Test-day or 305-day milk yield for genetic evaluation of Gir cattle

The objective of this work was to compare genetic evaluations of milk yield in the Gir breed, in terms of breeding values and their accuracy, using a random regression model applied to test-day records or the traditional model (TM) applied to estimates of 305-day milk yield, as well as to predict genetic trends for parameters of interest. A total of 10,576 first lactations, corresponding to 81,135 test-day (TD) records, were used. Rank correlations between the breeding values (EBVs) predicted with the two models were 0.96. The percentage of animals selected in common was 67 or 82%, respectively, when 1 or 5% of bulls were chosen, according to EBVs from random regression model (RRM) or TM genetic evaluations. Average gains in accuracy of 2.7, 3.0, and 2.6% were observed for all animals, cows with yield record, and bulls (sires of cows with yield record), respectively, when the RRM was used. The mean annual genetic gain for 305-day milk yield was 56 kg after 1993. However, lower increases in the average EBVs were observed for the second regression coefficient, related to persistency. The RRM applied to TD records is efficient for the genetic evaluation of milk yield in the Gir dairy breed.

The 2017/18 beet campaign – Suiker Unie

In the Netherlands the beet acreage increased by more than 20% compared to 2016. With an excellent growing season with a beet yield record of more than 93 t/ha of beet, more than 8 mn t of beet were processed in the two Dutch sugar factories. The campaign in the Netherlands lasted up to 152 days, which is a new record. In 2017 some major expansion projects, two new beet washing plants, were realized resulting in daily peaks of up to 30,000 t/d beet processing. The Anklam factory in Germany had a good beet campaign with stable beet slicing rates and an excellent beet quality until the end of the campaign. The beet cultivation and harvest, main investments and process disturbances of the 2017/18 campaign at the three Suiker Unie factories Anklam (D), Dinteloord (NL) and Vierverlaten (NL) are discussed.

Stalagmite water content as a proxy for drip water supply in tropical and subtropical areas

In this pilot study water was extracted from samples of two Holocene stalagmites from Socotra Island, Yemen, and one Eemian stalagmite from southern continental Yemen. The amount of water extracted per unit mass of stalagmite rock, termed "water yield" hereafter, serves as a measure of its total water content. Based on direct correlation plots of water yields and δ18Ocalcite and on regime shift analyses, we demonstrate that for the studied stalagmites the water yield records vary systematically with the corresponding oxygen isotopic compositions of the calcite (δ18Ocalcite). Within each stalagmite lower δ18Ocalcite values are accompanied by lower water yields and vice versa. The δ18Ocalcite records of the studied stalagmites have previously been interpreted to predominantly reflect the amount of rainfall in the area; thus, water yields can be linked to drip water supply. Higher, and therefore more continuous drip water supply caused by higher rainfall rates, supports homogeneous deposition of calcite with low porosity and therefore a small fraction of water-filled inclusions, resulting in low water yields of the respective samples. A reduction of drip water supply fosters irregular growth of calcite with higher porosity, leading to an increase of the fraction of water-filled inclusions and thus higher water yields. The results are consistent with the literature on stalagmite growth and supported by optical inspection of thin sections of our samples. We propose that for a stalagmite from a dry tropical or subtropical area, its water yield record represents a novel paleo-climate proxy recording changes in drip water supply, which can in turn be interpreted in terms of associated rainfall rates.

Stalagmite water content as a proxy for drip water supply in tropical and subtropical areas

In this pilot study water was extracted from samples of two Holocene stalagmites from Socotra Island, Yemen, and one Eemian stalagmite from southern continental Yemen. The amount of water extracted per unit mass of stalagmite rock, termed "water yield" hereafter, serves as a measure for its total water content. The stalagmites' water yield records vary systematically with the corresponding oxygen isotopic compositions of the calcite (δ18Ocalcite). Low δ18Ocalcite values are thereby accompanied by low water yields and vice versa. Based on the paleoclimatic interpretation of the δ18Ocalcite records, water yields can be linked to drip water supply. High drip water supply caused by high precipitation rates supports homogeneous deposition of calcite with low porosity and therefore a small fraction of water-filled inclusions, resulting in low water yields of the respective samples. A reduction of drip water supply fosters irregular growth of calcite with higher porosity, leading to an increase of the fraction of water-filled inclusions and thus higher water yields. The results are consistent with the literature on stalagmite growth and supported by optical inspection of thin sections of our samples. We propose that for a stalagmite from a tropical or subtropical area, its water yield record represents a novel paleoclimate proxy recording changes in drip water supply, which can in turn be interpreted in terms of associated precipitation rates.

The effectiveness of mixed-model smoothing for prediction of lactation yields

The accurate prediction of lactation yield for a dairy cow has been a long standing goal for improving management. Historically the approach has been to assume that yield as a function of time follows a lactation curve which can be assigned a form that applies to all cows, and that cows differ in the parameters of this common curve. This has led to a plethora of forms being suggested for this common curve, of which perhaps the most well-known is that of Wood(1967). The biggest problem with this approach is the assumption that all cows and all management systems combine to produce individual lactations described by a single form of ‘lactation curve’. A novel approach using mixed-model smoothing was investigated in this study which: (i) fits a shape of lactation, assuming no specific parametric form , to daily yield records of a group of cows by using a patterned (co)variance matrix to describe deviations from a linear trend for time postpartum in a mixed model; and (ii) allows individual yields to be predicted using this ‘mean’ curve and the deviation of an individual's yield record from this mean.

The effectiveness of mixed-model smoothing for prediction of lactation yields

The accurate prediction of lactation yield for a dairy cow has been a long standing goal for improving management. Historically the approach has been to assume that yield as a function of time follows a lactation curve which can be assigned a form that applies to all cows, and that cows differ in the parameters of this common curve. This has led to a plethora of forms being suggested for this common curve, of which perhaps the most well-known is that of Wood(1967). The biggest problem with this approach is the assumption that all cows and all management systems combine to produce individual lactations described by a single form of ‘lactation curve’. A novel approach using mixed-model smoothing was investigated in this study which: (i) fits a shape of lactation, assuming no specific parametric form , to daily yield records of a group of cows by using a patterned (co)variance matrix to describe deviations from a linear trend for time postpartum in a mixed model; and (ii) allows individual yields to be predicted using this ‘mean’ curve and the deviation of an individual's yield record from this mean.