359 Intake and Growth Performance of Feedlot Lambs Fed Diets with Hi-a and Low-a Corn Cobs and Bermudagrass Hay

Hi-A™ corn is a unique type of lines and hybrids that were developed by the Texas A&M AgriLife Corn Breeding Program and have high anthocyanin and antioxidants. A completely randomized design trial was used to evaluated effects of Hi-A and low-A (regular) corn cobs and bermudagrass hay (BGH) in feedlot diets fed to female Rambouillet lambs (n = 10/treatment), with initial body weight (BW) of 30.7+1.2 kg, on dry matter intake (DMI), BW, average daily gain (ADG), and growth:feed ratio (G:F). After 14 days of adaptation, lambs were individually fed a total mixed ration with 80% concentrate and 20% of one of the roughages (Hi-A, low-A, or BGH) for 63 days. Hay was chopped, while cobs were ground using a hammermill with a 9.52-mm screen. Data were analyzed using repeated-measures ANOVA. The BW was not affected by the diet but increased (P < 0.001) during the trial. Diet did not influence the ADG. However, the ADG was lower (P < 0.001) in the d-42 (0.12 kg/d) than the rest of the trial (0.22 kg/d), after a period of constant high temperatures. The interaction diet vs. day affected (P < 0.05) DMI. In general, lambs increased (P < 0.05) DMI (g/d) and decreased (P < 0.05) relative DMI (%BW) in the final part of the trial, when the animals were getting closer to the harvesting date. Lambs had lower (P < 0.05) DMI of BGH diets than Hi-A diets from d-42 to d-63 and Low-A diets from d-49 to d-56. The G:F ratio was not affected by the diet but decreased (P < 0.05) from the middle to the end of the trial. Corn cobs are valuable as alternative roughage for feedlot lambs, with intake and growth performance comparable to BGH.

PSV-7 Sire fecal egg count EBV are predictive of offspring response to an artificial gastrointestinal nematode infection in Rambouillet sheep

Gastrointestinal nematodes (GIN) pose a significant risk to the health and productivity of Rambouillet sheep, a noted wool and meat producing breed, in the United States. Capturing phenotypic measurements of Rambouillet while infected with GIN is essential for the calculation of estimated breeding values (EBV) as a selection tool to improve host resistance to GIN. Weaned (age= ~120 d.) Rambouillet lambs (n = 75) were each inoculated with 10,000 Haemonchus contortus L3 larvae and placed in a feedlot. Lambs were offspring of two representative sires, A (n = 26) and B (n = 49), with post-weaning fecal egg count EBV (PFEC) from LAMBPLAN, of -9.94 and +9.20%, respectively. Lamb fecal egg count (FEC), packed-cell volume (PCV) and body weight (BWT) measurements were captured at 7-day intervals for 6 subsequent weeks. Actual FEC were loge transformed (lnFEC) to meet normality and then backtransformed least squares means (LSM) are reported. lnFEC, PCV and BWT were analyzed using a mixed model with repeated measures including fixed effects of sex, sire and average daily gain (ADG) classification (for lnFEC and PCV), and sex and sire (for BWT). Significant differences (P = 0.0216) in average lnFEC were observed between offspring from sires A [2242 eggs per gram (epg)] and B (2914 epg). Weekly lnFEC differed (P < 0.0001) and a trend identified between sexes (females = 3414 epg vs males = 2712 epg, P = 0.0909). Interestingly, females exhibited a higher average PCV than males, (34.93% v. 31.15%, P < 0.0001), suggesting potential pathological differences by sex in response to GIN infection. Artificial GIN infections offer a more controlled test than under natural conditions and are a viable option to aid in identifying Rambouillet sheep more resistant to GIN. These results indicate EBV calculated with FEC from a natural GIN infection are predictive of the response of Rambouillet lambs to an artificial infection of H. contortus.

Crude glycerin is an efficient alternative to corn in the diet of feedlot lambs

The objective of this study was to evaluate the intake, digestibility, nitrogen balance, and performance of feedlot lambs fed diets containing crude glycerin. A total of 30 Ile de France lambs were confined to individual pens at an average age of 45 d: 15.1 kg initial body weight and 32.2 kg final body weight. The animals were distributed in a completely randomized design and fed three diets containing fresh sugarcane as forage (50 %) and concentrate (50 %), with or without the inclusion of 100 and 200 g vegetable crude glycerin per kilogram dry matter (DM) replacing corn. Dietary glycerin inclusion reduced the intake of ether extract (P<0.001) and total carbohydrates (P=0.048) as well as the apparent digestibility of ether extract (P<0.001), but it had no effect on the intake and digestibility of the other nutrients nor on lamb performance. The apparent nitrogen balance of lambs on the three diets was positive. Although it does not affect the intake and digestibility of most nutrients, the inclusion of 100 and 200 g kg−1 DM of crude glycerin in the diet tends to worsen lamb performance, indicating that the ideal level of inclusion should be below 100 g kg−1 DM of crude glycerin.

Effect of Feeding Frequency on Intake, Digestibility, Ingestive Behavior, Performance, Carcass Characteristics, and Meat Quality of Male Feedlot Lambs

The study was conducted to evaluate the effects of feeding frequencies (one, two, three, and four times per day) on the performance of male feedlot lambs. Forty Santa Inês male lambs were used with an average age of 120 days approximately and initial body weight of 24.90 ± 1.8 kg (mean ± S.D.). The lambs were distributed to treatment groups in a completely randomized experimental design, with 10 animals per treatment, placed in individual pens. A standard diet consisted of Tifton-85 hay and concentrate with a ratio of 60:40, respectively. The different feeding frequencies did not influence (p > 0.05) the intake of nutritional components, blood parameters, weight gain, ingestive behavior, carcass characteristics, or meat quality of male feedlot lambs. The feeding frequency of 3 and 4 times per day promoted the highest digestibility of neutral detergent fiber (NDF; p = 0.008) and total digestible nutrients (TDN; p = 0.002). The feeding frequency of 3 times per day promoted the highest digestibility of crude protein (CP; p = 0.005). The time devoted to rumination (min/kg DM) was increased (p = 0.029) when the diet was supplied once a day compared to the other feeding frequencies. Based on these results, the recommended feeding frequency for male feedlot lambs is once a day. When feeding at this frequency, the ingestive behavior, productivity, carcass characteristics, and meat quality of male feedlot lambs will not be compromised.

In vitro ruminal fermentation kinetics of diets with crambe cake protein replacing soybean meal protein by gas production technique

The objective of this study was to evaluate ingredients and diets containing increasing levels of crambe cake protein replacing soybean meal protein, with in vitro ruminal fermentation parameters using a gas production technique. Diets were formulated for feedlot lambs and contained different levels of crambe cake protein (0, 250, 500, 750, and 1000 g kg-1) replacing soybean meal protein. Corn silage was used as roughage. Carbohydrate digestion rates were estimated using the in vitro gas production technique and the cumulative gas production kinetics were analyzed using the bicompartmental logistic model. The parameters values of ruminal degradation kinetics were generated using the R statistical program with the Gauss-Newton algorithm and then subjected to analysis of variance and regression (when necessary) according to a completely randomized experimental design with five treatments and five replications. Upon carbohydrate fractionation of ingredients and experimental diets, it was observed that corn grain and corn silage presented the highest levels of total carbohydrates (TC), with values of 128.3 and 464.8 g kg-1 dry matter (DM) in fraction B2, respectively. Lower TC content was found for soybean meal and crambe cake (CC). There was a predominance of fractions A + B1 in the ingredients and experimental diets. The B2 fraction decreased in the diets with the inclusion of the CC protein, and CC presented the highest C fraction. Protein fractionation (g kg-1 DM and g kg-1 crude protein - CP), the ingredients and diets showed a higher proportion of fractions A and B1 + B2. In in vitro degradation, the diet without CC (0 g kg-1 DM) showed the highest final cumulative gas production (365.04 mL g-1 of incubated DM), while the CC presented the lowest volume (166.68 mL g-1 of incubated DM). The gas volume of non-fibrous carbohydrate fermentation and fibrous carbohydrate degradation rate exhibited a quadratic effect according increasing levels of CC (Pmax = 265.8 g kg-1 DM and Pmin = 376.3 g kg-1 DM, respectively). The lag time and final gas volume showed a decreasing linear effect with increasing levels of CC protein. The degradation rate of non-fibrous carbohydrates and the final volume of fibrous carbohydrates did not differ. Replacing soybean meal protein with CC protein at the level of 250 g kg-1 of dry matter in diets formulated for feedlot lambs leads to good profiles of ruminal fermentation kinetics with respect to the degradation of fibrous and non-fibrous carbohydrates.

Feedlot-finishing lambs with different levels of soybean pre-cleaning by-product as the roughage source

An experiment was conducted in the Sheep Farming Laboratory at the Federal University of Santa Maria to examine the effect of different levels of replacement of sorghum silage with soybean pre-cleaning by-product (SPCB) on nutrient intake, performance and feeding behavior; as well as to undertake an economic analysis of feeding finishing lambs in a feedlot system. The study involved 32 uncastrated Texel × Ile de France crossbred male lambs weaned at 60 days of age. Treatments consisted of diets in which the roughage source (sorghum silage) was replaced with SPCB at the levels of 0, 33.5, 66.5 or 100% (DM basis). A 45:55 roughage:concentrate ratio was used (DM basis). The diets were composed of a roughage feed based on sorghum silage and/or SPCB, and a concentrate consisting of crushed maize, soybean meal and limestone. In addition, mineral salt was freely available to the animals. The lambs were slaughtered upon reaching the pre-established live weight of 35 kg. Intake on a DM basis showed a quadratic response (P ≤ 0.05) in all forms it was evaluated and expressed, except for the NDF fraction, which increased linearly (P ≤ 0.05) with SPCB inclusion. Average daily weight gain was not significantly influenced (P > 0.05) by the different SPCB levels, averaging 292 g/day. As regards the feeding behavior characteristics evaluated, the number of daily feeding bouts increased linearly (P ≤ 0.01) with the SPCB content of the diets. Total feed cost decreased linearly (P ≤ 0.01), whereas the profit per kilogram of gain and profit obtained per day in the feedlot period increased linearly (P ≤ 0.01) with SPCB inclusion. The use of soybean pre-cleaning by-product as the roughage source in the finishing of feedlot lambs proved to be a viable alternative in both the productive and economic terms.

Effects of Algae Meal Supplementation in Feedlot Lambs with Competent Reticular Groove Reflex on Growth Performance, Carcass Traits and Meat Characteristics

There is growing interest in increasing omega-3 fatty acid (FA) contents in ruminant meat by means of dietary manipulation, but the effects of such manipulation on productive results and meat quality need to be ascertained. The aim of the present study was to assess the effects of supplementing lambs with competent reticular groove reflex (RGR) with marine algae as a source of omega-3 fatty acids on growth performance, carcass traits, and meat quality characteristics. Forty-eight feedlot lambs were distributed into three equal groups: the control group neither consumed marine algae nor had competent RGR, the second group received daily 2.5% of algae meal mixed in the concentrate, and the last group consumed the same amount of algae meal, but emulsified in a milk replacer and bottle-fed. Lambs in the second and third groups had competent RGR. There were not any negative effects on performance, carcass or meat quality parameters with algae supplementation. However, the results of the oxidative stability parameters were not conclusive. Ageing for 6 days improved meat tenderness and color, and increased lipid oxidation. In conclusion, algae meal inclusion in the diet of fattening lambs with competent RGR has no detrimental effects on animal performance, carcass traits or meat quality characteristics.

Analysis of the productive and immune response of lambs infected with gastrointestinal nematodes and fed with saccharin

Objective: Determine the productive and immune response of Blackbelly lambs infectedwith gastrointestinal nematodes (GIN) and fed with saccharin.Design/ methodology/ approach: A total of 18 Blackbelly lambs, with an initial live weight (LW) of 13.9 + 3.2 kg, were randomly assigned to three different treatments (T): T1, anthelmintic treatment + basal diet (CTah); T2, basal diet without anthelmintic treatment (STah); and T3, grazing lambs without anthelmintic treatment (STPS). This experiment followed a completely randomized design with repeated measures over time; mean values were compared using Lsmeans. The parameters evaluated included live weight (LW), fecal egg count per gram (FEC), packed-cell volume (PCV), plasma protein (PP), white blood celldifferential count (LEU), and IgA concentration by ELISA with Haemonchus contortusand Trichostrongylus colubriformis antigens.Results: STah and CTah lambs showed higher FEC (885 ± 142) and LW (29.73 ± 5.06kg). Grazing lambs (STPS) had lower PCV (26.4 ± 0.5%) compared to the STah andCTah lambs (27.4 to 28.4%) due to the high prevalence of H. contortus. The IgAconcentration in grazing lambs ranged from 20.2 to 24.5% of the positive standardserum titer. The feedlot lambs (STah and CTah) showed values close to 5%.Study limitations/ implications: Due to anthelmintic resistance problems, it wasimpossible to maintain grazing lambs free of infection; therefore, this group was notincluded.Findings/ conclusions: Saccharin increases sheep resilience and achieves adequateweight gains in parasitized lambs.