Polyunsaturated fatty acid (PUFA) deposition in lambs’ muscles could be influenced by their mothers’ diet. The aim was to study the profile of fatty acids in the muscle of lambs from ewes supplemented with different sources of PUFA to achieve a healthier meat for the consumer. On day 100 of gestation, pregnant ewes grazed on natural grass were divided into three groups (n = 20) and supplemented with PUFA: Group A: 700 g of a ration rich in PUFA, Group B: 700 g of a ration for sheep + 20 mL of fish oil and Group C: 700 g of the same ration. After parturition, each group was subdivided: ten ewes continued with the same diet until the end of lactation; the other ten were fed only natural grass. The values of n-3 and n-6 PUFA and alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid (LA) and arachidonic acid (AA) were analyzed in Longissimus lumborum muscles of lambs at 90 and 120 days of life. The feeding of ewes during lactation favorably influenced the lipid profile of the lamb muscle, increasing the concentration of n-3 and n-6 PUFA, ALA, LA, AA, DHA and EPA. The supplementation of ewes with fish oil and/or a ration rich in PUFA improved the LA/ALA ratio in lambs’ meat.

The objective of this study was to determine the impact of metabolic changes occurring in induced subclinical gestation toxaemia in ewes on metabolic parameters and vigour in the first 72 h of their lambs’ life. Fifty-one adult Corriedale ewes of known gestation date and fed on a natural pasture were randomly divided into four groups at day 145 of gestation. Group A (ewes with single pregnancies) and group C (ewes with twin pregnancies) were fed on a natural pasture [...] ABSTRACT The objective of this study was to determine the impact of metabolic changes occurring in induced subclinical gestation toxaemia in ewes on metabolic parameters and vigour in the first 72 h of their lambs’ life. Fifty-one adult Corriedale ewes of known gestation date and fed on a natural pasture were randomly divided into four groups at day 145 of gestation. Group A (ewes with single pregnancies) and group C (ewes with twin pregnancies) were fed on a natural pasture

Esta revisión sintetiza y discute información sobre los cambios en el metabolismo energético de ovejas gestantes y sus crías recién nacidas, y las modificaciones que induce la esquila preparto sobre el metabolismo y la termorregulación de ovejas gestantes y sus corderos. Durante la gestación la disponibilidad de glucosa en la sangre materna debe aumentar para ser dirigida a la unidad-feto placentaria, promoviendo el adecuado desarrollo fetal, el que es máximo durante el último tercio de la gestación. El aumento de la glucemia preparto en las ovejas se explica por una resistencia transitoria a la insulina. Luego del parto, los neonatos deben preservar su homeostasis, mantener su glucemia y su temperatura corporal en forma independiente en rangos compatibles con la vida. Los neonatos dependen principalmente de las reservas de glucógeno y de la gluconeogénesis para mantener la glucemia, y de las reservas de grasa parda para generar calor. El estatus metabólico de las ovejas durante la gestación influye directamente sobre la cantidad de glucógeno y de grasa parda del cordero al nacimiento. La esquila preparto es un manejo que está siendo cada vez más utilizado por los productores, ya que los corderos nacen más pesados y tienen mayores tasas de supervivencia que los nacidos de ovejas no esquiladas. La esquila preparto adelanta la resistencia a la insulina previa al parto, por lo que la unidad feto-placentaria comienza a captar más glucosa más tempranamente. Consecuentemente, los depósitos de glucógeno muscular y hepático y las reservas de grasa parda son mayores en los neonatos hijos de ovejas esquiladas, y son utilizados como combustibles para la generación de energía y de calor metabólico. En resumen, la esquilada preparto favorece características metabólicas y morfológicas del cordero que aumentan la tasa metabólica y por tanto la generación de calor, lo que reduce las muertes por hipotermia.

The objective of the essay was to determine the influence of protein–energy supplementation on the gastrointestinal nematode population during spring rise in ewes and their offspring as a non–chemical alternative in Integrated Parasite Control. One hundred twenty six Corriedale ewes were divided into two groups, one supplemented with protein–energy blocks from one month before lambing until weaning and the other without supplementation. Every 17 days, faecal matter was randomly collected from 20 ewes and 20 lambs from both groups. Modified McMaster and coproculture were performed, estimating the pathogenicity index for each gender. Lambs´ weight at birth, marking and weaning were recorded and the daily weight gains from birth to marking and from marking to weaning were calculated. Eggs count per gram of faeces were higher (P<0.05) in the non–supplemented group and their lambs. The predominant genus in dams and lambs were Haemonchus contortus and Trichostongylus spp. The pathogenicity index in the non–supplemented dams was higher than 1 from the faecal egg count increase. The lamb body weights and average daily gains were higher in those lambs born to the supplemented dam group (P<0.05). In conclusion, the supplementation contributed to the non–chemical control of the most prevalent gastrointestinal nematode in periparturient ewes, H. contortus, and environmental contamination for lambs at the dam foot.

The objective of the study was to characterize differences in the time to onset of puberty and reproductive variables between East Friesian and Corriedale ewe lambs in an extensive pastoral system. The study was carried out for two consecutive years, and 73 pure-breed ewe lambs were evaluated (35 East Friesian and 38 Corriedale). Plasma progesterone was determined weekly between 4.5±0.5 and 7.2±0.5 months old. The time to onset of puberty was assumed when the progesterone levels were ≥0.6 ng/mL [...] ABSTRACT The objective of the study was to characterize differences in the time to onset of puberty and reproductive variables between East Friesian and Corriedale ewe lambs in an extensive pastoral system. The study was carried out for two consecutive years, and 73 pure-breed ewe lambs were evaluated (35 East Friesian and 38 Corriedale). Plasma progesterone was determined weekly between 4.5±0.5 and 7.2±0.5 months old. The time to onset of puberty was assumed when the progesterone levels were ≥0.6 ng/mL