Cull Dairy Cows Research Articles

Dairy Cow Culling Decision. 1. Techniques for Evaluating the Effect on Herd Income

A technique is described for culling cows on a combination of screening the entire herd on short-term income through next calving interval and then picking the final cull candidate on long-term income. Initial evaluation of the entire herd is on short-term income times the removal of the cull cow during the calving interval. Then, the final comparison of cull candidates on long-term income includes the effect of maturity on performance over probable remaining herd life and allows for the possibility of replacement during the planning period. The combined culling technique estimates both short-term income through next calving interval and long-term income over estimated remaining herd life by future mo. The net present value of long-term income resulting from presently retaining the cow is converted to a uniform annual cash flow. This cash flow peaked for second lactation, held relatively constant through fifth lactation, declined 9% in sixth with an additional 9% decline for later lactations. The pattern of attrition or removal differed from commercial herds in that most voluntary culling for cows that had not reached maturity was in midlactation, not late lactation.

Culling Dairy Cows

Culling decisions present a serious challenge, both for the dairyman and for the veterinarian who provides service to the farm. Culled cows represent a substantial expense to the producer. The cost of rearing youngstock averages approximately 20 percent of the overall operating expenses of a dairy. Rearing excess heifers to replace cows unavoidably lost from production addes a significant burden to the financial load borne by the dairyman.

Effect of trenbolone acetate on ovarian function in culled dairy cows.

The ovarian cycles of 48 culled dairy cows were monitored by assaying plasma progesterone concentrations. Twenty-four cows received a subcutaneous implant of 300 mg trenbolone acetate (Finaplix; Hoechst) at the beginning of the study. Of the implanted cows, two were pregnant, six continued to cycle although their peak progesterone concentrations were significantly lower than in control cows (5.65 +/- 0.71 compared with 8.19 +/- 0.47 ng/ml; P less than 0.01). Prolonged periods (13 to 92 days) of low progesterone concentrations (less than 1 ng/ml) occurred in 12 of the implanted cows. In six of seven cows in which normal cycles had not resumed by the time of slaughter two to five ovarian follicles of diameter greater than or equal to 10 mm were found post mortem. Persistent luteal function (greater than 35 days) occurred in the absence of pregnancy or gross uterine pathology in five of the implanted cows, two of which had recovered spontaneously by the time they were slaughtered. There was no difference in plasma luteinising hormone concentrations between the implanted and control cows. It is concluded that trenbolone acetate affected the ovarian cycle of the cows in several ways through changes other than the modification of tonic luteinising hormone secretion.

Microbiological Screening Tests to Detect Antibiotic Residues in Cull Dairy Cows

Two microbiological procedures were evaluated to detect antibiotic residues in dairy cows at slaughter. Inhibition of Bacillus subtilis growth was used for determining the presence or absence of antibiotic residues. The two tests differed only in the concentration of B. subtilis used. The Swab Test on Premises (STOP) was used to detect antibiotic residues in kidney and muscle tissue and the Live Animal Swab Test (LAST) was used to detect residues in urine of cull dairy cows. Kidney samples from 3% of cull dairy cows were positive. Confirmation by standard reference procedures and a subsequent investigation on antibiotic residues in urine from 317 cows and heifers with known antibiotic treatment histories suggest that a high percentage of false-positive readings occurred in urine. In addition, 23 % of urine samples were difficult to interpret in that B. subtilis growth surrounding Swabs dipped in urine was reduced. While producer response was generally favorable for an on-farm screening test for antibiotic residues detection in cows going to slaughter, interpretation problems, difficulty in collecting urine samples, and concerns over the complexity and sensitivity make it unlikely that the acceptance of the LAST will be widespread on dairy farms.

The effect of feeding period and trenbolone acetate on the potential of culled dairy cows for beef production

ABSTRACTSixty-four Friesian/Holstein cows culled from dairy herds were selected for uniformity and general health. They were allocated to five groups of 12 on the basis of body condition and live weight excluding the two cows at each extreme. These four cows indicated the range of condition and live weight in the sample and were slaughtered at the beginning of the trial with one group of 12 cows. Of the remaining four groups, two were implanted with 300 mg trenbolone acetate (Finaplix, Hoechst) and two used as unimplanted controls; one implanted group and one control group were slaughtered after 60 days and the remaining cows after 100 days. All cows were individually fed to appetite on a pelleted diet of 500 g dried lucerne and 500 g barley per kg. After slaughter the left side of each carcass was cut into primal joints and then separated into fat, lean and bone.Implantation resulted in greater live-weight gains to 60 days (1·35 v. 112 kg/day, P > 0·05) and to 100 days (1·31 v. 0·92 kg/day, P < 0·01), greater lean meat production and an increase in the lean proportion of carcasses.Feeding cows for 100 days rather than for 60 days led to higher slaughter weights but daily live-weight gain decreased and food intake increased progressively between 60 and 100 days. Carcasses from cows slaughtered at 100 days had significantly higher lean, fat and bone weights (P < 0·01) but as a proportion of side weight only the fat proportion of the carcass was significantly increased (P < 0·05).It was concluded that the supplementary feeding of cull cows produced heavier carcasses but at these high rates of gain increased yield was at the expense of proportionately more fat in the carca?.s. This problem was partially countered by implantation with trenbelone acetate.

Factors determining the carcass value of culled dairy cows

Data from 763 cows culled during the period September 1973–May 1982 on two experimental farms have been analysed. The carcass value of each individual cow was adjusted for seasonal fluctuations in price per kilogram carcass weight. The grade was assessed through in vivo scoring by experts of a cooperative slaughterhouse. A model was used for the analysis of the carcass variables considering the effects of farm, age at culling, stage of lactation, breed, season, year and reason for culling. This model explained 40, 52, 44 and 31% of the total variance in carcass value, live weight, grade and dressing percentage, respectively. The correlation of carcass value with live weight, dressing percentage and grade was 0.88, 0.69 and -0.42, respectively.

Efficacy and the Assessment of Hazards of Residues Following the use of Trenbolone Acetate (Finaplix) in Cull Dairy Cows

These experiments investigated the efficacy and safety of the use of anabolic agents for finishing cull dairy cows over a two month period before slaughter. The safety of the treatment was assessed by measuring the residues of trenbolone acetate (TBA) and its metabolites in samples collected during the treatment period and at slaughter.

A possible relationship between the flinch, step and kick response and milk yield in lactating cows

Short-term increases in the milk yield of lactating dairy cows were found to be associated with increases in the occurrence of flinching, stepping and kicking which occurred curred during the milking process. Since the nature of the observed relationship between increased objectionable behaviours during milking and milk yield is unknown, culling dairy cows using behaviour during milking as the sole criterion may not be economically justifiable.

The Role of Dairy Cattle Genes In United States Beef Production

Cattle carrying genes from dairy breeds or dairy-beef crossbreds make up 20 to 25% of the United States beef supply. Dairy breeds may contribute desired growth and milk traits, but compared to beef breeds at equal finish they have lower dressing percent, ratio of gain to feed, and cutout percent; overall palatability of the beef is close to equal. Dairy cows have higher maintenance requirements, longer postpartum intervals, and more teat and udder problems. Cull dairy heifers and cows bred to beef sires for special purposes may be utilized to a greater extent. Crossbred dairy-beef cows may create a desirable blend of traits and exploit heterosis and complementarity. However, a continuous flow of genes from dairies to the beef supply except as a by-product does not appear likely in the short term. Diverting any selection differential from dairy to beef characters, except those of dual benefit, such as calving ease, does not appear warranted. For the long term, research to quantify and clarify cause and effect relationships among characters such as milk production, ratio of muscle to bone, maintenance requirements, appetite, and gastrointesrinal tract capacity should have high priority, because the results would be useful for both dairy and beef production.

THE ASSOCIATION BETWEEN CLINICAL DISEASE, PRODUCTION AND CULLING OF HOLSTEIN-FRIESIAN COWS

A study of the association between disease occurrence, level of production and culling in 18 southern Ontario purebred Holstein-Friesian herds was conducted. The rate of culling increased by approximately 3% per year of age (P < 0.05). Culled cows had lower milk production, were milked longer and had longer calving intervals in the lactation completed prior to culling, than their herdmates (P < 0.05). After control for age effects, the associations between production level and culling were not significant. Culled cows had a lower rate of ketosis and higher rates of foot problems and dystocia in the last completed lactation than nonculled cows. Culled cows had higher rates of nonparturition-related metritis and lower rates of ovarian cystic disease than nonculled cows. Despite the differences in disease occurrence and level of production between culled and nonculled cows, clinical disease(s) observed by veterinarians and poor production explained only a small proportion of culling in dairy cows. Key words: Association, culling, disease, production, Holstein-Friesian

PERFORMANCE AND CARCASS CHARACTERISTICS OF CULL DAIRY COWS GIVEN TESTOSTERONE-ESTRADIOL IMPLANTS

Twenty-eight cull dairy cows of similar physiological age were fed an alfalfa silage, high-moisture corn ration to appetite once daily for 70 days. At the start of the trial, 14 cows were implanted with a growth promotant (Synovex H). All animals maintained a high rate of gain during the feeding period (1.19 kg/day), but there were no differences between implanted and nonimplanted cows both for feedlot performance and carcass characteristics. Key words: Cull cows, implant, growth

Pharmacological aspects of chloramphenicol administration by the intramammary route to lactating dairy cows

Concentrations of chloramphenicol (C M) were determined, by microbiological assay, in the milk and blood serum of 17 culled dairy cows after intramammary infusion of an approved parenteral CM product (Gloveticol) and in the milk of 16 lactating cows after treatment with two approved CM products for intramammary infusion, at dosages ranging from 1 to 30 g/cow. C M was quickly absorbed from the udder into the blood circulation; the doses of 12.5 and 25 g/cow were almost completely absorbed within 20 hours. Absorption half-life (t1/2ab) from fully functioning quarters was 57+/-18 minutes, and the t1/2ab from partially functioning quarters was 125+/-37 minutes. Mean peak serum C M concentrations were 6.1, 16.2, and 37.4 microg/ml after the cows had been infused with 5, 12.5, and 25 g, respectively. These values were considerably higher than the corresponding peak serum C M concentrations reported following intramuscular injection of equivalent doses of the drug. C M residues were not detectible microbiologically in milk from treated quarters 20 hours after treatment with 5 g or 6.25 g, and 36 hours after treatment with 15 g. Drug concentrations in the milk from the non-treated quarters were approximately 70 per cent of the corresponding serum drug levels. Serum CM concentrations of potential therapeutic value in the treatment of gram-negative bacterial infections, i.e. > 5 microg/ml, were maintained for 8 hours after cows had been infused with 12.5 g, and for 12 hours after infusion with 25 g. The implications of the improved systemic availability of C M infused by the intramammary route over the intramuscular route are discussed in terms of potential therapeutic efficacy, local irritation, and duration of drug residues.

Dapsone Residues in Milk and the Organs of Cows After Intramammary and Intrauterine Administration

Dapsone was injected into the udders of lactating and culled dairy cows and the concentration and persistence of the drug in milk and body organs were determined. The drug appeared to be well distributed in the udder and was quickly eliminated, chiefly by absorption into the general blood circulation. Residues in milk were not detected 48, 56 and 60 h after treatment with preparations containing 0·55, 1·0 and 3·0 g dapsone, respectively. When a preparation containing 1·0 g dapsone was injected into a single quarter of the udder of each of several cows, residues were not found in any body organ 48 h after treatment; when two or more quarters were injected, residues were detected in the kidney, urine and bile. Following intrauterine administration of a commercial preparation containing 1·0 g dapsone, the drug was detected in the serum during 24 h and in the milk during 12 h. The presently available microbiological assay methods for the detection of antibiotic residues are unsuitable for the assay of dapsone.

Survey of abomasal parasitism of culled dairy cows in southern Britain.

Survey of abomasal parasitism of culled dairy cows in southern Britain.

Studies of bovine genital tracts: Mycoplasma isolations from dairy cows

Mycoplasma was isolated from the genital tracts of 8 of 96 culled dairy cows. Procedures were used to reduce the possibility of uterine contamination by vaginal fluids. The mycoplasma isolates were identified by the fluorescent antibody technique as: Mycoplasma bovigenitalium (4), M. canadense (1), an untyped bovine pathogen from the mammary gland designed as ST-6 (2), and an isolate that could not be identified with the labeled antibodies used in this study. All isolations were made from vaginal swabs, except in one case of pyometra where M. bovigenitalium was isolated concurrently from the uterus and vagina, along with Pasteurella hemolyticum . These results suggest that mycoplasma may be found in the cervico-vaginal flora of some cattle but are rarely isolated from the uterine environment.

Dehydration in Desert Cattle and Camels

Dehydration in Desert Cattle and Camels

Título en español.

La Estación Experimental Agrícola del Recinto Universitario de Mayagüez llevó a cabo en la Subestación de Corozal un estudio para determinar si es posible que una vaca desechada de un hato lechero pueda criar un becerro adoptivo en adición al suyo. Los datos obtenidos indicaron que estas vacas pueden criar satisfactoriamente los dos becerros hasta los 8 meses de edad. El experimento comprendió dos tratamientos: en el tratamiento I se destetó el becerro adoptivo a los 4 meses de edad, complementándose el pastoreo durante los 4 meses siguientes con 4 libras de alimento concentrado por día por animal. El becerro propio continuó con la madre hasta los 8 meses de edad. En el tratamiento II ambos becerros fueron criados por la madre hasta los 8 mesed de edad. El análisis estadístico de los datos obtenidos indicó que el destete del becerro adoptivo a los 4 meses no es ventajoso. Aunque al término de 8 meses para ambos casos estos becerros pesaron 11.95 libras más que los adoptivos que continuaron con la vaca nodriza durante igual período, el peso adicional no compensa los gastos adicionales incurridos en la compra de alimento, comederos y mano de obra requeridos por estos becerros. A los 4, 6 y 8 meses de edad, las ganancias en peso de los becerros propios fueron significativamente superiores comparadas con las de los adoptivos. El peso al nacer también resultó significativamente superior a favor de los propios. El sexo del becerro no afectó las ganancias al hacerse las comparaciones pertinentes. Se presentan los datos de tasas de ganancia diaria tanto de los becerros propios como de los adoptivos. No se experimentó dificultad alguna respecto de la adopción por parte de la vaca nodriza. El intervalo entre los partos en el caso de las vacas que parieron por lo menos dos veces fue de 395.24 días. Veintitrés de las vacas, nueve de las cuales nunca parieron, tuvieron problemas reproductivos.

Título en español.

Se sacrificaron 102 toros de 18 meses de edad, y se determinó la blandura de su carne mediante el método Warner-Bratzler. Estos animales representaban cruces entre toros Brahman, Charolesa o Angus y vacas lecheras desechadas. Las comparaciones demostraron que los asados de costilla de los cruces con Angus eran más blandos que los de los otros dos cruces. No hubo diferencia significativa en cuanto a la blandura de la "gallina" entre los animales del cruce con Angus y los de cruce con Charolesa, aunque el promedio de la medida de blandura favoreció a los primeros. Se demostró definitivamente en todos los cruces comparados que la "gallina" es más tierna que el asado de costilla.

A note on the influence of parity of dam on daughter heifer performance and on selection of replacements in dairy cattle

One of the causes of culling dairy cows is low milk yield and to the extent that this has any genetic basis one might expect the daughters of old cows to outyield their contemporaries from younger and hence less selected mothers. This is quite apart from any confounding effects resulting from the non-genetic influences of dams' parity. The rate of genetic improvement derived from the culling process will be modified within a population by the extent to which farmers choose to retain the progeny of older rather than younger cows. Milk yields for recorded cows in Scotland, available to the Livestock Records Bureau, have been used to obtain some information on these points.