Filipe Alexandre Boscaro de Castro

Influence of pre and postnatal energy restriction on the productive performance of ewes and lambs

The objective of this study was to evaluate the influence of feeding energy levels during the last third of gestation and lactation on performance of ewes and lambs up to weaning. The experiment was carried out in the sheep raising sector of Universidade Estadual de Londrina (UEL), from August to December of 2007. Thirty-two adult lambs with 105 days of gestation, average live weight of 57.55 kg and average body condition scores of 3.42 were used in the beginning of the experiment. The animals were confined in collective pens, distributed randomly in three treatments: 2.4; 2.2 and 2.0 Mcal of metabolizable energy (ME)/kg of dry matter (DM). Feed supply was ad libitum during the last third of gestation and lactation. Weaning occurred at 70 days. Body weight, body condition score and milk production of ewes and body weight of the lambs were analyzed. There were no significant differences for body weight and body condition of ewes at lambing; however, the level of 2.4 Mcal enabled better results for those characteristics at weaning and higher gain in weight and body condition scoring during the experiment. Severe energetic restriction (2.0 Mcal ME/kg DM) determined lower average daily milk production. Lambs from levels 2.4 and 2.2 presented similar weights in all measurements and were superior to those in level 2.0. Lambs from level 2.4 presented higher average weight gain from birth to weaning. The energetic restriction upon lambs at the end of gestation and during lactation limits the performance of ewes and lambs up to weaning.

Desempenho em confinamento e componentes do peso vivo de cordeiros mestiços de três grupos genéticos

The objective of this research was to evaluate the performance in feedlot and the production of carcass and non-carcass components of lambs from the genetic groups Texel x Hampshire Down (THD), Texel x Ile de France (TIF) and Texel x Suffolk (TS). Seventeen castrated lambs were used, being six THD, six TIF and five TS. The average age and weight at the beginning of the experiment were, respectively, 120 days and 31.0±3.2kg. Lambs were fed lot for 51 days, where they received a daily commercial concentrate ration (18% CP and 74% TDN), in the proportion of 1.5% of body weight, and had free access to chopped in natura sugar cane. There was no significant difference (P>0.05) for weight gain, final weight and body condition score among the genetic groups. However, TS lambs presented greater (P 0.05) among genetic groups for feed conversion. Weights and dressing percentages of hot carcass were also similar among genetic groups. There were few differences among genetic groups for non-carcass components. TS lambs presented greater (P<0.05) percentages of intestines and weights of heart than the other lambs. It can be concluded that in the lamb production any of the genetic groups studied can be used, for their performance and the production of live weight components were quite similar.

Desempenho, consumo e morfometria in vivo de cordeiros Santa Inês alimentados com rações contendo torta de girassol em substituição ao farelo de algodão

This study was conducted with the aim to determine the optimal level of protein replacement of cottonseed meal protein by sunflower cake in diets for Santa Ines lambs, through the evaluation of consumption, weight gain, feed conversion and morphometric measurements. Thirty Santa Ines lambs, bulls, with age and weight at the beginning of the experiment of 80 days and 21.45±2.16kg, respectively, were confined for 60 days. A completely randomized experimental design was used, where the animals were divided into 5 treatments with 6 replicates per treatment. For the treatments, the protein from the cottonseed meal was replaced by the protein of the sunflower cake (0, 20, 40, 60 and 80% of substitutions). For morphometric determinations, the following measurements were taken: pre-slaughter body length, leg length, leg perimeter, height of the dorsum; hip height; chest girth, hip width and chest width. Final weight, dry matter intake and feed conversion were not affected by the experimental diets, although the average daily gain was lower for diets with higher content of sunflower cake. For consumption parameters, there was a difference only in the consumption of ether extract in relation to metabolic weight (g/kg PV 0, 75), where lambs receiving diets with higher levels of sunflower cake ingested larger amounts of ether extract. Regarding the morphometric measurements, there was a linear decrease of the height of the dorsum and hip width with the inclusion of sunflower cake in the diet. The replacement of cottonseed meal protein by sunflower cake protein negatively affected the weight gain of Santa Ines lambs. However, it affected little or nothing the parameters of consumption and in vivo morphometric measurements.

Influence of environmental factors on ponderal performance and morphometric characteristics of lambs of different genetic groups from birth to weaning

The objectives of this work were to evaluate the environmental effects (age of dam, type of birth and sex of lamb) and genetic groups (Hampshire Down and Ile de France, ½ and ¾ Hampshire Down, Ile de France and Suffolk, and ½ Texel) on performance and morphometric characteristics (height, length and heart girth) of lambs; to test regressions to predict live weight of lambs from body measurements; and to describe the growth type of the measurements as function of the weight. Weights and measurements were collected from birth to weaning, every 14 days. For evaluations of performance in relation to environmental effects and genetic groups, only data from birth and from weaning were used; for type of growth all collected data were used. Lambs from younger ewes (2 teeth) presented smaller average for weight at birth, heart girth and height at weaning. Single-birth lambs presented greater averages than twins. Genetic group influenced all traits evaluated, except heart girth at birth and average heart girth gain. Means for birth weight were higher in ¾ Ile de France (3.93±0.16 kg) and lower in ½ Texel lambs (3.04±0.24 kg), and for weaning, they were higher in ½ Texel (14.86±0.87 kg) and lower in Ile de France lambs (11.66±0.83 kg). Year of birth influenced all traits. Heart girth and length showed a negative allometric growth in relation to weight, while between weight and height the relation was positive allometric. The factors that most influenced the performance of lambs from birth to weaning are the type of birth, genetic group and year of birth. Correlations between body weight and morphometric measurements are significant, so it is possible to predict one from the other.

Performance, carcass and meat quality of ewes supplemented with magnesium oxide

The objective of this study was to evaluate the performance, the carcass and meat characteristics of ewes supplemented with magnesium oxide. Eighteen 6-year-old Santa Ines ewes were used in a completely randomized experimental design, where three levels of supplementation (0.0, 0.1 and 0.2% magnesium oxide in the concentrate) were tested, with six replicates. Final weight, weight gain, feed intake and feed conversion were not affected by levels of magnesium supplementation. Hot and cold carcass weights showed linear increasing and quadratic responses, respectively, according to supplementation with magnesium. Carcass measurements such as length, depth, and measures of arm and leg were not affected by supplementation. Depth and width of the longissimus muscle and rib-eye area were not affected; however, marbling and ether extract increased linearly with supplementation. Water loss and color were not affected. Lipid oxidation and shear force were not affected by supplementation, while the myofibrillar fragmentation index showed a quadratic regression. There was a linear decrease in pH with magnesium supplementation. Supplementation with magnesium can improve carcass and meat pH, but can act negatively by increasing the amount of marbling and ether extract of meat.