@article {3672,
	title = {Genetic evaluation for farm profitability in a commercial grazing dairy herd of Uruguay},
	journal = {New Zealand Journal of Animal Science and Production},
	volume = {80},
	year = {2020},
	month = {09/2020},
	pages = {55-59},
	address = {Online},
	abstract = {The objective of this study was to develop a genetic evaluation model for farm profitability in a seasonally calving pasture-based
dairy herd in Uruguay using crossbred cows. Total lactation yields of milk (MILK), fat (FAT) and protein (PROT) were calculated
for each cow-lactation using the test-interval method. Somatic cell score (SCS) was calculated as the average of log2 (somatic cell
count) for each cow-lactation. Mating records were used to calculate days from start of mating to conception (SMCO). Cow live
weight (LWT) was recorded once per lactation. Cows were scored annually for udder depth (UD), udder support (US), front and
rear teat placement (FT and RT). In total there were 4,081 lactations from 2,371 cows recorded from 2015 to 2017. The cows were
the progeny of 97 sires. Breeding values (BV) for MILK, FAT, PROT, LWT, SMCO, SCS, UD, US, FT and RT were estimated
with a multi-trait repeatability animal model that included the fixed effects of contemporary group (year-lactation number) and
deviation from median calving date, and the random effects of animal, cow permanent and residual error. Estimates of BVs for
these traits were combined in a selection index to rank cows for farm profitability. The index was calculated as I= {\textendash}0.074{\texttimes}BVMILK
+2.13{\texttimes}BVFAT +7.25{\texttimes}BVPROT {\textendash}1.48{\texttimes}BVLWT {\textendash}3.60{\texttimes}BVSMCO {\textendash}36.84{\texttimes}BVSCS +30.86{\texttimes}BVUD +19.67{\texttimes}BVUS +21.10{\texttimes}BVFT +20.07{\texttimes}BVRT.
The index has been used to select the best cows as mothers of future replacements, cull the cows with the lowest selection index
value, and for the selection and culling of heifer replacements.
Keywords: genetic evaluation; genetic parameters; selection index; Uruguay},
	issn = {1176-5283},
	author = {Laborde D and Lopez-villalobos N}
}
