Predicting lean growth while accounting for correlated traits.

Lean tissue growth rate is usually estimated from indirect measurements including growth rate. A procedure to determine prediction equations for lean tissue growth rate is proposed. The procedure restricts the regression of fat growth rate on predicted lean growth rate to be equal to the regression of fat growth rate on actual lean growth rate. The restriction can be phenotypic or genetic if suitable parameter estimates are available. When applied phenotypically, selection on predicted lean tissue growth rate will result in selection differentials for both fat and lean tissue growth rates that are proportional to those obtained by direct selection for lean tissue growth rate. This restriction is desirable because expected correlated changes in fat are used to justify selection for lean tissue growth. Conventional prediction procedures have ignored correlated changes and obscured the original intent of using lean tissue growth rate as a biological selection criterion. When using conventional procedures to predict a biological selection criterion from indirect measurements, changes in important correlated traits may depend more on the choice of indirect measurements than on the choice of selection criterion.     

The Content of β-endorphin-like Immunoreactivity in Porcine Corpus Luteum and the Potential Roles of Progesterone, Oxytocin and Prolactin in the Regulation of β-endorphin Release from Luteal Cells in vitro

The amount of β‐endorphin‐like immunoreactivity (β‐END‐LI) in porcine corpora lutea from several stages of the oestrous cycle and the effects of progesterone, oxytocin, and prolactin on β‐END‐LI secretion in vitro by luteal cells were studied. Porcine corpora lutea obtained on days 1–5, 6–10, 11–13, 14–18, and 19–21 of the cycle were used to prepare extracts for β‐END‐LI determination. Additionally, corpora lutea from days 11–13 and 14–18 were enzymatically dissociated and isolated luteal cells were used for further study of β‐endorphin secretion in vitro. Cells were cultured in serum‐free defined M 199 medium (10⁶ cells/ml) at 37°C under 5% CO₂ in air, for 12 h. The influences of the following factors on β‐END‐LI secretion by luteal cells were tested: progesterone (10^–9, 10^–7 and 10^–5M ), oxytocin (0.01, 0.1, 1 and 10 ng/ml), and prolactin (0.1, 1, 10 and 100 ng/ml). The β‐END‐LI contents in extracts and media were measured by radioimmunoassay. The tissue concentration of β‐END‐LI was lowest on days 1–5 of the cycle (0.35 ± 0.03 ng/g wet tissue). Subsequently, it constantly increased to the highest value on days 14–18 (16.58 ± 0.52 ng/g wet tissue) and on days 19–21 it declined (11.10 ± 0.52 ng/g wet tissue). Progesterone at a low dose (10^–9 M ) resulted in significant (p < 0.05) increases and decreases in β‐END‐LI secretion by luteal cells from days 11–13 and 14–18, respectively. Higher doses of progesterone (10^–7 and 10^–5 M ) had no effect on β‐END‐LI release, compared with the control group. All dose‐levels of oxytocin used decreased β‐END‐LI secretion by luteal cells on days 11–13 and 14–18 of the cycle. Prolactin at doses of 0.1 and 1 ng/ml on days 11–13, and all doses tested on days 14–18 resulted in decreases in β‐END‐LI release from luteal cells. These results document evident changes in β‐END‐LI content in the pig corpus luteum during its development and indicate the potential roles of progesterone, oxytocin, and prolactin in luteal cell secretion of β‐END‐LI.     

Effectiveness of Cabergoline for Termination of Pregnancy in Silver Fox (Vulpes vulpes fulva)

Red foxes ( Vulpes vulpes ) are a major pest species in Europe and Australia. Traditional methods of control such as hunting or poisoning are no longer sufficient or feasible. As with domestic dogs and cats, prolactin (PRL) in the vixen is an essential luteotropin during the second half of gestation. Hence, PRL inhibitors such as cabergoline have been used to induce abortions. Eighteen mated silver fox vixens (three groups of six foxes each) were treated orally with a placebo of paraffin oil (I), or with 15  μ g/kg cabergoline in feed once (II) or twice (III), on day 30 (I and II) or days 30 and 32 (III) post-coitum. Blood samples were taken prior to and after treatments and concentrations of PRL and progesterone (P₄) were determined. Normal parturitions were observed in five of six, five of six and two of six vixens in groups I, II and III, respectively. In group III plasma concentrations of PRL and P₄ decreased significantly but only temporarily. This drop in hormone concentrations was more pronounced in the vixens that did not carry to term. In conclusion, doses in excess of 15  μ g/kg of cabergoline are likely to prevent the development of fetuses to term in pregnant vixens.     

Control of Johne's disease in four commercial dairy herds in Iowa

A 6-year study was conducted in 4 dairy herds in Iowa in which Johne's disease was diagnosed previously. Fecal specimens were collected at 6-month intervals from animals 2 years of age and over for mycobacteriologic examination. Serum samples were obtained at 3-month intervals and tested by enzyme-linked immunosorbent assay (ELISA). The antigen used in the ELISA was a potassium chloride extract of a field strain of Mycobacterium paratuberculosis. The ELISA reactions were observed in 87% of the cows from which M. paratuberculosis was isolated. Dairy producers that participated in the Johne's control program reported reduced economic losses. Increased income was attributed to improved milk production, increased value of vaccinated animals sold as replacements to other dairy herds in which Johne's disease had been diagnosed, and the increased market value of slaughter animals removed from the herd.     

Ultrasonography as an aid to controlled breeding in the llama (Lama glama).

An ultrasonic linear array scanner with a transrectal probe was used to observe ovarian and uterine changes associated with the reproductive cycle in llamas. 'Waves' of follicular development and regression occurred in unstimulated females, during which the dominant follicle reached a maximum size of 9 to 13 mm; both ovaries were equally active. Ovulation was induced by mating in 80 per cent of cases, and when mating was accompanied by the administration of human chorionic gonadotrophin the ovulation rate increased to 90 per cent and the time to ovulation decreased from two to three days to one to two days. Some spontaneous ovulations occurred. Corpora lutea reached a maximum size of 12 mm (non-pregnant) or 14 mm (pregnant) after seven or 16 days, respectively. The lifespan of the corpus luteum was approximately 11 days in non-pregnant llamas and the regression time was advanced by the administration of prostaglandin or embryo recovery. Pregnancy could be diagnosed as early as 19 days after mating.     

Potential attachment area of the first mandibular molar in dogs.

Tooth root and root trunk surface area measurements were taken from 20 first mandibular molar (M1) teeth obtained randomly from canine cadaver specimens. The mean root surface area for all teeth was 497.1 +/- 116.2 mm2. The cumulative surface areas of the mesial (MR) and distal (DR) roots were 251.4 +/- 70.2 mm2 and 211.7 +/- 51.9 mm2, respectively. The root trunk surface area was 34.0 +/- 21.4 mm2. Surface area measurements for individual roots and the root trunk were significantly different. Cumulative individual root surface area (MR + DR) was 93.2% of total root surface area. The MR surface area contributed most to total root surface area (50.6%) and cumulative individual root surface area (54.3%). The mean distance from the beginning of the root trunk to the furcation was 2.1 mm. On the basis of the linear variation of the percentage of root surface area of the M1, 44.6% of the total root surface area was 3 to 7 mm apical to the most coronal aspect of the cementoenamel junction. The MR was heart-shaped, compared with the more cylindrical shape of the DR.     

Persistence and mobility of chlorsulfuron and metsulfuron under different soil and climatic conditions

The persistence and mobility of chlorsulfuron and metsulfuron were studied in Italy at four field locations. Chlorsulfuron was applied pre-emer-gence to wheat at 15 and 30 g a.i. ha^?1 in the autumn of 1986 and metsulfuron early post-emergence at 8 g a.i. ha^?1 in the spring of 1987. Soil samples were taken periodically at each location for 1 year. Trials were conducted until 1989 at three locations. After the wheat harvest in 1989, chlorsulfuron and metsulfuron residues in the soil were measured by bioassay in plots that had been treated annually for 3 years and also in plots that had received single treatments. Chlorsulfuron at both application rates dissipated to levels below 0.3 g a.i. ha^?1 over 12 months at three locations while, at the fourth, which received only 250 mm rain during the study, significant levels of residues were still present after 15 months. The degradation of chlorsulfuron applied at 30 g a.i. ha^?1 followed first-order kinetics, with half-lives of 149, 70, 59 and 51 days at the four locations. Chlorsulfuron mobility was high at three locations while, in the silty clay soil of the fourth, the herbicide was confined to the upper 30 cm, despite the high rainfall. Metsulfuron applied in spring was detected only in the first soil sample collection. It was present in all sampled layers at one location but, in the others, was confined to the surface layer. There was no evidence of herbicide accumulation in the soil with repeated applications. Persistance et mobilité du chlorsulfuron et du met-sulfuron dans différents sols et sous différentes conditions climatiques La persistance et la mobilité du chorsulfuron et du metsulfuron au champ ont étéétudiées en Italie sur quatre sites. Le chlorsulfuron était appliqué en pré-levée sur le blé aux doses de matière active (m.a.) 15 et 30 g ha^?1à l'automne 1986 et le metsulfuron en post-levée précoce à la dose 8 g m.a. ha^?1 au printemps 1987. Des échantillons de sol étaient prélevés périodiquement sur chaque site pendant 1 an. Les essais ont été conduits jusqu'en 1989 sur trois des sites. En 1989, après la récolte du blé. les résidus de chlorsulfuron et de metsulfuron dans le sol ont été mesurés par des essais biologiques dans des parcelles qui avaient été traitées chaque année pendant 3 ans, ainsi que dans des parcelles qui n'avaient reçu qu'un seul traitement. Le chlorsulfuron aux deux doses disparaissait jusqu'à des niveaux inférieurs à 0.3 g m.a. ha^?1 en 12 mois sur trois des sites, alors que sur le quatrième, qui n'a reçu que 250 mm de précipitations pendant l'étude, des résidus étaient présents en quantité significative après 15 mois. La dégradation du chlorsulfuron appliquéà la dose 30 g m.a. ha^?1 suivait une cinétique du premier ordre, avec des demi-vies 149, 70, 59 et 51 j sur les quatre sites. La mobilité du chlorsulfuron était élevée sur trois des sites alors que sur le quatrième oú le sol était une argile limoneuse, l'herbicide était confiné aux 30 cm superficiels en dépit de précipitations élevées. Le metsulfuron appliqué au printemps n'était détecté que dans le premier prélèvement. Sur un des sites, il était présent dans toutes les couches, mais était confinéà la couche superficielle sur les autres sites. Après des applications répétées, aucune accumulation d'herbicide n'était observée dans le sol. Persistenz und Mobilität von Chlorsulfuron und Metsulfuron in verschiedenen Böden und bei unterschiedlicher Witterung Die Persistenz und Mobilität von Chlorsulfuron und Metsulfuron wurden in Italien an 4 Standorten unter Freilandbedingungen untersucht. Chlorsulfuron wurde im Herbst 1986 bei Weizen im Vorauflauf mit 15 und 30 g AS ha^?1 und Metsulfuron im Frühjahr 1987 im frühen Nachauflauf mit 8 g AS ha^?1 angewandt. Von jeder Versuchsfläche wurden über einen Zeitraum von 1 Jahr periodisch Bodenproben entnommen. Die Versuche wurden an 3 Standorten bis 1989 durchgeführt. Nach der Weizenernte 1989 wurden mit Biotests die Rückstände von Chlorsulfuron und Metsulfuron in den Böden mit jährlicher (über 3 Jahre) sowie mit einmaliger Behandlung bestimmt. Die Chlorsulfuron-Rückstände nahmen an 3 Standorten bei beiden Aufwandmengen nach 12 Monaten auf 0,3 g AS ha^?1 ab. Am 4. Standort, wo während der Untersuchung nur 250 mm Niederschlag gefallen waren, wurden nach 15 Monaten noch signifikante Rückstände gefunden. Der Abbau von Chlorsulfuron folgte an allen Standorten bei einer Aufwandmenge von 30 g AS ha^?1 einer Kinetik erster Ordnung mit Halbwertszeiten von 149, 70, 59 und 51 Tagen. Die Mobilität von Chlorsulfuron war an 3 Standorten hoch, während es in dem schluffigen Tonboden des 4. Standortes trotz hohen Niederschlags in den oberen 30 cm verblieb. Das im Frühjahr ausgebrachte Metsulfuron wurde nur in der 1. Bodenprobenserie gefunden. An einem Standort lagen in allen beprobten Bodenschichten Rückstände vor, doch sonst waren sie auf die oberste Bodenschicht beschränkt. Bei wiederholter Anwendung konnte keine Herbizidakkumulation im Boden festgestellt werden.     

The effects of straw disposal and depth of cultivation on the growth, nutrient uptake and yield of winter wheat on a clay and a silt soil

Abstract. Experiments were conducted for one year on two different soil types. On a clay soil straw was either (a) burnt, (b) baled leaving the stubble, or (c) chopped and spread. The soil was tine cultivated to depths of 5, 10 or 15 cm or ploughed to 20 or 30 cm before winter wheat was sown conventionally. In addition, a direct-drilled crop was sown after each straw treatment. On a silt loam soil the direct-drilled, tine cultivated to 15 cm and ploughed to 30 cm treatments following burning or chopping and spreading straw were repeated.
Tine cultivation incorporated less straw than ploughing, decreased plant establishment and early growth but did not decrease yield. Direct-drilling through chopped straw decreased yield on the silt loam but not on the clay soil. Short straw (< 5 cm) was easier to incorporate than longer straw. Ploughing was the most efficient method of straw incorporation because it inverts soil. Early effects on crop growth and nutrient uptake following straw incorporation were transient and associated with large amounts of straw in the seeded layer of soil.     

Isotypic antibody responses in cattle infected with Haemophilus somnus

Bovine antibody responses to Haemophilus somnus were compared on the basis of clinical and bacteriological findings. Serum IgG1 and IgM antibody titres were significantly increased in clinically normal cattle that were bacteriologically positive for H somnus from the nasal or vaginal mucosae compared with clinically normal, negative cows. IgG2 titres did not differ significantly between these two groups. However, IgG2 antibody was significantly higher in animals with H somnus disease (pneumonia or abortion) than in clinically normal cattle (whether bacteriologically positive or negative), while IgG1 and IgM titres did not differ between diseased and bacteriologically positive, clinically normal cattle. These antibody trends were duplicated in experimental H somnus abortion or pneumonia, with the greatest response occurring within the IgG2 subclass. Cattle vaccinated systemically with killed whole H somnus produced a predominant IgG2 response with minimal IgG1 and IgM responses. These results demonstrate that IgG2 antibody is consistently elevated in H somnus disease, and suggest that this response may be useful in discriminating diseased from asymptomatic cattle.     

Nephrolithiasis resulting in intermittent ureteral obstruction in a cow

Bilateral nephrolithiasis with intermittent ureterolithiasis was diagnosed in a 7-year old Holstein cow. Two episodes of ureterolithiasis resulted in severe azotemia which resolved after spontaneous movement of the stone. A third episode of obstruction one year after the initial episode resulted in rupture of one kidney, necessitating euthanasia. The histopathological examination of the kidney was diagnostic for chronic pyelonephritis. Corynebacterium sp. was cultured from a nephrolith. In this case it is believed that the chronic pyelonephritis predisposed to the calculi formation.