Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Dairy Science


A high rate of calf mortality can represent a major economic loss to the dairy farmer. Despite increased knowledge in calf rearing, mortality rates of 10 to as high as 25% are not uncommon. The loss of heifer calves alone cost dairymen an estimated $81 million in 1975. This figure does not include the additional costs of extra labor, medication and veterinary expenses, and the loss of genetic potential. The most critical period for calf survival is the first 2 to 3 wk of life. During this time, the calf depends upon colostral immunoglobulins absorbed during the first 24 h of life for protection against pathogenic microorganisms. Antigenic stimulation after birth activates the calf's own immune system, but significant endogenous synthesis of immunoglobulin does not occur until about the fourth week of life. Studies on the newborn calf have shown that age at first feeding, amount of colostral immunoglobulin consumed, and "mothering" by the dam, all exert a strong influence on the amount of immunoglobulin absorbed. Attainment of an adequate level of circulating maternal immunoglobulins is of utmost importance for survival of the calf, since calf losses to infectious disease are highly correlated with low levels of serum immunoglobulins. Season of the year has been related to the immunoglobulin status of young calves. A survey of serum immunoglobulin levels in 1-wk-old market calves in Scotland showed a marked seasonal variation in mean serum immunoglobulin concentration, with high mean values during summer months (21). Lowest mean values occurred during winter months and coincided with the time of highest calf mortality. However, the observed seasonal variation may have been managemental in origin since the summer calves in this survey were born on pasture and nursed, while most winter calves were removed from their darn and bucket fed. A later study in Scotland (64), conducted from January thru July under uniform management conditions, showed no seasonal variation in- immunoglobulin status of neonatal calves. The influence of high temperature on immunoglobulin absorption was recently investigated (72) in Arizona. Newborn calves were housed under shade, cooled shade, or in hutches. Hutch-housed calves were exposed to higher ambient temperature and had lower serum immunoglobulin concentrations and a higher mortality rate. This study examined the influence of season of the year (winter vs. summer) and the related factors of temperature and humidity on colostrum immunoglobulin absorption and immunoglobulin status of dairy calves raised in outdoor hutches in South Dakota. Other relationships studied included (1) influence of lactation number and season of the year on immunoglobulin concentration in colostrum, and (2) influence of season on feed intake and weight gain of calves.

Library of Congress Subject Headings

Natural immunity
Calves -- Mortality
Calves -- Feeding and fees -- Climatic factors


Includes bibliographical references (pages 52-57)



Number of Pages



South Dakota State University


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