Comparative evaluation of udder and body conformation traits of first lactation ¾ Holstein x ¼ Jersey versus Holstein cows = Comparación de las características de conformación de la ubre y el cuerpo de vacas de primera lactancia ¾ Holstein x ¼ Jersey versus Holstein

To facilitate the process of decision-making in selecting specific breeds for crossbreeding, this study aimed to determine the conformation traits of ¾ Holstein (HO) x ¼ Jersey (JE) crossbreds, relative to their pure HO contemporaries during the first lactation. All measurements were objectively recorded on first-calf heifers between 40 and 100 days in milk. Crossbreds had smaller stature (-9.62 cm; P = 0.0001), narrower rump width (-1.55 cm; P = 0.005), shallower body depth (-6.45 cm; P = 0.04), smaller heart girth (-10.43 cm; P = 0.0001), narrower chest width (-2.18 cm; P = 0.006), and lower foot angle (-4.61°; P = 0.02) than HO first-calf heifers. Among udder traits, HO x JE crossbreds had deeper (+3.80 cm; P = 0.006) and narrower (-2.32 cm; P = 0.001) udders with longer front teats (+0.54 cm; P = 0.04) compared with HO. It is suggested that certain aspects of the mammary conformation of ¾ HO x ¼ JE crossbreds, as identified in this study, may be animal-associated risk factors of concern for cow culling, mainly in high input production systems.Con el objetivo de facilitar la selección de razas para cruzamiento se realizó una evaluación comparativa de las características de conformación de vacas cruza ¾ Holstein (HO) x ¼ Jersey (JE) versus vacas HO. Todas las mediciones fueron registradas en vaquillonas de primer parto de 40 a 100 días en lactancia. En relación con la raza HO, para la cruza se registró una menor estatura (-9,62 cm; P = 0,0001), ancho de grupa (-1,55 cm; P = 0,005) y ancho de pecho (-2,18 cm; P = 0,006), más estrechos, profundidad corporal (-6,45 cm; P = 0,04) y perímetro torácico (-10,43 cm; P = 0,0001) menores y menor ángulo de pezuña (-4,61°; P = 0,02). Entre las características de la glándula mamaria, la cruza presentó ubres más profundas (+3,80 cm; P = 0,006) y estrechas (-2,32 cm; P = 0,001), con pezones anteriores más largos (+0,54 cm; P = 0,04) que la raza HO. Se sugiere que ciertos aspectos de la conformación de la glándula mamaria de la cruza ¾ HO x ¼ JE podrían ser factores de riesgo asociados al animal de importancia en el descarte de vacas, principalmente en sistemas lecheros intensificados.EEA RafaelaFil: Bretschneider, Gustavo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Arias, Dario Raul. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Cuatrin, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentin

Estimation of body weight by an indirect measurement method in developing replacement Holstein heifers raised on pasture = Estimación del peso corporal mediante un método indirecto en vaquillonas Holstein de reposición criadas sobre pasturas

Scale is the most accurate means of measuring the actual body weight (BW) in developing heifers. However, when it is not available, indirect tools to estimate BW are needed. The objective of this study was to evaluate the distance between the left and right coxal tuberosity (DLRCT) as potential estimator of shrunk BW (SBW) of developing Holstein heifers as compared with the actual weight measured by an electronic scale. The study included pre-breeding Argentinean Holstein females from 3 to 21 months of age. A dataset comprising 496 observations was used to quantify the relationship between the DLRCT (cm) and the SBW (kg) by the least squared method. The power function Y = 0.131X2.0758, where X = DLRCT provided the best fit (P < 0.0001) for predicting SBW. A dataset comprising 194 observations was used to assess the strength of agreement of the power function. The Lin correlation coefficient value was 0.97 and the computed 95% CI was 0.965-0.979. The mean difference between observed and estimated SBW was -0.99 kg. There was no significant difference (t = -0.83; P = 0.41) in the mean SBW between observed and estimated data. As a predictor of SBW, particularly in heifers ≥ 5 months of age and ≤ 350 kg BW (i.e. ≤ 45 cm), the DLRCT demonstrated to be a useful alternative that can be easily applied during any practice usually performed on replacement heifers, without requiring a squeeze chute.El método más preciso para medir el peso corporal (BW) es la balanza. Sin embargo, cuando la misma no está disponible son necesarios métodos indirectos para estimar el BW. El objetivo de este estudio fue evaluar la distancia entre la tuberosidad coxal izquierda y derecha (DLRCT) como potencial estimador del BW desbastado (SBW) de vaquillonas Holstein en desarrollo, las que fueron pesadas simultáneamente con una balanza electrónica. El estudio incluyó hembras Holstein Argentino preservicio de 3 a 21 meses de edad. Se usaron 496 observaciones para cuantificar la relación entre la DLRCT (cm) y el SBW (kg) por el método de los cuadrados mínimos. La función exponencial Y = 0,131X2,0758, donde X = DLRCT tuvo el mejor ajuste (P < 0,0001) para predecir el SBW. Se emplearon 194 observaciones para validar la función. El coeficiente de correlación de Lin fue 0,97 y el IC 95% fue 0,965-0,979. La diferencia media entre el valor observado y estimado del SBW fue -0,99 kg. No hubo diferencias significativas (t = -0,83; P = 0,41) entre la media observada y estimada del SBW. Como un estimador del SBW, particularmente en vaquillonas ≥ 5 meses de edad y ≤ 350 kg BW (i.e. ≤ 45 cm), la DLRCT demostró ser una alternativa útil que puede ser usada fácilmente durante cualquier práctica habitual realizada sobre las vaquillonas en desarrollo, sin necesidad de instalaciones especiales para la sujeción ni el manipuleo del ganado.EEA RafaelaFil: Bretschneider, Gustavo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Cuatrin, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Arias, Dario Raul. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Vottero, Dante Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentin

Effect of ensiling a total mixed ration on feed quality for cattle in smallholder dairy farms = Efecto de ensilar una ración totalmente mezclada sobre la calidad nutritional para el ganado en pequeñas explotaciones lecheras

The aim of this study was to assess the impact of ensiling a total mixed ration (TMR) on chemical composition, fermentation and sensory characteristics. Whole-plant corn (WPC) was ensiled alone, as a control, or in combination with other available local feeds. Ensiled feedstuffs were manually mixed and packed into mini-silos. Thereafter, they were stored and allowed to ferment for 75 days. Mould growth was not observed. Color was scored as good for both silage treatments, whereas odor was scored as moderate for TMR silage and good for WPC silage. The pattern and rate of decrease of pH during the storage was not different between silage treatments. However, mean pH values were different (P < 0.01; 3.81 vs. 4.38) between WPC- and TMR-silages, respectively. Relative to WPC silage, the concentration of dry matter (DM) (36.58 vs. 64.25 %; P = 0.001), crude protein (9.89 vs. 18.15 %; P = 0.005) and metabolizable energy (P = 0.03; 2.51 vs. 2.80 Mcal/kg DM) was higher for TMR silage, as expected. Furthermore, the neutral detergent fibre content decreased along the storage but at a different rate (P = 0.04) for each silage treatment. The rate of decrease, expressed as percentage/day, was -0.16 and -0.05 for WPC- and TMR- silage, respectively. Overall, TMR silage had adequate attributes to cope with dairy cow requirements. It is suggested that the ensiling of TMR, composed by locally available feedstuffs, is a simple and low cost technology that could aid smallholder dairy to improve their net daily income.El objetivo de este estudio fue determinar el impacto del ensilado sobre la composición química y las características fermentativas y sensoriales de una ración totalmente mezclada (TMR). La planta entera de maíz (WPC) fue ensilada sola, como control, o combinada con otros alimentos disponibles en la región. Los alimentos ensilados se almacenaron en minisilos durante 75 días. No se observó desarrollo de moho. La variable de color se calificó como buena para ambos tratamientos, mientras que el olor se calificó como moderado para el ensilaje de TMR y bueno para el ensilaje de WPC. No hubo diferencias en el patrón y la tasa de disminución del pH entre los tratamientos. Sin embargo, los valores promedios de pH difirieron (P < 0,01; 3.81 vs. 4.38) entre los ensilajes de TMR y de WPC, respectivamente. La concentración de materia seca (MS) (36,58 vs. 64,25 %; P = 0,001), proteína bruta (9,89 vs. 18,15%; P = 0,005) y energía metabolizable (P = 0,03; 2,51 vs. 2,80 Mcal/kg MS) resultó, como era esperado, mayor para el ensilaje de TMR. El contenido de fibra detergente neutro disminuyó durante el almacenamiento, aunque a una velocidad diferente (P = 0,04) para cada tratamiento. Expresada como porcentaje/día, la tasa de disminución fue -0,16 y -0,05 para los ensilajes de WPC y de TMR, respectivamente. Se sugiere que el ensilado de TMR es una tecnología simple y de bajo costo que podría ayudar a mejorar, mediante una mejor alimentación del ganado lechero, los ingresos económicos de los pequeños productores lecheros.EEA RafaelaFil: Bretschneider, Gustavo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Mattera, Juan. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Cuatrin, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Arias, Dario Raul. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Wanzenried Zamora, Rosana Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentin

Productive response to two concentrate allocation strategies in dairy cows grazing with restricted pasture allowance

The objective of this study was to compare the effects of two concentrate allotment strategies on the performance of dairy cows grazing on restricted pasture and supplemented with conserved forage. Dairy cows fed equal amounts of concentrate (fixed daily rate: 5.5 kg DM/cow) were compared to cows supplemented with concentrate according to their lactation stage as follows: 10.0, 5.0, and 1.5 kg DM/cow daily during early, mid, and late lactation, respectively (average daily dose: 5.5 kg DM/cow). There was a supplementation strategy × lactation stage interaction (P < 0.05) for energy-corrected milk (ECM). For early lactation cows, supplementation at a variable rate increased ECM yield by 14.61% (P < 0.05). There was a supplementation strategy × lactation stage interaction (P < 0.05) for body weight change. At late lactation stage, cows supplemented at a fixed rate gained weight (+ 0.16 kg/day), whereas those supplemented at a variable rate lost weight (– 0.08 kg/day; P < 0.05). No significant effect was found for body condition score. The prioritization of milk production rather than the attenuation of body reserve mobilization suggests that concentrate allowance based on lactation stage may be unsuitable for minimizing the negative energy balance in early lactation cows.EEA PergaminoFil: Bretschneider, Gustavo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Agencia de Extensión Rural Necochea; ArgentinaFil: Salado, Eloy Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Cuatrin, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Mattera, Juan. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Forrajeras; ArgentinaFil: Pece, Mariela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Arias, Dario. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Cuffia, Maira. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dieguez, Virginia. Actividad Privada; Argentin

Search for the Bs0→μ+μ−γB_s^0 \rightarrow \mu^+\mu^-\gamma decay

International audienceA search for the fully reconstructed $B_s^0 \rightarrow \mu^+\mu^-\gamma$ decay is performed at the LHCb experiment using proton-proton collisions at $\sqrt{s}=13$ TeV corresponding to an integrated luminosity of $5.4\,\mathrm{fb^{-1}}$. No significant signal is found and upper limits on the branching fraction in intervals of the dimuon mass are set \begin{align} {\cal B}(B_s^0 \rightarrow \mu^+\mu^-\gamma) < 4.2\times10^{-8},~&m(\mu\mu)\in[2m_\mu,~1.70]\,\mathrm{GeV/c^2} ,\nonumber {\cal B}(B_s^0 \rightarrow \mu^+\mu^-\gamma) < 7.7\times10^{-8},~&m(\mu\mu)\in[1.70,~2.88]\,\mathrm{GeV/c^2},\nonumber {\cal B}(B_s^0 \rightarrow \mu^+\mu^-\gamma) < 4.2\times10^{-8},~&m(\mu\mu)\in[3.92 ,~m_{B_s^0}]\,\mathrm{GeV/c^2},\nonumber \end{align} at 95% confidence level. Additionally, upper limits are set on the branching fraction in the $[2m_\mu,~1.70]\,\mathrm{GeV/c^2}$ dimuon mass region excluding the contribution from the intermediate $\phi(1020)$ meson, and in the region combining all dimuon-mass intervals

Measurement of the Branching Fraction of B0→J/ψπ0B^{0} \rightarrow J/\psi \pi^{0} Decays

International audienceThe ratio of branching fractions between $B^{0} \rightarrow J/\psi \pi^{0}$ and $B^{+} \rightarrow J/\psi K^{*+}$ decays is measured with proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb$^{-1}$. The measured value is $\frac{\mathcal{B}_{B^{0} \rightarrow J/\psi \pi^{0}}}{\mathcal{B}_{B^{+} \rightarrow J/\psi K^{*+}}} = (1.153 \pm 0.053 \pm 0.048 ) \times 10^{-2}$, where the first uncertainty is statistical and the second is systematic. The branching fraction for $B^{0} \rightarrow J/\psi \pi^{0}$ decays is determined using the branching fraction of the normalisation channel, resulting in $\mathcal{B}_{B^{0} \rightarrow J/\psi \pi^{0}} = (1.670 \pm 0.077 \pm 0.069 \pm 0.095) \times 10^{-5}$, where the last uncertainty corresponds to that of the external input. This result is consistent with the current world average value and competitive with the most precise single measurement to date

First observation of the Λb0→D+D−Λ\Lambda^0_b \to D^+ D^- \Lambda decay

International audienceThe $\Lambda^0_b \to D^+ D^- \Lambda$ decay is observed for the first time using proton-proton collision data collected by the LHCb experiment at a center-of-mass energy of $13 \mathrm{TeV}$, corresponding to an integrated luminosity of $5.3 \mathrm{fb}^{-1}$. Using the $B^0 \to D^+ D^- K_{\mathrm{S}}^0$ decay as a reference channel, the product of the relative production cross-section and decay branching fractions is measured to be $${\cal R}=\frac{\sigma_{\Lambda^0_b}}{\sigma_{B^0}} \times \frac{{\cal B}(\Lambda^0_b \to D^+ D^- \Lambda)}{{\cal B}(B^0 \to D^+ D^- K_{\mathrm{S}}^0)}=0.179 \pm 0.022 \pm 0.014$$ where the first uncertainty is statistical and the second is systematic. The known branching fraction of the reference channel, ${\cal B}(B^0 \to D^+ D^- K_{\mathrm{S}}^0)$, and the cross-section ratio, $\sigma_{\Lambda^0_b} / \sigma_{B^0}$, previously measured by $\mathrm{LHCb}$ are used to derive the branching fraction of the $\Lambda^0_b \to D^+ D^- \Lambda$ decay $${\cal B}(\Lambda^0_b \to D^+ D^- \Lambda)=(1.24 \pm 0.15 \pm 0.10 \pm 0.28 \pm 0.11) \times 10^{-4},$$ where the third and fourth contributions are due to uncertainties of ${\cal B}(B^0 \to D^+ D^- K_{\mathrm{S}}^0)$ and $\sigma_{\Lambda^0_b} / \sigma_{B^0}$, respectively. Inspection of the $D^+ \Lambda$ and $D^+ D^-$ invariant-mass distributions suggests a rich presence of intermediate resonances in the decay. The $\Lambda^0_b \to D^{*+} D^- \Lambda$ decay is also observed for the first time as a partially reconstructed component in the $D^+ D^- \Lambda$ invariant mass spectrum

Search for the Bs0→μ+μ−γB_s^0 \rightarrow \mu^+\mu^-\gamma decay

International audienceA search for the fully reconstructed $B_s^0 \rightarrow \mu^+\mu^-\gamma$ decay is performed at the LHCb experiment using proton-proton collisions at $\sqrt{s}=13$ TeV corresponding to an integrated luminosity of $5.4\,\mathrm{fb^{-1}}$. No significant signal is found and upper limits on the branching fraction in intervals of the dimuon mass are set \begin{align} {\cal B}(B_s^0 \rightarrow \mu^+\mu^-\gamma) < 4.2\times10^{-8},~&m(\mu\mu)\in[2m_\mu,~1.70]\,\mathrm{GeV/c^2} ,\nonumber {\cal B}(B_s^0 \rightarrow \mu^+\mu^-\gamma) < 7.7\times10^{-8},~&m(\mu\mu)\in[1.70,~2.88]\,\mathrm{GeV/c^2},\nonumber {\cal B}(B_s^0 \rightarrow \mu^+\mu^-\gamma) < 4.2\times10^{-8},~&m(\mu\mu)\in[3.92 ,~m_{B_s^0}]\,\mathrm{GeV/c^2},\nonumber \end{align} at 95% confidence level. Additionally, upper limits are set on the branching fraction in the $[2m_\mu,~1.70]\,\mathrm{GeV/c^2}$ dimuon mass region excluding the contribution from the intermediate $\phi(1020)$ meson, and in the region combining all dimuon-mass intervals

First observation of Λb0→Σc(∗)++D(∗)−K−\Lambda_{b}^{0} \rightarrow \Sigma_c^{(*)++} D^{(*)-} K^{-} decays

International audienceThe four decays, $\Lambda_{b}^{0} \rightarrow \Sigma_c^{(*)++} D^{(*)-} K^{-}$, are observed for the first time using proton-proton collision data collected with the LHCb detector at a centre-of-mass energy of $13\,\rm{TeV}$, corresponding to an integrated luminosity of $6\,\rm{fb}^{-1}$. By considering the $\Lambda_b^0 \rightarrow \Lambda_c^{+} \overline{D}^0 K^{-}$ decay as reference channel, the following branching fraction ratios are measured to be, $$\frac{\cal{B} (\Lambda_{b}^{0} \rightarrow \Sigma_{c}^{++} \rm{D}^{-} {K}^{-})}{\cal{B}(\Lambda_{b}^{0} \rightarrow \Lambda_c^{+} \rm \overline{D}^0 {K}^{-})} = {0.282}\pm{0.016}\pm{0.016}\pm{0.005}, \frac{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_{c}^{*++} \rm {D}^{-} {K}^{-})}{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_c^{++} \rm {D}^{-} {K}^{-})} = {0.460}\pm{0.052}\pm{0.028}, \frac{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_{c}^{++} \rm {D}^{*-} {K}^{-})}{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_c^{++} \rm {D}^{-} {K}^{-})} = {2.261}\pm{0.202}\pm{0.129}\pm{0.046}, \frac{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_{c}^{*++} \rm D^{*-} K^{-})}{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_c^{++} \rm D^{-} K^{-})} = {0.896}\pm{0.137}\pm{0.066}\pm{0.018},$$ where the first uncertainties are statistical, the second are systematic, and the third are due to uncertainties in the branching fractions of intermediate particle decays. These initial observations mark the beginning of pentaquark searches in these modes, with more data set to become available following the LHCb upgrade

First observation of Λb0→Σc(∗)++D(∗)−K−\Lambda_{b}^{0} \rightarrow \Sigma_c^{(*)++} D^{(*)-} K^{-} decays

International audienceThe four decays, $\Lambda_{b}^{0} \rightarrow \Sigma_c^{(*)++} D^{(*)-} K^{-}$, are observed for the first time using proton-proton collision data collected with the LHCb detector at a centre-of-mass energy of $13\,\rm{TeV}$, corresponding to an integrated luminosity of $6\,\rm{fb}^{-1}$. By considering the $\Lambda_b^0 \rightarrow \Lambda_c^{+} \overline{D}^0 K^{-}$ decay as reference channel, the following branching fraction ratios are measured to be, $$\frac{\cal{B} (\Lambda_{b}^{0} \rightarrow \Sigma_{c}^{++} \rm{D}^{-} {K}^{-})}{\cal{B}(\Lambda_{b}^{0} \rightarrow \Lambda_c^{+} \rm \overline{D}^0 {K}^{-})} = {0.282}\pm{0.016}\pm{0.016}\pm{0.005}, \frac{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_{c}^{*++} \rm {D}^{-} {K}^{-})}{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_c^{++} \rm {D}^{-} {K}^{-})} = {0.460}\pm{0.052}\pm{0.028}, \frac{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_{c}^{++} \rm {D}^{*-} {K}^{-})}{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_c^{++} \rm {D}^{-} {K}^{-})} = {2.261}\pm{0.202}\pm{0.129}\pm{0.046}, \frac{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_{c}^{*++} \rm D^{*-} K^{-})}{\cal{B}(\Lambda_{b}^{0} \rightarrow \Sigma_c^{++} \rm D^{-} K^{-})} = {0.896}\pm{0.137}\pm{0.066}\pm{0.018},$$ where the first uncertainties are statistical, the second are systematic, and the third are due to uncertainties in the branching fractions of intermediate particle decays. These initial observations mark the beginning of pentaquark searches in these modes, with more data set to become available following the LHCb upgrade