Behaviour Of Lambs Research Articles

Ensiling Sorghum with Urea, Aerobic Exposure and Effects on Intake, Digestibility, Ingestive Behaviour and Blood Parameters of Feedlot Lambs.

This study was carried out to evaluate the effect of ensiling sorghum silage with urea and amending the aerobic exposure nutrients intake and apparent digestibility, ingestive behaviour and blood serum metabolites of feedlot lambs. Forty uncastrated crossbred Dorper × Santa Inês lambs, aged 150 ± 15 days and with an initial body weight of 21.73 ± 2.40 kg, were used. Animals were assigned in a 2 × 3 factorial arrangement. Thus, six silage diets were produced with various urea addition levels (UA: 0 and 5 g/kg on a natural matter basis) and periods of aerobic exposure of silages (PAE: 0, 24 and 48 h). An effect was observed for nutrient intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fibre corrected for ash and protein (NDFap) and total digestive nutrients TDN (g/day) and for the total apparent digestibility of DM, OM and CP. There was an interaction effect between urea levels and aerobic exposure for ether extract (EE) and NDFap intakes (g/kg) and nonfibrous carbohydrate (NFC) digestibility (g/kg) (p = 0.012). The addition of 5 g/kg of urea to sorghum ensilage improved the digestibility parameters without changing dry matter intake and ingestive behaviour. The addition or not of urea does not change the blood parameters of the animals.

The effect of different processing methods of linseed on growth performance, nutrient digestibility, blood parameters and ruminate behaviour of lambs.

Oilseeds such as linseed, canola and sunflower contain unsaturated fatty acids that play important functions in the body. The aim of this study was to assess the effects of different levels of processing linseed on growth performance, nutrient digestibility, blood parameters and ruminate behaviour of lambs. Fifty-six Moghani male lambs (3 months of age, initial average body weight = 28 ± 1.2kg) were allocated to seven experimental diets in randomized design (eight lambs per each treatment). The experimental diets were as follows: (1) control diet (without linseed), (2) 5% raw linseed, (3) 10% raw linseed, (4) 5% micronized linseed, (5) 10% micronized linseed, (6) 5% extruded linseed and (7) 10% extruded linseed. Lambs were fed ad libitum a basal diet as total mixed ration consisting of 25% concentrate and 75% hay. The results showed that linseed level and processing method had no significant effect on dry matter intake. Average daily gain, final body weight and feed conversion ratio (FCR) in lambs were affected by experimental diets. The use of 10% micronized linseed and 10% of extruded linseed in the lambs' diet improved dry matter and crude protein digestibility significantly (p < 0.001). Blood glucose concentration observed for lambs fed 10% of micronized or extruded linseed (LS) was not different from that observed in other groups, only from the values shown by lambs fed diets 1 (control) and 2 (5% raw LS). The lowest cholesterol and the highest blood urea nitrogen concentrations were related to lambs fed the control diet (p < 0.001). Feeding processed linseed relative to control diet had no effect on feeding behaviour in lambs. Results of this research showed that the use of extruded and micronized linseed at the level of 10% can improve FCR, nutrient digestibility, and blood parameters.

Replacing ground Rhodes grass hay with soyhulls in the pelleted diet: effects on ingestive behavior, nutrient digestibility, blood metabolites, growth performance, and economic viability of intensive fattening Lohi lambs.

This study aimed to evaluate the effects of replacing soyhulls (SH) for ground Rhodes grass hay (RGH) in a pelleted diet on ingestive behavior, digestibility, blood metabolites, growth performance, and economic viability of fattening Lohi lambs. A total of thirty male lambs (age: 5months; body weight 20.4 ± 0.24kg) were allotted to one of the three diets (n = 10 lambs/diet) under a completely randomized design. The diets were with 25% RGH inclusion (control), replacing 15% RGH with 15% SH as a fiber source (SH-15), and containing only 25% SH inclusion on a dry basis (SH-25). Ingestive behavior parameters like time spent (min/day), bouts frequency (number/day), and bout length (min/bout) for feeding, drinking, rumination, chewing, standing, and lying were not influenced (P > 0.05) by replacing RGH with SH. The dry matter (DM) and neutral detergent fiber (NDF) chewing rate, rumination rate, and feeding efficiency were also not changed (P > 0.05) by dietary treatments, whereas total dry matter and NDF intakes, and their rumination efficiencies were lower (P < 0.05) for the SH-25 than for the rest of the treatments. The digestibility of NDF and acid detergent fiber (ADF) was higher (P < 0.05) for the SH-25 than for the rest of the treatments. The concentrations of blood metabolites like glucose, blood nitrogen, and cholesterol were not changed (P > 0.05) among the treatment groups. Similarly, performance parameters like dry matter intake, initial and final body weight, average daily gain, and feed conversion ratio were similar (P > 0.05) across the treatments. However, the incidence of loose fecal consistency was higher (P < 0.05) for SH-25 than for the control. The values of economic efficiency were better for SH-25-fed lambs than those fed the rest of the treatments. Based on the results, substituting SH for RGH in a pelleted diet improved the digestibility of fiber fractions, and economics without affecting the growth performance, and blood metabolites of fattening lambs. However, lower rumination efficiency and loos fecal consistency are evidencing less effectiveness of SH fiber.

Processing methods of flint corn and protein supplement in forage-free diets for feedlot lambs.

Diets without forage increase the productivity in less time and favor greater practicality and better quality carcass. The corn grain is mostly used associated with pellets but processing these ingredients can bring benefits. The present study evaluated the effect of diets without forage based on whole or coarse ground corn associated with pelleted or ground protein supplement on performance, eating behavior, carcass characteristics, and ruminal morphology of feedlot lambs. Thirty-five Dorper × Santa Inês lambs were used, with 23.85 ± 3.88 kg of initial body weight and 88 ± 9 days old. The experimental design was in a randomized complete block, defined by body weight and age. The experimental diets were control (CONT), containing 90% of concentrate and 10% of forage (coastcross hay), and 4 diets without forage: WC+P, 70% whole flint corn and 30% pelleted protein supplement; WC+G, 70% whole flint corn and 30% ground protein supplement; GC+P, 70% ground flint corn and 30% pelleted protein supplement; and GC+G, 70% ground flint corn and 30% ground protein supplement. There was an interaction between treatments and experimental periods for DMI in kg/day (P = 0.01) and g/kg of BW0.75 (P < 0.01; Table 3). For the DMI in kg/day, no significant differences were observed between the treatments in any of the experimental periods. However, for DMI expressed in g/kg of BW0.75, the animals fed WC+P had lower DMI than the animals on the CONT (P < 0.01) only in the first period. The ADG, FBW, and FE were not affected by the treatments. Compared to CONT, forage-free diets decreased ingestion time (min/day) and rumination and chewing (min/day and min/g of dry matter). There was no effect of treatments for any of the carcass traits evaluated. The diets did not cause lesions suggestive of ruminitis. Forage-free diets containing whole or ground corn associated with pelleted or ground protein supplement can be used successfully for feedlot lambs; they provide proper performance and carcass characteristics, without harming the animal's health.

Effect of different levels of physically effective neutral detergent fibre from forage in whole corn grain-based diets for feedlot lambs

Context The minimum requirements of physically effective neutral detergent fibre of forage (peNDF-F) in finishing diets for feedlot lambs has not been consolidated. Aims The present study evaluated the effect of increasing levels of peNDF-F on growth performance, blood metabolites, carcass characteristics, and ingestive behaviour of feedlot lambs fed a whole corn grain-based diet. Methods Forty-five Dorper × Santa Inês rams, with an initial bodyweight (BW) of 22.6 ± 5.3 kg (mean ± s.d.) and 88 ± 10 days old (mean ± s.d.), were used. The experimental design was a randomised complete block (five treatments and nine blocks), defined by the initial BW and age at the beginning of the experiment. The experimental diets were formulated to be isonitrogenous and isoenergetic. The experimental diets were as follows: ground corn-based diet with 72 g/kg of peNDF-F from coastcross (Cynodon sp.) hay (CONT, positive control); whole corn grain-based diet without coastcross (Cynodon sp.) hay (0peNDF-F); whole corn grain-based diet with 36 g/kg of peNDF-F from coastcross (Cynodon sp.) hay (36peNDF-F); whole corn grain-based diet with 72 g/kg of peNDF-F from coastcross (Cynodon sp.) hay (72peNDF-F); whole corn grain-based diet with 108 g/kg of peNDF-F from coastcross (Cynodon sp.) hay (108peNDF-F) (DM basis). Key results The increasing concentrations of peNDF-F in whole corn-based diets reduced the dry-matter intake (P &lt; 0.0001), average daily gain, feed efficiency, final BW, carcass characteristics (P &lt; 0.05), AST (P = 0.01), and glucose concentration (P ≤ 0.03). Additionally, the increasing concentrations of peNDF-F decreased the area (P ≤ 0.02) and the length of ruminal papillae (P = 0.008). The rumination and chewing times (min/day) showed a quadratic response; a longer rumination time (P = 0.001) was observed with 72peNDF-F and the longer chewing time (P = 0.006) with 108peNDF-F. Conclusions Whole corn grain-based diets can be used without the addition of peNDF-F for lambs. Implications Thus, utilisation of whole corn grain diet can be a strategy to successfully feed and fatten lambs to slaughter.

Effect of spineless cactus [Nopalea cochenillifera (L.) Salm Dyck] on nutrient intake, ingestive behaviour, and performance of lambs.

The objective of this study was to evaluate the effect of increasing levels of spineless cactus (SC) [Nopalea cochenillifera (L.) Salm Dyck] on nutrient intake, ingestive behaviour, and performance of lambs in a feedlot. Thirty-two male (non-castrated) Santa Inês lambs with a mean initial body weight (BW) of 20.4 ± 2.60 kg were distributed across four levels of spineless cactus: zero, 24, 52, and 75% of total diet dry matter (DM). Over 56 days, the animals had their intake and performance monitored. The inclusion of SC influenced (p<0.05) in a quadratic way the dry matter intake and total digestible nutrients, but linearly decreased (p<0.05) the neutral detergent fiber intake. Drinking water intake decreased linearly (p<0.05) with the inclusion of SC in the diet. The inclusion of SC influenced (p<0.05) in a quadratic way the digestibility of organic matter in the diet. The increase in the level of SC in the diet increased linearly (p<0.05) the feeding and rumination efficiencies of the lambs. The maximum daily gain of 0.237 kg/day was achieved with 44% SC in the diet. It is recommended to include up to 40% of spineless cactus in the diet of lambs.

Overnutrition of Ewe in Late Gestation and the Impact on Placental Efficiency and Lamb's Performance.

The objective of the study was to evaluate energy or energy/protein supplementation in the ewe diet, in the last third of gestation, on maternal placental and endocrine characteristics, as well as its effects on the behavior of neonatal lambs and productive performance until weaning. A total of 128 ewes were used, and the experimental diet was fed from 100 days gestation until lambing, with the birth of 172 lambs. The ewes were distributed into three treatments: CTL (control, n = 43) with metabolizable energy (ME) and crude protein (CP) intake according to NRC (1985); ME (energy supplementation, n = 44) plus 21% ME; and MECP (energy/protein supplementation, n = 41) plus 26% ME and CP. Body weight, body condition score, serum hormone concentrations, placental characteristics, lamb performance and behavior, and production efficiency of the ewe from lambing to weaning were measured. ME and MECP ewes were heavier before (p = 0.006) and just after lambing (p = 0.002) and had higher serum triiodothyronine (p = 0.001) and cortisol (p = 0.004) concentrations on the day of lambing. ME ewes had higher placental efficiency (p = 0.036) and lower total cotyledon weight (p = 0.011). ME and MECP diets increased both lamb birth weight (p = 0.015) and weaning weight (p = 0.009). Production efficiency at birth and at weaning was not influenced (p > 0.05) by treatments. Lamb behavior was influenced by the ME and MECP diets, reducing the time to kneel (p ≤ 0.05), to try to stand (p ≤ 0.05), and the latency to stand (p ≤ 0.005). It is concluded that overnutrition in the last third of gestation was positive for the ovine production system, with improved production rates, hormonal profile, placental characteristics, and neonatal behavior.

Effects of Extending Milk Replacer Feeding during the Fattening Period on the Behaviour and Welfare of Lambs: A Preliminary Study.

There is a lack of information on the behavioural and welfare effects of sustaining artificial milk feeding in fattening lambs. Therefore, the present work aimed to study the effects of prolonged artificial milk feeding during fattening with a high concentrate diet on the behaviour of lambs. The behaviour of 16 non castrated male lambs of the Manchega sheep breed (eight lambs were in the group that were fed daily a bottle of milk, and the other eight were in the weaned group) was recorded with four fixed cameras just before bottle feeding (~8:30 a.m.) of the unweaned group till four hours later, every day for 7 weeks. The solid diet (pelleted concentrate plus cereal straw) and housing conditions were the same in both groups. Solid feeds were offered ad libitum. There were no differences between groups in time spent eating nor in drinking, playing, scratching and oral activity behaviours (p > 0.05), but resting episodes were longer in weaned lambs (p < 0.05). Weaned lambs presented a higher frequency of self-grooming behaviour (p < 0.05), while the unweaned group performed a higher frequency of interaction behaviour (p < 0.05). In conclusion, the behaviours of lambs that were fed daily a bottle of milk during the fattening period did not substantially differ from the weaned individuals.

Short-term energy supplementation before lambing improves maternal behaviour, udder volume, colostrum viscosity and lamb birthweight in ewes under extensive grazing

The aim of the present experiment was to evaluate the effect of short-term energy supplementation before lambing on maternal and lamb behaviour and colostrum production in a large-scale trial in Merino sheep under extensive grazing. It was hypothesized that prepartum supplementation would improve ewe-lamb bonding at birth, increase udder volume and colostrum production while reducing colostrum viscosity. Milk production between weeks 2 and 5 of lactation was measured to test whether this variable was also affected. A complete randomised designed experiment was conducted over three non-consecutive years (Y1 = 2009, Y2 = 2010, Y3 = 2012) with pregnant adult ewes (Y1: n = 87; Y2: n = 65; Y3: n = 71) from a synchronised mating. Ewes remained under extensive grazing on natural grassland from mating until 5 weeks after lambing. On day 123 of gestation, ewes were randomly assigned to one of two dietary treatments: grazing ewes (Control) or grazing ewes daily supplemented with 250 g of maize and 250 g of oat per head (SUPPL) until day 144 of gestation. Behavioural and performance variables were measured in ewes and lambs. Data showed that SUPPL ewes returned to their offspring more quickly once the newborn was ear-tagged and weighted than Control ewes (P < 0.05). In addition, lambs born to SUPPL ewes tended to suck earlier than Control (P < 0.10). Udder volume in SUPPL ewes was 25% greater than in Control ewes (P < 0.05). Colostrum produced by SUPPL ewes was less viscous than in Control ewes (P < 0.05) and colostrum volume tended to be higher in SUPPL ewes (P < 0.10). Overall, birthweight was significantly greater in lambs born to SUPPL ewes compared with Control (P < 0.05). Milk production between weeks 2 and 5 of lactation was not affected by the dietary treatment (P > 0.05). The present experiment also showed a significant interannual variation in some parameters of interest. A beneficial effect of short-term prepartum supplementation on maternal behaviour, udder volume, colostrum viscosity and lamb birthweight was shown in Merino sheep under extensive grazing. This work also highlights that a practical low-cost supplementation strategy for sheep producers in extensive systems may have clear implications in lamb survival, animal welfare and farm productivity.

Mother’s scent for motherless neonates: Responses of artificially reared lambs to ewe’s inguinal wax odor

Mammalian newborns depend on their mother’s milk to satisfy their initial needs of protection and nutrition. They reach the source of milk in following visual, tactile and olfactory cues. In particular, parturient ewes produce an odorous wax in the inguinal glands close to the teats. When presented separately to newly born lambs, this inguinal wax (IW) elicits arousal, head orientation, licking and increased respiratory rate indicative of their avidity for it. The present study assessed whether transferring IW into the environment of artificially fed lambs would improve their responses to the novelty of the situation. We first assessed whether suckled lambs preferred an IW-scented teat to a scentless control teat. Then, we assessed whether a teat odorized with IW was more easily learned as suckable relative to a control teat. Finally, the lambs’ growth performance from postnatal days (PND) 0 and 20 was compared in groups reared with or without IW spread on the milk-feeder in their home pen. The behavioral assays did not evidence any significant effect of IW odor on previously suckled lambs’ attraction and appetence responses. However, relative to the scentless control condition, being exposed to an IW-smeared milk-feeder led to a higher body weight at 20 days after birth. In the conditions of the present study, namely after suckling initiation, IW odor appeared not to be a strong determinant of short-term attraction or appetitive behavior in neonate lambs. The continued presence of IW, a familiar odor, in the artificial suckling context may improve artificially-reared lambs’ emotional state that may affect their weight gain.

Intake, digestibility, ruminal parameters, and performance in lamb fed with increasing levels of red propolis extract.

The objective of this study was to examine the effect of increasing levels of red propolis extract (RPE) on the intake, digestibility, feeding behavior, rumen parameters, metabolic parameters, and performance of feedlot lambs. Thirty-five uncastrated male Santa Inês lambs with an initial weight of 17.08 ± 2.36kg were used in a completely randomized design with five treatments (0, 7, 14, 21, or 28mL RPE/animal/day). The animals were confined for 68days. Red propolis extract induced a negative quadratic response (P < 0.05) in the intakes of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, non-fibrous carbohydrates, and metabolizable energy. The apparent digestibility coefficients of dry matter, organic matter, and neutral detergent fiber, as well as the rumen concentration of NH3-N, also responded quadratically (P < 0.05) to RPE. Feeding efficiency increased linearly (P < 0.05) with the inclusion of RPE, whereas rumination efficiency was maximum (P < 0.05) at the RPE level of 16mL/day. Red propolis extract induced a linear response (P < 0.05) in serum total protein, albumin, creatinine, and gamma-glutamyl transpeptidase. There was a quadratic effect on final body weight and average daily gain with minimum values for inclusion of RPE of 12.89mL/day and 10.93mL/day respectively. Feed efficiency rose linearly (P < 0.05) with the increasing concentrations of RPE in the diet. The inclusion of 21mL RPE/day (8.5mg total flavonoids/mL) in the diet of feedlot lambs is recommended to reduce the rumen NH3-N production and increase the animals' performance.

Effect of weaning and feed provision times on the performance and several behavioural traits of post-weaning lambs.

The aim of the present study was to assess if weaning time (morning or evening) and feed provision (immediate or 4h delayed) can influence growth performance and expression of juvenile lamb behaviour immediately after and at the age of 50-125days old. Forty lambs were randomly assigned to 4 groups: E1 (evening + immediate), E2 (evening + delayed), M1 (morning + immediate) and M2 (morning + delayed). All lambs were especially active during the first hour after weaning. However, their activity within the first 24h after weaning was mainly affected by their circadian rhythms, since lambs were more active during the day compared to night. On the other hand, no effect of alfalfa hay provision on lamb activity during these first 24h was observed. At the age of 50-125days old, body weight was measured, and an isolation and flight distance test was implemented. There were no significant differences among lambs in body weight, number of jumps and heart rates assessed during isolation test and flight distance. However, the number of vocalizations was lower (65-110th day, P < 0.05) for the E2 compared to E1 lambs. Breed also slightly affected (95th day, P < 0.05) the average heart rate of lambs, with greater values for Karagouniko compared to Chios lambs. It is concluded that no discernible effects of weaning or feeding time were observed on growth performance and the display of stress-induced behavioural components of juvenile lambs till the age of 125days old.

Effects of concentrate starch level and free-choice provision of straw on performance, feeding behaviour and feed sorting of fattening lambs

The importance of forage in small ruminants’ behaviour is well known, but very few experimental studies have investigated the feeding behaviour of lambs offered ad libitum and as a free choice provision of concentrate and wheat straw. This experiment was conducted to investigate the effect of concentrate starch level on growth performance and behaviour, preference toward straw and rumen fermentation in lambs offered ad libitum forage and concentrate. Twenty-four Iranian Arabic male lambs (mean ± standard deviation; 18.8 ± 2 kg of BW) were used in a completely randomized design with 3 treatments (8 lambs per treatment) for a period of 84 days. Experimental treatments were included 3 levels of starch (27.1%, 35.4% and 43.6% of dietary dry matter (DM)) and wheat straw was offered as a free-choice provision. Total DMI was not different among treatments; however, intakes of straw (P < 0.01), peNDF (P = 0.003), water (P = 0.05), and ME (P = 0.005) linearly increased with increasing level of starch in the concentrates. The increased dietary starch concentration linearly increased total gain (P = 0.02), and average daily gain (P = 0.01), but linearly decreased feed conversion ratio (P = 0.02). Increasing starch in the concentrates linearly increased sorting for straw particles retained on the 19-mm sieve and tended to increase sorting for particles retained on the 8-mm sieve. In contrast, sorting against the fine particles was observed with increasing starch content of the concentrates. Eating time decreased linearly as the amount of starch in the diets increased. Time spent ruminating per kg DM and NDF intake linearly increased with increasing starch in the diet. Standing time increased linearly (P = 0.04) as starch content of the diets increased. Lambs fed low starch diet had higher pH values than medium starch (at 2, 4, and 6 h post-feeding) and high starch (at 0, 2, 4 and 6 h post-feeding) diets. These findings suggest that under free-choice provision of straw and concentrate lambs are able to adjust their sorting behaviour in favor of physically effective NDF and more forage intake with increasing concentrate starch level, which could be an adaptive response to attenuate low rumen pH.

Effects of Oil Supplements on Growth Performance, Eating Behavior, Ruminal Fermentation, and Ruminal Morphology in Lambs during Transition from a Low- to a High-Grain Diet.

Simple SummaryFeed efficiency is generally associated with a considerable consumption of grains by ruminants. However, high-grain feeding may induce digestive problems in ruminant animals. The gradual adaptation to high-grain diets can be considered an effective strategy to reduce these issues. Free-oil supplementation in the adaptation diets of lambs is not common, but may smooth the transition from a high-forage to a high-grain diet, which was evaluated in this study. Lambs received diets without free-oil or containing palm or soybean oil (80 g/day) during and after the adaptation period. In lambs fed free-oil, particularly soybean oil, dry matter intake, daily weight gain, and ruminal pH increased, while concentrations of branched chain fatty acids in the rumen decreased, and the feed efficiency, as well as development of ruminal epithelia, improved compared with those fed the control diet.The objectives of this study were to investigate the effect of a maximum recommended oil supplementation on growth performance, eating behavior, ruminal fermentation, and ruminal morphological characteristics in growing lambs during transition from a low- to a high-grain diet. A total of 21 Afshari male lambs with an initial body weight (BW) of 41.4 ± 9.1 kg (mean ± SD) and at 5–6 months of age were randomly assigned to one of three dietary treatments (n = 7 per group), including (1) a grain-based diet with no fat supplement (CON), (2) CON plus 80 g/d of prilled palm oil (PALM), and (3) CON plus 80 g/d soybean oil (SOY); oils were equivalent to 50 g/kg of dry matter based on initial dry matter intake (DMI). All lambs were adapted to the high-grain diet for 21 d. In the adaptation period, lambs were gradually transferred to a dietary forage-to-concentrate ratio of 20:80 by replacing 100 g/kg of the preceding diet every 3 d. Thereafter, lambs were fed experimental diets for another 22 days. Fat-supplemented lambs had greater DMI, body weight (BW), and average daily gain (ADG), with a lower feed to gain ratio (p < 0.05), compared to CON lambs. The highest differences of DMI between fat-supplemented and CON-lambs were observed in week 3 of the adaptation period (p = 0.010). PALM- or SOY-supplementation lowered DM and NDF digestibility compared with CON (p < 0.05), and SOY caused the lowest organic matter (OM) digestibility compared with CON and PALM lambs (62.0 vs. 67.6 and 66.9; p < 0.05). Ruminal pH was higher for PALM and SOY compared with CON (p = 0.018). Lambs in SOY tended to have the highest ammonia-N concentrations (p = 0.075), together with a trend for higher concentrations of propionic acid, at the expense of acetic acid in ruminal fluid, on the last day of the adaptation period (diet × time, p = 0.079). Fat-supplemented lambs had lower isovaleric and valeric acid concentrations compared with CON on d 40 (diet × time, p < 0.05). PALM and SOY-fed lambs had a longer eating time (min/d and min/kg of DMI), chewing activity (min/d), meal frequency (n), and duration of eating the first and second meals after morning feeding (p < 0.05), and the largest meal size (p < 0.001). Fat supplemented lambs had greater ruminal papillary length (p < 0.05) and width (p < 0.01), and thicker submucosal, epithelial, and muscle layers, compared with the CON (p < 0.01). Blood metabolites were not influenced by dietary treatments (p > 0.05). The results from this study suggest that fat supplementation to high-grain diets may improve the development of ruminal epithelia and modify ruminal fermentation via optimized eating behavior or the direct effect of oils on the ruminal environment, resulting in better growth performance in growing lambs.

Performance, fecal egg count and feeding behavior of lambs grazing elephant grass (Pennisetum purpureum Schum.) with increased levels of protein supplementation

The current study investigated the effect of increased protein supplementation levels on fecal egg count, performance and feeding behavior of lambs grazing elephant grass (Pennisetum purpureum Schum.). The treatments consisted of five levels of crude protein (CP) in an isoenergetic supplement (0%, 8%, 16%, 24% and 32% CP) provided to growing lambs. Fifty lambs at initial live weight of 20.2 ± 2.94 kg were slaughtered after 75 days of protein supplementation. Ether extract intake decreased with the increase of CP in the supplement. Average daily weight gain was over 60% greater for lambs receiving supplement with 16% and 24% CP than lambs in the control group. Protein supplementation did not affect grazing and ruminating behavior but lambs in the control group spent from 82% to 88% less time eating the supplement (4.01 min; P < 0.01) and visited the supplement trough 3.01 times a day. Fecal egg count remained low with the increase of protein in the supplement in the beginning of the grazing period. Intake, weight gain, carcass length and rump width of the lambs enhanced as CP in the supplement increased, with optimal performance obtained with 8% CP in the supplement for lambs grazing elephant grass.

Early signals of parasitism expressed through behaviour but modulated by social context

Sickness behaviours are believed to be an adaptive response to infection. However, the degree to which these behaviours can be expressed may be impacted by an individual's social environment. Here we tested, first, whether parasitism reduces the activity behaviour of lambs, Ovis aries , second, whether this occurs prior to other observed costs of parasitism and, third, whether the infection status of other individuals affects the degree to which these behaviours are expressed. Sixty lambs were separated into replicate groups within three treatments: (1) parasitized: all lambs were infected with the parasitic nematode Teladorsagia circumcincta ; (2) nonparasitized; all lambs were dosed with water; (3) mixed: some of the group were infected and some were dosed with water. Activity behaviour was monitored before, during and after parasite infection. Parasitized groups had reduced activity levels following infection, and this occurred before any other impact or measure of parasitism was detected. Infected animals in the mixed groups had reduced activity levels following infection, but the level of change was less than that in animals in the fully parasitized groups. Activity levels remained low until lambs were treated with anthelmintic when activity levels of the groups that had been parasitized returned to the same level as nonparasitized groups. These findings show that parasite-induced behavioural changes occur earlier than other more commonly observed signals of infection, but the infection profile of an individual's group can shape these behavioural responses to infection. • Domestic lambs were experimentally infected with a gastrointestinal nematode. • Parasitized lambs had reduced activity levels following infection. • This occurred before any other measure or impact of parasitism was detected. • However, these behavioural changes were affected by group infection status. • Thus, an individual's social environment can affect their response to infection.

Performance, nutritional behavior, and carcass characteristics of feedlot lambs fed diets with non-forage fiber source or sodium bicarbonate.

The study was carried out to evaluate the effect of sodium bicarbonate (SB) supplementation in diets and compare its chemical effect with the fiber effect of soybean hulls on performance, nutritional behavior, and carcass characteristics of feedlot lambs. Twenty-eight ram lambs (Dorper × Santa Inês), with an initial body weight of 30.2 ± 4.5kg and 94 ± 8.4days old, were used. They were assigned to a randomized complete block design, defined by initial age and body weight. Experimental diets were positive control, diet containing soybean hulls in 400g/kg dry matter (DM) (CONT), and three diets based on ground flint corn containing 10 (10SB), 20 (20SB), or 30 (30SB) g/kg DM of SB. Among the SB levels, the buffer supplementation quadratically increased dry matter intake, average daily gain, feed efficiency, as well as increased final and slaughter body weight, which led to higher hot and cold carcass weights, loin muscle area, leg compacity index, and weight of neck, shoulder, rib, and leg cuts, with higher values for the 20SB. Feeding SB linearly decreased the area and height of the papillae. None of the animals presented liver abscess; however, two animals from 30SB and one from CONT had F-rumen lesions. The use of SB provided a similar animal performance when compared to the treatment containing soybean hulls. This shows that the chemical effect of the buffer was efficient and provided greater safety for this type of diet without causing damages to the rumen health. Among the SB levels, the best results were observed in the 20g/kg level (20SB), which shows that the buffer can be used as a strategy for diets with high inclusion of corn and no fiber source.

Hura crepitans Seeds for Control of Eimeria spp. in Lambs as an Alternative to Conventional Therapies.

Simple SummaryThe anticoccidial effect of Hura crepitans seed was evaluated for 3 weeks. For this, 21 lambs were used, which were housed individually in raised wire-mesh pens with individual water troughs and feeders. The lambs were randomly divided into three groups (n = 7) that received different doses of Hura crepitans seeds. The treatment was administered at the beginning of the experiment once orally. Faecal samples were taken for quantitative analysis of oocysts and blood for haematological and biochemical analyses. Lambs that received the seeds showed significant excretion of coccidia oocysts between days 5 and 7 post-treatment, without affecting feed intake and growth. Most blood parameters analysed showed values within the reference interval, while urea and BUN levels increased slightly but without statistical difference. We can conclude that Hura crepitans seeds, at doses of 4 and 6 g/kg, favour the expulsion of coccidia oocysts, without affecting either the health or the productive behaviour of lambs.To evaluate the anticoccidial effect of the Hura crepitans seed, 21 cross-breed lambs, 23 ± 3 kg live weight (PV) and 70 ± 6 days old, were used. Animals were housed individually in raised wire-mesh pens, with individual water troughs and feeders. Lambs were randomly divided into three groups (n = 7) that received different doses of Hura crepitans seeds: 4 g/kg B.W. (group 1), 6 g/kg B.W. (group 2) and 0 g/kg B.W. (control group or group 0). The treatment was administered at the beginning of the experiment once orally and the study lasted 21 days. Stool samples were taken for quantitative analysis of oocysts using the McMaster technique and blood for haematological and biochemical analysis. Lambs that received the seeds showed a higher excretion of coccidia oocysts between days 5 and 7 after treatment (p < 0.05) due to the antiparasitic effect of these seeds, without affecting their productive performance (daily feed intake (DFI)- total weight gain (TWG), daily weight gain (DWG)). In addition, the daily feed consumption (DFC) and dry matter intake (DMI) were similar between the groups. The analysed enzymes (ALT, AST, GGT and FA) and creatinine showed reference values. Only the urea and BUN levels were slightly increased, but without statistical difference between the groups. Therefore, the Hura crepitans seed, at doses of 4 and 6 g/kg, favours the expulsion of coccidial oocysts, without affecting either the health or the productive behaviour of lambs.

Sexual performance and semen quality of pubertal lambs treated with different weaning methods.

The objective of this study was to determine the effect of the weaning method on lamb stress, body weight, sexual behavior, and semen quality of Saint Croix male lambs. The present study was carried out during the late spring and summer of 2018 in the northeast of Mexico. Sixty male lambs born as twins or triplets (3.2 0.6 kg birth weight) and weaned at 60 d of age (19.21 1.8 kg weaning weight) were divided into two weaning methods: complete separation from the dams (CS; the lambs were moved to a pen that was at 500 m of distance from the dams) and separation with contact from the dams (SCD); the lambs were physically separated by a steel mesh that prevented the lambs from having the possibility of sucking milk from their mothers, but they maintained permanent visual and auditory contact. Cortisol levels were determined 3 d before and 7 d after weaning. Lambs were evaluated as 3-month-old lambs for sexual behavior and semen quality for 9 weeks. The effects of the weaning method (M), week (W), and the interaction M W were significant on body weight and cortisol levels (). The SCD lambs had higher cortisol levels at 3, 5, and 7 d after weaning than CS lambs (). The CS lambs had higher body weight during the first 4 weeks after weaning than SCD lambs (). The weaning method had no effect on scrotal circumference, sexual behavior, and semen quality traits, except for progressive sperm motility, being better for the lambs that were completely separated (). The results from this study show that complete separation of lambs and ewes at weaning is an effective method to reduce lamb stress and improve lamb growth after weaning, but it did not have long-term effects on sexual behavior and semen quality of Saint Croix male lambs.

Grazing behaviour, intake, digestion, performance and endoparasitic infection of lambs raised at different stocking rates under low-input farming systems

Twenty-four Boutsiko breed lambs were allocated to three groups of equal average live weight (LW: 20.8 kg) and pastured at three stocking rates: SR1, SR2 and SR3 (representing 60, 80 and 100 lambs/ha respectively) under low-input farming practices. Animals were grazed on a semi natural sward daily, during a 60 days period. Sward height in all treatments remained above 7 cm during the trial and the herbage gross chemical composition was similar between treatments. On average, the lambs grazed 372 min, ruminated 140 min and spent 88 min on other non-feeding activities during the daily pasturing. Lambs consumed at the start and the finish of the trial 714 g and 1014 g of herbage DM/day, or 70.5 and 99.0 g/kgW0.75/day respectively. Herbage DM digestibility (in vivo) was moderate averaging 61% and no differences were observed between the three groups of lambs. The daily live weight gain of lambs (DLWG) was different (p&lt;0.01) between the stocking rates, where lambs on plot SR1 had the highest gain (0.0918 kg LW/day) and lambs on SR2 and SR3 plots the lowest gain (0.0344 and 0.0531 kg LW/day respectively). Faecal egg counts (FEC) for gastrointestinal parasites (GIN) from lambs grazing plot SR3 were low, while high numbers of Moniezia spp. eggs were present in faecal samples of all groups of lambs at the end of the experiment. It is concluded that lamb fattening on pasture can be achieved at reasonable stocking rates, without the use of anthelmintics, if a local hardy breed is used.