Cross-breeding cattle for milk production in the tropics: achievements, challenges and opportunities

This paper reviews experiences with cross-breeding for milk production in the tropics. Data were compiled from 23 different studies evaluating the performance of different grades of cross-bred animals as well as local breeds. Relative performance of indigenous breeds compared with different grades of cross-breeds was calculated for three climatic zones. Traits considered were milk yield per lactation, age at first calving, services per conception, lifetime milk yield and total number of lactations completed. At 50 percent Bos taurus blood, lactation milk yields were 2.6, 2.4 and 2.2 times higher than those of local cattle in the highland, tropical wet and dry, and semi-arid climatic zones, respectively; lactation lengths increased by 1.2, 1.2 and 1.9 months in the above-mentioned climatic zones, respectively; there was a reduction in calving interval by 0.8 times and in age at first calving by 0.9 times. Similarly, cross-breds with 50 percent B. taurus genes had 1.8 times higher lifetime milk yields and a 1.2 times higher number of total lactations. Although cross-breeding faces a number of challenges such as better infrastructure, higher demand for health care, there are many advantages of using it. These are higher production per animal, higher income for the families and provision of high-value food. It is therefore likely to continue to be an important livestock improvement tool in the tropics in the future, where farmers can provide sufficient management for maintaining animals with higher input requirements and access to the milk market can be secured

Near-Threshold Production of omega Mesons in the pp -> pp omega Reaction

The total cross section for omega production in the pp -> pp omega reaction has been measured at five c.m. excess energies from 3.8 to 30 MeV. The energy dependence is easily understood in terms of a strong proton-proton final state interaction combined with a smearing over the width of the state. The ratio of near-threshold phi and omega production is consistent with the predictions of a one-pion-exchange model and the degree of violation of the OZI rule is similar to that found in the pi-p -> n omega/phi reactions.Comment: Report in LaTeX2e. 12 pages with 2 eps figure

Comparison of eta and eta' production in the pp -> pp eta(eta') reactions near threshold

The total cross section of the pp -> pp eta' reaction has been measured at two energies near threshold by detecting the final protons in a magnetic spectrometer. The values obtained are about a factor of 70 less than for the corresponding eta production, in good agreement with the predictions of a one-pion-exchange model.Comment: 10 pages, Latex with 3 eps figure

Subthreshold K+ production in deuteron and alpha induced nuclear reactions

Double differential cross sections have been measured for pi+ and K+ emitted around midraidity in d+A and He+A collisions at a beam kinetic energy of 1.15 GeV/nucleon. The total pi+ yield increases by a factor of about 2 when using an alpha projectile instead of a deuteron whereas the K+ yield increases by a factor of about 4. According to transport calculations, the K+ enhancement depends both on the number of hadron-hadron collisions and on the energy available in those collisions: their center-of-mass energy increases with increasing number of projectile nucleons

Body weight gain and carcass yield of llamas (Lama glama) subjected tofattening under four feeding types

Universidad Nacional Agraria La Molina. Escuela de Posgrado. Maestría en Producción AnimalEl objetivo del estudio fue evaluar la ganancia de peso y rendimiento de carcasa dellamas machos diente de leche sometidas a engorde con cuatro tipos de alimentación (T1:Pastura natural; T2: T1 + dosificación vitamínica; T3: T1 + heno de alfalfa; T4: T2 + henode alfalfa). Se utilizó un diseño completamente al azar con arreglo factorial de 2x2 con unanálisis de covarianza (peso vivo inicial como covariable). Se emplearon 32 llamas asig-nadas al azar a uno de los cuatro tratamientos por 84 días. La carga animal empleada fuede 1.3 unidades llama/ha. La ganancia diaria de peso (GDP) se evaluó en los periodos deengorde a 14, 28, 42, 56, 70 y 84 días. La GDP por periodo de engorde fue significativamentediferente entre periodos, donde los primeros tres periodos (14, 28 y 42 días) mostraronmejor GDP (337, 237 y 160 g/d, respectivamente). La GDP por tipo de alimentación fuemayor en T3 (157 g/d) durante el periodo de 84 días (p<0.01) y el mejor rendimiento decarcasa se obtuvo en T4 (53.60%) seguido por el T3 (53.20%) (p<0.01). Se concluye quela mayor GDP se logra hasta los 42 días y el mejor rendimiento de carcasa se logra en lapastura natural + suplementación con heno de alfalfa (T3)The aim of this study was to evaluate the bodyweight gain and carcass yield ofyoung male llamas (milk tooth) subjected to fattening with four types of feeding (T1:Natural pasture; T2: T1 + vitamin injection; T3: T1 + alfalfa hay; T4: T2 + hay alfalfa). A completely randomized design with a 2x2 factorial arrangement with a covariance analysis(initial live weight as covariate) was used. Thirty-two llamas were randomized assignedto one of the four treatments for 84 days. The stocking rate was 1.3 animal units/ha. Dailyweight gain (DWG) was evaluated in the fattening periods at 14, 28, 42, 56, 70 and 84days. The DWG per fattening period was significantly different between periods, in thefirst three periods (14, 28 and 42 days) showing the best DWG (337, 237 and 160 g/d,respectively). The DWG per feed type was higher in T3 (157 g/d) during the 84-dayperiod (p<0.01) and the best carcass yield was obtained in T4 (53.60%) followed by T3(53.20%) (p<0.01). It is concluded that the highest DWG is achieved at day 42 and thebest carcass yield is obtained with natural pasture + alfalfa hay supplementation (T3)

Genetic parameters of characters associated with the uniformity of fibre diameter in alpacas Huacaya in Puno, Peru

El objetivo del presente estudio fue estimar los parámetros genéticos (heredabilidad y correlaciones genéticas) para caracteres asociados a la uniformidad del diámetro de fibra en el vellón de alpacas tuis del fundo Mallkini (Puno, Perú). Se utilizaron muestras de las zonas corporales de muslo, costillar medio y paleta de 1127 animales a la primera esquila (573 machos y 554 hembras) nacidos en 2015 y 2016. Las muestras fueron analizadas bajo la norma IWTO-12 del equipo Sirolan Laserscan. El archivo de pedigrí contaba con 10&nbsp;481 alpacas dando un coeficiente de consanguinidad de 0.16%. Los parámetros genéticos se estimaron mediante los softwares ASReml y Pedigree Viewer. Los caracteres evaluados fueron el diámetro de fibra (DF) y su desviación estándar (DE), coeficiente de variación (CV) y factor de confort (FC). El análisis genético se realizó utilizando un modelo animal multivariado, que incluye el efecto genético aditivo del animal como efecto aleatorio; año de esquila, punta y sexo como efectos fijos, y edad de esquila como covariable lineal. Las heredabilidades para todas las características por zona fueron moderadas (0.12 a 0.38) y para las zonas en conjunto resultaron también moderadas, excepto para el coeficiente de variación (0.17 a 0.43). La correlación genética entre el diámetro de fibra y la desviación estándar mostró un valor elevado y positivo (0.80), mientras que para el factor de confort fue alto y negativo (-0.93) y para el coeficiente de variación fue negativo y bajo (-0.06). En conclusión, existe un alto grado de correlación genética entre el diámetro de fibra (DF) y su desviación estándar (DE), de modo que seleccionando por ambos caracteres se lograría reducir la variabilidad de finura en los vellones. Los caracteres evaluados fueron el diámetro de fibra (DF) y su desviación estándar (DE), coeficiente de variación (CV) y factor de confort (FC). El análisis genético se realizó utilizando un modelo animal multivariado, que incluye el efecto genético aditivo del animal como efecto aleatorio; año de esquila, punta y sexo como efectos fijos; y, edad de esquila como covariable lineal. Las heredabilidades para todas las características por zona fueron moderadas (0,12 a 0,38) y para las zonas en conjunto resultaron también moderadas, excepto para el coeficiente de variación (0.17 a 0.43). La correlación genética entre el diámetro de fibra y la desviación estándar, mostró un valor elevado y positivo (0.80), que no fue el caso para el factor de confort, que tuvo una correlación negativa y alta (-0.93), y con el coeficiente de variación que alcanzo su valor negativo y bajo (-0.06). En concreto, existe un alto grado de correlación genética entre el diámetro de fibra (DF)&nbsp; y su desviación estándar (DE); por lo cual, seleccionando por ambos caracteres lograría &nbsp;reducir la variabilidad de finura en los vellones, y de esta manera poder implementar programas en mejoramiento genético de alpacas. Palabras claves: Alpaca, parámetros genéticos, diámetro de fibra, ASReml.The aim of this study was to estimate the genetic parameters (heritability and genetic correlations) for characters associated with the uniformity of fibre diameter in fleece of young (tuis) alpacas of the Mallkini farm (Puno, Peru). Samples were taken from the thigh, mid-rib and shoulder of 1127 animals at the first shearing (573 males and 554 females) born in 2015 and 2016. The samples were analysed under the IWTO-12 standard of the Sirolan Laserscan equipment. The pedigree file had 10&nbsp;481 alpacas giving a coefficient of inbreeding of 0.16%. The genetic parameters were estimated using ASReml and Pedigree Viewer software. The characters evaluated were the fibre diameter and its standard deviation, coefficient of variation and comfort factor. The genetic analysis was carried out using a multivariate animal model, which includes the additive genetic effect of the animal as a random effect; year of shearing, group/category and sex as fixed effects, and age of shearing as a linear covariable. The heritability for all the characteristics by body area was moderate (0.12 to 0.38) and for the mean of the three body areas was also moderate, except for the coefficient of variation (0.17 to 0.43). The genetic correlation between the fibre diameter and the standard deviation showed a high and positive value (0.80), while for the comfort factor it had a high and negative correlation (-0.93) and for the coefficient of variation was negative and low (-0.06). In conclusion, there is a high degree of genetic correlation between the fibre diameter and its standard deviation, so that selecting for both characters would reduce the variability of fineness in the fleeces

Eta-Helium Quasi-Bound States

The cross section and tensor analysing power t_20 of the d\vec{d}->eta 4He reaction have been measured at six c.m. momenta, 10 < p(eta) < 90 MeV/c. The threshold value of t_20 is consistent with 1/\sqrt{2}, which follows from parity conservation and Bose symmetry. The much slower momentum variation observed for the reaction amplitude, as compared to that for the analogous pd->eta 3He case, suggests strongly the existence of a quasi-bound state in the eta-4He system and optical model fits indicate that this probably also the case for eta-3He.Comment: LaTeX, uses elsart.sty, 10 pages, 3 Postscript figures, Submitted to Physics Letters

The association between body-mass index and patient outcome in septic shock: a retrospective cohort study

Zusammenfassung: HINTERGRUND: Es bestehen keine Daten über die Assoziation zwischen dem Body Mass Index (BMI) bzw. BMI Kategorien und der Mortalität von septischen Schock-patienten. METHODEN: Die Datenbank einer interdisziplinären Intensivstation wurde retrospektiv nach erwachsenen Patienten mit septischem Schock durchsucht. Von allen Patienten wurde der BMI, demographische, klinische und laborchemische Parameter gemeinsam mit Outcomevariabeln dokumentiert. Die Studienpatienten wurden wie folgt anhand des BMI kategorisiert: BMI 30 kg/m2, Fettleibigkeit. Bivariate und multivariate logistische Regressionsmodelle wurden verwendet, um den Zusammenhang zwischen dem BMI und Outcome-variabeln zu untersuchen. RESULTATE: 301 septische Schockpatienten wurden identifiziert. Der BMI war bivariat mit der Mortalität auf der Intensivstation assoziiert (OR, 0,91; 95% CI, 0,86-0,98; p = 0,007). Es gab keine signifikante Assoziation zwischen dem BMI und der Mortalität auf der Intensivstation. Allerdings waren höhere BMI Werte trendmässig mit einer niedrigeren Intensivstations-mortalität assoziiert (OR, 0,93; 95% CI, 0,86-1,01; p = 0,09). Während übergewichtige (OR, 0,43; 95% CI, 0,19-0,98; p = 0,04) und fettleibige (OR, 0,28; 95% CI, 0,08-0,93; p = 0,04) Patienten ein unabhängig niedrigeres Risiko auf der Intensivstation zu versterben hatten als normalgewichtige Patienten, gab es keinen Unterschied im Sterberisiko zwischen normal- und untergewichtigen Patienten (p = 0,22). Ein hoher BMI war unabhängig mit einer geringen Häufigkeit eines akutem Deliriums (p = 0,04) und einer geringeren Intensivwieder-aufnahmerate (p = 0,001), aber mit mehr Harnwegsinfektionen (p = 0,02) assoziiert. SCHLUSSFOLGERUNG: Bis zu einem BMI von 50 kg/m2 scheint keine Assoziation zwischen BMI und schlechterem Überleben auf der Intensivstation oder im Krankenhaus bei septischen Schockpatienten zu bestehen. Im Gegenteil, hohe BMI Werte könnten sogar das Risiko am septischen Schock zu versterben reduziere

Polarisation of the omega meson in the pd-->3He+omega reaction at 1360 and 1450 MeV

The tensor polarisation of omega mesons produced in the pd-->3He+omega reaction has been studied at two energies near threshold. The 3He nuclei were detected in coincidence with the pi0pi+pi- or pi0gamma decay products of the omega. In contrast to the case of phi meson production, the omega mesons are found to be unpolarised. This brings into question the applicability of the Okubo-Zweig-Iizuka rule when comparing the production of vector mesons in low energy hadronic reactions.Comment: 11 pages, 4 figure