Factors influencing average milk yield of herds at two levels of production.
An experiment was started in 1950 designed to find out what proportion of the difference in milk yield between herds is genetic in origin. Sixty-five pairs of twins were split at birth equally between farms having high-yielding herds and farms having low-yielding herds. A previous paper on this experiment reported on the growth of the twins, the present paper on milk yield and on management practices in the herds. Twenty-four pairs of twins survived to complete one lactation and these provide an estimate of 24%±18% for the genetic part of the difference between the herds. Aspects of rearing of the twins and of management of the herds were examined. Twins in the high-yielding herds were served and calved earlier than those in the low-yielding group but they had a longer interval between service and calving. Differences between average heifer yields and average cow yields were from one-and-a-half to two times greater in the high- than in the low-yielding herd group. There were no obvious quantitative differences in feeding practice between the two groups although differences in body size suggest that twins in the high group were done better. For the age at first service there was a positive rank correlation of 0·30 between body size differences and subsequent differences in first lactation milk yield. There was no single factor of management or environment which appeared to be the cause of the yield difference between the herds.
Genetic differences among Holstein-Friesian herd improvement registry herds.
Abstract Genetic differences among 442 Holstein-Friesian HIR herds that had been on test from March, 1952, to April, 1961, were examined. First lactations initiated at under 36 months of age for 37,890 individuals were studied by two approaches. In the first, differences between bull breeder herds were compared by the progeny test evaluation of sires produced in a specific herd but progeny tested in another herd. Among 19 breeder herds that sold a large number of sons to other herds, four times the variance of breeding values of those sons, attributable to the herd in which they were bred, represented 12.4 and 18.7% of the herd component for milk yield and percent fat. The mean genetic merit of 282 sons originating from these breeder herds was 92 kg of milk above the 479 sons from nonbreeder herds and 143 kg above the 67 sires originating from outside the United States. The second approach involved a comparison of the herd component of variance from multiherd progenies of sires with the herd component from single-herd progenies. The fraction of the herd variance for the population of 442 herds that was genetic was 9.3% for milk yield and 8.9% for fat per cent. The results indicate that the genetic differences among these Holstein HIR herds are small but real, contributing about 10% of the variance among herd averages for milk. While the herd average would be more useful to correct for environmental differences among herds, it also should receive some positive attention for estimating genetic differences between individuals in different herds.
Code switching in Ahdaf Soueif's The Map of Love
This article examines the phenomenon of code switching in The Map of Love (1999) by the Egyptian—British writer Ahdaf Soueif. Though she chooses English as a medium for her creative expression, Soueif deploys Arabic in her narrative to represent different aspects of the linguistic and cultural norms of Egyptian society. The article's methodology is informed by Kachru's framework on contact literature and his categorization of the occurrence of literary code switching or bilingual creativity into different strategies that encompass cultural and linguistic processes. The results indicate the predominance in The Map of Love of the discourse strategies of employing lexical borrowing, culture-bound references and translational transfer. Finally, the article analyzes the functional motivation of code switching in the postcolonial context of the novel and how the use of certain creative strategies might enhance or diminish the narrative's effectiveness and readability.