WHO 2006 child growth standards: implications for the prevalence of stunting and underweight-for-age in a birth cohort of Gabonese children in comparison to the Centers for Disease Control and Prevention 2000 growth charts and the National Center for Health Statistics 1978 growth references

OBJECTIVES: To assess the proportion of children being stunted and underweight-for-age at 3, 9 and 15 months in Lambaréné, Gabon, using the WHO child growth standards released in 2006 as compared with the Centers for Disease Control and Prevention (CDC) 2000 and the National Center for Health Statistics (NCHS) 1978 child growth charts/references. DESIGN AND SETTING: Prospective birth cohort in Lambaréné, Gabon. SUBJECTS: Two hundred and eighty-nine children from birth to 15 months of age. METHODS: Weight and length were recorded at 3, 9 and 15 months. Corresponding Z scores for stunting and underweight-for-age were calculated for the three different standards/references. Children with a height-for-age or weight-for-age below -2 SD of the corresponding reference median (Z score < or = -2) were classified as stunted or underweight-for-age, respectively. RESULTS: With the new WHO 2006 standards a higher proportion (4.0%) of 3-month-old infants were underweight compared with the CDC (1.0%) or the NCHS (0.7%) child growth charts/references. In contrast to the NCHS references or the CDC charts, this proportion did not increase from 3 to 9 months or from 9 to 15 months. The proportion of children being stunted was highest (above 20%) with the WHO 2006 standards at all three ages. Again, in contrast to the old standards, this proportion did not increase from 3 to 9 months or from 9 to 15 months. CONCLUSIONS: The present results show considerably different growth faltering patterns for Gabonese children depending on the growth charts used to assess the prevalence of stunting and underweight. Shifting to the new WHO child growth standards may have important implications for child health programmes.     

Influence of abomasal infusion of high levels of lysine or methionine, or both, on ruminal fermentation, eating behavior, and performance of lactating dairy cows

Four multiparous late-lactation Holstein cows were fed a basal ration designed to be co-limiting in intestinally absorbable supplies of methionine and lysine. Cows were supplemented with no amino acids, lysine by abomasal infusion to 140% of the calculated intestinally absorbable requirement, methionine by abomasal infusion to 140% of requirement, or both amino acids in a 4 x 4 Latin square design with 28-d periods. Unsupplemented cows consumed 23.8 kg/d of dry matter and produced 36.9 kg/d of milk containing 3.70% fat, 3.22% protein, and 4.82% lactose. Cows ate less dry matter and produced less milk and milk lactose, and tended (P = .06 or .08) to produce less milk protein when abomasally infused with methionine alone or together with lysine. Infusion of lysine alone resulted in production values numerically between those of unsupplemented cows and those cows supplemented with methionine alone or together with lysine. Evaluation of the results with two metabolic models of dairy cows indicated that performance of unsupplemented cows may have been limited by delivery of metabolizable or digestible protein, or intestinally absorbable lysine, isoleucine, or histidine, depending on the metabolic model used to evaluate animal performance. Regardless, results are consistent with those using nonruminant species, which have shown that imbalanced profiles of intestinally absorbable amino acids are associated with reduced dry matter intake and animal performance. Results also show that negative effects on performance of lactating dairy cows can occur if methionine is supplied at levels substantially in excess of calculated intestinally absorbable requirements, either alone or together with lysine.     

Reducing phosphorus concentration in pig diets by adding an environmental objective to the traditional feed formulation algorithm

A multi-objective optimization method based on the traditional least-cost formulation program was developed to reduce both feed cost and total phosphorus (P) content in pig feeds. The objective function of the proposed method comprises a traditional economic term and a term that assigns a cost (β) to the excess and unavailable P (EUP) in the diet, the latter estimated by the difference between P requirements and available P supplied by the diet. To evaluate this method, feeds for growing (20–65 kg live weight) and finishing pigs (65–105 kg) formulated with two balanced protein levels (90 and 130 g/kg) and two available phosphorus levels (3.2 and 2.6 g/kg) were evaluated in two economic contexts (France and Quebec) over a 12-month period (June 2002–May 2003). Microbial phytase was added to the feeds at rates of 0, 250, 500 and 750 phytase units. All feed formulas contained the required available P and other nutrients. The increase in β reduced the total P and EUP in feed formulas. During the period studied, EUP decreased by 5% or more for an increase in feed cost of about 1.5% in France and 1% in Quebec. For some months however, the economically optimal solution was close to a solution that produces substantially less EUP at slightly higher cost. For example, in nearly half of the months, a reduction of 10% or more was achieved in Quebec for the same 1% increase in ingredient cost. The reduction in EUP with increasing β occurred independently of the addition of microbial phytase. The combined effect of microbial phytase incorporation and the proposed feed formulation method on EUP reduction is almost additive. Thus, the combined use of these two techniques can promote the sustainability of the swine industry by contributing to the reduction of P excretion in swine operations with small increases in feeding cost. The proposed method can be applied to minerals other than P or to other livestock production systems in which mineral excretion can be estimated from feed composition.     

Production of micro-cuttings from acorns to test the plasticity of response to contrasting soil water regimes

We collected acorns from selected Quercus robur and Quercus petraea mother trees growing at stations with different depths to the water table. We produced pairs of micro-cuttings from these single acorns. The obtained pairs of cuttings represented phenotypes of high similarity according to photosynthetic parameters. These pairs of cuttings were used to test the plasticity of response to contrasting water regimes. For each pair, one cutting was submitted to drought and the other was submitted to waterlogging. Drought response was recorded according to gas exchange traits (stomatal closure and water use efficiency). The response to waterlogging was recorded according to the capacity to form hypertrophied lenticels and to maintain the CO₂ assimilation rate. Intermediary phenotypes presenting both high water use efficiency and the capacity to develop hypertrophied lenticels were expected.     

Can the impact of deer browsing on tree regeneration be mitigated by shelterwood cutting and strip clearcutting?

Silvicultural treatments creating large canopy openings failed to restore regeneration of balsam fir (Abies balsamea (L.) Mill.) due to browsing pressure from white-tailed deer (Odocoileus virginianus Zimmermann). Consequently, we tested two alternative silvicultural treatments aimed at improving balsam fir establishment on Anticosti Island (Québec, Canada). In 1998 and 1999, we set up shelterwood seed cutting using three harvest intensities (0, 25 and 40% of basal area) and strip clearcutting with scarification using three different strip widths (15, 30 and 45 m), both with fenced and unfenced regeneration plots, in balsam fir stands. After 8 years, shelterwood seed cutting did not allow the establishment of new balsam fir seedlings, nor the development of unbrowsed balsam fir seedlings. In the strip clearcutting, deer browsing suppressed growth of palatable species in all strip widths. This favoured the development of unpalatable species, especially white spruce (Picea glauca (Moench) Voss). Our study demonstrates that the use of silvicultural treatments alone is unlikely to restore balsam fir regeneration on Anticosti Island, as long as the deer population remains higher than 20 deer/km².