Wheat gluten feed in diets for intensive bull beef production

International audienc

Effect of a viable yeast culture on digestibility and rumen fermentation in sheep fed different types of diets

International audienc

Effet du cimatérol sur le métabolisme de l'azote chez des taurillons à l'engrais

International audienc

Effect of dietary cimaterol on performance and carcass traits in bulls and on aspects of digestion in cattle and sheep

International audienc

Minimal dietary physical structure level for Belgian Blue double-muscled finishing bulls.

The minimal amount of dietary physical structure for Belgian Blue double-muscled fattening bulls was investigated with four feeding regimens. The trial involved 52 bulls weighing 330 kg at the start and 680 kg at slaughter. All diets were fed ad libitum and consisted of concentrates and maize silage in different ratios. The structural value (SV), currently in use in Belgium as an index of dietary physical structure for dairy cattle, of the diets amounted to 0.79, 0.62 and 0.45 units per kg DM for the HSV (high), MSV (moderate) and LSV (low) group, respectively. The fourth group (LSVs) received the same diet as the LSV group, but additional straw was provided ad libitum, to evaluate whether bulls were capable of compensating for a possible lack of physical structure by eating straw. From the start until 600 kg no differences in growth rate were found. From 600 kg until slaughter (680 kg), the LSV group had the highest growth rate (1.35 vs. 1.14 kg$\cdot$d$^{-1}$). That same group also had the highest DM– and NEF-intake during the first 84 days of the trial. Although not significantly different, the MSV group had the highest amount of lean meat in the carcass (776 g$\cdot$kg$^{-1}$) and the lowest amount of fat (100 g$\cdot$kg$^{-1}$). The level of physical structure did not affect meat quality. Overall, no external signs of subclinical or clinical acidosis were observed. The length of the rumen papillae was not affected by the diets. Histological examination of the ruminal epithelium revealed that MSV and LSV exhibited the severest morphological changes. However, it is unclear whether the welfare of these animals was endangered by a shortage of physical structure. Based on the zootechnical performances, no adverse effects were found when feeding a diet with an SV of 0.45$\cdot$kg$^{-1}$ DM.Le seuil de fibrosité d'une ration chez les taurillons Blanc-Bleu Belge culards. Le seuil de fibrosité de la ration a été étudié chez des taurillons Blanc-Bleu Belge culards soumis à quatre régimes différents. L'essai a été réalisé sur 52 taurillons pesant au début de l'expérience 330 kg et à l'abattage 680 kg. Les animaux, nourris ad libitum, ont reçu des rations à base de concentré et d'ensilage de maïs dans des proportions variables. L'indice de fibrosité (actuellement utilisé en Belgique chez les bovins laitiers) des régimes a atteint respectivement 0,79, 0,62 et 0,45 unités par kg de MS pour le groupe HSV (haut), le groupe MSH (modéré) et le groupe LSV (bas). Le quatrième groupe LSVs a reçu le même régime que le groupe LSV, mais complémenté avec de la paille fournie ad libitum, afin d'évaluer si les taurillons sont capables de compenser, en mangeant la paille, la perte de fibrosité de la ration. Du début jusqu'à 600 kg, la vitesse de croissance n'a pas été significativement différente. De 600 kg jusqu'à l'abattage (680 kg) le groupe LSV a eu la vitesse de croissance la plus élevée (1, 35 vs. 1,14 kg$\cdot$j$^{-1}$). Pour ce même groupe, les quantités de matière sèche et d'énergie nette ingérées ont été les plus élevées pendant les 84 premiers jours de l'essai. Bien que non significativement différent, le groupe MSV a eu la proportion la plus élevée de viande maigre dans la carcasse (776 g$\cdot$kg$^{-1}$) et la proportion de gras la plus faible (100 g$\cdot$kg$^{-1}$). La fibrosité des rations n'a pas affecté la qualité de la viande. De façon générale, aucun signe extérieur d'acidose subclinique ou clinique n'a été observé. La longueur des papilles ruminales n'a pas été affectée par le type de rations. L'examen histologique de l'épithélium du rumen a montré que les changements morphologiques ont été les plus sévères pour les groupes MSV et LSV. Cependant, il n'est pas démontré que le bien-être de ces animaux soit altéré par le manque de fibrosité des rations. Aucun effet négatif sur les performances zootechniques n'a été observé avec une ration ayant un indice de fibrosité de 0,45 unité par kg DM

Mode of delivery is associated with different hematological profiles in the newborn calf

Several studies on babies have shown that the type of delivery can influence the hematological and immune status of the newborn. In bovine medicine, some authors reported the hematological pattern of the newborn calf, but never related it with the calving process or other perinatal factors. The purpose of the present study was to evaluate the hematological profile in newborn calves in relation to the type of delivery. A total of 41 healthy calves were enrolled; 16 Friesian calves which were born by vaginal delivery without assistance (VD), and 25 Belgian Blue calves that were born by elective Caesarean section (CS). As soon as the calves were born, a complete clinical examination was performed to verify viability and maturity. At 10 min after birth, 2 mL venous blood was collected to perform the blood gas and acid-base evaluation. Blood samples were subsequently collected from the jugular vein within 30 min after birth, and at 1, 2, 3, 7, and 14 days of age. An automatic analyzer was used to determine hemoglobin concentration (Hb), hematocrit (Ht), and red and white blood cell counts, while differential leukocyte count was performed microscopically. Statistical analysis was applied to assess differences between the groups and within the group for all parameters between each sampling time (P ≤ 0.05). All the calves were born alive, viable, and mature. There were no acidotic calves, but statistical analysis revealed many differences, as higher pH, base excess (BE) (P ≤ 0.05), PO(2) (P < 0.001), and sO(2) (P < 0.0001) in the VD group. Levels of hemoglobin concentration, hematocrit, and red blood cell number were constantly higher in CS calves (P < 0.001). In comparison with the VD calves, white blood cell and neutrophil absolute number were higher at birth and at 14 days of age in the CS group (P < 0.001 and P ≤ 0.05). The mode of delivery, therefore, seems to have an influence on the oxygenation levels and on the hematological and nonspecific immunity profile of the newborn calf

Evidence for placental compensation in cattle

Prenatal development is known to be extremely sensitive to maternal and environmental challenges. In this study, we hypothesize that body growth and lactation during gestation in cattle reduce nutrient availability for the pregnant uterus, with consequences for placental development. Fetal membranes of 16 growing heifers and 27 fully grown cows of the Belgian Blue (BB) breed were compared to determine the effect of body growth on placental development. Furthermore, the fetal membranes of 49 lactating Holstein Friesian (HF) cows and 27 HF heifers were compared to study the impact of dam lactation compared to dam body growth. After parturition, calf birth weight and body measurements of dam and calf were recorded, as well as weight of total fetal membranes, cotyledons and intercotyledonary membranes. All cotyledons were individually measured to calculate both the surface of each individual cotyledon and the total cotyledonary surface per placenta. Total cotyledonary surface was unaffected by breed or the breedxparity interaction. Besides a 0.3 kg lower cotyledonary weight (P=0.007), heifer placentas had a smaller total cotyledonary surface compared with placentas of cows (0.48 +/- 0.017 v. 0.54 +/- 0.014 m(2), respectively, P<0.001). Within the BB breed, fetal membranes of heifers had a 1.5 kg lower total weight and 1.0 kg lower intercotyledonary membrane weight (P<0.005) compared with cows. A cotyledon number of only 91 +/- 5.4 was found in multiparous BB dams, while growing BB heifers had a higher cotyledon number (126 +/- 6.7, P<0.001), but a greater proportion of smaller cotyledons (<40 cm(2)). Within the HF breed, no parity effect on intercotyledonary membrane weight, cotyledon number and individual cotyledonary surface was found. Placental efficiency (calf weight/total cotyledonary surface) was similar in HF and BB heifers but significantly higher in multiparous BB compared with multiparous HF dams (106.0 +/- 20.45 v. 74.3 +/- 12.27 kg/m(2), respectively, P<0.001). Furthermore, a seasonal effect on placental development was found, with winter and spring placentas having smaller cotyledons than summer and fall placentas (P<0.001). Main findings of the present study are that lactation and maternal growth during gestation entail a comparable nutrient diverting constraint, which might alter placental development. However, results suggest that the placenta is able to manage this situation through two potential compensation mechanisms. In early pregnancy the placenta might cope by establishing a higher number of cotyledons, while in late gestation a compensatory expansion of the cotyledonary surface is suggested to meet the nutrient demand of the fetus