Effects of daily protein intake levels on the oral stereotypic behaviours in energy restricted lambs

Effects of daily protein intake levels on oral stereotypic behaviours (OSB) in energy restricted lambs were investigated. Thirty-eight male lambs were randomly allotted to three treatments. Lambs in the first group (AL) received their ration (12.1 MJ ME/kg DM; 148.6 g CP/kg DM) at ad libitum level, whereas the second group (RP1) (12.1 MJ ME/kg DM; 177.4 g CP/kg DM) and the third group (RP2) (12.1 MJ ME/kg DM; 214.9 g CP/kg DM) received their rations at restricted levels. Recording of behaviours was carried out once a week using time sampling technique during a 7-week experimental period. OSB were significantly (P<0.001) affected by the treatments. RP2 group showed higher oral stereotypies than the others. It was concluded that increasing the daily protein intake under energy restricted conditions may have additive effects on the development of stereotypic oral behaviours.     

Behaviour and welfare of veal calves fed different amounts of solid feed supplemented to a milk replacer ration adjusted for similar growth

Veal calves in Europe are typically fed large quantities of milk replacer and small amounts of solid feed, a diet known to lead to the development of abnormal oral behaviours in these animals. These abnormal oral behaviours are thought to be an indication of frustration, chronic stress, and hence poor welfare. The present study investigated how different feeding strategies, differing in solid feed and milk replacer provision, affected the behaviour and welfare of veal calves across time. Four treatment groups (A–D) comprising of 12 Holstein–Friesian bull calves each (7.6 ± 0.1 weeks old and 54.7 ± 0.3 kg at arrival), penned in groups of three, were fed one of four amounts of a solid feed mixture, i.e. 50% concentrates, 25% fresh maize silage, and 25% wheat straw (on dry matter [DM] basis): A = 0, B = 9, C = 18, and D = 27 g DM/kg^0.75/d. Provision of milk replacer was adjusted to achieve similar average daily gain across treatments. Behaviour was recorded around feeding (10 min continuous focal observations of individual calves) and throughout the day (7 sessions of 30 min scan sampling at 5 min interval every 2 h from 06:30 h) every week for four months. In an attempt to find an easy practical method to measure behavioural response to feeding strategy, two 3-min behavioural tests were carried out: (1) in months 1 and 3, calves were presented with a ball and latency to make oral contact with it was recorded; and (2) in month 1, calves were presented with an overall and time spent orally manipulating (i.e. chewing or licking) it was recorded using scan sampling every 10 s. Calves in treatment D displayed less abnormal oral behaviours around feeding, less tongue playing throughout the day, and more chewing in the first two months, compared to treatment A. Treatment B only led to lower tongue playing levels compared to A and treatment C had no benefit in terms of reducing abnormal oral behaviours. Although a solid feed dose–response was expected on the display of abnormal behaviours in veal calves, treatment C did not fit within this expectation. These findings point to a more complex relationship between solid feed and abnormal oral behaviour frequency in veal calves. The two behavioural tests distinguished the different treatments as expected, and thus showed a solid feed dose–response. Because of an increase in chewing and ruminating efficiency over time, amounts of solid feed should be increased with age to maintain high levels of chewing and ruminating. Moreover, high levels of chewing and ruminating may have to be maintained long enough at the beginning of the fattening period to lead to a reduction in abnormal oral behaviours.     

Extending the interval between second vaccination and slaughter: I. Effects on growth,scrotal size and stress responses of immunocastrated ram lambs

Immunocastration provides a less invasive means of castrating lambs. Considering increasing consumer awareness, the efficacy of this technique on commercial slaughter lambs needs to be further investigated and its effects on growth and stress responses need to be established. This study compared the growth rate, testes size and stress responses of immunocastrated lambs with that of lambs physically castrated with a Burdizzo clamp, as well as intact rams. A total of 40 Dohne Merino ram lambs (average live weight = 45.4±3.68 kg) were randomly allocated to the following four treatment groups: control (intact; R), Burdizzo-castrated (on day 2; B), immunocastrated with a 4-week (ICS4), or a 6-week (ICS6) interval between the second immunocastration vaccination and slaughter. Within the immunocastration treatments, the reaction to vaccination was assessed through injection site scoring, recording the local injection site surface temperature and assigning a walking score. The response to Burdizzo castration was assessed by scoring the reaction during the procedure, testes palpation reaction, walking gait and measuring testis temperature. Additional parameters recorded included BW, serum cortisol concentration, scrotal circumference and rectal temperature. Pain behaviours were described for the short-, medium- and long-term effects after the two methods of castration. Predominantly, tissue-hardening and bruising occurred at the injection sites of immunocastrates, but little effect was observed on walking comfort and no effect on injection site temperature or rectal temperatures. After Burdizzo castration, lambs spent more time in abnormal postures, and from day 3 (D3) to D8 of the trial, discomfort was observed during testes palpation and walking in B lambs. Serum cortisol concentrations were elevated in B lambs on D3 and D15, indicating physiological stress. Thus, immunocastration improved the welfare of castrated lambs as assessed by cortisol secretion, scrotal swelling and pain behaviours, without influencing growth rate.     

Effects of dietary aluminum source and concentration on mineral status of feeder lambs

A 100 d experiment was conducted to determine the effects of aluminum (Al) source and concentration on mineral status, emphasizing phosphorus (P), of 50 feeder lambs. Six treatments, fed at 10% of the total diet, were formulated using two sources of Al, AlCl₃ and an Al-based water treatment residual (WTR, 11.1% Al), with varying levels of Al and P: (1) control (10% sand, C), (2) low WTR (2.5% WTR and 7.5% sand, L-WTR), (3) AlCl₃ with added P (1% AlCl₃, 9% sand, and 0.4% P, AlCl₃ + P), (4) high WTR (10% WTR, H-WTR), (5) AlCl₃ (1% AlCl₃ and 9% sand, AlCl₃), and (6) high WTR with added P (10% WTR and 0.4% P, H-WTR + P). The total Al varied from 0.037 to 1.2% among diets. Only lambs fed the high WTR diet without P supplementation (H-WTR) decreased feed intakes. These lambs consumed about half as much feed as lambs on all the other treatments, and had lower (P < 0.05) BW from d 84 on. Lambs receiving the H-WTR had the lowest bone Ca, P and Mg concentrations (fresh basis, mg/cm³) and lowest bone mineral content (BMC) as determined by radiographs (mm of Al). Results for the lambs on H-WTR were confounded by the greatly reduced feed intake of animals on this treatment. Plasma P decreased in all lambs consuming Al, regardless of Al source, but the effects were less severe in animals provided additional P supplementation (AlCl₃ + P and H-WTR + P). Apparent absorption of P was affected by concentration and source of Al in two metabolism trials (n = 42) beginning on d 34 and d 70, respectively. In the first trial, d 34, lambs receiving AlCl₃ treatment had reduced apparent P absorption, −17.7% (P < 0.05), when compared to all other treatments. In the d 70 trial, lambs receiving both AlCl₃ and H-WTR treatments were negatively impacted (P < 0.05) compared to the control, −20.9 and −2.5% apparent P absorption, respectively, but were no longer different from one another (P > 0.05). Diets containing 1.2% Al as WTR without P supplementation depressed feed intakes, weight gains, plasma P concentrations (P < 0.05), and BMC. However, given adequate P supplementation, even lambs consuming this amount of Al did not suffer detrimental effects, as lambs on H-WTR + P did not differ from the control (P > 0.05) in feed intakes, weight gains, or BMC.     

Structural,ultrastructural and immunohistochemical evidence of testosterone effects and its ablation on the bulbourethal gland of the Artibeus planirostris bat (Chiroptera,Mammalia)

This study evaluated the effects of testosterone in the bulbourethral glands (BG) of the bat, Artibeus planirostris, by performing castration and posterior hormonal supplementation of the animals. The results showed a decrease in testosterone levels in animals 15 days after castration, which induced a small reduction in epithelium height, percentage of AR+ cells, and an increase in the amount of basal cells. This reduction became more severe in groups castrated for longer periods (19 and 22 days), where there was also an increase in apoptotic cells. Moreover, the hormonal supplementation increased testosterone levels (after 3 and 7 days of supplementation), causing a glandular reactivation that increased the epithelium height and AR expression. In conclusion, BG took longer to respond to ablation of testosterone than other reproductive glands, since it showed evident aspects of regression only in animals 22 days after castrated.     

Comparison of the behaviour of Awassi lambs in cafeteria feeding system with single diet feeding system

This study was carried out to compare behavioural activities of Awassi lambs in cafeteria feeding system with conventional feeding (control) that animals fed concentrate. Sixteen, 3-month-old male lambs were housed individually for 42 days. The main effect was on the feeding systems, cafeteria and control. Cafeteria lambs (n=8) were offered the main ingredients (barley, cotton seed meal (CSM), wheat bran and alfalfa straw), while control animals (n=8) were fed a single diet (48% barley, 22% cottonseed meal, 18% wheat bran, 10% alfalfa and 2% vitamin–mineral mixture; having 2467 Kcal ME and 161 g kg⁻¹) with the same main ingredients with slightly higher nutrient content for growth. Food and water intakes were recorded daily, while behavioural observations were recorded twice a week for a period of 1 h at 5 min intervals at 13:00, 16:00, 19:00, 22:00, 01:00, 04:00, 07:00 and 10:00 h after the initiation of daily feeding. After every 5 min, each lamb was monitored to determine its eating, ruminating, drinking, walking, standing, playing, resting and other activities.Cafeteria lambs selected a diet that matched their growth requirement as did control lambs. However, cafeteria lambs ate more (P<0.01). Cafeteria animals preferred cotton seed meal (42.4%) to barley (32.9%) without changing their water intake, final live weight and daily gain (P>0.05). Cafeteria lambs also had higher rates of eating (22% versus 19%, P<0.01), ruminating (24% versus 23%, P>0.05) and resting (29% versus 23%, P<0.01) than the control lambs. On the other hand, cafeteria lambs spent less time standing (19% versus 25%, P<0.01) and walking (1.5% versus 2.1%, P<0.01) compared with control animals. In conclusion, cafeteria lambs selected a diet that matched their presumed biological (behavioral and nutritional) needs without changing their growth performance.     

Comparable amounts of sex steroids are made outside the gonads in men and women: Strong lesson for hormone therapy of prostate and breast cancer

The objective of this study was comparison of circulating androgens and their metabolites as well as estrogens measured for the first time by a validated mass spectrometry technology in 60–80-year-old men and women of comparable age.Castration in men (n = 34) reduces the total androgen pool by only about 60% as indicated by the decrease in the serum levels of the glucuronide metabolites of androgens compared to intact men (n = 1302). Such data are in agreement with the 50 to 75% decrease in intraprostatic dihydrotestosterone (DHT) concentration after castration. Most interestingly, the same amounts of androgens and estrogens are found in postmenopausal women (n = 369) and castrated men of comparable age.The most significant therapeutic implication of these findings is the absolute need to add a pure (nonsteroidal) antiandrogen to castration in men with prostate cancer in order to block the action of the 25 to 50% DHT left in the prostate after castration. Not adding an antiandrogen to castration in men treated for prostate cancer is equivalent to not prescribing a blocker of estrogens in women suffering from breast cancer because they are postmenopausal and have low circulating estradiol.     

Use of lincomycin to control respiratory infections in lambs: Effects on health and production

The efficacy of lincomycin to control respiratory infections in lambs was assessed in two trials. In trial I, 72 lambs with active mycoplasmal pneumonia were allocated as follows: lambs in group T2 were treated with lincomycin (5 mg kg⁻¹ bodyweight, intramuscularly) twice 2 days apart, those in group T3 with lincomycin (5 mg kg⁻¹ bodyweight, intramuscularly) thrice with 2-day intervals, those in group O with oxytetracycline (20 mg kg⁻¹ bodyweight, intramuscularly) twice 4 days apart and those in group C were controls. In trial II, 48 25–30-day-old clinically healthy lambs were allocated as follows: lambs in group P2 received two injections of lincomycin (5 mg kg⁻¹ bodyweight, intramuscularly) when 30- and 60-day-old, lambs in group P1/30 received one injection of lincomycin (5 mg kg⁻¹ bodyweight, intramuscularly) when 30-day-old, lambs in group P1/60 received one injection of lincomycin (5 mg kg⁻¹ bodyweight, intramuscularly) when 60-day-old and lambs in group C were controls. In trial I, treatment with lincomycin was associated with improved clinical scores; clinical cure rate 42 days after treatment was 87%, 100%, 87% and 0% for group T2, T3, O and C, respectively (P < 0.001); treated lambs produced 18.5% (T2) or 26.5% (T3) heavier carcass than controls; no lung lesions were seen in group T3 lambs, whilst they were evident in 22% of group T2 or group O lambs and in 72% of control lambs; microorganisms were isolated from lung tissue samples of 5 group C and 1 group O lambs. In trial II, administration of lincomycin was associated with smaller clinical scores; prevalence rate of respiratory disorders at the end of the trial was 17%, 42%, 42% and 58% for group P2, P1/30, P1/60 and C, respectively (P < 0.01); treated lambs were >4.5% heavier than controls; lung lesions were recorded in 1 group P2, 2 group P1/30 and group P1/60 and 5 group C lambs; microorganisms were isolated from 1 group P2, 3 group P1/30, 2 group P1/60 and 5 group C lambs. It is concluded that administration of lincomycin is effective for the treatment and the prevention of mycoplasmal atypical pneumonia in lambs.     

Net and metabolizable protein requirements for body weight gain in hair and wool lambs

Protein is one of the limiting factors in animal production, and the knowledge of protein requirements by livestock is crucial for the success of a commercial animal raising enterprise. Thirty-four castrated lambs, 17 of them F1 Ideal × Ile de France wool lambs and the remaining ones were Santa Inês hair lambs, with homogeneous initial BW, were used in the experiment. Five animals from each genotype were slaughtered in the beginning of the experimental period and used as reference. Diets (D) were composed of concentrate mix (C) and Cynodon sp. c.v. Tifton 85 hay (R), combined in three different ratios: D1 = 60C:40R; D2 = 40C:60R and D3 = 20C:80R. Animals of each group of three lambs, that showed simultaneously an initial BW of 20 ± 0.14 kg at the beginning of the dietary regimen, were slaughtered when one of them reached 35 kg, what always happened to be the one fed with D1. Net requirements for BW gain in wool lamb, fleece-free, ranged from 101 to 110 g of protein/kg BW, and for hair lamb ranged from 110 to 118 g of protein/kg BW. Net protein requirements for wool production ranged from 634 to 642 g/kg of produced wool. Hair lambs presented a 7.8–9.5% higher estimated net protein requirements than wool lambs, according to BW and daily weight gain (DG). Total net protein requirements for Santa Inês and wool lambs, with 30 kg of initial BW and an approximate 200 g mean DG, were 48.5 and 45.4 g/day, respectively. Metabolizable protein requirements for Santa Inês and wool lambs, with 20 kg of initial BW and an approximate 200 g mean DG were 59.4 g and 76.5 g/day, respectively. Net protein requirements for wool production was 64 g/100 g of produced wool. Thus, under the conditions of this experiment, it is concluded that hair lambs showed a higher concentration of protein in the body, more efficient use of the ingested protein and a consequent additional BW gain when fed isoproteic diets as compared to F1 Ideal × Ile de France wool lambs.     

Effect of suplemental nitrogen source and feeding frequency on nutrient supply to lambs fed a kikuyu grass (Pennisetum clandestinum) hay-based diet

Eight castrated male lambs (35 ± 4 kg live weight), fed a basal diet of kikuyu grass hay, were used in a replicated 4 × 4 Latin Square experiment with a 2 × 2 factorial arrangement of treatments to evaluate the effect of supplemental feeding frequency and source of rumen degradable N on intake, digestibility, ruminal fermentation, and microbial protein yield. Treatments were supplementation with cassava meal plus calcium caseinate or cassava meal plus urea offered at a rate of 7 g/kg live weight daily in one or two meals per day. Lambs were fed twice daily in such manner to allow ad libitum comsumption of forage. There was significant feeding frequency by N source interaction on variables of intake. In general, intake of feed components was higher (P ≤ 0.05) by lambs offered the caseinate-supplement twice daily over intake observed in lambs given the others diet treatments. Digestibility of feed components was neither affected by supplemental N source (DM, P = 0.541; OM, P = 0.585; NDF, P = 0.828) nor by feeding frequency (DM, P = 0.122; OM, P = 0.175; NDF, P = 0.591). Urinary excretion of N increased (P ≤ 0.05) in lambs supplemented twice daily whereas N retention was similar for all treatments (N source, P = 0.748; feeding frequency, P = 0.418). Microbial protein entering into the small intestine was affected by the interaction between feeding frequency and N source such as an increasing (P < 0.10) in this variable was observed when lambs received the caseinate but not the urea supplement twice daily. Efficiency of microbial protein synthesis, however, was not affected by treatments (N source, P = 0.588; feeding frequency, P = 0.334). Rumen pH averaged 6.70 and it was neither affected by N source (P = 0.827) nor by feeding frequency (P = 0.740). Ruminal concentration of ammonia N was not affected by feeding frequency (P = 0.144) while it increased (P < 0.05) when urea rather than caseinate was the supplemental N source (mean of 7.61 mg/dl vs. 6.00 mg/dl). Concentration of sugars in rumen fluid was higher (P ≤ 0.05) in lambs supplemented once a day compared to twice daily (mean of 49.4 mg/dl vs. 34.4 mg/dl) for both N sources. A significant (P ≤ 0.05) N source by feeding frequency interaction effect was observed for ruminal concentrations of α-amino N compounds. In urea treatment α-amino N concentration increased (P ≤ 0.05) in lambs receiving the supplement twice daily compared to once a day (mean of 4.59 mg/dl vs. 3.70 mg/dl) while in caseinate treatment it was higher (P ≤ 0.05) in lambs offered the supplement in one meal per day compared to twice daily (mean of 5.29 mg/dl vs. 4.07 mg/dl). In conclusion, for ruminants fed a tropical grass-based diet, starch-rich supplement containing non-protein N as N source may be offered only once a day whereas the supply of nutrients may be improved if degradable true protein is included as N source and supplement is offered in two meals per day.     

Effects of feeding system on carcass and non-carcass composition of Churra Tensina light lambs

Thirty-eight single male lambs (3.6 ± 0.08 kg live weight at birth) were used to study the influence of feeding system on carcass and non-carcass composition of Churra Tensina light lambs. Treatments: indoor (IND), lambs housed indoors consuming concentrate ad libitum until weaning at 53 days of age, and ewes grazing 8 h a day without their offspring and receiving a supplement of barley meal after grazing; grazing (GR), ewes and lambs grazed continuously without concentrate and lambs were unweaned. When lambs reached 22–24 kg live weight they were slaughtered. Carcass and non-carcass composition was recorded. GR lambs displayed higher carcass shrink (P < 0.05) and lower dressing percentage (P < 0.01) than concentrate-fed lambs. IND lambs had more body fat mainly due to the heavier kidney (P < 0.001) and subcutaneous (P < 0.001) fat depots. Total non-carcass weight was not affected by treatment (P > 0.05), but red organ (heart, lung and trachea, thymus, liver, spleen, kidney, diaphragm, pancreas, gall bladder, bladder, and testicles and penis), digestive tract (stomach, small intestine and large intestine) and head, skin, and feet (HSF) weights differed between treatments (P < 0.05). IND lambs had heavier red organs and HSF (P < 0.05) although this difference disappeared when expressed as a percentage of empty body weight. Small intestine weight in grazing lambs was heavier (P < 0.001) and, consequently, the total digestive tract differed similarly (P < 0.01). Treatment influenced the weights (P < 0.05) of all joints except leg (P > 0.05), showing heavier joints for IND carcasses. The feeding system had a greater effect on subcutaneous fat (P < 0.001) than on intermuscular fat (P < 0.05) in most of the standardized joints. IND carcasses produced a greater proportion of muscle/bone in all joints, except neck, whereas GR produced a greater proportion of muscle/total fat due to the lower amount of fat recorded in this treatment. The percentage of fatty acids was not affected by treatment (P > 0.05) although the percentage of C18:3 was greater and the ratio of C18:2/C18:3 was lower in grazing-fed lambs. The absence of any effect of treatment on the fatty acid percentages may be influenced by the short raising period and by the similar amount of intramuscular fat in both treatments. It is concluded that light lambs reared under grazing conditions can produce carcasses of acceptable quality, due to the lower percentage of subcutaneous fat, but with a similar intramuscular fat content.     

Socio-spatial criteria are important for the establishment of maternal preference in lambs

At lambing, ewes (Ovis aries) tend to isolate themselves from the flock and this is believed to be beneficial to the early relationship with their young. Later, they return to the flock and lambs progressively interact with other conspecifics. This study focused on the importance of isolation and socio-spatial factors on maternal recognition in lambs. All the ewes gave birth in individual 2 m² pens and lambs were able to interact freely with their mothers. A first experiment investigated the role of isolation: INT1 lambs could progressively interact with other mothers and young in a pen which was increased in surface area from birth to 24 h (0–6 h: 1 ewe, 1 litter, 2 m²; 6–12 h: 2 ewes, 2 litters, 4 m²; 12–24 h: 4 ewes, 4 litters, 8 m²); ISO lambs remained in small pens (2 m²) and only with their mothers for 24 h. The lambs were submitted to a 5 min choice test between their own mothers and an alien ewe. At 12 h INT1 lambs, unlike ISO lambs, showed a clear preference for their mothers. ISO lambs still did not show any maternal preference at 24 h. The second experiment investigated the relative importance of social interactions while keeping the same space allowance for the two groups: INT2 lambs as described for INT1 in Experiment 1, and SPA lambs that remained isolated from the flock with their mothers but had the same increase in pen surface area as INT2 lambs. Both INT2 and SPA lambs displayed a preference for their own mothers at 12 h but INT2 lambs did so more rapidly. Our data also suggest that INT1 and INT2 lambs chose their own mothers at a distance. These results demonstrate that progressively increasing social interactions with flock members other than the mother facilitates the establishment of a preference for the mother in lambs. Increasing space allowance only also seems to have facilitating effects. This suggests that a rich socio-spatial environment from birth has beneficial effects on the development of filial bonding.     

Sexual performance of Awassi ram lambs reared in different sex composition groups

The objective of this study was to evaluate the effect of sex composition of the group of lambs before puberty on later sexual performance in Awassi ram lambs. Thirteen Awassi ram lambs of the same age were raised in either all-male group (n = 7) or in a group mixed with females (n = 6) from weaning to puberty. Blood samples, body weights (BW) and scrotal circumferences (SC) of ram lambs were recorded between eight and 10 months of age. Sexual performance testing was performed at 9 months of age by individually exposing ram lambs to oestrous females on five occasions. Body weight and SC were greater (P < 0.01) in the all-male compared with the mixed group. Plasma testosterone concentrations were not influenced (P > 0.05) by treatment. Plasma testosterone concentrations were significantly correlated (P ≤ 0.05) with BW (r = 0.3) and SC (r = 0.4). No treatment effects were detected regarding bouts of leg-kicking. Bouts of anogenital sniffing, the frequency of mount attempts and mounting frequency were greater (P < 0.05) in the all-male group. Even though the frequency of raising the fat tail of females was similar between the two treatments, the mixed group tended to be (P = 0.08) more efficient in doing so than the all-male group (higher tail raising/mount). Results of the current study indicate that mixing groups of ram and ewe lambs before puberty may be insufficient to improve later sexual performance of ram lambs.     

Evaluation of diets containing shrimp shell waste and an inoculum of Streptococcus milleri on rumen bacteria and performance of lambs

With the main objective of test an inoculum of chitin-degrading rumen bacteria, 15 lambs with an average BW of 22.8 kg were allotted at random (5 per treatment) to diets containing: T1 = soybean meal, corn meal and corn stover (control treatment), T2 = inclusion on the diet of 250 g of shrimp shell waste (SSW) per 1000 g (DM bases), in replacement of ingredients contained in T1, and T3 = T2 + inoculum made of Streptococcus milleri (chitin-degrading bacterium; 0.12 g animal⁻¹ d⁻¹). In general, the feed intake, weight gain and feed conversion were similar (P<0.05) between T1 and T3, but the lambs feed SSW without inoculum (T2) presented the lowest values. Concentration of total and cellulolytic bacteria was similar among treatments after 30 d, but decreased in T2 and T3 after 60 d. The population of chitinolytic bacteria increased (P<0.05) in the rumen of lambs fed 25% SSW. This increment was observed in lambs feed with or without inoculum. It is concluded that SSW can be efficiently used as a feedstuff for ruminants without any requirement of an adaptation period to the diet and decreasing the diet cost, if an inoculum of chitinolytic bacteria is added.     

Influence of maternal undernutrition on the behaviour of juvenile lambs

The objective of the present experiment was to determine the implications of prenatal undernutrition on the behaviour of juvenile lambs. Dams of one group (C) were fed 100% of the recommended requirements throughout pregnancy, while those of two other groups were fed 50% of the control nutrient allowance during the first 30 days of pregnancy (R1) or 50% of the control nutrient allowance from days 31–100 of pregnancy (R2). Between 2 and 5 months old, behaviour of lambs was tested by the implementation of 2 types of test: isolation and novelty. There were no statistical differences between lamb treatments in escape behaviour and heart rates during isolation test, or the latency to approach a novel or a familiar object in the novelty test in tests conducted at 2, 3, 4 and 5 months of age.Male lambs showed a tendency of turning to the right-hand side of the test pen, irrespective of treatment group, between the age of 2 and 5 months old. A greater proportion of C compared to R1 males turned right at the age of 2 and 5 months old (P < 0.05). Significant differences concerning laterality were found also between C and R1 female lambs at the age of 2 and 4 months old (P < 0.001), between C and R2 male lambs at the age of 2 months old (P < 0.05), between C and R2 female lambs at the age of 4 and 5 months old (P < 0.01), between R1 and R2 male lambs at the age of 2 and 5 months old (P < 0.05) and between R1 and R2 female lambs at the age of 2 months old (P < 0.001).It is concluded that prenatal undernutrition during different periods of pregnancy had no effect on fear-related behaviour, but effect on laterality at the early stages of lamb age between 2 and 5 months old.     

Efficacy of marbofloxacin against respiratory infections of lambs

The trial was carried out in a sheep flock with mixed Mannheimia haemolytica/Mycoplasma spp. respiratory infection; 60 lambs were included therein and allocated as follows: lambs in group MH were subcutaneously injected with marbofloxacin (3.0 mg/kg bodyweight) on two occasions, once daily 2 days apart – lambs in group ML3 were given marbofloxacin (2.0 mg/kg) on three occasion, once daily for three consecutive days – lambs in group ML2 were given marbofloxacin (2.0 mg/kg) on two occasions, 2 days apart – lambs in group T were subcutaneously injected with tilmicosin (15 mg/kg) on two occasions, 4 days apart – lambs in group C were untreated controls. The lambs were monitored before and after treatment and the clinical findings were scored; they were euthanatised 42 days after treatment for pathological examination of the lungs. Groups were similar at the start of a field trial with respect to all parameters (general clinical condition, presence of nasal discharge, presence of ophthalmic discharge, results of lung auscultation) evaluated (P > 0.05). After treatment, no systemic or local adverse reactions were observed in any lamb. Forty-two days after treatment, the median general clinical assessment score of groups MH, ML3 and T was 0, that of group ML2 was 1 and that of group C lambs was 2 (P < 0.01). Treatment with marbofloxacin was associated with improved clinical scores; the results were similar for all evaluations 14 days after treatment and subsequently. Clinical cure rate 42 days after treatment was 100, 100, 42, 100 and 0% for group MH, ML3, ML2, T and C lambs, respectively (P < 0.01). After controlling for initial weight, treatment was found to have a significant effect on carcass weight (P < 0.01). Pairwise differences in lung lesion scores between any of the four treated groups and the untreated controls were significant (P < 0.02). It is concluded that marbofloxacin is effective against respiratory infections of lambs at a dose rate of 3.0 mg/kg bodyweight given on two occasions, once daily 2 days apart or at a dose rate of 2.0 mg/kg given on three occasions for three consecutive days.     

Influence of undegraded intake protein on intake,digestion, serum hormones and metabolites,and nitrogen balance in sheep

In Exp. 1, 20 ewes of mixed breeding were fed grass hay : straw mixtures, assigned to one of four supplemental treatments and evaluated during six collection periods. Supplemental treatments were control (no supplement), and low, medium, and high levels (5.2%, 22.1%, and 41.3% of DM, respectively) of undegraded intake protein (UIP). Supplements were formulated to be similar in degraded intake protein (DIP; 21%). Digestibilities of DM, OM, and CP were increased (P < 0.10) with protein supplementation and in medium and high compared with low UIP supplemented ewes. Digestibility of CP also was increased (P < 0.10) in ewes on high compared with medium treatments. Serum insulin was not influenced (P > 0.10) by UIP treatment, except in collection period four. In contrast, serum glucose and growth hormone were not influenced (P > 0.10) by UIP treatment. In Exp. 2, four wether lambs fed the same treatments as in Exp. 1, were used in two 4 × 4 Latin squares trials. In trial 1 lambs received a grass hay diet (6.7% CP) and in trial 2 lambs were fed 40 : 60 blend (6.6% CP) of grass hay and spring wheat straw. In both trials, N intake, urinary N, N digestion, apparent N absorption, and N retention were increased (P < 0.10) with protein supplementation. In addition, in trial 1, urinary N, N digestion, and apparent N absorption were increased (P < 0.10) in medium and high compared with low UIP and also in high compared with medium UIP treatments. In trial 2 of Exp. 2, total feed intake (g/kg BW), digestibility of DM and OM, BW, and fecal N were increased (P < 0.10) with protein supplementation. Organic matter digestion, BW, N intake, and N retention were increased by medium and high compared with low UIP. Fecal N, BW, N intake, and N retention were increased (P < 0.10) in high compared with medium UIP. These data indicate that increasing levels of UIP supplementation increases DM, OM, and CP (N) digestibility, serum urea N concentration, and N retention in sheep fed low quality forage.     

Effect of dietary inclusion of Ficus infectoria leaves as a protectant of proteins on the performance of lambs

This study examined the effects of dietary inclusion of tanniferous leaves of Ficus infectoria as a protectant of proteins on the performance of lambs. Twenty-four lambs were randomly divided into four groups of six each in a completely randomized block design and fed four iso-nitrogenous supplements formulated to contain 0, 1.0, 1.5 and 2.0% condensed tannins (CT) through dried and ground leaves of F. infectoria. The diets were designated as CT-1.0, CT-1.5 and CT-2.0, respectively, and fed to lambs on a basal diet of wheat straw to meet requirements for maintenance and growth. Blood-biochemical profile was monitored in all the lambs at 0, 45, 90, 135, 180 days of feeding. The average daily growth rate and wool growth for a period of 180 days showed a significant (P < 0.05) increase by the supplementation of CT at 1.5% through F. infectoria leaves. Although addition of CT up to 1.5% in the supplement did not interfere with the nutrient intake or digestibility, a depressing effect on DM, OM and ADF digestibility at 2.0% CT level was apparent without any detrimental affect on intake. Digestible crude protein (DCP) and total digestible nutrients (TDN) values of the composite diets were comparable, except for significantly (P < 0.05) lower TDN (%) in CT-2.0 than the control. Intake of DCP, digestible organic matter and TDN was comparable irrespective of dietary treatments, though lambs under CT-2.0 had significantly (P < 0.05) lower intake as compared to their counterparts given diet CT-1.0. Feeding of CT containing diets particularly at 1.5 and 2.0% levels significantly (P < 0.05) influenced N utilization and improved its retention, however, the microbial protein synthesis as estimated by urinary excretion of purine derivatives was not affected by the dietary treatments. Haematological (haemoglobin and packed cell volume) and biochemical parameters (serum glucose, total protein, albumin, globulin, A:G ratio, alanine aminotransferase and aspartate aminotransferase were similar among the dietary treatments except for significant (P < 0.05) reduction in serum urea concentration of lambs fed 1.5 and 2.0% CT in the supplement. It may be concluded that CT from F. infectoria leaves at 1.5% in supplement could be used as a protectant of proteins for improving the performance of lambs.     

Effect of group size on feed intake,aggressive behaviour and growth rate in goat kids and lambs

The effects of different group sizes on feed intake, growth and behaviour in penned kids and lambs were studied in an experiment (Exp. 1) with 30 kids and 30 lambs used in 3 periods. In each period, animals were divided into five group sizes. The group sizes were one, two, three, four or five animals per pen. In a second experiment (Exp. 2) 36 kids and 36 lambs were allotted to two groups of one and five animals per group. The diet consisted of Jackfruit (Artocarpus heterophyllus) and Acacia (Acacia mangium) foliages, sugar-cane (Saccharum officinarum) and concentrate. The foliages were given ad libitum, equal to 130% of intake of fresh matter of the group the previous day, and concentrate and sugar-cane were given at a level of 10 g dry matter (DM)/kg initial body weight. The time for each period in Exp. 1 was 21 days, with the last 7 days for data collection. The behaviour observations were done during the last 4 days of each data collection period. The time for Exp. 2 was 84 days.In Exp. 1, the kids had a higher total DM intake (DMI) (P = 0.011) and DMI of Jackfruit (P < 0.001) than the lambs. Total intake increased linearly as group size increased (P = 0.03). When feeding Jackfruit or sugar-cane aggressive behaviours recorded per pen or per animal increased linearly with group size. In Exp. 2, there was no difference in total DMI between kids and lambs, but kids had a significantly higher DMI of Jackfruit and a lower DMI of sugar-cane. Total DMI and DMI of Jackfruit and sugar-cane were similar for the group sizes of five animals and one animal, but kids showed a higher total intake and intake of Jackfruit in the group sizes of five animals, while a higher intake was obtained in single pens for lambs. The weight gain was higher (P < 0.05) for the lambs compared to the kids, but similar for the animals in the group size of one or five animals. The feed conversion ratio (FCR) was significantly lower for the lambs compared to the kids, but not different between group sizes. The water intake of the lambs was higher (P < 0.05) than that of the kids in both experiments and the animals in the pens with high density drank more water than the animals in individual pens only in Exp. 2. In conclusion, increasing the number of animals in the pens increased feed and water intake and also aggressive behaviours and did not improve growth rate or feed conversion ratio.     

Effect of individual and mixed live yeast culture feeding on growth performance,nutrient utilization and microbial crude protein synthesis in lambs

This study investigated effects of feeding three individual, and a mixed, yeast culture (Kluyveromyces marximanus NRRL3234, Saccharomyces cerevisiae NCDC42, Saccharomyces uvarum ATCC9080 all in a 1:1:1, ratio) on growth performance, nutrient utilization and microbial crude protein (CP) synthesis in feedlot lambs during the post-weaning phase of growth. Sixty weaner lambs (90 ± 3.5 d old and 15.9 ± 0.50 kg BW) were fed for 91 d in five equal groups. The control group of lambs received sterilized culture medium while the treatment groups were fed a yeast culture in addition to a ad libitum total mixed ration (TMR). The yeast culture, dosed at 1 ml/kg body weight (BW) had 1.5–2.0 × 10⁹ live cells/ml. Yeast culture supplementation did not influence intake and digestibility of organic matter (OM), CP, neutral detergent fiber (NDF), acid detergent fiber (ADF) and hemicellulose and the metabolizable energy (ME) level of the diets were similar between control and yeast supplemented lambs. Lambs in all groups were in positive N balance, but N intake and N voided in feces and urine, as well as N balance, did not change due to yeast culture supplementation. Urinary allantoin excretion was similar, but purine derivatives absorbed (mM/d) were higher (P<0.05) in yeast culture supplemented lambs. Yeast culture supplementation improved (P<0.05) microbial CP synthesis. Supplementation of SC and mixed yeast improved (P=0.002) BW gain of lambs by 21% and 16% respectively. All yeast culture supplemented lambs had higher feed efficiency in comparison to control lambs. Among the three yeast cultures used, S. cerevisiae had the most potential as a growth promoting feed additive in feedlot lamb production, and it may serve as an alternate to antibiotics and ionophores as a growth promoter of weaner lambs.