We read with interest the enlightening article by Romieu et al. (1) on breastfeeding in relation to risk of breast cancer among women in Mexico City. The widespread practice of long-duration lactation has given these researchers the ability to address questions that could not be easily answered using data from most industrialized countries. We were, however, puzzled by a few points made in the ...

The presence of pesticides in human milk (HM) is of great concern due to the potential health effects for the breastfed infant. To determine the relationships between HM pesticides and infant growth and development, a longitudinal study was conducted. HM samples (n = 99) from 16 mothers were collected at 2, 5, 9 and 12 months of lactation. A validated QuEChERS method and Gas chromatography-tand...

Lactation means of somatic cell scores from sample days were used to estimate the components of variation for additive genetic, permanent environmental, and herd-sire interaction effects. Data included records of 4314 Ayrshire, 7845 Brown Swiss, 18,115 Guernsey, 1,135,752 Holstein, 67,862 Jersey, and 787 Milking Shorthorn cows from across the US. Records were preadjusted for length of lactation...

1. In mammals, nutrient allocation during lactation is a critical component of maternal care as milk intake promotes juvenile growth and survival, and hence maternal and offspring fitness. 2. Milk composition varies widely across mammals and is hypothesized to have arisen via selection pressures associated with environment, diet and life history. These hypotheses have been proposed based on obs...

Early lactation parameters are difficult to estimate from commercial dairy records due to the small number of records available before the peak of production. A biological model of lactation was used with weekly milk records from a single Holstein herd to estimate these early lactation parameters and the secretion rate of milk from the average cell throughout lactation. A genetic analysis of th...

The objective of this study is to quantify the milk production response per cow and per hectare (ha) for an incremental stocking rate (SR) change, based on a meta-analysis of published research papers. Suitable experiments for inclusion in the database required a comparison of at least two SRs under the same experimental conditions in addition to details on experimental length and milk producti...

The objective of this study was to investigate the association of polymorphisms at the STAT5A and FGF2 gene loci with fertility, lactation milk yield and lameness in dairy cattle. Five hundred and eighteen primiparous Holstein cows were included in the study. Several reproductive traits were considered including conception rate (0/1) at first insemination, conception rate (0/1) in a 305-day lac...

The morphometric, productive and reproductive traits of indigenous cattle at Sylhet district were studied. A wide variety of coat colours among the cattle of the selected areas was observed. Most of them were of roan colour. The body is small, compact and less fleshy. Wither height and hearth girth were 89.03±11.11 and 112.09±16.68 cm, respectively. The average body length was 119.85±16.96 cm a...

Early-life adversity can affect health, survival and fitness later in life, and recent evidence suggests that telomere attrition may link early conditions with their delayed consequences. Here, we investigate the link between early-life competition and telomere length in wild meerkats. Our results show that, when multiple females breed concurrently, increases in the number of pups in the group ...

test day records of first lactation holstein cows from 1996 to 2008 were obtained from animal breeding center of iran and used in this research. data consisted of 872125 test-day milk records of 95816 cows from 59 herds. (co)variance components and genetic parameters were estimated using random regression model via gibbs sampling method. two order legendre polynomials and third coefficient of w...