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Final

ANEQ 330 Lecture Notes - Lecture 2: Maltese Lira, Standard Deviation, HeritabilityExam


Department
Animal Sciences
Course Code
ANEQ 330
Professor
Richard Mark Enns
Study Guide
Final

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Homework 3 and 4
ANEQ 330
80 points
Due July 12 @ 10:00pm
Show all workIF you use a spreadsheet, include a printout of that with appropriate labels
1. A flock of sheep have 140% lambing. The goal is increased fleece weight with smaller
fiber diameter. There are 960 ewes mated at a ratio of 1:40. Rams are used for one breeding
season only. Rams are two years old when offspring are born. Ewes first lamb at 2 years of age
and are retained for five lambings but 10% of ewes fall out each year because of non-pregnancy
and/or death loss (equal loss from all age groups). Fleece weight heritability is 0.3 and phenotypic
sd 1 lb.
A. Calculate the direct response to selection on fleece weight.
In this example, we are performing phenotypic selection on fleece weight, therefore, the formula
that we need to use is the following:
!"# $
% = &
'()*'+
,
-
&
./
,
-0123
45)46
Where:
78*9:;*7<
= corresponds to the selection intensity of males and females, respectively
=>
= corresponds to the heritability of fleece weight
?@
= Phenotypic standard deviation of fleece weight
A8*9:;*A<
= Corresponds to the generation interval for males and females, respectively
!"# $
% = 0
BCDE*)*DCDE
3
-
0
FCG
3
-0D*HI3
B*)GCJKDJ*LM
!"# $
% =
FCKNG*HI
ECJKDJ*LM
à 0.166272424 lb/yr
à
0.166 lb/yr
The complete explanation of where the values used in the previous formula are coming from
can be seen in the next page.

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Problem 1 A
Phenotypic selection exercise
Data:
Ram lambs
Ewe Lambs
Number of females=
960
672
672
Weaning rate %=
140%
Ewes to ram
40
(Lm) Gen Int Males =
2
Rams Needed=
24
(Lf) Gen Int Females
=
3.7917
heritability=
0.3
pheno SD=
1
Prop Saved
I bar
pheno var=
1
Males (24/672) =
0.04
im =
2.15
Females (234/672) =
0.35
if =
1.06
Age distribution for females
Ewe Age
"X"
Number Ewes
Whole #
Age*Ewe#
2
1
234.4265097
234
468
3
0.9
210.9838588
211
633
4
0.81
189.8854729
190
760
5
0.729
170.8969256
171
855
6
0.6561
153.807233
154
924
weighted age females
Total Ewes =
4.0951
960
960
3640
3.7917
Ram Age (prog.born)
Number of rams
Age*number
2
24
48
24
2
Gen. Interval for
males

Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Change in BV/t=
(im+if)*h2*pheno SD
Lm + Lf
Answer to 1 A
Change in BV/t=
0.166
lb/yr
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