Inheritance of colour and coat in the Belgian Shepherd dog.

The several colours and coats of the Belgian Shepherd dog are shown to be due primary to combinations of the following genes: dominant black (As), dominant yellow (Ay), chinchilla (ch), long hair (l) and wire hair (Wh). The gene for black and tan (at) is or has been present in the breed. All of the dominant yellow dogs exhibit a black facial mask and extensive suffusion of black guard hairs on the body.

Projection of lactation milk yield from part records in crossbred dairy cows.

First lactation records of a total of 242 Jersey (JH), Brown Swiss (BH) and Holstein-Friesian (FH) halfbreeds from Hariana cows were studied for projecting 300 d milk yield from 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38 and 40 weeks' milk yield. The correlation coefficients between 300 d milk yield and part records ranged from 0.84 to 0.9 in the JH, 0.80 to 0.90 in the BH and 0.72 to 0.86 in the FH groups. Prediction equations and standard errors of estimation for prediction of 300 d milk yield for an individual animal are presented. It is suggested that part records up to 16, 22 and 22 weeks may be used for projecting 300 d yield with sufficient accuracy in the JH, BH and FH groups respectively.

Genetic, environmental and interaction effects on lifetime production efficiency of crossbred ewes.

A total of 399 crossbred ewes born in 2 yr were maintained either on irrigated or dryland hill pastures. The ewes were sired by North Country Cheviot, Dorset, Finnsheep or Romney rams mated to Suffolk or Columbia-type ewes. The crossbred ewes were mated to Hampshire rams throughout the study and had the opportunity for either 4 or 5 yr of production. Annual feed cost was calculated based upon estimated annual metabolizable energy (ME) requirements for maintenance, ewe growth, pregnancy and lactation. Income from weaned feeder lambs and from orphan lambs sold shortly after birth, feed cost and net revenue were analyzed during each ewe's first production year, as well as for the entire period of the experiment. Crossbred group significantly affected income from lambs produced, feed cost and net revenue for the ewes' first production year. Crossbred group and crossbred group X management system interactions generally influenced lifetime income from lambs produced and from orphans sold, gross income, total cost and net revenue per ewe. Finnsheep X Suffolk ewes performed best on irrigated pastures but were below average for lifetime net revenue on hill pastures. Finnsheep X Columbia ewes performed best on hill pastures and, with Dorset X Suffolk and Dorset X Columbia ewes, were well above average for lifetime net revenue on irrigated pastures as well. Suffolk crossbreds consistently performed better on irrigated than on hill pastures. While most ewes with Columbia-type inheritance were more efficient on hill than on irrigated pastures, this result was not always consistent.

Influence of oncogenicity of Marek' disease virus on evaluation of genetic resistance.

Resistance to Marek's disease ( MD) is, in part, genetically determined and linked to the major histocompatability complex. The genetic resistance of 9 previously characterized lines of chickens and also of the inbred UCD-003 and 4 congenic lines was evaluated by challenge with JM-10. Five lines were highly resistant. These included the N-line and two derivatives from N-line (N-2 and N-5), PDRC strain, and one of the congenic UCD lines. The PDRC genotype is unknown, but the 3 related lines carry the B21 allele and the UCD line carries the BQ allele, which appears to be similar to B21. The UCD-003 and the other 3 congenic lines were moderately resistant while S-strain, P-2 and P-5 lines were highly susceptible to JM-10. The total MD incidence varied from 0 to 100% among the lines. Challenge with highly oncogenic virus isolates like GA-5, and especially the recently isolated RB-1B, caused high incidences of MD in all lines and, thus, did not permit differentiation of genetic resistance levels as was possible with the less oncogenic JM-10.