NEW TRICH RULES
The Texas Animal Health Commission has adopted some changes to the Trichomoniasis control program as follows:
- if a bull is sold and later found to be infected, other bulls from the herd of origin may be required to be tested if the bull was not exposed to females after its sale and prior to testing by the new owner;
- if a bull has strayed on to property not owned or managed by the bull’s caretaker and is found to be infected then other bulls from the unit of origin and bulls on the premises where the bull was last located must all be officially tested;
- the TAHC can evaluate the effectiveness of a herd control plan to monitor progress;
- all premises under a Trich Herd Certification Program must have perimeter fences adequate to control movement in and out of the premises.
(TAHC Newsletter, 11/6/14)
EFFECT OF CALVING DATE AND WINTERING SYSTEM ON COW AND CALF PERFORMANCE AND FINANCIAL RETURN
Over four years, 217 3/4 Red Angus -1/4 Simmental cows were assigned to either:
- March calving (MAR), wintered on native range;
- March calving (MAR), wintered on corn residue;
- June calving (JUN), wintered on native range;
- June calving (JUN), wintered on corn residue;
- August calving (AUG), wintered on corn residue.
All cows were assigned to their respective group at least one year before data were collected.
There were no significant differences between the two wintering managements in any cow, calf, feedlot, or carcass measures.
Before calving, AUG cows were significantly heavier and higher in Body Condition Score than JUN which were heavier and higher than MAR. At weaning, MAR cows were significantly lighter than JUN and AUG but condition did not significantly differ. Calf weaning weights were significantly higher for JUN. There were no significant differences in pregnancy rate, birth weight, calving rate, calving difficulty, or weaning rate.
All MAR calves were placed on feed after weaning. Some JUN and AUG calves also were placed on feed after weaning and some were grazed to yearling stage and then placed on feed. For calf-feds, JUN had significantly heavier on-feed, slaughter, and carcass weight than MAR or AUG; there were no significant differences in ADG, feed efficiency, or any carcass traits. JUN yearlings gained significantly faster than calf-fed and AUG yearlings gained significantly faster and more efficiently than calf-feds. There were no significant differences in any carcass traits.
Calculated at weaning, net returns per calf were lowest for MAR cows.
For calf feds, there was no significant difference in net return across the three calving periods for retained ownership through feeding. If calves had been purchased for feeding, calves from MAR cows had significantly higher net return. There was no significant difference in net return due to cow wintering management, either for retained ownership or purchased feeders.
For cow-calf operations retaining ownership through grazing to yearling, returns were significantly higher for JUN than AUG but this was not true for purchasing as weaned calves.
For JUN, net return after finishing and sold on live weight was significantly higher from yearlings than calf-feds for either cow-calf retained ownership, purchasing as weaned calves, or purchasing as feeders. But for marketing on a carcass value grid, there was a significant advantage in net return only for purchasing as feeders. For AUG the only significant difference was higher return for purchasing for calf feeding and marketing on a grid.
The authors stressed that these results should be evaluated in light of “seasonal changes in the cost of inputs and the value of outputs”.
(Prof. Anim. Sci. 28:249: Univ. of Nebraska)
PERFORMANCE OF HEIFERS SIRED BY HEREFORD, BRAFORD, AND BONSMARA
Brangus females were bred to Hereford, Braford, and Bonsmara (a South African breed containing Africander, Hereford, and Shorthorn); Angus females were bred to Hereford and Bonsmara. Heifers were retained from all five groups.
Pregnancy rate and weaning rate did not significantly differ among the five heifer groups. Calf weaning weight was significantly heavier from Braford X Brangus females over Bonsmara X Brangus and from Bonsmara X Angus over Hereford X Angus. At weaning, females out of Brangus dams were significantly heavier and lower in Body Condition Score than those out of Angus dams. There was no significant difference in ratio of calf weaning weight to dam weight. NOTE: While Bonsmara-sired females performed acceptably, they appeared to offer no important advantage over a similar type more readily available in the US.
(J. Animal Sci. 2014 So. Sec. Meeting Abst. 6; Louisiana St. Univ.)
PART-TIME CONFINEMENT MANAGEMENT OF BEEF COWS
A study was conducted comparing two rations for mature dry cows: 1) low-energy ration containing 64% wheat straw, 27% distillers grain, costing $130/T or 2) high-energy ration contained 35% wheat straw, 29% corn, 27% distillers grain, costing $157/T. In order to provide equal nutrient consumption, the low-energy ration required approximately 50% more feed/day/cow than the high-energy ration. Utilizing data from that study, a simulation study was conducted on dry cows managed for 120 days from weaning to 30 days before calving in one of the following groups:
- maintained in drylot on low-energy ration;
- maintained in drylot on high-energy ration.
For year-round grazing, a base herd of 500 cows was assumed. Because less pasture/cow was required for those maintained for four months in drylot than grazed year-round, approximately 39% more total cows could be maintained year-round on the same land resource.
An economic analysis was made of the three systems. Net return/cow was $364 for year-round grazed, $237 for low-energy drylot, and $298 for high-energy drylot. (The authors noted these high returns reflect current all-time high cattle prices.) Net return/system was $182,000 for year-round grazed, $165,000 for low-energy drylot, and $208,000 for high-energy drylot. These net returns/system reflect that fewer cows could be maintained on year-round grazing and that approximately 25% less total $feed/cow was required for high-energy vs. low-energy. (Note: These results indicate part-time confinement management of dry beef cows may provide opportunity depending on relative costs, especially of land for grazing and alternative sources of cow nutrition.)
(Proceedings of 2014 Eng Foundation Symposium, p. 19; Texas A&M Univ.)
SEXED VS. NON-SEXED SEMEN
This study at two locations used Angus X Hereford cows, 441 in the first year and 452 in the succeeding year. After heat synchronization, approximately one-half of the cows were timed inseminated with sexed semen and one-half with non-sexed semen from the same bull. Overall, heat was synchronized in 84.6% of cows. As is the typical procedure, non-sexed semen contained approximately 20 million sperm/straw and sexed semen approximately 2.1 million sperm/straw. At 18 days after AI, all cows were placed with cleanup bulls for 50 days, with 25 cows per bull. Reproductive results were as follows:
|AI pregnancy %, all cows||35||56|
|AI pregnancy %, sync cows||41||66|
|Final pregnancy % to AI *||42||64|
|Final pregnancy % to bull *||58||36|
|% male calves to AI||91||57|
|% male calves overall||66||55|
* Within cows classified as pregnant, pregnant to AI or bull
All above differences between sexed and non-sexed were significant. While a high percent of males resulted from AI with sexed semen, because only about 1/3 of cows conceived to sexed semen the overall percent males was only about 2/3.
There was no significant difference in pounds of calf weaned/cow exposed to breeding or $ value/cow exposed to breeding. NOTE: For those wishing to produce large numbers of heifers for breeding replacements, use of heifer-sexed semen could change economics.
(Proceedings of 2014 Am. Soc. of Anim. Sci. Western Section Meeting, p. 25; Oregon St. Univ.)
EFFECTS OF EARLY WEANING ON PERFORMANCE AND TOTAL NUTRIENT REQUIREMENTS
Calves from a group of 84 cows were weaned at 90 days of age (EW) or 205 days of age (NW). All cattle were maintained in drylot using the same ration of 60% distillers grain and 40% crop residue. EW cows received 15 lb/dry matter/cow/day and EW calves had free-choice access. NW pairs were limit fed the total amount consumed by EW cows + calves.
Over the period from early to normal weaning, EW cows gained 46 lb more and were heavier at normal weaning time. However, Body Condition Score did not differ. During the early to normal weaning period, NW calves gained 22 lb more. Together, EW cows and calves consumed 23.5 lb DM/unit/day and NW pairs 22.3 lb DM/unit/day. The authors concluded this “implied similar feed utilization” and “the data suggest weaned cows and calves require the same amount of feed as pairs together and early weaning does not reduce the feed energy needed to support the pair”.
(2014 Am. Soc. of Anim. Sci. Midwestern Section Abst. 101: Univ. of Nebraska)
GENETIC DIVERSITY AND VIRAL INFECTIONS
Genetic diversity from heterosis or hybrid vigor is well documented to increase many production and economic factors. Resistance to harmful viruses may also be a factor. Recent research found that viruses replicate faster and are more virulent in genetically identical mice than in those that are genetically diverse. The authors concluded that, while this study used mice, for livestock producers “maybe using multibreed herds might limit the ability of a pathogen to become highly virulent”.
(Proc. of the Royal Society B:Biological Sciences; 11/12/14; Univ. of Utah, National Institutes of Health)
EPD AVERAGES, ADJUSTMENTS, AND BREED COMPARISONS
The U. S. Meat Animal Research Center, Clay Center, NB, annually updates research that allows producers to: 1) see how individuals rank within a breed, 2) compare different breed average EPDs and, 3) adjust EPDs for direct comparison of individuals from different breeds. Tables showing this information can be accessed at https://animalscience.tamu.edu/livestock-species/beef/publications/#genetics .