Survival from birth to 1 month, 1 month to weaning, weaning to 1 year and birth to 1 year was studied in crosses of native carpet wool breeds (Chokla, Malpura and Jaisalmeri) with Rambouillet. Least-squares analysis of data considering survival as 1 and mortality as 0, showed that the year and season of birth affected survival significantly during all age periods except from birth to 1 month and from 1 month to weaning where season had no significant effect. Sex (studied only for pre-weaning survival), ewe's weight at lambing and birth weight of lamb did not influence survival except that the ewe's weight a significant influence on survival from 1 month to weaning. Genetic groups did not differ significantly. Rambouillet X Malpura F1s had a higher survival rate than the other 2 F1s. There was a non-significant decline in survival with an increase in Rambouillet inheritance, except that 5/8 Rambouillet -3/8 Chola crossbreds had a slightly higher survival rate than Rambouillet X Chokla F1s. Interbreeding F1 and 3/4 crossbreds did not result in any significant decline in survival. The results show that the introduction of exotic fine-wool inheritance up to 50% and interbreeding of halfbreds will not result in any decline in survival.

Inheritance of fruit hairiness, fruit skin co!our and leaf lobing was studied in intervarietal crosses of okra, Abel~i~oschzcs esczrle~ztzcs (L.) hloench. Fruit hairiness was found t o be monogenically controlled, the alleles for prickly hairs and smooth hairs showing interaction. Fruit skin colour was controlled digenitally. Light crcam colour and pink shading were both dominant over green. T h e inheritance of leaf lobing was monogenic with incomplete dominance.

SummaryFirst 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.

No abstract

No abstract