The Application of Artificial Insemination (AI) technology in cattle breeding has been a promising method in developing dairy cattle production. The...

It was reasoned that technologies that increase the reproductive rate of males and females in dairy cattle would realize higher responses to selection. The authors tested this hypothesis using deterministic simulation of breeding schemes that resembled those of dairy cattle in Kenya. The response to selection was estimated for four breeding schemes and strategies. Two breeding schemes were simulated, based on artificial insemination (AI) and multiple ovulation and embryo transfer (MOET) reproductive technologies. The strategies were defined according to the use of conventional semen (CS) and X-chromosome-sorted semen (XS). The four strategies therefore were AI with CS (AI-CS) and XS (AI-XS), and MOET with CS (MOET-CS) and XS (MOET-XS). The four strategies were simulated based on the current dairy cattle breeding goal in Kenya. A two-tier closed nucleus breeding programme was considered, with 5% of the cows in the nucleus and 95% in the commercial. Dissemination of superior genetic materials in the nucleus was based on all four breeding strategies, while in the commercial only the AI-CS strategy was considered. The strategies that increased the reproductive rates of both males and females (MOET-CS and MOET-XS) realized 2.1, 1.4, and 1.3 times more annual genetic gain, return and profitability per cow, per year, respectively, than strategies that increased the reproductive rates only of males (AI-CS and AI-XS). The use of CS or XS, however, did not affect response to selection in the two schemes. The findings demonstrate that reproductive technologies such as MOET maximize response to selection in dairy cattle breeding. Keywords: artificial insemination, conventional semen, deterministic simulation, multiple ovulation and embryo transfer, X-chromosome-sorted semen

Genetic evaluation records for the Canadian Holstein, Ayrshire, Jersey, and Brown Swiss bulls and cows born from 1950 and 1960, respectively, were used to study the generation intervals (L) along the four-path selection model. The objectives of the study were to determine the L in the four dairy cattle breeds and the effects of some environmental factors and variations among herds or artificial insemination (AI) studs on the L achieved. Total L of the four selection paths was reduced by 55% from 29.2 yr in 1980 to 13.2 yr in 2016 in the Holstein breed. Substantial reductions in total L were also observed in the Ayrshire, Jersey, and Brown Swiss populations between 1980 and 2016. Unlike progeny year of birth, housing system, agricultural region in Québec (region) — as well as their interaction — were not important on realised L of sires and dams used on Canadian dairy farms. There were significant variations among herds and AI studs on the age of sires and dams used for breeding. The considerable variations in realised L among herds and AI studs offer opportunities to increase the annual rate of genetic progress in the four Canadian dairy cattle populations.

CLAIMS have been made that certain American breeds of dairy cattle are of immemorial antiquity in their modern form. These claims are set out in herd books, the earliest of which were published in America, and even in publications having the cachet of the U.S. Department of Agriculture. History cannot substantiate these claims, and Mr. Parmalee Prentice has successfully demolished them by his careful examination of the evidence and this record of his conclusions. American Dairy Cattle Their Past and Future. By E. Parmalee Prentice ; with Chapters on Dairy Cattle in America, by Ernest L. Anthony, Lloyd Burlingham, Clifford L. Clevenger, Clifford T. Conklin, Lynn Copeland, Herbert P. Davis, Rockefeller Prentice and Edwin G. Woodward. Pp. xix + 453 + 51 plates. (New York and London: Harper and Brothers, 1942.) 3 dollars.

Early fetal loss in dairy cattle is a major factor contributing to repeat breeding. If the average fertilization rate in cattle is 85-95% and the incidence of repeat breeders is 56-72% of the herd, then embryonic or early fetal loss (EFL) accounts for 15-25% wastage. It was the purpose of this project to evaluate the effects that changes in body condition score (BCS) and breeding a potentially pregnant cow have on EFL during two periods: between 24-28 days after artificial insemination (AI), and between 28-42 days after AI.

Competitive dairy cattle judging at the collegiate and 4-H levels were started in 1908 and 1919, respectively, but few studies have been conducted to determine the benefits of competitive judging programs. Collegiate judging team programs have had a positive effect on participants and benefited personal character traits. Judging team participation has influenced evaluation, communication and decision-making skills, and confidence. Each year, several thousand youth from 4-H, FFA, and colleges participate in judging program activities that are taught by extension agents, vocational agriculture teachers, breed association and AI personnel, and other industry volunteers. Judging programs help youth learn critical life skills, such as critical thinking, self discipline, situation analysis, decision making, organization, verbal expression, and defense of decisions. International dairy cattle judging activities provide youth and adults with significant learning experiences regarding the globalization of animal agriculture. Academic institutions should continue to provide leadership and training programs to ensure that adequate numbers of volunteers and professional educators are trained for the future.

Two intensive systems of husbandry practices, Garut West Java and Yogyakarta Central Java, were chosen for this study. Both areas have been voluntarily made into a pilot farm for the application of RIA progesterone to improve reproductive performance. Five dairy cattle from Garut West Java, which according to Health Extension and Artificial Insemination Technicians anamneses and according to farmers who own the animal, were showing reproductive failure and were selected from those cattle for the study. Other fifteen dairy cattle from Yogyakarta area, with anamneses of having low reproductive performance, were also selected for this study. Milk progesterone sample were collected twice a week for five consecutive weeks period of time to follow the biological reproductive status of every animal, while samples from dairy cattle at Yogyakarta were collected three times post Artificial Insemination (AI) services, as according to Artificial Insemination Database Application (AIDA) procedure, to monitor the failure of AI, success rate of AI, and ovarian activities of the cattle. Result of the study in Garut shows that RIA progesterone indicates that animals need special treatments and most AI failed due to lack of historical information of the dairy cows. RIA progesterone leads to a suggestion that it can be use as a tool to monitor the reproductive disorder, as the recommendation made for those cows to anticipate reproductive disorder overcome the problems. Similar result found in Yogyakarta, which almost 50% of the observed animals failed to AI due to miss-estrus detection. Furthermore, from the RIA for milk progesterone, information of the reproductive disorder figures can be drawn and early suggestion could be made to anticipate losses. Overall, beside the reproductive historical record, RIA progesterone is important tool to be applied in the animal husbandry system in Indonesia as to improve the herd productivity and has an economical value to reduce operational cost at waiting period for feeding animal up to INS Rp 224,000 — 336,000 per head animal.

In the daily cattle industry, uncertainty still remains regarding the most desirable site of inseminate deposition to maximize AI conception rates. The effect of site of inseminate deposition on nonreturn rates was determined from 2195 cornual and 2428 uterine body-bred dairy cattle. Twelve technicians from various areas of Pennsylvania and New York were chosen on the basis of their accuracy of semen deposition in retraining sessions, average nonreturn rates, and their willingness to cooperate in the study. For a 3-mo period (June, July, and August 1988), technicians alternated weeks of cornual and uterine breeding on all dairy cattle inseminated. One-half (.25ml) of each semen unit was deposited approximately 5.1cm into each uterine horn for cornual insemination. No significant difference in nonreturn rates was found between horn-bred (70.8%) and body-bred (69.5%) cows. The range of differences in percent nonreturn rates for technicians was 19 and 30% for body and cornual inseminations, respectively. A significant difference in nonreturn rates was found between technicians and between months with significantly higher average nonreturn rates (6.8%) in June. Cornual and uterine body deposition of semen yielded similar results; therefore, depositing an inseminate in the uterine horns to maximize fertility is unnecessary.

Artificial insemination (AI) is among the most effective reproductive biotechnologies that afford widespread propagation of genes carried by superior males. A cross-sectional study followed by a simple random sampling technique was conducted from December 2021 to May 2022 to assess the constraints of artificial insemination (AI) provision in and around Kacha Bira district, Southern Ethiopia, using a structured questionnaire. A total of 200 respondents were surveyed accordingly. In this study, the education level of farmers revealed no statistically significant difference (P > 0.05) with the identification of time of insemination. Conception failure (62.5%), unavailability of artificial insemination technicians (7.5%), dystocia (3.5%), and both conception failure and unavailability of artificial insemination technicians (4.5%) were found to be the major constraints of AI service in the study area according to dairy cattle owners' response and revealed a statistically significant difference (P < 0.05) with AI service. Although statistically significant (P < 0.05), differences in AI service interruptions during both regular working hours and weekends and holidays were also observed. Among total respondents, 20.5% of dairy cattle owners got AI service at right time, but 79.5% of them used it at the wrong time. Regarding inbreeding problems, 77.5% of dairy cattle owners responded that there was no inbreeding problem and the remaining 22.5% of farmers indicated presence of inbreeding problem of which 10.5% and 10% had a perception that local breeds had low milk production and low genetic improvement than exotic breeds, respectively. On the other hand, 11.5% of dairy cattle owners responded that local breeds have a similar level of disease resistance to that of exotic breeds (11%). 48.5% of dairy farmers reported that bellowing is the most frequent sign that they used to detect heat followed by vulval discharge (23%) and mounting on other cows (10%). Majority (78.5%) of the dairy cattle owners interviewed were found to be not satisfied with the artificial insemination services. In general, different AI technicians and cattle and dairy cattle keeper-related factors constrain the AI service and its result in survey site. Therefore, smallholder dairy cattle owners should be trained sufficiently about the AI service strategies, usage, and proper management of dairy farms and the technical constraints should be avoided in order to provide AI service sufficiently.

Revised! ENY-251, a 23-page fact sheet by P. E. Kaufman, P. G. Koehler, and J. F. Butler, describes the biology and management of the most important external parasites of dairy cattle in Florida. Includes references and tables of pesticide information. Published by the UF Department of Entomology and Nematology, May 2009. ENY-251/IG050: External Parasites of Dairy Cattle (ufl.edu)