Short communication: Correlation of methane production, intensity, and yield with residual feed intake throughout lactation in Holstein cows

The environmental impact of dairy production can be reduced in several ways, including increasing feed efficiency and reducing methane (CH4) emissions. There is no consensus on their relationship. This study aimed at estimating the correlations between residual feed intake (RFI) and CH4 emissions expressed in g/d methane production (MeP), g/kg of fat- and protein-corrected milk methane intensity (MeI), or g/kg of DM intake methane yield (MeY) throughout lactation. We collected CH4 data using GreenFeed devices from 107 Holstein cows, as well as production and intake phenotypes. RFI was predicted from DM intake, fat- and protein-corrected milk, BW, and body condition score. Five-trait random regression models were used to estimate the individual variance components of the CH4 and production traits, which were used to calculate the correlations between RFI and CH4 traits throughout lactation. We found positive correlations of RFI with MeP and MeI ranging from 0.05 to 0.47 throughout the lactation. Correlations between RFI and MeY are low and vary from positive to negative, ranging from -0.18 to 0.17. Both MeP and MeI are favorably correlated with RFI, as is MeY during the first half of lactation. These correlations are mostly favorable for genetic selection, but the confirmation of these results is needed with genetic correlations over a larger dataset.

Comparison of methane production, intensity, and yield throughout lactation in Holstein cows

Genetic selection to reduce methane (CH4) emissions from dairy cows is an attractive means of reducing the impact of agricultural production on climate change. In this study, we investigated the feasibility of such an approach by characterizing the interactions between CH4 and several traits of interest in dairy cows. We measured CH4, dry matter intake (DMI), fat- and protein-corrected milk (FPCM), body weight (BW), and body condition score (BCS) from 107 first- and second-parity Holstein cows from December 2019 to November 2021. Methane emissions were measured using a GreenFeed device and expressed in terms of production (MeP, in g/d), yield (MeY, in g/kg DMI), and intensity (MeI, in g/kg FPCM). Because of the limited number of cows, only animal parameters were estimated. Both MeP and MeI were moderately repeatable (>0.45), whereas MeY presented low repeatability, especially in early lactation. Mid lactation was the most stable and representative period of CH4 emissions throughout lactation, with animal correlations above 0.9. The average animal correlations of MeP with DMI, FPCM, and BW were 0.62, 0.48, and 0.36, respectively. The MeI was negatively correlated with FCPM (<-0.5) and DMI (>-0.25), and positively correlated with BW and BCS. The MeY presented stable and weakly positive correlations with the 4 other traits throughout lactation, with the exception of slightly negative animal correlations with FPCM and DMI after the 35th week. The MeP, MeI, and MeY were positively correlated at all lactation stages and, assuming animal and genetic correlations do not strongly differ, selection on one trait should lead to improvements in all. Overall, selection for MeI is probably not optimal as its change would result more from CH4 dilution in increased milk yield than from real decrease in methane emission. Instead, MeY is related to rumen function and is only weakly associated with DMI, FPCM, BW, and BCS; it thus appears to be the most promising CH4 trait for selection, provided that this would not deteriorate feed efficiency and that a system of large-scale phenotyping is developed. The MeP is easier to measure and thus may represent an acceptable alternative, although care would need to be taken to avoid undesirable changes in FPCM and BW.

Crack Use Sites and HIV Risk in El Salvador

“The Social Context of Crack Use and Related Sexual Risk in El Salvador” study was designed to increase knowledge of the locations where drugs are consumed in urban San Salvador, the social dynamics within such sites, and their implications for HIV risk and prevention efforts. In-depth interviews with crack smokers reveal several different types of sites where drugs are consumed and risky sex may occur including trances (generally houses where crack is sold and consumed), brothels, motels, drug users' own homes, abandoned buildings, the street, parks, or cantinas. These range from private sites, where site “gatekeepers” strictly control access, to public sites where access is more open. However, even in more public sites there is considerable social interaction, rules regarding site usage, and in some cases gatekeeper control of the site. Social dynamics already normative at drug use sites may support a site-based, peer-led intervention approach.

Humane Orientation as a New Cultural Dimension of the GLOBE Project

We validate, extend, and empirically and theoretically criticize the cultural dimension of humane orientation of the project GLOBE (Global Leadership and Organizational Behavior Effectiveness Research Program). Theoretically, humane orientation is not just a one-dimensionally positive concept about being caring, altruistic, and kind to others as discussed by Kabasakal and Bodur (2004), but there is also a certain ambivalence to this concept. We suggest differentiating humane orientation toward in-group members from humane orientation toward out-group members. A multicountry construct validation study used student samples from 25 countries that were either high or low in humane orientation ( N = 876) and studied their relation to the traditional GLOBE scale and other cultural-level measures (agreeableness, religiosity, authoritarianism, and welfare state score). Findings revealed a strong correlation between humane orientation and agreeableness, welfare state score, and religiosity. Out-group humane orientation proved to be the more relevant subfacet of the original humane orientation construct, suggesting that future research on humane orientation should make use of this measure instead of the vague original scale. The ambivalent character of out-group humane orientation is displayed in its positive correlation to high authoritarianism. Patriotism was used as a control variable for noncritical acceptance of one’s society but did not change the correlations. Our findings are discussed as an example of how rigid expectations and a lack of tolerance for diversity may help explain the ambivalent nature of humane orientation.

The relationship between community structural characteristics, the context of crack use, and HIV risk behaviors in San Salvador, El Salvador

This paper explores community structural factors in different low-income communities in the San Salvador, El Salvador, that account for differences in the social context in which crack is used and HIV risk behaviors among crack users. Results suggest that both more distal (type of low-income community, level of violent crime, and poverty) and proximate structural factors (type of site where drugs are used, and whether drugs are used within or outside of community of residence) influence HIV risk behaviors among drug users. Additionally, our results suggest that community structural factors influence the historical and geographic variation in drug use sites.

Positive emotions in earthquake survivors in El Salvador (2001)

The purpose of this study was to analyze, within a more extensive intervention program, the existence of positive emotions and positive coping in the refugees at the two largest shelters created after the earthquakes of El Salvador in January, 2001. One hundred and fifteen survivors were interviewed in the shelters about different aspects related to positive cognitions and emotions experienced during their sojourn at the camps, as well as their perception of aspects of posttraumatic growth. The results show that most of the people affected by the earthquake revealed a consistent pattern of positive reactions and emotions. The potential implications of these results in the individual sphere, as buffering elements to protect people from the effects of a traumatic experience receive comment.

Codependency: a disorder separate from chemical dependency

This study examined the relationship between codependency (an excessive preoccupation with the lives, feelings, and problems of others), chemical dependency of a significant other, and depression. The Significant Others' Drug Use Survey (SODS) determined whether the subject was in a relationship with a significant other at risk of being chemically dependent. Beck's Depression Inventory (BDI) was used to assess depression. Two hypotheses were tested: first, that codependency exists independently of chemical dependency and, second, that codependent people tend to be more depressed than non-codependents. Results supported the first hypothesis, but not the second. A significant correlation between depression and having a significant other likely to be chemically dependent was observed. The usefulness of the concept of codependency is discussed with proposals for subsequent research.