP requiring laser treatment had a lower RWG at the 2nd (p < 0.01) and 4th weeks of age (p < 0.05) and had a lower TCI at the 2nd week of age (p < 0.001) than those with no ROP/mild ROP. Multivariate logistic analysis demonstrated that GA <29.5 w (p < 0.01), hypotension (p < 0.05), RWG <2.9 g/kg/d (p < 0.05) and TCI <98.5 kcal/kg/day (p < 0.001) at the 2nd week of age were independent risk factors for severe ROP requiring laser treatment.Conclusions: Poor weight gain and low calorie intake at the 2nd week of age were associated with severe ROP requiring laser treatment in VLBW infants. Monitoring weight gain and calorie intake during this period are essential and may improve the outcome of ROP.Abbreviations: BPD, bronchopulmonary dysplasia; IVH, intraventricular haemorrhage; NEC, necrotising enterocolitis; PDA, patent ductus arteriosus; PRC, packed red cells; PVL, periventricular leucomalacia; RDS, respiratory distress syndrome; ROP, retinopathy of prematurity; RWG, relative weight gain; SGA, small for gestational age; TCI, total calorie intake; VLBW, very low birthweight.

Birth weight and blood pressure: 'J' shape or linear shape? Findings from a cross-sectional study in Hong Kong Chinese women.

ObjectivesTo investigate the association between birth weight and blood pressure (BP) and to determine the effect of body size change from birth to adulthood on BP.DesignA cross-sectional design to collect retrospective data.Participants1253 female nurses aged 35–65 years in Hong Kong.Main outcome measuresBirth weight, height, weight, BP, waist circumference, demographics and lifestyle factors were collected by a self-administered questionnaire through mail survey. These self-reported variables have been validated in a pilot study. The conditional relative weight (CRW), which was calculated as a residual of current weight regressed on birth weight, was used to express higher or lower relative weight gain from birth to adulthood.ResultsNo significant linear association between overall range of birth weight and BP was found. The curve estimation showed a significant quadratic curvilinear association (‘J’ shape). In the piecewise-linear analysis, a significant inverse association between birth weight z-scores and BP was observed in the birth weight ≤3.1 kg group (systolic BP (SBP): coefficient B=−1.73, 95% CI −3.17 to −0.30; diastolic BP (DBP): B=−1.12, 95% CI −2.19 to −0.06). A positive but non-significant association occurred in the birth weight >3.1 kg group. Participants who belonged to the lowest 10% birth weight category but at the current top 10% BMI group had higher BP than participants in other BMI groups. The CRW z-score was positively associated with BP (coefficient B: 4.18 for SBP and 2.87 for DBP).ConclusionsUnlike most previous studies, we found a ‘J’ shape association rather than a linear association between birth weight and BP. Women with large percentile crossing of body size from birth to adulthood were more likely to have elevated BP. A higher weight gain from birth to adulthood than expected led to higher BP.

Divergent selection for shape of growth curve in Japanese quail. 7. Effect of egg storage at high temperature on embryo development and hatchability

1. Hatching time, hatchability of fertile eggs and embryo mortality in relation to (1) physical quality of fresh eggs and (2) embryonic development during storage and incubation periods were analysed after egg storage for 1, 5 or 10 d at 30°C in the meat-type lines of Japanese quail, HG and LG, divergently selected for high and low relative weight gain between 11 and 28 d of age, respectively, and constant body weight at 49 d of age.2. In both lines, the increase of egg storage temperature from 12°C (standard level) to 30°C increased the egg weight loss during storage, shortened the incubation period and reduced the hatching success.3. Similar to standard egg storage temperature, LG quail hatched earlier than HG quail after egg storage at 30°C and early and late mortality of both lines increased with a prolonged period of egg storage. In contrast to the standard egg storage conditions, no line differences in hatchability were observed.4. The results did not identify a relationship between the decrease in hatchability or embryo viability and line differences in external egg parameters as well as any important role of undesirable changes induced by a high storage temperature on albumen viscosity.5. The pattern of embryonic death, low developmental rate of embryos and a dichotomy between the development of the extra-embryonic vascular system and the embryo itself during egg storage at high temperature implied that an insufficient nutrient supply in consequence of developmental delay could represent a key factor in increasing early and late embryo mortality.

Divergent selection for shape of growth curve in Japanese quail. 3. Onset of sexual maturity and basic characteristics of early lay

1. The onset of lay, quality of eggs during early lay and gonadal development of both sexes were analysed in meat-type lines of Japanese quail, HG and LG divergently selected for high and low relative weight gain between 11 and 28 d of age, respectively, and constant body weight (BW) at 49 d of age. 2. The LG line was sexually mature at an earlier age and lower BW than the HG line. This corresponded with the trend during embryonic and early postnatal development. 3. Analysis of gonads also confirmed earlier sexual development in the LG than in the HG line. In both lines, the growth of testes was detected about one week earlier than the growth of ovary. 4. Despite the different age and BW at onset of lay, HG and LG quail commenced lay at the same degree of maturity (about 90% of adult BW). This implied that the onset of sexual maturity could be identified as a point on the growth curve which terminates the linear phase. 5. When compared with the LG line, the HG line was characterised by a longer acceleration and shorter retardation phase of the growth curve. This difference is seen as an important determinant of line differences in growth and reproductive performance.

Divergent selection for shape of growth curve in Japanese quail. 1. Responses in growth parameters and food conversion

1. HG and LG quail lines selected for high and low relative weight gain between 11 and 28 d of age (RG 11–28 ), respectively, and an unselected C line were compared. Mature body weight of both selected lines was held at that of the C line. Progeny of generation 6 were used for analysis. 2. Divergent selection for RG 11–28 brought about opposite changes in the growth rates shortly after hatching. 3. Parameters of the Richards function were used to describe the growth curve. The largest differences between HG and LG lines occurred in age ( t + ) and body weight ( y + ) at the inflection point of the growth curve (on average for both sexes 28% and 20%, respectively). For HG quail, the parameter t + was 5 d later than that for LG quail (18.6 vs 14.1 d for males and 20.6 vs 15.6 d for females, respectively), and consequently the parameter y + was greater (90.3 vs 84.0 g for males and 104.5 vs 96.1 g for females, respectively). The shape of the growth curve expressed by the y + / A ratio was substantialy different for HG and LG quail (44.8% vs 39.6% for males and 43.5% vs 36.8% for females, respectively. 4. The food/gain ratios for the fattening period (3 to 35 d of age) were 3.21, 3.47 and 3.34 for the HG, LG and C lines, respectively. The HG quail started to utilise food more efficiently than the LG quail as early as 10 to 14 d, that is, at the age when their relative growth rate first became greater. 5. The relative deviations of the HG and LG lines from the C line are discussed.

Behaviour and weight changes at weaning and regrouping of pigs in relation to teat quality

One hundred and one individually marked healthy piglets in 10 litters were followed from birth to 9 weeks of age in order to elucidate the relationships between weight changes and behaviour at weaning and regrouping. The piglets were weighed once a week and additionally at extra instances just before and after weaning and regrouping. The pigs were weaned by removal of the mother 6 weeks post-partum and the litters were mixed two by two, 7 days later, so that the pigs with weight rank 1, 3, 5 etc. in one litter were mixed with the corresponding pigs of the other litter. The behaviour of the pigs was recorded on video during 24 h before and after weaning and regrouping, and at 9 weeks of age (before moving to the fattening unit) by obtaining 20 s of continuous recording every fifth minute. Both weaning and regrouping markedly increased the frequencies of eating, drinking, aggression and submission, although the latter was only substantially increased by regrouping. Piglets having had the largest weight gain between 3 and 4 weeks post-partum (indicating good teat quality) ate less solids on all observations, except just before moving to the fattening unit, and drank less water before weaning. The same piglets had a lower relative weight gain at regrouping than their litter mates. During weaning, those pigs gaining more weight than their litter mates were more submissive, but there was no effect on aggression. When the pigs were regrouped, the pigs gaining more weight than their pen mates were more aggressive and those gaining less weight were more submissive. Aggression and submission were not observed in all pigs. During regrouping, those pigs showing submission were those that had used more productive teats that those that performed both aggressive and submissive behaviour. Pigs that showed aggression at regrouping were heavier than their pen mates and had a higher weight gain. In general, we conclude that the teat quality determines the nutritional change of the piglet at weaning, and also the degree of agonistic interactions at weaning and subsequent regrouping.

A COMPARISON OF THE EFFECT OF INCREASING DIETARY CONCENTRATIONS OF WHEAT ERGOT ON THE PERFORMANCE OF LEGHORN AND BROILER CHICKS

The effects of increasing concentrations of dietary wheat ergot (0.308% total alkaloids) on the performance of growing male Single Comb White Leghorn and commercial broiler chicks was studied in two experiments. As the concentration of ergot increased from 1 to 8% in the diet, there was a progressive decrease in the performance of both strains of chicks relative to birds given the control diets that contained no ergot. The broiler chicks were slightly more sensitive than the Leghorn chicks to the effects of ergot. In general, however, after 3 and 4 wk of exposure, birds which consumed 1% dietary ergot had an approximately 10% lower relative weight gain than the control birds, whereas those exposed to 8% ergot had an 80% lower relative weight gain. During the first 2 wk of both experiments, there was a progressive decrease in relative weight gain in all dietary ergot concentrations, with the exception of the 1% ergot diet. After 2 wk, feed consumption and weight gain of birds consuming the intermediate concentrations of ergot (2–5%) stabilized or tended to increase slightly relative to the controls. Mortality was low on diets containing up to 3% dietary ergot but above this concentration there was a dramatic and progressive increase in deaths with increasing ergot concentrations. Key words: Ergot, Leghorn, broiler, chick, feed consumption, growth, short-term exposure