Question

1. Joe estimated the heritability of conception rate in his heifers and it was much higher than he expected at 0.25. Joe’s brother estimated the heritability of conception rate at his farm and it was much lower at 0.03. Both brothers knew that heritability varied by population but they still didn’t understand why there values were so different. What could have Joe don at his ranch to increase the heritability over the estimated heritability of his brother? (3 pts)

2. If Jan was raising ducks,

(a) What is the repeatability of the number of goslings hatched in a nest if the phenotypic variance was 0.3 and the producing ability variance was 0.2? (1 pt)

(b) If the average number of goslings hatched in a nest was 6 and Jan’s goose had 8 goslings in her nest, what would her producing ability be? (1 pt)

Answer 1

1)

We are allowed to do only 1 question at a time. Please post again for other questions.

Conception is important to allow reproduction to occur and high rates of conception to allow effective breeding. Therefore the conception rate is the percentage of matings that result in conception.

  High rates of conception are especially important in the reproduction of agricultural animals. When breeding livestock species, often artificial insemination is used in order to service more animals at one time and to produce the desired amount of offspring. Breeding livestock animals is costly and time consuming so it is important to have a high rate of conception so as not to waste money and time during breeding, whether it is natural or artificial insemination. Livestock animals are usually bred for a specific purpose and to produce offspring with desired traits so it is important to have high conception rates so this can occur when desired.

  With the use of estrus synchronization methods on the rise, one might expect an increase in conception rates. Another element under management is correct use of the synchronization protocol, and the accurate detection of estrus in the animals. It is essential to be accurate in protocol use and heat determination. If either of these are off even slightly, the probability of successful implantation and conception is greatly reduced.

Conception rates depend greatly on two factors: management and environment. The term management includes all aspects of animal husbandry, shelter, comfort, water access, etc. ​Under the broad category of management falls the element of animal nutrition. The fastest way to improve conception rates as a producer, is to rake-through the feeding practices and types of feed being fed. If an animal isn’t receiving adequate amounts of essential nutrients, infertility will most often result. On the other hand, an over conditioned animal is also unlikely to reproduce. It is important to evaluate body condition score and alter feed practices as necessary to produce animals that are healthy enough to conceive.

Environment is also a factor that can be easily manipulated to improve conception rates. If animals are heat stressed or temperatures are too cold, rate of conception greatly decreases. It is important to adjust breeding seasons accordingly.

Therefore, to increase the heritability over the estimated heritability of his brother, he could have brought some changes in the environment of the farm and his management such as diet and nutrition of the animals. Receiving adequate amounts of essential nutrients is very important to increase the conception rate​. Along with increased conception rate, genetics should be utilized in the animals to get the desired characters in the offsprings. To increase the heritability over the estimated heritability ​healthy and fit parents with desired characteristics should be selected for mating.