Genetic parameters estimates for gestation length in beef cattle

Rocha, J. C. M. C.; Tonhati, Humberto; Alencar, M. M. de; Lôbo, Raysildo Barbosa

doi:10.1590/s0102-09352005000600013

Cited by 10 publications

(2 citation statements)

References 18 publications

(4 reference statements)

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“…Hanenberg et al (2001) and Knol (2001) estimated the heritability at 0.3 in sows. In cows and mares, the heritability of gestation length was estimated at 0.2 (Rocha et al, 2005;Valera et al, 2006). In those studies, gestation length was analysed as a trait of the mother, without taking the genetic effect of the young into account.…”

Section: Discussionmentioning

confidence: 99%

Genetic correlations between gestation length, piglet survival and early growth

2008

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Section: Discussionmentioning

confidence: 99%

Genetic correlations between gestation length, piglet survival and early growth

2008

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“…The estimated fetus weight at 290 days of gestation (average length of gestation in B . indicus cattle, [ 33 ]) in this study was 28 kg [ 2 ], while in the study of Ferrell et al [ 34 ], which was performed using B . taurus cows, the average estimated CBW was 38.5 kg.…”

Section: Resultsmentioning

confidence: 99%

Achieving Body Weight Adjustments for Feeding Status and Pregnant or Non-Pregnant Condition in Beef Cows

et al. 2015

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BackgroundBeef cows herd accounts for 70% of the total energy used in the beef production system. However, there are still limited studies regarding improvement of production efficiency in this category, mainly in developing countries and in tropical areas. One of the limiting factors is the difficulty to obtain reliable estimates of weight variation in mature cows. This occurs due to the interaction of weight of maternal tissues with specific physiological stages such as pregnancy. Moreover, variation in gastrointestinal contents due to feeding status in ruminant animals is a major source of error in body weight measurements.ObjectivesDevelop approaches to estimate the individual proportion of weight from maternal tissues and from gestation in pregnant cows, adjusting for feeding status and stage of gestation.Methods and FindingsDataset of 49 multiparous non-lactating Nellore cows (32 pregnant and 17 non-pregnant) were used. To establish the relationships between the body weight, depending on the feeding status of pregnant and non-pregnant cows as a function of days of pregnancy, a set of general equations was tested, based on theoretical suppositions. We proposed the concept of pregnant compound (PREG), which represents the weight that is genuinely related to pregnancy. The PREG includes the gravid uterus minus the non-pregnant uterus plus the accretion in udder related to pregnancy. There was no accretion in udder weight up to 238 days of pregnancy. By subtracting the PREG from live weight of a pregnant cow, we obtained estimates of the weight of only maternal tissues in pregnant cows. Non-linear functions were adjusted to estimate the relationship between fasted, non-fasted and empty body weight, for pregnant and non-pregnant cows.ConclusionsOur results allow for estimating the actual live weight of pregnant cows and their body constituents, and subsequent comparison as a function of days of gestation and feeding status.

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