Open Access
Size and number variation of adipocytes during the growth of Rasa Aragonesa lambs
(CIHEAM, 1995) Purroy Unanua, Antonio; Mendizábal Aizpuru, José Antonio; Soret Lafraya, Beatriz; Horcada, Alberto; Lizaso, G.; Mendizábal Múgica, Francisco Javier; Arana Navarro, Ana; Producción Agraria; Nekazaritza Ekoizpena
The size and number of adipocytes of different fat depots was studied in 45 male lambs of the Rasa Aragonesa breed, distributed in three groups of 15 lambs (G12, G24, G36), slaughtered respectively at 11.7 ± 0.67,24.5 ± 0.57 and 35.8 ± 1.74 kg live weight (LW) and at an age of 32 ± 5, 89 ± 8 and 123 ± 8 days. G12 lambs were slaughtered on the day of weaning, G24 and G36 lambs were weaned respectively at 16.2 ± 1.32 and 18.3 ± 2.46 kg LW and were fed from then onwards on concentrated fodder and barley straw ad libitum until they were slaughtered. The results obtained show that there is a significant increase in the amount of fat deposited in three internal (omental, mesenteric and kidney knob and channel) fat depots as the LW at slaughter increases (P<0.01). A similar phenomenon occurs in the size of the adipocytes, hypertrophy being more evident between 24 and 36 kg (P<0.01) than between 12 and 24 kg, except in the intermuscular fat depot, where the differences were between the two most extreme weight(P <0.01). The number of adipocytes in the omental and mesenteric fat depots increased significantly during the period of the study (P<0.01) while no variation occurred in the kidney knob and channel fat depot during the same period.
Open Access
Efecto de la alimentación con dietas ricas en acidos grasos poliinsaturados sobre el desarrollo del tejido graso de terneros
(Asociación Interprofesional para el Desarrollo Agrario, 2007) Sayed, S.; Abadía Durán, Silvia; Mendizábal Aizpuru, José Antonio; Arana Navarro, Ana; Soret Lafraya, Beatriz; Albertí, P.; Purroy Unanua, Antonio; Producción Agraria; Nekazaritza Ekoizpena
La carne de vacuno obtenida de terneros cebados con pienso presenta un menor valor de la relación de ácidos grasos poliinsaturados/saturados, beneficioso para la salud humana, que la obtenida de los temeros criados en pasto (Wood et al., 1999). Para contrarrestar este factor se está estudiando la utilización de materias primas con alto contenido en ácidos grasos poliinsaturados (por ejemplo semilla de lino) en las dietas utilizadas en el cebo de terneros. Por otra parte, cuando se utilizan materias primas que pueden dar lugar a grasas insaturadas, de fácil enranciamiento y que pueden acortar la vida útil de la carne, se recomienda la adición en la dieta de los animales de antioxidantes como, por ejemplo, la vitamina E (Robbins et al., 2003). El presente trabajo, englobado en un proyecto más amplio donde se estudia el efecto que la adición de lino y de vitamina E en el pienso de terneros tiene sobre el crecimiento, engrasamiento y características de la carne, se centra en profundizar sobre los posibles efectos que pudieran tener la utilización de estas dietas sobre el desarrollo y la celularidad del tejido graso.
Open Access
Conformación y engrasamiento de terneros de raza Retinta y cruzados RetintaxPirenaica y RetintaxLimusín
(Asociación Interprofesional para el Desarrollo Agrario, 2005) Mendizábal Aizpuru, José Antonio; Alzón, M.; Arana Navarro, Ana; Albertí, P.; Soret Lafraya, Beatriz; Purroy Unanua, Antonio; Producción Agraria; Nekazaritza Ekoizpena
En el presente trabajo se comparan terneros de raza Retinta en pureza y cruzados con dos razas de aptitud cárnica más mejoradas, la Limusín y la Pirenaica, con la finalidad de profundizar en el conocimiento de los parámetros de conformación y engrasamiento que muestran estos genotipos cruzados.
Open Access
Lipogenic enzyme activity in growing Rasa Aragonesa lambs
(CIHEAM, 1995) Arana Navarro, Ana; Soret Lafraya, Beatriz; Corroza Muro, Manuel; Mendizábal Aizpuru, José Antonio; Mendizábal Múgica, Francisco Javier; Horcada, Alberto; Eguinoa Ancho, Paola; Purroy Unanua, Antonio; Producción Agraria; Nekazaritza Ekoizpena; Química Aplicada; Kimika Aplikatua
The lipogenic enzyme activity of the following enzymes was studied: Glycerol 3-phosphate dehydrogenase (G3PDH), fatty acids synthetase (FAS), NADP-Malate dehydrogenase (ME) and Glucose 6-phosphate dehydrogenase (G6PDH) in five fat depots (omental, OM; mesenteric, MES; kidney knob and channel, KKC; subcutaneous, SC; intermuscular, IM) in 45 male Rasa Aragonesa lambs divided into three groups of 15 lambs (G12, G24, G36). They were slaughtered respectively at 11.70 ± 0.67; 24.50 ± 0.57 and 35.80 ± 1.74 kg of live weight (LW) and at 32 ± 5; 89 ± 8, and 123 ± 8 days old. The G12 lambs were slaughtered on the day of weaning, having consumed solely their mother's milk; those in the G24 and G36 groups were weaned at 16.20 ± 1.32 and 18.30 ± 2.46 kg LW respectively, were fed from then onward concentrated fodder and barley straw ad libitum until they were slaughtered. Between 24 and 36 kg LW an increase in the activity of the G3PDH and FAS lipogenic enzymes was observed. The increasine the 'de novo' synthesis (FAS) at 36 kg LW was matched by G6PDH activity, which indicates greater use of acetate as a precursor of fatty acids. Furthermore, the maintenance of ME activity during the period studied would indicate that the glucose rate utilization for the fatty acids synthesis was not modified throughout this period.
Open Access
Effects of addition of linseed and marine algae to the diet on adipose tissue development, fatty acid profile, lipogenic gene expression, and meat quality in lambs
(Public Library of Science, 2016) Urrutia Vera, Olaia; Mendizábal Aizpuru, José Antonio; Insausti Barrenetxea, Kizkitza; Soret Lafraya, Beatriz; Purroy Unanua, Antonio; Arana Navarro, Ana; Producción Agraria; Nekazaritza Ekoizpena
This study examined the effect of linseed and algae on growth and carcass parameters, adipocyte cellularity, fatty acid profile and meat quality and gene expression in subcutaneous and intramuscular adipose tissues (AT) in lambs. After weaning, 33 lambs were fed three diets up to 26.7 ± 0.3 kg: Control diet (barley and soybean); L diet (barley, soybean and 10% linseed) and L-A diet (barley, soybean, 5% linseed and 3.89% algae). Lambs fed L-A diet showed lower average daily gain and greater slaughter age compared to Control and L (P < 0.001). Carcass traits were not affected by L and L-A diets, but a trend towards greater adipocyte diameter was observed in L and L-A in the subcutaneous AT (P = 0.057). Adding either linseed or linseed and algae increased α-linolenic acid and eicosapentaenoic acid contents in both AT (P < 0.001); however, docosahexaenoic acid was increased by L-A (P < 0.001). The n-6/n-3 ratio decreased in L and L-A (P < 0.001). Algae had adverse effects on meat quality, with greater lipid oxidation and reduced ratings for odor and flavor. The expression of lipogenic genes was downregulated in the subcutaneous AT (P < 0.05): acetyl-CoA carboxylase 1 (ACACA) in L and L-A and lipoprotein lipase (LPL) and stearoyl-CoA desaturase (SCD) in L-A. Fatty acid desaturase 1 (FADS1), fatty acid desaturase 2 (FADS2) and fatty acid elongase 5 (ELOVL5) were unaffected. In the subcutaneous AT, supplementing either L or L-A increased peroxisome proliferator-activated receptor gamma (PPARG) and CAAT-enhancer binding protein alpha (CEBPA) (P < 0.05), although it had no effect on sterol regulatory element-binding factor 1 (SREBF1). In the intramuscular AT, expression of ACACA, SCD, FADS1 and FADS2 decreased in L and L-A (P < 0.001) and LPL in L (P < 0.01), but PPARG, CEBPA and SREBF1 were unaffected.