Lactational performance of straightbred Angus cows and three Angus-dairy-cross genotypes.

TitleLactational performance of straightbred Angus cows and three Angus-dairy-cross genotypes.
Publication TypeJournal Article
Year of Publication2013
AuthorsRoca-Fraga, F. J., Hickson R E., Lopez-Villalobos N., Kenyon P R., and Morris S T.
KeywordsCow efficiency project
Abstract

The objective of this study was to determine the milk yield and lactation curves of 117 threeyear-old Angus (AA), Angus×Friesian (AF), Angus×Jersey (AJ) and Angus×Kiwi-Cross (AK) cows, rearing singleton calves sired by either Angus or Simmental bulls. Milk yield was estimated using the weigh-suckle-weigh technique (WSW) recorded at day 32, 49, 80, 120 and 160 days postpartum (dpp). A third-order Legendre polynomial was fitted to lactation data using random regression. Cows from AF, AJ and AK groups reached peak lactation at a similar (P>0.05) stage of lactation (71±7, 74±6 and 82±9 days, respectively), but later (P<0.05) than AA cows (46±6 days). Peak milk yield was the greatest (P<0.05) for AF cows (12.1±0.4 kg) followed by AK and AJ cows (11.4±0.5 kg 10.9±0.3 kg, respectively). Cows from AJ and AK groups produced more milk at peak lactation (P<0.05) than AA cows (9.8±0.31 kg). Overall, AF cows produced more (P<0.05) milk from day 32 to day 160 (1337.3±22.3 kg) than AJ and AA cows (1244.5±19.9 kg and 1017.5±19.99 kg, respectively), although their milk production did not differ (P>0.05) from AK cows (1307.8±31.6 kg). Angus×Friesian, AJ and AK cows produced more milk throughout lactation than AA cows

URLhttp://www.aaabg.org/aaabghome/AAABG20papers/rocafraga20142.pdf
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