Effects of metabolizable energy intake on post weaning lamb growth performance, carcass tissue composition and internal fat depend on animal characteristics: A meta-analysis.

This study aimed to establish the quantitative relationship between metabolisable energy intake (MEI) and growth performance, carcass tissue composition and internal fat, taking into consideration animal precocity, maturity and tail nature. Data from 67 publications were used in the meta-analysis. Diets were characterized and three classes were identified (low medium and high energy density diets). Breeds were characterized according to tail nature, precocity and maturity stage. Average daily gain (ADG) responded to MEI in all animals weighing less than 60% of their adult weight regardless their precocity or their tail nature. At the same level of MEI, the higher the diet energy density, the higher the ADG. In animals weighing less than 42% of adult weight and receiving a high starch diet, carcass muscle and internal fat responded to MEI. Whereas, for animals that weighed between 43% and 75% of adult weight, increases in MEI influenced carcass adipose tissue.

In vitro assessment of the anthelmintic activity of Hedysarum carnosum Desf. at different phenological stages and from six locations in Tunisia.

Gastrointestinal nematodes are compromising productivity of grazing sheep and goats. Therefore, scientists have been looking for cost-effective alternative options. Forage legumes (Fabacea Family) contain tannins that could improve livestock performance and their health as well. The present study aimed to (i) determine the in vitro anthelmintic (AH) activity of 19 acetonic extracts of Hedysarum carnosum Desf on Haemonchus contortus by a larval exsheathment assay (LEA); (ii) test the anthelmintic activity of condensed tannins using a deactivating reagent, polyvinylpolypyrrolidone (PVPP); (iii) study the effect of location and the phenological stage on the percentage of exsheathment. The LEA was used at different concentrations (150, 300, 600, 1200 µg mL-1 of acetonic extract/mL of purified buffer solution (PBS)). The larval exsheathment is concentration, location, phenological stage dependent. All extracts, caused a delay of the percentage of exsheathment over 50% so the AH activity of H. carnosum was confirmed. After addition of PVPP, the % exsheathment was similar to the 150 µg mL-1 concentration. The biplot showed that Loc1(S), Loc4(B), Loc 5(PF), Loc 6(BM) and Loc 6(PF) were isolated from other plant extract sample. Our in vitro study showed that H. carnosum seems to be a promising alternative to AH drugs.

Carcass traits and meat fatty acid composition of Barbarine lambs reared on rangelands or indoors on hay and concentrate.

The objective of this study was to compare carcass and meat quality between Barbarine lambs raised on rangelands and those reared indoors. A total of 24 weaned male lambs (23.2 kg) were allotted into two groups. The first group (GS) grazed pasture dominated by natural shrubs and was supplemented with 100 g of concentrate. The second group (HS) received oat hay and 200 to 300 g supplement of the same concentrate in order to obtain the same average daily gain (ADG) as the GS group. Six lambs from each group were slaughtered. Lambs to be slaughtered were randomly identified at the beginning of the trial. Carcass traits (offals percentage, dressing percentage, cuts yield, tissue composition, fatness and conformation) were determined; pH and meat and fat color were measured. Samples from longissimus lumborum were collected to analyze fatty acid composition. The GS group was characterized by a higher offals percentage, associated with higher lungs, heart, liver and kidney percentage. Carcass dressing percentage defined as the rate between hot carcass weight and empty BW was lower by 3.4% in the GS group. No differences were observed for carcass meat yield and carcass and leg compactness. Shoulder bone percentage of the GS group was higher, without differences in fat and lean percentages. Fat thickness, kidney and tail fats were lower in the GS lambs. However, intramuscular fat content was not affected. Percentages of saturated fatty acids and polyunsaturated fatty acids (PUFA) were not modified, whereas levels of n-3 and long n-3PUFA (EPA, DPA and DHA) as well as Δ5 desaturase plus Δ6 desaturase index were higher for the GS group. Thrombogenic and atherogenic indexes were not altered. No significant effects were observed for meat pH, meat and fat color. Despite having the same ADG, lambs from the GS group were less fatty, and their meat was richer in beneficial fatty acids.

Effect of concentrate level and slaughter body weight on growth performances, carcass traits and meat quality of Barbarine lambs fed oat hay based diet.

This study was conducted to evaluate concentrate level (CL) and slaughter body weight (SW) effects on growth performances, carcass traits and meat quality of Barbarine lambs. Twenty-four weaned male lambs (23.1 kg), receiving an oat-hay based diet, were allotted into two groups. The LCL group received low concentrate level (300 g) and the HCL group received high concentrate level (600 g). Lambs were slaughtered at two prefixed weights (35 and 42 kg). For each group and each weight, six lambs were slaughtered. Lambs from HCL group had higher ADG, carcass yields, carcass compactness and subcutaneous fat thickness, and lower carcass meat proportion. CL increase did not affect meat pH, meat and fat color, chemical and fatty acid composition. Late slaughtering improved carcass yields and increased carcass adiposity. However, it did not affect carcass meat proportion and shoulder tissue composition. SW had effect on meat color and fatty acid composition.

Differences in preovulatory follicle dynamics and timing of preovulatory LH surge affect fertility of maiden sheep reared in semi-arid extensive conditions.

In the current study follicular dynamics, pituitary function, ovulatory response and luteal activity of 30 maiden Barbarine sheep were analyzed according to oestrus occurrence and lambing outcome after oestrus synchronisation with cloprostenol. Animals were retrospectively classified in three groups named as O- (n=7, ewes not displaying oestrus), O+L- (n=7, ewes showing oestrus but failing to lamb) and O+L+ (n=16; ewes showing oestrus and lambing thereafter). All the sheep ovulated and daily transrectal ultrasonographies revealed that preovulatory follicles were present at cloprostenol injection in all the animals. In sheep O+L+ and O+L-, 50% and 57% of the ovulatory follicles were the largest follicles at cloprostenol treatment (mean size of 4.1+/-0.26 mm and 4.3+/-0.74 mm, respectively). In O- ewes, the same percentage was higher (86%, P<0.05 when compared to group O+L+; mean size of 4.0+/-0.46 mm). The number of large follicles and the final diameter of the ovulatory follicles at oestrous tended thereafter to be higher in group O+L+ (1.4+/-0.1 and 6.4+/-0.2) than in groups O+L- (1+/-0.2 and 5.7+/-0.36) and O- (0.9+/-0.2 and 5.9+/-0.5, respectively). Conversely, the number of medium follicles at oestrus detection was higher in the group O+L- (2.1+/-0.3, P<0.05) than in the other two groups (1+/-0.2 and 1+/-0.3 for O+L+ and O- respectively). Timing of preovulatory LH surge was earlier for ewes O- (24.0+/-4.75, P<0.05) than for sheep O+L+ and O+L- (37.9+/-2.45 h and 38.0+/-4.75 h, respectively) and 94% of O+L+ ewes had a LH surge between 16 h and 64 h after cloprostenol injection compared to 57% in O+L- and O- groups (P<0.05). Thus, maiden Barbarine sheep failing to display oestrus or conceive showed alterations in their follicular dynamics and, thereafter, pituitary function and ovulatory response.

Free choice consumption of minerals by lambs fed calcium-adequate or calcium-deficient diets.

Four growth trials were conducted to determine whether lambs have the ability to recognize a dietary Ca deficiency and to correct that deficiency by consuming minerals offered free choice. In trial 1, lambs were fed a control or Ca-deficient diet with 0, 1, 5 or 10 mineral choices, only one of which provided Ca. Daily gains and feed efficiencies of lambs fed control diets tended to be superior to those of lambs fed Ca-deficient diets. Consumption of free choice calcium carbonate was greater (P less than .05) for lambs fed Ca-deficient diets than for those fed control diets. However, total Ca intake was greatest (P less than .05) for lambs fed control diets. In trial 2, lambs were fed diets containing .35, .20 or .06% Ca with zero or four mineral choices in either a constant or varied location. Daily gains were highest (P less than .05) for lambs fed the control diet. Performance of lambs fed diets deficient in Ca was not improved by providing free choice minerals. Although free choice Ca intakes were higher (P less than .05) for lambs fed Ca-deficient diets, total intake of Ca decreased with severity of dietary Ca deficiency. In trial 3, lambs were fed a (1) Ca-adequate diet, (2) Ca-deficient diet, (3) Ca-deficient diet with four mineral choices (one of which contained Ca) or (4) Ca-deficient diet with seven times the daily Ca requirement offered once weekly. Lambs fed control diets gained faster (P less than .05) than those fed deficient diets with free choice minerals. Ca intakes were greater (P less than .05) for control lambs than for those fed Ca-deficient diets with Ca available free choice. In trial 4, lambs were fed either a control or a Ca-deficient diet for 42 d. All lambs were then offered both control and Ca-deficient diets in separate compartments of the feed bunks. Although performance, bone and serum data followed trends similar to those observed in trials 1, 2 and 3, differences between treatment groups were not significant. Data from these trials support the recommendation that, when possible, required minerals should be provided in the diet rather than on a free choice basis.