1 edition of Herd bull fertility found in the catalog.
Bibliography: p. 135.
|The Physical Object|
|Pagination||xvi, 56 p. :|
|Number of Pages||43|
nodata File Size: 3MB.
Fig 5: Calf suckling is the main factor inhibiting cyclicity in beef cows after calving The second most important factor controlling resumption of ovarian activity post calving is cow body condition at calving. A health program in bulls reduces or eliminates the risk of transmitting diseases that can cause reproductive failure in females at different stages of pregnancy.
Obviously having extended mating periods where bulls are run for 5-6 months will solve this problem but lead to inefficient Herd bull fertility management due to extended calving periods. Fig 5: Calf suckling is the main factor inhibiting cyclicity in beef cows after calving The second most important factor controlling resumption of ovarian activity post calving is cow body condition at calving.
Remember, since the estrous cycle in cows is approximately 20 days, in a group of none synchronized cows a ratio of 1:40 means the bull only has to breed 2 cows per day on average. How to achieve targets for beef herd fertility To achieve these targets it is important to pro-actively manage the herd to ensure all areas of potential fertility inefficiency are being addressed. Bulls with larger scrotal circumferences are more fertile and have The vet will also collect a semen sample and determine Herd bull fertility percentage of motile sperm and normal sperm.
" Planning for all possibilities is the best way to prepare for a successful calving season. J Am Vet Med Assoc 171: 639—642. Trich can cause very low fertility, low pregnancy rates, extended breeding seasons and low calf crops. Over-development of bulls with a high energy ration can create problems, such as excessive fat in the scrotum increased heat stressdecrease semen production and quality, and risk of digestive issues and lameness.
The age and weight at which puberty occurs also varies greatly among breeds and level of nutrition during development; however, research with various breeds suggests that a practical indication of eminent puberty is when scrotal circumference is between 27 and 29 cm Lunstra et al. J Am Vet Med Assoc 171: 639—642. There is a positive genetic correlation between a sire's scrotal circumference, the scrotal circumference of his sons, and the pregnancy rate of his daughters.
Additionally, bulls with small scrotal circumference at one year of age tended to have small scrotal circumference at two years of age.
One of the main reasons for this is that few farms have fertility data that can be easily produced in a useable format without considerable effort. These diseases can be vaccinated and managed for. Controlling infectious diseases that affect fertility• and did they have bad calvings.
Percent calf crop sired by individual sires in multiple sire pastures Adapted from Lehrer et al.
A working herd bull will use his energy reserve during the breeding season.
A veterinarian will evaluate the bull on the following criteria: a physical examination, scrotal circumference measurement, and evaluate semen quality for motility and morphology.
Nutrient Requirements of Beef Cattle NRC 2000.