Some factors related to height and circumference of udders among lactating holstein cows

الملخص EN

The effects of some factors on Height (HU) and Circumference (CU) of udders were investigated in 201 lactating Holstein cows using the GLM (General Linear Model) method.

The overall means of HU and CU were 62.13 and 109.69 cm, respectively.

The effects of month of calving, daily milk yield, California Mastitis Test score, and body condition on HU and CU were not significant.

Parity affected HU and CU significantly (p < 0.01) ; with advancing age HU decreased while CU increased.

Shape of udder affected HU (p < 0.01) and CU (p < 0.05).

HU of dish, round and pendulous shaped udders were 59.48, 61.85 and 58.37 cm, in the same order.

The corresponding CU were 116.87, 112.08 and 117.76 cm.

HU and CU were affected by the texture of the udder (p < 0.05).

HU of spongy, semi-spongy and non-spongy udders was 61.35, 59.69 and 58.65 cm, respectively.

The corresponding CU were 111.24, 116.49 and 119.00 cm.

The heritabilities of HU and CU were 0.20 and 0.04, respectively.

The genetic and phenotypic correlation coefficients between HU and CU were –0.68 and –0.52, respectively.