Age-related body weight constraints on prenatal and milk provisioning in Iberian red deer (Cervus elaphus hispanicus) affect allocation of maternal resources

Maternal phenotypic characteristics can influence key life history variables of their offspring through maternal effects. In this study, we examined how body size constraints on maternal weight in yearling and subadult compared to adult hinds (age class effects) affected prenatal (calf birth weight, calf to hind weight ratio) and postnatal (milk) provisioning of Iberian red deer calves. Age correlated with all prenatal and postnatal investment traits except calf gains, although correlations were weaker than those with maternal weight. Once the effect of linear increase in weight with age was removed from models, yearlings showed additional reductions in calf birth weight, calf gains, and milk provisioning. The low-calf birth weight might increase the risk of calf mortality during lactation, as this occurs primarily during the first day of life and is strongly related to birth weight. Yearlings showed a greater prenatal allocation of resources in terms of greater calf to hind weight ratio probably as an extra effort by yearling mothers to balance calf neonatal mortality. It might compensate young mothers to produce low-quality calves while still growing rather than waiting for the uncertain possibility of surviving to the next reproductive season.     

Effect of supplemental dietary biotin on performance of lactating ewes

Seventy-two lactating Chios ewes were used in two experiments to determine effects of supplemental dietary biotin on productivity and milk composition. The first experiment started after weaning on day 42 postpartum, and lasted 20 weeks, while the second started on week 24 postpartum and lasted 12 weeks. In both experiments, ewes were allocated, after equal distribution relative to milk yield, body weight, time of lambing, and lactation number (i.e., two or three), into three groups of 24 ewes each, and were accommodated in three floor pens/groups of eight ewes/treatment. Ewes were fed one of three diets varying in supplemental biotin (BIOTIN0, no supplemental biotin; BIOTIN3, 3 mg supplemental biotin/ewe/day; BIOTIN5, 5 mg supplemental biotin/ewe/day) in each experiment. Milk, fat, protein, lactose and ash yield, and milk fat content increased linearly (P<0.012) with increased dietary biotin in both studies. Dietary biotin supplementation improved the productive performance of these lactating ewes at both an early and late stage of lactation.     

Daily milk intake and body water turnover in suckling mink (Mustela vison) kits

Daily (24 h) milk intake and body water turnover were measured in eight litters of suckling mink (Mustela vison) kits (6–9 kits litter⁻¹) during weeks 1–4 post partum using the tritiated water (³HHO) dilution technique. The biological half-life of body water turnover in the mink kits increased linearly from 0.9 days in week 1 (3–5 days post partum) to 1.9 days in week 4 (22–24 days post partum). The daily milk intake varied markedly among the mink kits within a litter and increased significantly with increasing body mass from (mean±SEM) 10.9±0.4 g per kit during week 1 to 27.7±1.0 g per kit during week 4. Throughout the study, male kits were ∼10% heavier and had a significantly higher milk intake than female kits. The results were corrected for water recycling between the dam and her kits, ranging from ∼4 to 15% of the daily milk water intake, and the calculated daily milk yield of the 2 year old lactating mink dams increased from 87±7 g day⁻¹ in week 1 to 190±15 g day⁻¹ in week 4 post partum. The average body growth rate of the mink kits ranged from 2.9 g kit⁻¹ per day in week 1 to 5.4 g kit⁻¹ per day in week 4, and the calculated mean intake of mink milk per unit of body weight gain was remarkably stable at 4.0 (g g⁻¹) during weeks 1–3 post partum, but increased to 5.6 (g g⁻¹) in week 4 post partum. The amount of metabolizable energy supplied to the kits by the daily milk yield of the dam increased from ≈450 to ≈990 kJ day⁻¹, which corresponded well with the calculated daily energy requirements of the kits. The tritiated water dilution technique was found feasible and reliable for repeated measurements of milk intake in suckling mink kits up to 4 weeks of age.     

Impact of three THI levels on somatic cell count,milk yield and composition of multiparous Holstein cows in a subtropical region

In Egypt, cow's milk represents 52.11% of the total milk production. Climatic condition is mainly expected to impact the welfare and productive performance of livestock animals. Thus, we aimed to explore the impact of temperature-humidity index (THI) on somatic cell count (SCC), milk production and composition on daily milk test records (33600) of Holstein cows under subtropical Egyptian conditions with different levels of THI. Our results revealed that daily milk yield and composition (fat%, protein %, yielded fat, yielded protein and the percentage of lactose) were higher in low THI (31.91 kg, 3.91%, 3.22%, 418 kg, 349 kg and 4.20%, respectively) when compared with high THI. SCC significantly increased 36% from low to high THI. In addition to, it was increased with advanced parities 231.11% from 2nd to 7th parities. At high THI level, SCC was negatively correlated with total MY (r=−0.12 P<0.05), 305 MY (r=−0.16 P<0.05), protein % (r=−0.15 P<0.01), fat% (r=−0.14 P<0.01) and lactose % (r=−0.26 P<0.01). The current study concluded that dairy cows performance was better in most of the investigated parameters at low THI than those in high THI. Thus, indicating a detrimental effect of THI on both welfare and economic return.     

Effect of individual characteristics on a mathematical model of human thermoregulation

A multi-segmental mathematical model of human thermoregulation was tested for its capability to predict individualized physiological responses. We compared the model predictions obtained for an average person with measured individual responses of subjects exposed to mild cold. Secondly, body composition (BC) data, the resting metabolic rate (MR), and the actual measured MR during the test were used as input into the model.

The data was obtained from 20 subjects (age: 19–36 years; BMI: 17–32 kg/m²). BC, MR, rectal and skin temperatures were measured for 1 h at 22 °C, followed by 3 h at 15 °C.

A mean bias of 1.8 °C, with a standard error of 0.7 °C, resulted for the mean skin temperature of an average person at 15 °C. When subjective BC and measured MR were incorporated the bias was −0.2±0.9 °C. For the hand-back skin temperature the bias ± standard error fell from 5.3±2.8 °C for an average person to 2.0±2.5 °C, when using individualized characteristics. Trunk skin temperatures were not significantly affected by the adjustments.

In conclusion, this study shows that on a group level predictions of skin temperatures can be improved when adopting individualized body characteristics and measured MR, but the predictions on an individual level were not improved.     

Relationship of body composition to somatotype.

The purpose of this study is to determine the relationship in college-aged women between somatotype using both Sheldon's ('69) and Heath and Carter's ('67) procedures, and body composition, as measured by whole-body 40K counting and body density. Sheldon's endomorphy is closely associated with height and weight; Heath and Carter's first component is significantly related to weight and body fatness. Lean body mass (LBM) as a weight or as a percent is not closely related to Sheldon's mesomorphy or Heath and Carter's second component. However, when LBM and height are used as independent variables to estimate somatotype, both variables are significantly related to Heath and Carter's second component, accounting for 61% of the variance. Thus Heath and Carter's second component is significantly associated with LBM for a given body height. Most of the variation in Sheldon's ectomorphy and Heath and Carter's third component can be accounted for by weight and height. Sheldon's somatotype for all three components is not as closely related to body composition as Heath-Carter's. Body composition, as measured by either 40K counting or body density, is found to be important in accounting for variation in Heath and Carter's first and second components.     

Ultrasonic measurements of subcutaneous adipose tissue thickness in man

Subcutaneous adipose tissue thickness (SCATT) has for many years been measured using skinfold calipers, but calipers have several disadvantages, not least that they compress the skinfold. Measuring SCATT using ultrasound was validated by comparing thicknesses at 12 sites with soft-tissue radiographs in 24 adults and with depth gauge measurements on a cadaver. Correlation coefficients ranged from 0.87 to 0.99, and the regression statistics showed no significant difference between ultrasound and the other procedures. The standard errors of estimate of body density from SCATT measured by calipers and ultrasound in 63 young men was +/- 7.8 and 7.3 kg X m-3, respectively. Although problems in the identification of the adipose tissue-muscle interface can arise, ultrasound is a viable alternative to skinfold calipers and is to be preferred when measuring uncompressed SCATT.     

Gastric gas and fluid emptying assessed by magnetic resonance imaging

Magnetic resonance imaging (MRI) was used to characterize the volumes and rates of gastric emptying of both liquid and gas following the ingestion of beverages of varying carbonation and carbohydrate levels. Eight subjects drank 800 ml each of four test beverages in a counterbalanced order: water, a non-carbonated carbohydrate-electrolyte solution (NC), a lightly carbonated carbohydrate-electrolyte solution (PC), and a carbonated cola (CC). T2-weighted, echoplanar images (25-30 contiguous slices, 1 cm thick, 256 x 128 matrix, TE = 80, 40 cm FOV) of the abdomen were collected at minutes 3,110, 20, 30, 45, and 60 following beverage ingestion. Images were analyzed for gas and liquid volumes. Water and NC emptied the most rapidly, with half times of 21(3) and 31(3) min, respectively [mean (SE)]. PC emptied significantly slower [47 (6) min] and CC slower yet [107 (8) min]. The carbonation content of the beverage accounted for 84% of the variation in emptying time, whereas carbohydrate content did not account for any significant variation. The gastric gas volume of the CC was higher at 2 min post-ingestion compared with all other drinks; however, the rate of emptying of the gas was the same among all beverages. Significantly greater total gastric volumes (gas+ liquid) were associated with the ingestion of CC, and accordingly produced a greater severity of gastric distress, as evaluated with a gastric distress inventory. The high gastric gas volumes (approximately 600 ml) after ingestion of CC suggested a potential source of error in body composition using standard hydrostatic weighing methods. This prediction was tested in nine additional subjects. Ingestion of 800 ml of CC prior to hydrostatic weighing resulted in a 0.7% underestimate of body density and thus an 11% overestimate of percentage body fat compared to measurements made before beverage consumption.     

Estimation of body composition from bioelectrical impedance of body segments

This study provides values of anthropometric measurements and specific impedance, for a sample of 104 adults. The hypothesis that the body composition can be estimated more accurately from measurements of lengths and impedance values of the body segments than from the whole body was tested. The impedance of upper and lower extremities (arm and leg) and trunk were used to compute estimates of body composition parameters (FFM, FM, %F, TBW, ECW). The results were compared with those estimated by the impedance of the whole body. These comparisons demonstrated that significative differences resulted from body composition obtained by segmental impedance and by the whole body.     

Growth status, age, and grade as predictors of school continuation for Guatemalan Indian children

Schooling is considered by many researchers and agencies as an important contributor to individual and national development for populations living in the less developed countries. Accordingly, programs to increase school enrollment and continuation from grade to grade are being developed for many of these countries. This paper investigates the relationship of physical growth status (height, weight, and body composition), grade in school, and age to school continuation for a sample of Indian children living in a village near Guatemala City. It was found that physical growth status, a reflection of health and nutritional status, does not predict school continuation. A child's age and current grade in school do predict continuation. Most children leave school after reaching 9 years of age or after completing the second grade. It is suggested that children may learn enough to satisfy their parents' expectations by this age or grade. Also, the child's economic value to his or her family may be a significant reason for school drop-out.     

Short and plump physique of Mexican-American children

Mexican-American children are shorter but relatively heavier than non-Hispanic whites and blacks. The objectives of this paper are to assess the extent to which this "short and plump" physique occurs in data collected in two national surveys (HANES I and II); to determine variations by age, sex, and socioeconomic status; and to investigate the anthropometric characteristics that may account for the overweight. Three groups, defined on the basis of reported ancestry and observed race, are studied: Mexican-Americans (MEXAME), non-Hispanic Whites, (EURAME), and blacks (BLACK). Short stature was clearly associated with the poverty index (PI) in all three groups. MEXAMEs with a PI greater than 1.6 were similar in stature to EURAMEs at the same income level at ages 1-11 years but not at 12-17 years. On the other hand, MEXAMEs were shorter than BLACKs at all ages and income levels. The body mass index (kg/cm2) and poverty were unrelated. With respect to the anthropometric characteristics examined that are related to the body mass index, MEXAMEs and EURAMEs were similar in sitting height as a proportion of total height, arm muscle and fat areas, and triceps skinfold but different in the following ways: MEXAMEs had narrower elbow but broader bitrochanteric breadths and larger chest circumferences and subscapular skinfolds. Greater upper body dimensions and fatfolds seem to best describe the physique of MEXAMEs. However, in multiple regressions, these anthropometric characteristics failed to account fully for the greater relative weight of MEXAMEs as compared to EURAMEs.     

Effects of evaporative cooling on the regulation of body water and milk production in crossbred Holstein cattle in a tropical environment

The aim of this study was to determine how evaporative cooling modifies body function with respect to water metabolism and other variables relevant to milk synthesis in crossbred cattle. The study was conducted on two groups of 0.875HF:0.125RS crossbred Holstein cattle (87.5%) housed in an open-sided barn with a tiled roof (non-cooled animals) and in a close-sided barn under an evaporative cooling system (cooled animals). The maximum ambient temperature and relative humidity for the non-cooled group were 33 degrees C and 61%, with the corresponding values for the evaporatively cooled barn being 28 degrees C and 84%, respectively. The temperature humidity index (THI) of under non-cooled conditions was higher (P < 0.05) than that in the cooled barn. Rectal temperatures and respiration rates of non-cooled animals were higher (P < 0.05) than those of cooled animals. Daily dry matter intake (DMI) of cooled animals was higher while water intakes were lower (P < 0.05) than those of non-cooled animals. The mean absolute values of plasma volume, blood volume, and extracellular fluid (ECF) of cooled animals were significantly higher (P < 0.05) than those of non-cooled animals throughout all stages of lactation. Milk yields of cooled animals were higher by 42%, 36% and 79% on average than those of non-cooled animals during early-, mid- and late-lactation, respectively. The decline in milk yields as lactation advances was markedly apparent in late-lactating non-cooled animals, while no significant changes in milk composition at different stages of lactation were observed in either group. Mean arterial plasma concentrations, arteriovenous concentration differences (A-V differences) and the extraction ratio across the mammary gland for acetate, glucose and triglyceride of cooled animals were not significantly different compared with values for non-cooled animals. No differences were seen in plasma hormonal levels for triiodotyronine (T(3)) and insulin-like growth factor-1 (IGF-1), but plasma cortisol and thyroxine (T(4)) levels tended to be lower in non-cooled animals. This study suggests that low cooling temperature accompanied by high humidity influences a galactopoietic effect, in part through increases in ECF, blood volume and plasma volume in association with an increase in DMI, which partitions the distribution of nutrients to the mammary gland for milk synthesis. Cooled animals were unable to maintain high milk yield as lactation advances even though a high level of body fluids was maintained during long-term cooled exposure. The decline in milk yield, coinciding with a decrease in net energy for lactation as lactation advances, could be attributed to a local change within the mammary gland.     

Milk composition and lactational output in the greater spear-nosed bat, Phyllostomus hastatus

Growth rates of mammalian young are closely linked to the ability of the mother to provide nutrients; thus, milk composition and yield provide a direct measure of maternal investment during lactation in many mammals. We studied changes in milk composition and output throughout lactation in a free-ranging population of the omnivorous bat, Phyllostomus hastatus. Fat and dry matter of milk increased from 9 to 21% and from 21 to 35% of wet mass, respectively, throughout lactation. Energy increased from 6 to 9 kJ · g⁻¹ wet mass, primarily due to the increase in fat concentration. Total sugar levels decreased slightly but non-significantly. Mean sugar level was 4.0% of wet mass. Protein concentration increased from 6 to 11% of wet mass at peak lactation and then decreased as pups approached weaning age. Total milk energy output until pups began to forage was 3609 kJ. Milk levels of Mg, Fe, Ca, K, and Na averaged 0.55 ± 0.26, 0.23 ± 0.2, 8.75 ± 4.17, 5.42 ± 2.11, and 9.87 ± 4.3 mg · g⁻¹ dry matter, respectively. Of the minerals studied, calcium appears to be most limiting in this species. The high degree of variability in foraging time, milk composition and milk yield between individuals at the same stage of lactation could potentially yield high variance in reproductive success among females of this polygynous species. Accepted: 23 January 1997     

Effects of two levels of monoterpene blend on rumen fermentation, terpene and nutrient flows in the duodenum and milk production in dairy goats

Twenty-six Alpine and Saanen goats, 12 fitted with a rumen cannula and a T-type cannula in the duodenum, were used in a 6-week experiment on the effect of a monoterpene blend on rumen fermentation, duodenal terpene and nutrient flows, milk yield and composition. The monoterpene blend consisted of 45.2, 36.7, 16.0 and 2.2 mol/100 mol terpene for linalool, p-cymene, α-pinene and β-pinene, respectively. The four compounds were considered as good models of northwest Mediterranean sward terpenes and were supplied in the same proportions as in the spring diet of dairy goats in the Basilicata (Southern Apennine range, Italy). The goats were assigned to three experimental groups fed a total mixed ration with no terpene or with the monoterpene blend at two levels, 0.043 and 0.43 g/kg dry matter intake. Ruminal fermentation characteristics remained unchanged among groups. In average, the total volatile fatty acids (VFA) concentration was 89.0 mM and the proportions of acetate, propionate and butyrate were 66.4, 21.1 and 10.1 mol/100 mol VFA, with an acetate:propionate ratio of 3.19. In average, 0.0, 2.7, 3.5 and 23.5 mol/100 mol of the ingested amounts of linalool, α-pinene, p-cymene and β-pinene were recovered in the duodenum. The mean terpene composition of duodenal digesta was 11.7, 9.2 and 79.1 mol/100 mol terpene for p-cymene, α-pinene and β-pinene, differing markedly from the dietary blend in both supplemented groups. Apparent rumen digestibility of dry matter (0.40), of neutral detergent fibre (0.54), and of acid detergent fibre (0.45) was not affected by either level of terpene supplementation. Dry matter intake and milk production, milk fat content or milk fatty acid profile were not affected by terpenes. It is concluded that, because of extensive ruminal degradation of each terpene, the monoterpene blend had no effect on ruminal digestion of dietary constituents or on milk performance whatever the supplementation level.