California Poultry -Letter

Transcription

1 COOPERATIVE EXTENSION UNIVERSITY OF CALIFORNIA I California Poultry -Letter October 1978 COUNTY-STATE POULTRY AND EGG STATISTICS FOR 1977 The Agricultural Commissioners of California publish annual reports giving production and income data for crop and livestock commodities, including poultry and eggs, produced in their respective counties the preceding calendar year. Because of lack of uniformity in procedures used by the Commissioners in collecting and reporting these data, some errors and discrepancies may result, but each year we summarize the poultry and egg figures to follow any major changes in size and location of the California industry. These data are tabulated on page 4 for the 37 counties reporting income from eggs and/or poultry. Fryers It was not possible to obtain a state total for fryer production in 1977 from the Ag Commissioner reports because Fresno County, one of the important centers for this industry, withheld from publication the number it produced to avoid disclosureof individual firm data. However, the California Crop and Livestock Reporting Service figures (TableA) indicate a total of million, a significant growth of 7.2% over This is nearly twice the national increase. Merced and Stanislaus Counties, ranking 1st and 2nd (Table C), produced about two-thirds of the California fryer crop. Fresno would undoubtedly rank third if its production were known. Counties showing substantial declines in numbers raised were Los Angeles, Sonoma, and San Joaquin. Turkeys The national turkey crop for 1977 decreased 3.1%, but California dropped only 1.5%, according to the Crop and Livestock Reporting Service, or actually gained 7.8% if one accepts the total from the Ag Commissioner reports (Table -4). Fresno continues as the state's leading county (TableC), producing nearly twice the number in Madera, which ranked second. Tulare County registered the largest percentage increasefor1977; Los Angeles experienced the greatest loss, reflecting the decline of the turkey industry in southern California (Table B). Layers Some counties base their layer numbers on year-end inventories; others report average number on hand during the year or merely dozens of eggs produced (which we have converted to average layers on hand by dividingbyaverage rate of lay). These variations account for a part of the difference between Ag Commissioner and Crop Reporting Service figures for layer numbers (Table A). The size of the California layer flock has been relatively stable over the past four years. During the 1977 calendar year,therewas a modest increase of 0.6% in layer inventory in contrast to a jump of +2.8% in size of the U.S. flock. However, with 37.1 million layers, California easily retained its first place national ranking. Second place Georgia had 25.8 million birds of laying age. Th* University of California Cooperative Extension in compliance with the Civil Rights Act of 1964, Title IX of the Education Amendments of 1972, and the Rehabilitation Act of 1973 does not dircriminota on the basis of rocc, creed, religion, color, notional origin, sex, or mental or phyricol hondicop in any of its progromr or activities. Inquiries regarding this policy may be directed to: Warren E. Schoonover, 317Univsrrity Hall, University of California, Berkeley, California 94720, (415) University of California and the United States Deportment of Agriculture cooperating.

2 According to the Ag Commissioner re- the three counties --Riverside,SanDiego, ports, there was no change between 1976 and San Bernardino--accounted for 52.3% and 1977 in the ten top egg producing of the state's layers. The second larcounties, except for a switch in ranking gest concentration was in the north San for 2nd and 3rd places between San Ber- Joaquin Valley.with Stanislaus, San Joanardino and San Diego Counties (Table D). quin, and Merced counties reporting Riverside remained in first place, and 23.8% of the state's total. (continued) Table A: POULTRY AND EGG STATISTICS FOR CALIFORNIA Ag Commissioner California Crop & Livestock county totals Reporting Service totals Change Change millions -- percent millions percent Fryers Turkeys Poultry Layers Income * ;t $246.2 $ $216.2>k;? $253.9;\;:< ,9"+? 37.l:kkx" Egg Income Gross Income $387.9 $ $385.0 $ $634.1 $ $601.2 $ c State total unavailable because of missing data from Fresno County. +:yk Income from fryers and turkeys only. ++x+ Layers on hand January 1 of following year. Table B: POULTRY INDUSTRY DISTRIBUTION BETWEEN NORTHERN AND SOUTHERN CALIFORNIA Northern California * Southern California" No. Percent of total No. Percent of total millions percent millions percent Turkeys Poultry Income"" $ $ Layers Egg Income $ S225.6 h4.0 (12.4 Gross Income $ s ri2.7

3 Income Lower egg prices and a slightly reduced rate of lay resulted-in a 7 to 8 percent reduction in egg income in 1977 compared to Income from poultry (fryers and turkeys) substantially increased because of higher prices and a substantial growth in fryer production. The increase in poultry income more than offset the decline in egg income, resulting in a small increase in gross income for the industry (Table A). Stanislaus County, ranking 2nd in-fryers, 4th in eggs, and 7th in turkeys, easily topped all counties in gross income for 1977 (Table D). Milo H. Swanson Poultry Specialist Riverside Campus Table C; TEN TOP COUNTIES IN POULTRY MEAT PRODUCTION IN CALIFORNIA Fryers Turkeys Poultry Income '76-77 '76-77 '76-77 Rank & Co.* No. Change co. No. Change Co. Dollars Change millions percent millions percent millions percent l.merced Stansl Tulare S.Bdno Sonoma Monterey S.Joaqn Alameda L.A lo.madera Fresno Merced Madera S.Bdno Tulare Kings Stansl Placer L.A Kern Merced Fresno Stansl Ventura S.Bdno Tulare Madera L.A Kings Placer ;k Fresno eliminated from fryer ranks because fryer numbers not given separately < Table D: TEN TOP CALIFORNIA COUNTIES IN EGG PROD,UCTION/GROSS INCOME Gross Poultry Layers E J&g & Egg Income '76-77 '76-77 '76-77 Rank & Co. No. Change co. No. Change Co. Dollars Change millions percent millions percent millions percent l.rvsde S.Diego S.Bdno b.stansl S.Joaqn G.Ventura Sonoma Merced range.754 lo.s.clara, Rvsde S.Bdno S.Diego Stansl S.Joaqn Ventura Sonoma Merced Orange S.Clara Stansl S.Bdno Rvsde Merced Fresno S.Diego Ventura S.Joaqn Sonoma L.A ,

4 Table E: CALIFORNIA POULTRY AND EGGS - PRODUCTION AND VALUE BY COUNTIES County No. of fryers No, of Total income: No. of Gross turkeys poultryl/ layers income head head dollars head dollars dollars Alameda Butte. Calaveras El Dorado Fresno Glenn Humboldt Kern Kings Lake L.Angeles Madera Marin Merced Monterey Napa Orange Placer Riverside Sacramento San Benito S. Bdno. San Diego S.Joaquin S.L.Obispo S.Barbara S.Clara S.Cruz Solano Sonoma Stansls. Sutter Tulare Ventura Yolo Yuba 1,335,500 9: J; >'-?c Y< -k 385, ,000.k 1,075, ,421 -L 41,460,778 2,305,OOO >k k.'- >t 862,000 A- 5,004,000-2; 1,418,OOO Jc ;'; >k x 9; 3,221,OOO 33,761,OOO :'; 5,304,ooo >I: >'< :': -'- f: 72,000 ;'; 4,416,OOO -A :'r 416,000 1,312,OOO ;'; 749,000 1,691,290 $: 2,2&3,555 ;': 9: ;': 945, ,000 J: 188,000 1,190,000 f 377, ,459 :': ;'c ;k 58, , ,000 :k 1,166,700 A +< +: 1,453,ooo 9: 604,800 3'614, ,840,OOO 6,000 1,576 3,450,ooo 8,585,400 12,015 10,479,000 11,642,OOO 913,400 60,819,OOO 2,803, , ,500 6,841,200 3,840,OOO 1,026,OOO 1,367,OOO 14,962,OOO ik 5,330,ooo 1,880,800 55, ,600 2,666,OOO 478,300 4,860,OOO' 44,929,ooo 194, oco 6i6;938'OO0 3oo:ooo 45,000 9: 303,000 62,300 ;'r 522,300 63,150 5, ,030 33,180 23, ,000 86,200 93,300 1,043, , , , ,900 7,930,ooo 103,400 7'; 6,000,OOO 6,012,600 3,649,200 9: 409, ,000 75,400 77,000 1,716,OOO 4,378,OOO 3, ,200 2,627,OOO 1,800 9< 9< 1,673,OOO 544,640 * 5,660,OOO 564,000 38,251 1,306,OOO 513, ,935 4,760,OOO 803,000 1,225,100 9,419,500 2,118,OOO 2,235,Or)O 7,522,500 1,659,OOO 70,782,OOO i'750'000 62:339;000 51,408,OOO 32,587,OOO +< 4,360,800 5,755,ooo 717, ,100 15,955,ooo 48,121,OOO 46,800 1,019,000 24,455,800 17,150 J: 1,453,ooo 1,673,OOO 1,149, ,800 65,500,OOO 570,000 39,827 4,711,300 9,098, ,950 15,239,ooo 12,445,OOO 2,138,500 70,238,500 4,921,200 2,603,OOO 8,162,OOO 8,500,200 7&,622,000 2,107,000 3,117,ooo 77,301,000 51,408,OOO 37, 917.,(100 1,880,800 4,416,500 5,868,600 3,383,OOO 1,110,400 20,815,OOO 93,050, ,800 l~r,116,000 41,393, ,150 45,000 Dressed poultry meats include chickens, turkeys, pheasants, ducks, etc. Does not include chicks or poults. Where actual layer numbers were not reported, dozens of eggs reported were divided by assumed annual production of 19 dozen per layer. Includes some pullets and turkey hatching eggs. Includes chicks and pullets. Includes turkey eggs. Includes some egg products.

5 WET POX--AN OLD DISEASE WITH A NEW TWIST Introduction Fowl pox is a disease with a long history, having been recognized and described as a disease of birds in the 1880s. The disease is well known to poultrymen in California, especially at peak mosquito seasons, since the causative virus is transmitted by the bite of several species of mosquitoes. The classical disease in chickens or turkeys is recognized by the appearance of scabcovered, raised "wart-like" lesions, especially in the unfeathered'skin of the head (comb, wattles, facial skin). ~The incubation period is about a week in experimentally infected birds and the disease spreads s lowly in.a flock. The disease usually runs its course in a flock in 2 to 4 weeks. In most outbreaks the flock mortality is low (0 to 5%) with the major damaging effects including decreased feed consumption, poor weight gain in growing birds, ora slight drop in body weight and egg production in mature birds. In almost all outbreaks there are a few birds with involvement of the eyes, mouth and throat, or sinuses. These are the birds which die because of blindness (inability to find feed and water) and/or difficulty in eating or breathing. The natural disease or purposeful exposure to mild vaccine viruses is known to confer immunity of long duration to the classical disease as described above. Most producers vaccinate once between the ages of 4 to 12 weeks, depending on the type of operation, although revaccination is recommended in high risk situations or in force-molted chickens. After having painted a picture of a relatively benign viral disease that is easily prevented, we must now muddy this clear picture with the bad news--a form of pox that attacks previously vaccinated pullets during the early to mid lay cycle, rarely is accompanied by the characteristic skin lesions, presents itself mainly as a severe respiratory disease (sometimes with a bloody respiratory discha.rge), that kills 10 to 50% of the affected flock, is unresponsive to treatment or revaccination, and that persists in the affected flock for 8 to 12 weeks. The -bad news is WET POX and it has befallen several egg producers in California over the past year. This note is an effort to summarize the state of our knowledge (or ignorance) of this disease problem. The Disease Perhaps the best overview of the problem is presented by a summary of outbreaks seen in California and Indiana. The disease has uniformly affected chickens in environmentally controlled housing-- it is a closed house disease. A 1 though the disease affected a few pullet growing operations (late stage--l6 to 18 weeks), most outbreaks have involved laying hens in the first half of the production cycle (i.e., 25 to 35 weeks of age). The first evidence of disease is an increase in mortality, with a few birds showing respiratory signs. Dead or sick birds may have a few skin lesions, but virtually all have tracheal plugs. These plugs are formed by a markedly thickened tracheal lining with central accumulations of yellowish(sometimes blood-tinged) cheesy exudate. Early stage tracheal wet pox can be readily confused with laryngotracheitis and pther respiratory infections. Other lesions seen with frequency in wet pox cases include swollen watery eyes with cheesy exudate in the conjunctival sac, swollen sinuses containing cheesy exudate, or white to yellow plaques in the mucous membranes of the mouth, throat, esophagus or crop. Diagnosis of pox can be confirmed by either virus isolation or microscopic examination of lesions in the trachea or other locations. Culture of tracheal exudate from affected birds has yielded a variety of bacteria, including Pasteurella sp., coliforms, Pseudomonas, etc. Some affected flocks have been positiveformycoplasmas (either M. synoviae, gallisepticum or both). (continued) - 5

6 In addition to increased mortality, respiratory signs, and typical lesions, several producers have noted decreased feed consumption, weight loss, and a drop in egg production (5 to 20%). In some flocks shell quality problems (rough or soft shells) have accompanied the disease. The disease has progressed slowly in affected houses, persisting for at least 6 weeks and in some cases as long as 12 weeks. In operations with several closed houses, the disease has, in some cases, been confined to just one house; in others it has spread through several or to all closed houses on the ranch. However, chickens in adjacent open houses have remained free of the problem. The cumulative mortality in affected houses has ranged from 10 to 50 percent. A variety of antibiotics, stress packs, and revaccination programs have been administered to flocks with wet pox in attemptstotreat or control the disease. Generally, other than moderating the effects of secondary bacterial invaders, treatment is of little value. Unfortunately, revaccination has had little apparent effect on the course of the disease. Improvement in ventilation and increased feed levels of vitamin A (5 to 10,000 units per pound) have been recommended also, but their influence has not been critically evaluated. The Unknowns A number of questions have been asked about this form of fowl pox f,or which there are no good answers. Some of these and a series of related comments are: 1) Why is the trachea preferentially involved? Is a specific strain of virus involvedoris this site simply a reflection of a faulty secretory immune response? There has been speculation that a latent vaccine virus might be activated in some birds by some environmental irritant such as ammonia, dust, lowgrade tracheal infections, etc. 2) Why don't commercial vaccines protect against wet pox breaks? The lack of skin lesions would indicate that the birds are immu?e to the classical form of pox. However, some producers report obvious takes to revaccination, which indicates that the chickens weren't immune. Faulty vaccine or poor vaccination procedure are possibilities to be considered; but the immune competence of the chickens might be faulty also. 3) Why doeswetpox occur only in closed houses? The obvious answer would seem to involve air movement, but this is not always borne out. There may be more dust and ammonia in closed houses, but we still need to know where the virus comes from and why it persists so long in affected houses. 4) Why isn't there a better response to revaccination after the disease is recognized? Outbreaks of skin pox can be aborted successfully by revaccination. There has been a suggestion that orally administered pox vaccine might do a better job of inducing local (secretory) immunity in the upper digestive and respiratory tracts. There has not been adequate research as yet to substantiate this. Arthur A. Bickford Extension Veterinarian Davis Campus INVESTMENT CREDIT FOR POULTRY HOUSES New poultry houses may be eligible for an investment credit. For more information about this somewhat controversial tax deduction, consult a reliable tax accountant or write to A.D. Reed, Extension Economist, 285 Voorhies Hall, University of California, Davis, CA 95616, and request a copy of Economics Newsletter, February1978,"Investment Credit for Confinement Livestock Buildings." 6

7 TAKE ADVANTAGE OF SEASONAL PRICES TO.IMPROVE EGG INCOME Average annual egg prices may vary considerably from year to year. However, this does not hold for seasonal price patterns during the calendar year. They are rather consistent, with low prices from April through Julyandhigher prices in the fall and winter months. As a result, the industry is tending to change its production pattern to meet the seasonal demands of consumers. According to data taken from the San Diego County Egg Cost Study, the average blend price for unprocessed eggs, F.O.D. the ranch, for,the past -five years (July 1, 1973 to July 1, 1978) was 45c per dozen. The four low months of April, May, June, and July averaged 39c, whereas the other eight months averaged 48~ per dozen. March and October varied considerably from year to year but tended to average well above the low price months. 5oc 1 \ + 9 c / ivrra~e ----& T / /I / I Working towards a position of receiving a higher annual average egg price should be the goal in making your pullet replacement, force molting, and culling plans. Generally, producers may improve average returns by putting into effect the following practices: 1) Stock laying houses with 20-week-old replacement pullets during the period of May through September whenever possible. 2) Avoid using replacement pullets that hatched during September and October. Delay these hatch dates until November, December, or January. September and October hatched pullets do not fit easily into a force molt program since they end their first laying cycle in November and December of the following year,right in the middle of the highest egg price season. Also, their peak performance has occurred during the four low egg price months. 3) Use the low egg price period to force molt pullets that have been in lay eight or more months. This will shift production to higher egg price months. 4) Consider adopting a 2-year replacement program in which either half of the flock is replaced each summer with 20- week-old pullets or all of the flock is replaced every other year. The 20-weekold pullets would be kept through the fall and winter up to their first molt the following April, May, or June. After a second cycle of lay, the flock would be sol'd the next April with the house remaining empty until new pullets were housed during the summer. In summary, a planned replacement program which avoids the use of fallhatched chicks could improve the overall annual average price received for eggs, if seasonal price patterns which have prevailed in the past continue in the future. Avoiding fall hatches does not mean that replacement can be skipped. It merely means deferring to a more favorable month. Robert Adolph Farm Advisor San Diego County 7

8 LJCD SHELL QUALITY-REPRODUCTION-VIRUS PROJECT Egg shell quality problems have been a common complaint of many California producers in recent years. During 1976 and 1977, a commercial egg firm observed cecal tonsilitis in laying flocks which also were experiencing lowered egg production and were thought to have more poor shells than expected. These flocks were treated with antib?otics, which seemed to improve production and reduce undergrade eggs. Subsequent fieldtests, however, showed that the incidence of reddened and enlarged cecal tonsils was not different in antibiotic treated houses when compared to untreated control houses. Egg production was signifcantly higher in the treated houses, but Dr. Cutler, UC Veterinarian who conducted the studies, concluded that the beneficial effect seemed to be through some mechanism not involving the cecal tonsils. At about the same time, a problem of reduced hatchability was observed in commercial broiler hatching egg flocks. This appeared to be associated with an increase in the number of eggs with poor shells. Careful analysis of the problem failed to implicate flock management, nutrition, genetics, toxicity, or hatchery operation. At this time five hens laying poor shells and five laying good shells were autopsied. Four of five hens from the "bad" group had swollen and slightly reddened cecal tonsils, whereas only one from the "good" group had swollen tonsils and it was a nonlayer. This suggested that perhaps some disease agent was responsible for the poor shell quality and also the abnormal cecal tonsils. Since Infectious Bronchitis and Newcastle viruses have been reported to cause poor egg shells, it was 'thought that an investigation of the possible roleofviruses would be useful. A meeting was organized by the Pacific Egg and Poultry Association to discuss this with industry members. The meeting resulted in the development of a UC research proposal to the PePa Foundation which was funded starting in June of The project has four objectives as follows: 1) To establish an active virus research-laboratory; 2) To study records and other epidemiological factors associated with flocks with poor shell quality to determine the exact nature of the problem; 3) To make a detailed study of hens from afflicted flocks which have been individually caged and are known to be laying either good or poor shelled eggs; and 4) To challenge birds from normal, field vaccinated flocks with viral agents, including Newcastle Disease and Infectious Bronchitis, in order to determine if such agents are involved with the reproductive problems described. Under the direction of Dr. Ray Bankowski and Dr. R. H. McCapes, the laboratory has been established by hiring Mr. Bruce Reynolds, who is an experienced virus laboratory technician. The first efforts have been to develop serologic testing capability for Infectious Bronchitis Virus (IBV). Investigation with IBV has not been available to us in California for several years. As a result, our ability to evaluate egg shell quality, egg production, and other production disorders, as well as vaccination programs has been limited. The laboratory is currently working on the agar gel precipitin test, a tissue culture plaque reduction test, and hemagglutination inhibition (HI) test for IBV. In addition, Massachusetts and Connecticut strains of IBV are being propagated in embryos for challenge trials to be accomplished later in the fall and winter. The laboratory is developing antigen and testing capability for adenovirus by the agar gel precipitin tests with some emphasis being given to that strain responsible for the "egg drop syndrome" reported in Europe. Newcastle Disease Virus and avian influenza virus antigen capabilities are also available utilizing the agar gel precipitin test and the HI test. (continued)

9 These serologic testing capabilities, when fully developed, will be utilized to support the field and laboratory studies of the "LJCD Shell Quality-Reproduction-virus Project." Theywill not be available for general diagnostic work, as such use would overload the laboratory's capabilities. It is hoped that the new IBV tests will be efficient and can be used by our state laboratories in the future for routine work. The laboratory is also beginning to accept tissues for virus isolation and identification from the selected flocks involved in the field studies. Flock Record Studies Drs. Ralph Ernst and Richard MacMillan are developing information on the field occurrence, type and severity of the egg shell quality, egg production,andhatchability problems being experienced. These studies will explore the problem in depth and will attempt to examine the possible role of flock management, environment, and other factors in relation to the problem. These studies may be expanded to other cooperators after a definite experimental format is developed and if the need to do so exists. Adult Hen Reproductive Performance Trial Ralph and "Mac" are also handling this project with laboratory assistance from Dr. Art Bickford, the pathology service of the Veterinary Medical Teaching Hospital, and the Virus Laboratory itself. In this trial, adult broiler breeder hens and Leghorn hens are individually caged and egg production and shell quality recorded. Individuals with marginal or poor shell quality or egg production are *.serologically tested, sacrificed, and examined for evidence of disease, and samples are saved for later virus isolation attempts if indicated. This work hopes to be able to determine if an infectious agent is associated with some of the shell and production problems observed. Adult Bird Virus Challenge Trial This work will be started in late November or December of It will involve the virus challenge, at Davis, of normal, field-vaccinated adult leghorns and broiler breeders with various agents including Infectious Bronchitis and Newcastle Disease, which may be involved with the described reproductive problems. This work should help answer the question, "Is it possible that subacute virus disease is causing economic problems for California producers?" Ralph Poultry Davis Ernst Specialist Campus SEPARATE CRACKED EGGS PRIOR TO PROCESSING Most poultrymen attempt to separate cracked eggs from the remainder during gathering. Usually, this only includes the seriously broken ones and leakers. Recent University of California studies indicate that, on the average, more than 4 percent of the remaining eggs are also cracked. Our studies show that r-fig washers usually-crack about 1.25 percent of all sound shelled eggs; but when eggs are already cracked, 8.3 percent are turned into losses during the washing procedure with subsequent total loss in value. In addition, these leakers often require shutting down of the entire operation because of egg liquid on the rollers, This problem gets more serious as the flock ages. Flocks 20 to 39 weeks of age lost 5.3 percent of their cracks in this manner; flocks 40 to 59 weeks of age lost 8.8 percent; and for flocks 60 to 79 weeks, 11.3 percent of the cracked eggs were reduced to zero value. (continued) 9

10 -- I This problem is also highly correlated with shell thickness and the make of the washer. Change of Cracks to Loss in Egg Washer Shell thickness Percent Less than.0120 inches More than.0159 inches 8.2 Weighted average 8.3 Make of Washer Percent A 8.9 B 12.7 C 10.0 D 6.0 Obviously, egg gatherers cannot be asked to slow down their gathering rate in order to separate more of the cracks, but they should be required to separate all the cracks they see and not just the leakers. Donald Bell Farm Advisor Riverside County EGG SHELL PROBLEMS IN THE SAN JOAQUIN VALLEY During the first half of 1978, checked eggs became the major problem in laying flocks of the northern San Joaquin Valley. Egg processing plants were having from 30 to 100 percent of various lots of eggs rejected by the county inspectors because of shell damage. As far as is known, this particular problem was not occurring elsewhere in the United States, at least not to this degree of seriousness. We have never seen a problem so universal in nature. It occurred in all strains of chickens, all feeds, and all types of housing. There are strain differences in shell quality, but this is a normal occurrence. These checks were costing some poultrymen as much as $300 a month because, after excessive checks appeared, all the eggs were sent to the breakers. The egg processing plants added two to three extra workers on the line to pull checked eggs. In one plant, candlers were told to pull eggsifthey looked questionable. Of the eggs pulled, 30 percent were not checked. First, we went to the processing plant with the greatest breakage problem. Specific gravity was run on 10 lots of eggs, 180 eggs per sample. The specific gravity of the eggs was very good, about what would have been expected. Next, we went to the ranches and candled a case of eggs from each lot. The number of checks was what we considered normal for the age of the flock. Eggs were sent to the Davis campus to check for shell thickness. The shell thickness was acceptable, considering flock age. Egg handling procedureswere then checked on the ranch, during transportation to the,processing plant and at off-loading. Nothing was found that could be associated with the checked egg problem. Rations for layers were examined. Phosphorous-calcium levels were juggled in one trial with no beneficial results. Antibiotics and other additives were of little help. Water samples were taken from 30 ranches. Again, no results were found that could incriminate the water. Dr. Wade Brant provided us with an electromechanical egg developed in Great Britain. The egg is clear plastic with a red light in each end activated by three tiny batteries. The internal mechanism was adjusted so the red lights (continued) 10

11 I would come on when the plastic egg was dropped on a hard surface from a height of 9 mm. The egg was not run through the washer but was put on the line after the washer. It came out on the extra large egg line. The lights would come on if there were insult to the egg or excessive impact. The lights would not come on in any plant checked in the Valley. The electromechanical egg was then adjusted by smashing eggs against it so that the lights would not come on when a thin-shelled egg was cracked, but would come on when a good-shelled egg was hit without breaking. Again, the electromechanical egg was run through the processing lines, but the light failed to come on. We were now satisfied that the processing plants were not at fault, even though many eggs were checked during processing. Now the problem seems to have disappeared without being solved. We agree with the processing plant managers that the problem was brittle shells. Even some of the poultrymen will admit the shells were poor and that the processing plants were not responsible for the losses. There are numerous devices to measure egg shell strength and thickness, but there is no simple method for checking brittleness in the shell. In all our years with the poultry business, we have found no problems more difficult to solve than those involving egg quality. In many instances, the problem goes away before the solution has been found. Fred Price Farm Advisor KC) San Joaqu in \ ;I 1 ley PREVENT LOSS IN EGG VALUE DURING WASHING A University of_ California study of 117 different egg washers revealed that washing eggs resulted in a loss of value of almost one-third of a cent per dozen, due to egg shell damage. At 20 dozen eggs per hen, this equals 6.4~ per hen per year. Twenty-six of the 117 washers had Losses of over one-half cent per dozen, and losses in two washers actually exceeded 1% cents per dozen. Loss in value was directly correlated with increasing age. Loss in Egg Value During Washing, By Age of Flock!h!? Loss in Value 20 weeks.07c/dozen : Egg processors should make a routine practice of checking their equipment for excessive breakage. Precandle a sample of at least 500 eggs, mark the cracks, place them on the equip-lent with care, and then recandle to determine the extent of new breakage. Our studies indicate 1.25 percent would be average, but we have seen several individual washers exceed 4.0 percent. Individual producers who allow this problem to persist may easily lose up to 15 to 2Oc per hen per year--a very expensive problem! Donald Bell Farm Advisor Riverside County I I

12 COOPERATIVE EXTENSION U 5 DEPARTMENT OF AGRICULTURE UNIVERSITY OF CALIFORNIA Berkeley, California OFFICIAL BUSINESS Penohy lor Pll ole U5e $300 POSTAGE AND FEES PAID U.S. DEPARTMENT OF AGRICULTURE AGR 101 s. THIRD CLASS THE STORY BEHIND OUR CALIFORNIA POULTRY LETTER This is your first issue of a new newsle'tter written for California egg producers and allied industries. It replaces one or more letters you have been receiving in the past from our Farm Advisor staff. This is a joint project of Advisors and Specialists designed to cut costs and at the same time improve our service to you. We expect to publish on a monthly basis, bringing to you research reports, commentary on field problems, recommendations for improved practices, news items of current interest, and other information we hope will be helpful. Your suggestions on how we can make this a better newsletter are welcome. These, along with requests for addition to the mailing list, should be directed to Ralph Ernst, Department of Avian Sciences, University of California, Davis Ralph Ernst, Editor-in-Chief Milo Swanson, October Editor Poultry Specialist Poultry Specialist Davis Campus Riverside Campus

13 COOPERATIVE EXTENSION UNIVERSITY OF CALIFORNIA I California Poultrv J Letter November 1978 IN THIS ISSUE Controlled Feeding of Layers Feed Quality Problems Force Molting Methods Computer Modeling Drying Poultry Manure Georgia Poultry Industry Egg Wash Water Fatty Liver Shelf Life of Eggs Introduction of Staff CONTROLLED FEE.DING OF LEGHORN LAYERS HOLDS PROMISE For the purpose of evaluating the effects of controlled feeding on laying performance and the economics of egg production, we have conducted a series of experiments in Southern California using open-type housing. In February of 1975, Orange County Controlled Feeding Trial No. 4 was started when two popular strains of pullets were 24 weeks of age. The pullets were placed in standard 12" x 18" cages at the rate of three birds per cage. The diets fed to all treatments during the three- laycycle experiment were identical. Three feeding treatments were imposed on each strain. The first treatment consisted of three l-hour (3-1 Hr.) feeding periods per day (7:00-8:00 a.m., l:oo-2:00 p.m. and 7:00-8:00 p.m.). The second treatment allowed feeding activity during two 2-hour (2-2 Hr.) periods per day (7:00-9:00 a.m. and 7:00-9:00 p.m.). The third treatment served as a control permitting free access to feed 24 hours per day. Access to the feed troughs was controlled mechanically by a plywood lid hinged to the front of the feed trough. Timeclocks, set according to the prescribed treatments, triggered a hydraulic ram and cable system that opened and closed the lids. Although the experiment was conducted for three lay cycles, only the first two cycles will be reported here. For a more detailed account of the experimental procedures and results, refer to P.I.P. No. 11 (August 1978), which can be obtained from your local county farm advisor. Feed consumption of hens given the 3-l Hr. and 2-2 Hr. treatments was reduced an average of 12 percent and 9 percent, respectively, below control hens. This resulted in significant decreases in average body weight and sometimes smaller egg size (Table 1). In most cases, the resulting losses in egg size was reflected in the number of large and medium eggs produced. This loss in the number of large eggs could have been prevented, in part, by supplementing the AVG. EGG AND BODY WEIGHTS FOR THE THREE TREATMENTS (Strains A & B Combined) Table 1 AVERAGE EGG WEIGHT FINAL BODY WEIGHT TREATMENT 1st Cycle 2nd Cycle Comb. 1st Cycle 2nd Cycle Comb. grams pounds 3-l Hr. 58.la* 62.4 b 59.9 b 3.81 b 3.86 b 3.84 b 2-2 Hr. 58.4a 63.lab 60.4ab 3.80 b 3.99ab 3.90 b Full-Fed 58.9a 63.6a 60.9a 4.11a 4.20a 4.16a * Different letters within a column indicate significant differences. The Unlvwrity of California Cooperative Extension in compliance with the Civil Rights Act of 1964, Title IX of the Education Amendments of 1972, and the Rehabilitation Act of 1973 does not discriminate on the basis of rote, creed, religion, color, notional origin, sex, or mental or physical handicap in any of its pogroms or activities. Inquiries regarding this policy may L directed to: Warren E. Schoonov*r, 317 University Hall, University of California, Berkeley, California 94720, (415) University of California and the United States Department of Agricultura cooperatlnp.

14 diet with additional protein. Under most commercial conditions, diet fortification is recommended when limiting feed to laying hens. As can be seen in Table 2, nonsignificant depressions in egg production occurred as a result of the controlled feeding. In addition, the treatments imposed caused significant improvements in feed efficiency in terms of pounds of feed per dozen eggs produced. If we combine the two strains and average the lay cycles together, 3-l Hr. and 2-2 Hr. restriction programs improved feed efficiency approximately 10 and 8 percent, respectively. We can say, then, that in this experiment the full-fed control birds overconsumed in energy by approximately 8 to 10 percent, since there were no significant differences in rate of production. Part of this wasted energy can be accounted for in terms of excess body weight, since the full-fed birds were significantly heavier than the birds on controlled feeding (Table 1). Improved feed efficiency, coupled with little or no effect on egg production, can result in significant savings in spite of losses in egg size if the proper feed-egg price relationships exist. By using the production data obtained from this experiment and average egg and feed prices in the last twelve months (47c, 40~ and 22~ per dozen for large, medium and small eggs, respectively, and $6.06 per 100 pounds of feed), we have determined the average egg income after feed costs per hen housed (Table 3). For simplicity, the-strain data were combined. As a result of the improved feed efficiency, a trend toward higher profit margins was obtained in both lay cycles for both controlled groups. This trend did not become significant, however, until the second cycle. Combined improvements over both lay cycles of 58~ and 70~ per hen were observed for the 3-l Hr. and 2-2 Hr. treatment groups, respectively. Obviously, controlled feeding has its greatest effect on net income when feed prices are high. Another factor which can have an effect on net income is the price spread between large and medium eggs. If we limit the birds to the extent that losses in egg size occur at the same time that premium prices prevail for large eggs, we will be counteracting some of the positive effects gained in feed savings. This countereffect, however, may be economically justified if feed costs are sufficiently high. It becomes apparent, then, that the economic success of limiting energy intake of egg-type layers will depend on both performance data and egg-feed price relationships. The purpose of controlling?eed INTAKE REDUCTION, EGG PRODUCTION, AND FEED EFFICIENCY, BY STRAIN Tab1.e AVERAGE REDUCTION AVERAGE HEN-DAY STRAIN/ IN FEED INTAKE PRODUCTION FEED EFFICIENCY TREATMENT 1st Cycle 2nd Cycle 1st Cycle 2nd Cycle 1st Cycle 2nd Cycle percent percent pounds per dozen A 3-l Hr la* 49.3a 4.07 b 5.56ab 2-2 Hr a 52.8a 4.23ab 5.37 b Full-Fed a 52.6a 4.38a 5.95a B 3-l Hr a 55.6a 3.69 b 4.69 b 2-2 Hr a 54.9a 3.87 b 4.82 b Full-Fed a 53.7a 4.25a 5.38a Different letters within a column for each strain indicate significant differences. -2-

15 I the feed consumption of laying hens is and, therefore, strain should be considto reduce the overconsumption of energy. ered along with age and health of the Proper safeguards should be incorporated flock and environmental conditions when in the nutritional program to prevent practicing contmlled feeding. deficiencies in other essential nutrients so that losses in performance will Doug Kuney not result. Strain differences have been Staff Research Associate observed in this and other experiments Riverside Campus EGG INCOME AFTER FEED COST PER HEN HOUSED (Strains A & B Were Combined) Table 1 TREATMENT 1ST CYCLE 2ND CYCLE COMBINED 3-1 Hr. $3.12a* $1.64ab $4.76ab 2-2 Hr. 3.01a 1.88a 4.89a Full-Fed 2.82a b 4.19 b k Different letters within a column indicate significant differences. ii il r'i FEED QUALITY PROBLEMS During recent months, feed fat is thought to have been the cause of serious problems in commercial layers in three separate instances. In each case, on-farm mixing of feed was involved. This is an example of the type of contamination which can occur in feeds or feed ingredients. Protection against this kind of problem is difficult, but a good quality control program at the mill can help. Incoming ingredients should be carefully sampled before or as they are unloaded. The "Feed Ingredient Sampling Handbook," available from the California Grain and Feed Association, is an excellent guide to proper sampling. Some of these samples should be sent to a reliable lab for analysis. The number analyzed is a management decision and should be based on the previous experience which the mill has had with that ingredient and supplier. However, all samples should be kept until any danger of a problem with that lot of ingredient is past. What Can Ranches Do? Ranches can protect themselves by sampling each load of feed when delivered. These samples should be stored until all danger of a problem has passed. Put them in a clean container or plastic bag and hold them in a rodent-free place. If a problem is encountered, they can have these samples analyzed to see if the feed may have been responsible. Ranch Sampling Good representative samples can be obtained from a load of mixed feed by taking five grab samples evenly spaced during the unloading. To take a grab sample, use a cup sampler or feed scoop. Pass the container completely through the stream for each sample. Put the five samples in a large container and mix thoroughly before taking a smaller (1 or 2 pound) sample to save. Sampling from the tank after delivery is more difficult but can be done with a probe sampler. Again, five evenly distributed samples per truck load are recommended. Ralph A. Ernst Poultry Specialist Davis Campus -3-

16 VARIATIONS IN MOLTING METHODS TESTED We recently completed a trial in which a number of different methods for force molting Leghorn hens were compared. Variables tested were 7 versus 10 days of feed withdrawal, 0 versus 3 days of water removal, and feeding a low protein molt mash versus cracked mile during the rest period, which ended on the 28th day following initiation of the molt. All eight combinations of these variables were included in the test and were imposed on two popular strains of birds. Over the next 36-week period, all groups received a 17 percent protein lay mash. One significant effect noted was a difference in rate of body weight recovery. Those fed milo during the rest period regained their lost weight more rapidly after molting and weighed more at the end of the trial than those fed the low protein mash. POST-MOLT BODY WEIGHTS VS. PRE-MOLT I:;il,...l Faster body weight recovery was probably due to the higher energy and protein levels of the cracked mile. These levels were lower in the molt mash because of the diluting effect of calcium and phosphorus supplements. Another significant treatment effect was observed in egg size. Those hens receiving no water for the first three days of the molting period laid slightly larger eggs and a higher proportion of jumbo eggs than those given water. No other statistically significant treatment differences were obtained in this test. Performance factors evaluated included hen-day and hen-housed production, mortality, feed per hen-day, feed per dozen and per 24-0~. dozen eggs, shell quality, and albumen quality. None of these were affected by feed withdrawal time, presence or absence of water, or type of ration during the rest period. An economic analysis in which current feed and egg prices were used failed to show any significant treatment differences in feed cost per dozen or egg income over feed cost per hen housed. There were, as expected, some differences in performance of the two strains, but these were not associated with molting methods. Our general conclusion from this trial is that simple molting methods can be as effective as more complicated ones. The "University of California" method calls for: 1) eliminating artificial lights in open housing or reducing day length to eight hours in closed housing on day 1; 2) withholding feed for ten days but providing access to water at all times; 3) then feeding cracked grain for two to three weeks to hold the birds out of production; and finally, 4) returning to a regular lighting and feeding program for the remainder of the laying cycle. The above procedure is simple and low in cost. Under our testing conditions, it generally has resulted in performance equal to or better than more complex methods. However, we will continue to evaluate variations and new ideas for any possibility of improving our present recommendations. Milo H. Swanson Extension Avian Scientist Riverside Campus a il i/ -4-

17 FEED WITHDRAWAL TIMES FOR FORCE MOLTING HENS DURING HOT WEATHER During hot weather, it is sometimes difficult to get a good molt (complete stoppage of lay with all hens molting). This trial was designed to compare different periods of time for feed withholding for a molt starting June 1, This project is still in progress and the results are summarized from weeks of age (fourteen weeks following initiation of molt). Feed removal times compared were 7 days, 9, 10-l/2 and 14 days with l/2 day of feed on the afternoon of the 10th day. This was not the original design, but accidental feeding in the afternoon of the tenth day led to the last two treatments. All groups received a molt ration for sixteen days following the feed withholding period. The test was conducted in an open cage house cooled by roof sprinklers. Daily temperature recordings were made at cage height. The daily high temperature ranged from 84 to 96" F during the starvation period with a mean high of Body weights were taken just prior to removal of feed and at various times during the molt period (Figure 1). FIGURE 1. BODY WEIGHTS FOR THE TREATmENTS BEFORE AND DURING THE MOLT AND AT 7 WEEKS Body weight, as a percentage of the original weight, i"s a useful indication of the severity of the molting procedure. One possible indication that feed withholding time can be longer during hot weather was that there was no mortality for any treatment during the first six weeks of the trial. WEEKLY HEN-DAY PRODUCTION BY 4-WEEK PERIODS Table 1 4-WEEK PERIOD DAYS DAYS DAYS DAYS Weeks H.D. % H.D. % H.D. % H.D. % I Hen-day production in Table 1 shows a direct relationship to treatment as expected. A careful analysis at the end of the test will be necessary to compare different molting treatments. W. D. McKeen Farm Advisor San Bernardino County il t il EFFECTS OF FEED SHORTAGES Leghorn hens 65 and 70 weeks of age were subjected to 0, 12, 24, 48 or 72 hours of feed deprivation. Absence of feed for 12 or 24 hours had no significant effect on egg production Days folkwing Feed withdrawal 49 Hens deprived of feed for 48 hours ranged from no pause in production to a pause of less than 7 days while hens deprived of feed for 72 hours had a 7 to 10 day pause in production. It was calculated that hens deprived of feed for 48 and 72 hours lost an average of 3.3 and 5.6 eggs per hen, respectively, when compared to the control group. 7 days 104 days --e --t days l/, dwys _---- Dr. Carroll University Douglas of Florida -5-

18 COMPUTER MODELING -- AN AID TO EGG PRODUCTION REPLACEMENT SCHEDULING PROGRAM NO. 1-"Optimum Replacement Policy" Within the commercial egg industry, we see a wide range of opinions regarding the optimum production period for a flock of chickens. Individual poultrymen will sell their flocks as early as seventy weeks of age while others may keep their flocks to over three years of age. In a 1974 survey of California flocks, we found that nine percent practiced a no-molt policy, 33.5 percent routinely molted every flock once and 22 percent molted every flock twice. The remainder practiced a combination of the three programs -- varying from one flock to another. The basic question poultrymen must ask themselves is, "How long can we profitably lay a flock of chickens?" But to further refine the question, we should add "to maximize returns on investment." When we assume that our housing capacity plus the chickens in the house represents our investment, profits expressed on this hen-housed basis equated to a common period of time can be a meaningful measure of "return on investment." Computer modeling allows us to test a wide range of performance and economic conditions in combinations that would take endless amounts of effort to do otherwise. Performance factors and prices can be varied by flock age and also with the time of the year. This type of an approach can make our projections much more meaningful than previous techniques of merely using a sample set of data for all projections. The University of California has developed a computer program designed to determine an optimum overall replacement policy for an egg production firm. This assumes that the firm has more than one flock. and must maintain a continuous form of operation. For maximum benefits to an individual firm, input data must be representative of attainable performance for that firm. We first ask the manager to describe his current program with as much actual data as possible. Where experience is lacking, we do our best to help him fill in the missing information based upon industry norms. Egg production is described in terms of age at sexual maturity, production peak and production loss with each week of advancing age. Once peak is attained, subsequent production is described as a straight line. In addition, the computer has several standard production curves in storage. Mortality is described as a weekly percentage rate and is broken down into seven different periods. Feed consumption is based upon a standard curve stored in the computer with options of modifying the levels by uniform increments. In addition, poultrymen can-synthesize their own curves by choosing typical feed consumption levels at five-week intervals with computer interpolation of intermediate ages. Distribution of egg size is very difficult to describe and, therefore, we store distribution data on nine different average egg weight curves. These curves are based upon industry surveys and each curve is one-half ounce per dozen heavier than the last. Undergrade eggs are all eggs laid which do not receive the basic number one egg price. These eggs increase in a straightline fashion and are subtracted from the larger egg size categories only. -6-