This study evaluated the impact of supplementing ZH in combination with D3 on the growth performance, energy efficiency, carcass traits, and meat quality of feedlot lambs. Thirty-two Dorper × Katahdin cross lambs (37.3 ± 5.72 kg) were utilized in a 29 d experiment in a completely randomized block design with a 2 × 2 factorial structure consisting of two levels of ZH for 26 d (0 and 0.20 mg/kg PV⁻¹) and two levels of D3 for 7 d (0 and 1.5 × 10⁶ IU/d⁻¹). ZH improved (p ≤ 0.05) the average daily gain (ADG) and feed efficiency by 9.9% and 17.8%, respectively, as well as hot carcass weight (HCW) and dressing carcass by 4.3% and 2.6%, respectively. (p ≤ 0.03). However, ZH increased (p < 0.01) muscle pH and Warner–Bratzler shear force (WBSF) (2.5 and 23.0%, respectively). D3 supplementation negatively affected (p ≤ 0.02) dry matter intake (DMI) (last 7 d) and ADG by 15.7% and 18.1%. On the other hand, D3 improved the pH of the longissimus thoracis muscle by 1.7% (p = 0.03) without affecting WBSF. When D3 was supplemented in combination with ZH, it was observed that meat quality was improved by reducing muscle pH compared to lambs treated only with ZH. However, D3 did not improve the meat tenderness negatively affected by ZH supplementation.

The objective of this study was to evaluate the effects of zilpaterol hydrochloride supplementation strategies on growth performance, dietary energetics, carcass traits, and meat quality in feedlot finishing lambs. Twenty-four Dorper × Katahdin crossbred male lambs (45.5 ± 4.53 kg, mean ± SD) were used in a 27 d feeding trial. The zilpaterol supplementation strategies were: (1) control, no zilpaterol supplementation (CON); (2) zilpaterol administered once daily as a full dose in the morning feeding (ZMOR); (3) zilpaterol incorporated into the total mixed ration and continuously available throughout the day (ZMIX); and (4) intermittent zilpaterol supplementation applied in a daily alternating pattern, one day on, one day off (ZINT). A target dose of 0.20 mg/kg live weight of zilpaterol hydrochloride per administration was used for all supplemented treatments, with daily administration in ZMOR and ZMIX and alternate-day administration in ZINT. Compared to the CON, zilpaterol supplementation through the ZMOR + ZMIX strategies improved average daily gain (ADG) and feed efficiency (FE) by 28.6% and 18.5%, respectively. Additionally, dressing percentage and longissimus thoracis muscle area increased by 3.2% and 17.0%, respectively. The ZINT strategy also enhanced ADG by 20.9% and FE by 15.4%. However, ZINT did not improve hot carcass weight or dressing percentage. All zilpaterol supplementation strategies increased meat toughness by up to 39.2%. Results indicate that both the ZMOR and ZMIX strategies optimize the response to zilpaterol, with no evidence that ZMOR supplementation results in a diminished response.

The study evaluated the impact of supplementing ZH in combination with D3 on growth performance, energy efficiency, carcass traits, and meat quality of feedlot lambs. Thirty-two Dorper x Katahdin cross lambs (37.3±5.72 kg) were utilized in a 29 d experiment in a complete randomized block design with a 2x2 factorial structure consisting of two levels of ZH for 26 d (0 and 0.20 mg /kg PV-1) and two levels of D3 for 7 d (0 and 1.5x106 IU/d-1). ZH improved (P≤0.05) average daily gain (ADG) and feed efficiency by 9.9% and 17.8%, respectively, as well as hot carcass weight (HCW) and dressing carcass by 4.3% and 2.6%, respectively. (p≤0.03). However, ZH increased (p<0.01) muscle pH and Warner-Bratzler shear force (WBSF) (2.5 and 23.0%, respectively). D3 supplementation negatively affected (P≤0.02) dry matter intake (DMI) (last 7 d) and ADG by 15.7% and 18.1%. On the other hand, D3 improved the pH of the longissimus muscle (LM) by 1.7% (p=0.03) without affecting WBSF. When D3 was supplemented in combination with ZH, it was observed that meat quality was improved by reducing muscle pH compared to lambs treated only with ZH. However, D3 did not improve meat tenderness produced by ZH supplementation.

Salmonella spp. es una bacteria patógena perteneciente a la familia Enterobacteriaceae que puede adaptarse a diferentes condiciones ambientales y está distribuida ampliamente a nivel mundial. Puede provocar enfermedades transmitidas por los alimentos (ETA) en humanos, siendo los adultos mayores y los menores de 5 años los más afectados. Las frutas y verduras son alimentos que pueden contaminarse con Salmonella spp. a través del agua de riego, suelo o en cualquier etapa de la cadena agroalimentaria. Las principales cepas de Salmonella implicadas en ETAs son S. Thompson, S. Kiambu, S. Agona, S. Gaminara, S. Senftenberg; S. Enteritidis, S. Typhimurium, S. Anatum, S. Agona, S. Arizonae, S. Havana S. Javiana, S. Newport, S. Carrau, S. Braenderup, S. Saintpaul, S. Poona, S. Carrau, S. Uganda, S. Oranienburg y S. Sundsvall. Para reducir la propagación de Salmonella spp. se requieren medidas de control que se apliquen desde la etapa de producción a nivel de campo y terminen cuando los productos llegan a la mesa del consumidor. Existen normas de manipulación y seguridad de alimentos; su aplicación, permite garantizar la inocuidad de los alimentos y prevenir brotes de enfermedades transmitidas alimentos.

Diversos factores influyen en la muerte al arribo (MaA) del pollo de engorda a la planta de procesamiento. Para determinar el efecto de la combinación de factores ambientales en la MaA por categoría (aves ligeras y pesadas) y turno de producción, se realizó un estudio transversal de asociación durante el otoño en clima cálido subhúmedo extremoso. Se registró la temperatura ambiente, humedad relativa, Índice de Temperatura y Humedad (ITH) y tiempo de espera. La frecuencia de MaA por categoría de producción fue similar (0.15%; P>0.05). En el turno matutino las aves estuvieron en confort térmico (ITH 27.0) vs. emergencia térmica en el turno vespertino (ITH 36.0). Tiempo de espera superior a 121 minutos incrementó MaA en pollos de peso ligero (0.20%; P=0.003). La mayor frecuencia de MaA ocurre en condiciones severas y emergencia térmica (0.16%; P<0.005).

Twenty-four Pelibuey × Katahdin lambs were used under a randomized complete block design to evaluate the impact of filtering drinking water on growth-performance. Treatments consisted of ad libitum supply of filtered dam water (FILT; 256 ppm TDS) and unfiltered dam water (RAW; 776 ppm TDS). The experiment lasted 89 days. Based on TDS content, both FILT and RAW qualify as "safe drinking water" for livestock. However, water intake was 10% higher in lambs receiving FILT. Moreover, FILT consumption improved daily weight gain (8%, P = 0.03) and dietary energy utilization efficiency (2.9% P = 0.04). The results of this study indicate that filtering the water qualified as "safe" improves the productive performance of finishing lambs.