Influence of individual predisposition, maternal experience and lactation environment on the responses of pigs to weaning at two different ages

This study assessed the effect of predisposition to perform harmful social behaviour, maternal rearing environment, and lactation environment on the responses of pigs to weaning at 3 or 5 weeks of age. Predisposed and non-predisposed gilts were selected as dams for this study at 7 weeks of age. Selection was based on behaviour in a “tail chew” test and performance of harmful social behaviour towards penmates. The gilts were mated at puberty with boars of a similar predisposition, and farrowed at approximately 44 weeks of age. Half of the gilts of each predisposition were reared from the time of selection until farrowing in barren environments, and half in enriched environments. During lactation, gilts and litters were either housed in a similar environment to that which gilts had experienced during rearing, or in a different environment (i.e. in terms of being barren or enriched). Litters from each treatment group were weaned at either 3 weeks of age (early weaning), or 5 weeks of age. After weaning, piglets were regrouped and housed in slatted pens without access to substrates. Non-predisposition to perform harmful social behaviour was associated with reduced growth during the post-weaning period (P < 0.01), and increased belly nosing behaviour in response to early weaning (P < 0.05). These effects were not mitigated by maternal experience or lactation environment factors, and it is concluded that this type of selection may not be commercially viable. Rearing dams in barren rather than enriched environments led to reduced welfare in offspring. This was reflected in increased adrenocortical reactivity during the lactation period (P < 0.01), and increased belly nosing behaviour in response to early weaning (P < 0.05). The effect of barren maternal rearing environments on belly nosing behaviour by offspring was eliminated when pigs were housed in enriched lactation environments (P < 0.01). Enrichment during the lactation period also led to improved growth rates in the post-weaning period (P < 0.01). It is suggested that this effect was due to an enhanced ability to cope with the weaning process. Overall, the results show that both genetic and early environmental factors are important determinants of the responses of pigs to weaning. Adverse effects of barren maternal rearing environments may be overcome by housing pigs in enriched lactation environments.     

Evaluation of lamb performance and costs in motherless rearing of German Grey Heath sheep under field conditions using automatic feeding systems

Performance and costs were evaluated for 205 German Grey Heath lambs reared artificially under field conditions using three feeding and three weaning regimes. In phase 1 (pre-weaning), ad libitum feeding of milk replacer (MR) on an automatic lamb feeder was compared to restricted MR feeding on the modified calf feeder “Stand alone II^®” or with buckets. In phase 2 (after weaning at 12 kg body weight), abrupt weaning was compared to gradual weaning systems with reduction of the amount or the concentration of MR over 2 weeks. In phase 1, average daily gains (ADG) were highest in the Ad libitum group (0.262 ± 0.032 kg/d), followed by Bucket and Stand alone with 0.227 ± 0.036 kg/d and 0.209 ± 0.023 kg/d, respectively (P < 0.05). In contrast, feed conversion rate was best for group Stand alone (1.17:1), compared to 1.20:1 in group Bucket and 1.23:1 in group Ad libitum. In phase 2, abrupt weaning caused weight loss in lambs from the Ad libitum and Bucket groups, but not in group Stand alone. No post-weaning growth check was seen in lambs weaned gradually. In general, differences in body weight (BW) between groups were low, and on d 70, no significant difference was seen between feeding groups, whereas lambs weaned abruptly still had lower BW than lambs weaned by reducing the amount of MR (P < 0.05). Total lamb mortality was 3.9%, with no accumulation of infectious disease in any of the feeding or weaning groups. Economic analysis revealed that total costs in phase 1 were highest for group Stand alone (57–70 € per lamb), followed by the Bucket group (63 € per lamb). Although MR consumption was higher in the Ad libitum group, this method was the most cost-efficient (50–54 € per lamb), because purchase price of the feeder and labor costs were relatively low. In phase 2, gradual weaning systems added costs of 4.70–9.50 € per lamb. Our findings indicate that the most efficient way to rear 60–120 lambs artificially under field conditions is by using an automatic ad libitum lamb feeder followed by abrupt weaning.     

Effects of Tasco (a seaweed extract) and heat stress on N metabolism and meat fatty acids in wether lambs fed hays containing endophyte-infected fescue

Wether lambs (n = 27, average BW = 40 kg) were used to test response to forage treated with Tasco-Forage (an extract of the brown kelp Ascophyllum nodosum) prior to conserving, or to direct feeding of the extract (Tasco-EX). Hays made from endophyte (Neoyphodium coenophialum)-infested tall fescue (Festuca arundinacea)-based pasture received 0 or 3 kg of Tasco/ha prior to harvest. Lambs, blocked by weight, were randomly allotted to three diets: (1) control hay, (2) treated hay, and (3) #1 + Tasco-EX fed at 1% of the diet. Hays were low in CP (<7%) so all lambs were fed soybean meal (12% of the diet) in addition to trace mineralized salt. Diets were fed at 1.5% BW to prevent refusals. Total collections (7 d) were made during periods without or with applied heat stress. After each period, rumen contents were obtained to determine pH, NH₃ and VFA. Lambs were sacrificed post-trial. A subset was used to evaluate sensory traits and muscle fatty acids. Lambs were in negative N balance during the study and Tasco treatments did not affect N metabolism. Fecal N tended (P < 0.10) to increase with short duration heat stress causing a concomitant decrease (P < 0.05) in apparent N digestibility (58.6 versus 56.1%; S.E. = 0.7). Urinary N loss decreased (P < 0.001) with heat stress (8.0 versus 5.9 g/d; S.E. = 0.2), resulting in increased (P < 0.001) N retention (−2.1 versus −0.3 g/d; S.E. = 0.2). Apparent OM digestibility was not affected by heat stress but was greater (P < 0.05) for lambs fed Tasco-EX treatment than those fed treated hay. Treatment diets decreased (P < 0.05) ruminal butyrate. Heat stress increased (P < 0.05) acetate and total VFA and decreased (P < 0.01) ruminal pH. A tendency (P < 0.11) of increased 14:1ω5, decreased (P < 0.05) 18:0 and total saturated fatty acids in muscle was observed with Tasco diets. Meat sensory characteristics were not affected by treatment. Tasco may alter some aspects of rumen or lipid metabolism but has no effect on N metabolism or meat sensory characteristics of sheep fed restricted, low-quality diets.     

The effect of a combination of permanent breeding cage and low housing density on the reproductive success of farmed blue foxes

Social factors are known to affect the reproduction of many canids both in the wild and in farms. For example, reproduction in farmed silver foxes is regulated by social stress; foxes seem to benefit from noncramped housing conditions and permanent breeding cages. However, no comparable studies have been carried out in farmed blue foxes.

The aim of our experiment was to create an alternative, improved, economically viable and practical housing solution for blue foxes. Therefore, we compared reproductive performance of blue foxes in permanent breeding cages with low animal densities (L group, N = 79) and traditional housing with its changing social environment with high animal density (H group, N = 74). The reproductive data from the L and H groups were compared separately for primiparous and multiparous vixens because the reproductive performance in primiparous vixens was substantially lower (P < 0.001) than in multiparous vixens.

Altogether, 41 and 39% of the primiparous vixens in the H and L group whelped (P > 0.05), but only 28 and 34%, respectively, weaned at least one cub (P > 0.05), i.e., 72 and 66% of the primiparous vixens did not reproduce in the H and L group, respectively (P > 0.05). The total reproductive performance, expressed as cubs at weaning per breeding female, was 1.7 ± 3.5 for the H and 1.6 ± 2.9 for the L group (P > 0.05). In the primiparous vixens, the only statistically significant difference observed between the two housing systems was that the onset of oestrus occurred five days earlier in the H than in the L group (P < 0.05).

All multiparous vixens in the L group exhibited oestrus compared to 94% in the H group (P > 0.05). Furthermore, there was a nonsignificant (ns) trend for fewer barren females (9% versus 17%), more successfully reproducing vixens (83% versus 74%) and a higher number of live-born cubs (10.9 ± 4.7 versus 9.4 ± 3.9) in the L than in H group in the multiparous vixens (for all P > 0.05). This resulted in 1.7 and 1.4 cubs more per breeding and per mated vixen, respectively, at weaning in the L group (7.3 ± 5.0) compared to the H group (5.6 ± 4.2), but also this difference was nonsignificant.

Although our present results lack statistical significance, they are promising enough to encourage field experiments with sufficiently large number of animals to prove or disprove these preliminary findings that lower housing density and permanent breeding cage, together or separately, may enhance reproduction particularly in multiparous blue fox vixens.     

Effects of ileal endogenous nitrogen losses and dietary amino acid supplementation on nitrogen retention in growing pigs

The relationship between ileal endogenous nitrogen (N) losses and N retention was studied in two experiments with growing pigs of 40 to 60 kg. In Experiment 1, 13 ileal cannulated castrated males were fed diets based on maize starch, containing either soyabean meal (SBM) with a low trypsin inhibitor activity (TIA), a mixture of toasted and untoasted soyabean meal with a high TIA (mSBM), a commercial batch of peas, or rapeseed expeller cake (RC). Ileal endogenous N recovery was measured using the ¹⁵N-isotope dilution technique. Apparent ileal digestibility of crude protein (CP) for the SBM, mSBM, pea and RC diets were 82.8, 72.0, 76.7 and 68.7% (P < 0.05). True ileal CP digestibility for the diets was 96.5, 93.0, 94.0 and 87.5% (P < 0.05), and the recovery of ileal endogenous N was 3.08, 6.01, 4.55 and 5.36 g/kg DMI (P < 0.05). In Experiment 2, sixteen castrated males were used to determine N retention, using almost similar diets as in Experiment 1. The diets contained either SBM, mSBM or peas and were balanced for the contents of apparent ileal digestible (ID) CP (96 g/kg) and ID essential amino acids (EAA; at least 85% of requirement values). The fourth treatment was a diet with mSBM as protein source, but supplemented with EAA to the level of 95% of the requirement values (diet mSBMs). Apparent faecal CP digestibility for the SBM, mSBM, pea and mSBMs diets was 88.6, 87.2, 86.1 and 86.0% (P < 0.05). Urinary N excretion and N retention for these treatments were 0.39, 0.59, 0.40, 0.53 (P < 0.05) and 0.87, 0.80, 0.85, 0.84 g/kg^0.75/day (P < 0.05), respectively. Utilization of dietary ID N for N retention were 79.8, 73.3, 78.2 and 77.6% (P < 0.05), respectively. The study showed that increased ileal endogenous N losses are associated with higher losses of urinary N and with a lower N retention. Supplementation of extra essential AA to a diet causing a relatively high flow of ileal endogenous N, may compensate for the lower N utilization under these conditions, and thus limit effects on N retention.     

Evaluation of sperm functional attributes in relation to in vitro sperm-zona pellucida binding ability and cleavage rate in assessing frozen thawed buffalo (Bubalus bubalis) semen quality

The objective of this study was to evaluate sperm functional attributes in relation to in vitro sperm-zona binding ability and cleavage rate in assessing frozen thawed buffalo (Bubalus bubalis) semen quality. Frozen-thawed forty-eight ejaculates from eight Surti buffalo bulls (six ejaculates/bull) obtained by artificial vagina were used. Frozen semen from each bull was thawed, pooled, and subjected for sperm functional (six replicates) and in vitro fertilization (four replicates) tests. The progressive forward motility, plasmalemma functional integrity assessed by fluorogenic [6-carboxyfluorescein diacetate (CFDA), and propidium iodide (PI)], hypoosmotic swelling (HOS), and hypoosmotic swelling-Giemsa (HOS-G) test, mitochondrial membrane potential, sperm nuclear morphology, the number of sperm bound to zona and cleavage rate differed significantly (P < 0.05) between bulls. When the animals were grouped based on cleavage rate (group I, >40% cleavage rate, n = 5, and group II, <40% cleavage rate, n = 3), in vitro fertility parameters and all the sperm functional attributes except sperm nuclear morphology differed significantly (P < 0.05). The proportions of sperm with functional plasmalemma in the tail and intact acrosome assessed by HOS-G test (25.33, range: 17.48–40.27) were significantly (P < 0.001) lower than the functional plasmalemma in the tail assessed by HOS test (39.80, range: 27.85–54.67). The number of sperm bound to zona had significant correlations with the mitochondrial membrane potential (r = 0.90, P < 0.01) and plasmalemma integrity (fluorogenic, r = 0.74 and HOS, r = 0.79, P < 0.05) and HOS-G, r = 0.87, P < 0.01). The cleavage rate had significant (P < 0.05) correlations with the mitochondrial membrane potential (r = 0.70) and plasmalemma integrity measured by HOS-G test (r = 0.68). The present study indicates that these attributes could represent important determinants of buffalo sperm quality influencing cleavage rate.     

A note on the effects of co-mingling piglet litters on pre-weaning growth, injuries and responses to behavioural tests

The purpose of this study was to determine how co-mingling litters affected piglets’ pre-weaning growth, ear injuries, suckling behaviour and responses to behavioural tests used to measure coping abilities. Thirty sows and their respective litters were housed in standard farrowing crates until day 13 after birth. On day13, the partition between two neighbouring pens was removed for 20 litters allowing piglets to interact (forming 10 co-mingled litters). The remaining 10 control litters were kept in standard farrowing crates throughout the experiment. Three focal piglets from each litter were used for data collection. Focal piglets were weighed and ear injuries recorded on days 2, 4, 9, 12, 15 and 18 after birth. There were no differences in piglets’ weight gain before or after co-mingling. Ear injuries were more abundant in co-mingled litters on day 15 (P < 0.05) but these differences disappeared by day 18. Suckling behaviour was recorded on days 5, 8, 10, 14, 16 and 18 after birth. There were no differences in teat fidelity, suckling frequency and mother fidelity between treatments. Three behavioural tests, social challenge, isolation, and backtest, were performed before and after co-mingling. There were no treatment effects on piglets’ response to the isolation test and backtest. Co-mingled piglets showed longer latency for the first aggressive interaction (P < 0.05), spent more time in proximity to one another (P < 0.05) and performed less single bites (P < 0.05) than control piglets during the social challenge. In addition, the duration and frequency of aggressive interactions (P < 0.05) were lower in co-mingled piglets than control piglets. Co-mingling did not affect the frequency of single head thrusts or oral–nasal contact, but did tend to increase the frequency of escape attempts (P < 0.10). Our results suggest that co-mingling litters during lactation affects piglets’ social behaviour, by primarily decreasing aggressive interactions during social challenges.     

Examination of cyclic changes in bovine luteal echotexture using computer-assisted statistical pattern recognition techniques

B-mode sonography is a well-established diagnostic tool for determination of cycle stage in gynaecology. The aim of this study was to determine whether computer-assisted texture analysis of B- mode sonographic images of bovine luteal glands provides further information about the animal's plasma progesterone concentration and cycle stage. Four Simmenthal cows were examined during two consecutive estrous cycles with an ultrasound device equipped with a 7.5 MHz microconvex probe. During each examination three B-mode images of the corpus luteum (CL) were digitized and analyzed off-line using a computer-assisted texture analysis program. Size, echogeneity, and echotexture of the CL were characterized by the following texture parameters: area of cross-sectional planes of the CL (A), mean gray level (MGL), correlation (CORR), run percentage (RPERC), and long-run emphasis (LREM). Plasma progesterone levels (P4) were also determined. All parameters showed characteristic changes during the estrous cycle (P < 0.05). Variance component estimates for the effect of Day of estrous cycle on A, MGL, CORR, RPERC, and LREM were 56.6%, 64.6%, 77.6%, 89.9%, and 86.0%, respectively, and 20.6%, 24.5%, 7.2%, 0.0%, and 14.0% for the influence of the individual cow. The factor estrous cycle within cows was responsible for 22.8%, 10.9%, 15.2%, 10.1%, and 0.0% of the variability of A, MGL, CORR, RPERC and LREM values, respectively. Cyclic changes were similar in A and P4. In contrast to P4, which decreased already between Days –5 and –3 (Day 0 = ovulation), A stayed at constant high values until Day –3. Mean MGL values were higher (P < 0.05) on Days 7, 9, and 13 compared to Days 3 and –3. Mean CORR values were constantly high (P > 0.05) during the first days after ovulation and decreased continuously (P < 0.05) between Days 5 and 13. Thereafter, mean CORR values remained low (P < 0.05) until the next ovulation, except on Day –3 (P < 0.05). Mean RPERC rose between Days 1 and 9 from low to high values (P < 0.0001) remained at these high values (P > 0.05) between Days 9 and 15, and decreased (P < 0.05) afterwards to baseline values on Day –1. Mean LREM inclined steeply (P < 0.0001) from minimum to maximum between Days 1 and 5. From Days 7 to –3, mean LREM remained (P > 0.05) at a constant level close below the maximum value, and decreased to baseline values on Day –1. The results of this study show that statistical pattern recognition techniques provide new information about the luteal glands, thus facilitating a more accurate differentiation between different cycle stages in cows.     

Prolactin regulation of testicular development and sexual behavior in yearling Suffolk rams

The aim of this study was to determine how the yearly prolactin rhythm might affect the sexual development of Suffolk rams (latitude 50°N). Five rams were injected daily with bromocriptine (35–45 μg kg⁻¹ body weight) for 1 year, beginning in January (early winter) when rams were 11 months of age. Five control rams each received daily injections of the vehicle. In the controls, blood prolactin was <7.5 ng ml⁻¹ in winter, increased (P < 0.01) to a peak of 172.6 ± 11.9 ng ml⁻¹ after the spring equinox, and remained high during summer before declining (P < 0.01) to 29.6 ± 6.6 ng ml⁻¹ at the autumn equinox. Suppression of the seasonal rise in prolactin secretion with bromocriptine slowed testicular growth (50%; P < 0.05) in April and May (spring), thus delaying the time of peak testis size and sperm production by 1 month. Serum testosterone level was lower (50%; P < 0.01) in the treated rams than the controls in June and July (early summer), due mainly to reduced stimulation of the testes by smaller (P < 0.01) LH pulse releases or to smaller (P < 0.01) testosterone responses to LH releases, respectively. Suppression of prolactin also seemed to disrupt the central activation of gonadotropin secretion in that seasonal increases in serum FSH level and LH pulse amplitude and frequency were unusually slow (P < 0.05). These anomalies did not affect testis growth, which was normal from June until development was complete. Rams were sexually inexperienced when libido was first tested in July (non-breeding season). Both groups were equally capable of learning and expressing sexual behavior (i.e. normal mounting and ejaculation frequencies), which was more intense in September (breeding season; P < 0.05). Results support the hypothesis (based on the location of prolactin receptors) that the spring increase in prolactin secretion could target both the testes and the hypothalamic–pituitary system and be involved in the seasonal regulation of sexual function in the young adult Suffolk ram.     

Control of postpartum anestrous with an intra-vaginal progesterone device plus eCG or calf removal for 120 h in suckled crossbred cows managed in a pasture-based system

To control postpartum anestrus and reduce calving to conception interval, 167 crossbred non-pregnant cows that were 90–130 days postpartum were allotted randomly to one of the following treatments: PH (n = 59), intra-vaginal sponge with 250 mg of medroxyprogesterone acetate (MAP) for 7 days plus 50 mg of MAP and 5 mg 17-β estradiol (17β-E) in the first day of treatment (day −8), 500 UI eCG (day −3) and 1.5 mg 17β-E in 24 h after sponge removal (day 0); CR (n = 57), temporary calf removal for 120 h; CG (n = 51), control group without treatment. Estrus rate differed among treatments (P < 0.01) being greater in PH (78.2%), followed by CR (52.0%) and CG (22.9%). A greater proportion of cows in the PH (80.0%) and CR (54%) groups had ovulations when compared to CG (35.4%). Intervals to first estrus were 13.5 ± 6.3 days, 26.1 ± 6.4 days and 52.5 ± 7.5 days for the PH, CR and CG groups, respectively. First insemination conception was similar in the three groups. Postpartum intervals to first breeding (PFS) and to conception (PCI) were longer in CG than PH and CR groups (P < 0.05; P < 0.01). The PH and CR groups had a similar PFS but PCI was different (P < 0.02). Accumulated pregnancy rate at 30 and 60 but not at 90 days were different (30 days: P < 0.09; P < 0.01; P < 0.09; 60 days: P < 0.06; P < 0.01; P < 0.03) among treatments. After 90 days post-treatment, 9%, 18% and 33% of cows from the PH, CR and CG groups had not conceived. Similarly, 5.4%, 6.0% and 12.5% of cows from the PH, CR and CG groups, respectively, were culled from the herd because of lack of pregnancy after 180 days post treatment. In the group of cows evaluated by ultrasonography, only those cows having larger ovaries and dominant follicles had ovulations. It was concluded that the hormonal treatment was more efficient in inducing a fertile estrus and reducing calving to conception interval followed by the calf removal for 120 h. Each method can be considered as an important tool to reduce the postpartum anestrous period in dual purpose herds when AI is conduct in the tropics.     

Fattening Pelibuey lambs with sugar cane tops and corn complemented with or without slow intake urea supplement

One hundred and eighty Pelibuey lambs were fattened for 120 days with three treatments evaluating in situ DM disappearance, voluntary DM or OM intake, rumen degradation, rate of passage, NH₃ and VFA concentration, apparent digestibility, ruminal pH, total fermentable carbohydrates and weight gains. The first diet (T1), 60 lambs (25.7 ± 0.7 kg BW) plus two cannulated sheep were fed 100% sugar cane tops (SCT) per day; treatment 2 (T2), 60 lambs (25.4 ± 0.4 kg BW) plus two cannulated sheep diet was SCT supplemented with 200 g DM of slow intake urea supplement (SIUS) (a 4% urea mixture) per day. Treatment 3 (T3), 60 sheep (25.5 + 0.5 kg BW) plus two cannulated animals, fed SCT and corn crop chopped (C) mixture (40:60%) were supplemented with 200 g SIUS per day. Ruminal kinetics were determined thereafter in four adult ruminal cannulated sheep in metabolic cages. A 100% corn diet was added to the second trial (T4). At all times, fibrous forages were available and exceeded VDMI. Daily BW gain by SCT animals was 70 g/d compared to 135 g/d for SCT/SIUS and 218 g/d for SCT/C/SIUS diets (P < 0.05). Total forage intake was similar for T1 and T2 treatments and higher for T3 (P < 0.05). Kinetics observation showed a total DMI variation increasing from 474 g/d for T1; 597 g/d for T4 to 797 g/d for T2, and 917 g/d for T3, being different for the last two treatments compared with the first two (P < 0.001) and similar among SIUS diets. Rumen pH diminished from 6.8 to 6.7 at 2 h, when SIUS was offered, and stayed above 6.5 during the 12 h of sampling when SIUS was the only supplement and 6.3 when corn was added, while in SCT lambs, ruminal pH decreased to 6.2 by 6 h and rose again to 6.4 after 12 h favoring bacterial multiplication. Ammonia concentration and digestion of potential digestible and indigestible fractions were significantly augmented (P < 0.05) by SIUS. In vivo nitrogen digestibility was different (P < 0.05) among diets: T1, T2, T3, and T4 (36.5%, 74.1%, 76.5%, and 39.4%, respectively). In vivo digestibility of DM, OM, cellulose and hemicellulose was similar among T2 and T3 groups but different when T1 or T4 diets were offered (P < 0.05). NDF digestibility was higher for T3 (77.1%) and T2 (75.1%) but different from T1 (57.1%) and T4 (59.1%) (P < 0.01). In situ DM disappearance did not show differences among T2 and T3 diets at 9, 12, 24 and 48 h of incubation but differed in percentage for T1 and T4. Digestion rate constant (k_d) was similar among SIUS diets 0.038 and 0.039, but different from T1 and T4 diets 0.023; 0.021 (P < 0.05). True digestibility of NDF was higher (P < 0.05) in SCT/SIUS/C (32.5%) and SCT/SIUS (32.7%) compared with SCT (26.2%) and C (27.4%). Passage of NDF was different (P < 0.05) between T1 (0.059 h⁻¹) and T4 (0.061 h⁻¹) from 0.079 (T2) and 0.081 k_p/h (T3). The half-time (t_1/2) disappearance for hemicellulose was higher (P < 0.05) for SCT/SIUS (22.1 h) and SCT/SIUS/C (29.2 h) as compared to SCT (18.1 h). Kinetic performance among SCT and C diet did not have a statistical difference. Utilization of fibrous forages by lambs was higher (P < 0.05) for SIUS diets. VDMI and apparent digestibility showed better performance for DM and OM, lower acetate molar proportions and greater feed intake by both SIUS diets which was reflected in body weight gain.     

Effect of strategic supplementation with multi-nutrient urea molasses blocks on body weight and body condition score of Lohi sheep owned by tenants of Pakistan

The effect of strategic supplementation with multi-nutrient urea molasses blocks (MNUMB) on BW and body condition score (BCS) in Lohi ewes (treated, n = 514) during late gestation and lactation was compared with those (control, n = 391) grazing on only post-harvest crop residues and road side in the irrigated district of Okara in central Punjab (Pakistan). Analysis of variance revealed highly significant (P < 0.01) differences in body weight (BW) and body condition score (BCS) of ewes of various ages with different reproductive status and seasons under both flocks. Analysis of variance also revealed a significant interaction (P < 0.05) between reproductive status and seasons in favor of BCS. Ewes aged 48 months in average constituted the highest (34.5% and 35.6%), whereas those aged 60 months had the smallest (10% and 4%) proportion in the control as well as in the treated flock. Mean BW and BCS in ewes of control flock was 33.5 and 2.08 kg, and lower (P < 0.05) than 35.0 and 2.31 in ewes in the treated flock, respectively. Ewes aging 12, 24 and 36 months treated with strategic supplementation of MNUMBs were not only heavier (P < 0.01) but also had highest BCS of 2.34. Lactating ewes constituted highest proportion (39%, 51%) followed by pregnant (35%, 32%) ewes in both flocks, respectively. Proportion of dry (16%) and freshly conceived (9.5%) ewes tended to be higher in the control than in the treated flock. BW was 8–11% higher (P < 0.01) in pregnant than in lactating or dry ewes in both flocks with similar BCS. Seasons of autumn and summer were found to affect BW more (P < 0.01) than BCS. Pregnant ewes in treated flocks had gained highest BW, 10–12% higher than ewes under control (P < 0.01) or than non-pregnant ewes (P < 0.05) but lost at a rate of 5–6% at lambing. BW in lactating ewes in treated flock was higher (P < 0.01) than ewes in control. Lambs suckling ewes with strategic supplementation of MNUMBs grew at a faster rate (122 g/day) with 10–15% higher survival rate than those (97 g/day) in the control flock during lactation of 16 weeks but non-significantly. Based on this improvement it can be concluded that supplementation with appropriate sources of energy and N exerts desirable effects on the traits of economic importance in sheep.     

Behaviour during the first stage of labour in cattle: Influence of parity and dystocia

The aim of the study was to examine typical behavioural elements in suckling cows and heifers at the first stage of labour and how these are affected by parity and dystocia. For this purpose, the parturitions of 87 cattle (10 Simmental heifers; 77 multiparous cows, 55 Simmental, 21 Simmental × Limousin) were observed from the appearance of the amniotic sacs in the cervix up to the emergence of the foetal phalanges in the rima vulvae. The animals were divided into three groups: group 1—cows with eutocia, n = 68; group 2—heifers with eutocia, n = 10; group 3—cows with dystocia, n = 9.

Compared to cows, there was a lower proportion of heifers with calm behaviour, whereas a higher proportion of heifers showed pawing with the forefeet (P < 0.05).

There was a higher proportion of cows with dystocia which showed rubbing against the wall (P < 0.05), discharge of urine (P < 0.05) and scraping on the floor (P < 0.05) compared to cows with eutocia.

The differences in behaviour of cows and heifers should be considered in a system for monitoring parturition to avoid misconstruing the normal calving situation and to obviate unnecessary obstetric intervention in heifers. Behavioural elements which were more frequently detectable in cases of dystocia should draw attention to the possibility that there may be a problem in the first stage of labour.     

Effects of ensiled forage legumes on performance of store finishing lambs

Male Beulah speckled face lambs (initial live weight (LW) 28.8 ± 0.31 kg) were allocated to three dietary treatments to evaluate the performance of store lambs of a hill breed when offered ensiled lucerne (Medicago sativa), red clover (Trifolium pratense) or ryegrass. Second-cut silage bales (wilted and inoculated) were prepared from 3-year old lucerne and red clover stands and a 1-year old ryegrass sward. All the lambs were group-housed and offered ad libitum ryegrass silage during a 3-week co-variate period. This was followed by a week of dietary changeover period, after which the lambs were housed individually and offered their treatment diet ad libitum. All the lambs received a flat rate supplement of pelleted molassed sugarbeet (250 g fresh weight/day). Individual intakes were determined daily, and weekly measurements of LW and body condition score (CS) were made. Additional measurements were taken by scanning the lambs for depth of Longissimus dorsi (LD) muscle and subcutaneous fat. Over an experimental period of 7 weeks, the lambs offered red clover silage had a higher voluntary silage dry matter (DM) intake, total DM intake and metabolisable energy (ME) intake (P < 0.001) than lambs offered either lucerne or ryegrass silage. This resulted in a faster (P < 0.001) growth rate and increase (P < 0.001) in CS, with no difference between lucerne and ryegrass silages. The feed conversion efficiency (FCE) was 8.0 ± 0.61 kg feed/kg gain for lambs fed red clover silage, compared with 16.6 ± 2.82 and 10.6 ± 1.94 kg feed/kg gain for lucerne and ryegrass silage, respectively. The CP intake was higher (P < 0.001) for lambs fed the lucerne and red clover silages than for the ryegrass silage treatment. The concentration of plasma total protein (TP) was higher (P < 0.05) for lambs offered ryegrass silage versus lucerne and red clover silage. Urea concentrations were highest for lambs fed lucerne silage and lowest for those fed ryegrass silage (P < 0.05). The glucose concentration was higher (P < 0.05) for lambs offered red clover silage, whereas non-esterified fatty acids (NEFA) concentration was higher (P < 0.05) for lambs offered lucerne silage. Substituting ryegrass silage with red clover silage has the potential to improve the performance of finishing store lambs.     

Neuropeptide FF (NPFF) reduces the expression of cocaine-induced conditioned place preference and cocaine-induced sensitization in animals

The endogenous brain opioid system is believed to play an important role in mediating reward mechanisms. Opioid innervation is high in many limbic regions and reinforcing actions of many drugs of abuse, including cocaine, are thought to be mediated via endogenous opioid system. The aim of the present study was to indicate whether the anti-opioid peptide, neuropeptide FF (NPFF; FLFQPQRF-NH₂) was able to modify the rewarding effect of cocaine (5 mg/kg) measured in the expression of conditioned place preference (CPP) test in rats and the expression of sensitization to hyperlocomotor effect of cocaine (10 mg/kg) in mice. Our results indicate that NPFF (5, 10, and 20 nmol) given intracerebroventricularly (i.c.v.) inhibited the expression of cocaine-induced CPP at the dose of 10 nmol (P < 0.01) and 20 nmol (P < 0.001). Moreover, NPFF inhibited the expression of cocaine-induced sensitization to its hyperlocomotor effect at the dose of 20 nmol (P < 0.05) and acute hyperlocomotor effect of cocaine at doses of 5 nmol (P < 0.01), 10 nmol (P < 0.01), and 20 nmol (P < 0.05). Our study suggests that NPFF may participate in a rewarding effect of cocaine measured in the CPP paradigm. On the other hand, our experiments indicate that NPFF is involved in the mechanism of expression of sensitization to cocaine hyperlocomotion but this effect seems to be non-specific because NPFF also inhibited the acute hyperlocomotor effect of cocaine.     

Treatment with high-dose estrogen (diethylstilbestrol) significantly decreases plasma estrogen and androgen levels but does not influence in vivo aromatization in postmenopausal breast cancer patients

While growth factors and hormones are known to influence aromatase expression in experimental systems, little is know about potential factors influencing peripheral aromatization in postmenopausal women. The fact that peripheral aromatase activity is higher in old compared to young women and the finding of relatively high tissue estradiol (E₂) concentrations after the menopause suggests peripheral aromatization could be influenced by estrogen concentration. To test this hypothesis, we determined plasma hormone levels (n = 9) and in vivo aromatization (n = 3) in postmenopausal women suffering from advanced breast cancer before and during treatment (4 weeks) with diethylstilbestrol (DES) 5 mg three times daily. Plasma levels of cortisol (C), corticosteroid-binding globulin (CBG), and sex hormone binding globulin (SHBG) were significantly increased in all patients (P < 0.05 for all). While we found no change in total body aromatization and plasma estrone (E₁) levels, estradiol (E₂) and estrone sulfate (E₁S) were suppressed by a mean of 48.8 and 68.2%, respectively (P = 0.043 and 0.008). Surprisingly, plasma levels of androstenedione (A), testosterone (T), dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) were also suppressed by a mean in the range of 32.1 to 52.6% (P < 0.05 for all androgens). In contrast, no change in plasma progesterone or 17-hydroxyprogesterone was found. Thus, one possible explanation to our findings could be that DES administered in high doses reduces 17,20-lyase activity in the adrenal gland.     

Parity of female goats does not influence their estrous and ovulatory responses to the male effect

The objective of the present study was to determine whether parity is a factor that influences the estrous and ovulatory responses of female goats when they are stimulated by males that show increased sexual activity. To stimulate sexual activity, four adult male goats were subjected to photoperiodic treatment for 2.5 months comprising long days, with the treatment commencing on 1 November. On 14 April at 1900 h, a group of multiparous females (n = 21) and a group of 16 months-old nulliparous females (n = 19) were exposed to four bucks (two per group) for 15 days. Throughout the study period, the estrous behavior of these female goats was detected twice on a daily basis. Ovulations of the female goats were determined by ecography on days 7 and 18 after exposure to males. The sexual behavior of males was recorded twice every day from 0800 to 0900 h and from 1730 to 1830 h during the first 4 days after introduction in the pen of females. The total cumulative proportion of multiparous females that had ovulations (100%) and displayed estrous behavior (100%) during the 15 days of exposure to males did not differ (P > 0.05) from that of nulliparous females (100% and 95%, respectively). The interval between introduction of males and onset of estrous behavior did not differ (P > 0.05) between multiparous (1.9 ± 0.1 days) and nulliparous (1.7 ± 0.2 days) females. The proportion of females displaying a short estrous cycle was greater (P < 0.05) in multiparous (13/21, 62%) than in nulliparous (5/19, 26%) females. Duration of these shorter than typical estrous cycles did not differ (P > 0.05) between groups (multiparous: 5.2 ± 0.3 days, nulliparous: 4.5 ± 0.1 days). The number of anogenital sniffings was greater (P < 0.001) in males exposed to nulliparous than in those exposed to multiparous females. In contrast, the number of mounting attempts was greater (P < 0.01) in males that were introduced to multiparous than in those that were introduced to nulliparous does. The number of flehmen, nudging, self-marking with urine, and mounts was not different (P > 0.05) between males that were in contact with multiparous and nulliparous females. These results indicate that regardless of parity, female goats respond to male introduction if they are stimulated by males that were previously exposed to artificial long days to increase their sexual behavior.     

Chemical characterization and in vitro crude protein degradability of thin stillage derived from barley- and wheat-based ethanol production

A study was conducted to characterize the different carbohydrate and protein fractions of wheat- and barley-based thin stillage samples. In vitro crude protein degradability of wheat- and barley-based thin stillage was estimated relative to soyabean (SBM) and canola (CM) meal using a protease enzyme assay. Results of the carbohydrate analysis showed that wheat thin stillage had similar neutral (NDF, average 328.5 g kg⁻¹) and lower (P < 0.05) acid detergent fibre (ADF) than barley-based thin stillage. Relative to barley-based thin stillage, wheat thin stillage had higher (P < 0.05) crude protein (CP) and soluble CP content. However, the amount of CP associated with NDF and ADF was higher (P < 0.05) in barley-based thin stillage than in wheat thin stillage. Fractionation of true protein showed that most of the CP (average 707 g kg⁻¹ of CP) was present in the slowly degradable true protein fraction and was similar in both byproducts. Glutamic acid was the main amino acid in thin stillage and was higher (P < 0.05) in wheat than in barley-based thin stillage. However, barley-based thin stillage had higher (P < 0.05) levels of lysine, methionine, arginine, threonine, leucine and isoleucine than wheat thin stillage. Results of the in vitro trial indicated that effective degradability of CP (g kg⁻¹ of CP) followed the order (P < 0.05): SBM (665.0) > wheat thin stillage (614.0) > CM (531.0) > barley-based thin stillage (493.0). It was concluded that barley-based thin stillage had different chemical characteristics than wheat thin stillage. The reduced CP degradability of barley-based thin stillage relative to wheat thin stillage was attributed to a lower CP and a higher acid detergent in soluble CP level.     

Development to the blastocyst stage of immature pig oocytes arrested before the metaphase-II stage and fertilized in vitro

In vitro fertilization (IVF) and embryonic development of mature and meiotically arrested porcine oocytes were compared in the present study. After in vitro maturation (IVM) of cumulus-oocyte complexes for 48 h, 75.4% of them extruded a visible polar body (PB). Most of the oocytes with a first polar body (PB+ group) were at the metaphase-II (M-II) stage (91.4%). Most of the oocytes without a visible polar body (PB− group) appeared to be arrested at the germinal vesicle (GV) (41.6%) and metaphase-I (M-I) (34.0%) stages. After IVF of oocytes (day of IVF = Day 0), there was no difference between PB⁺ and PB⁻ groups in rates of sperm penetration, mono-spermy, however oocyte activation rate after penetration was greater in the PB+ than in the PB− group (P < 0.05). On Day 2, there was no difference between rates of embryos cleaved at the 2–4 cell stages in PB+ and PB− groups (42.1 ± 48.8% and 33.6 ± 2.1%, respectively). On Day 4, the rate of PB+ embryos developing beyond the 4-cell stage was greater than that of PB− embryos (P < 0.05, 31.7 ± 3.9% and 14.1 ± 1.5%, respectively), and PB+ embryos had more cells than the PB− embryos (P < 0.05, 8.3 ± 0.4 and 6.0 ± 0.8 cells, respectively). On Day 6, a greater proportion of PB+ embryos developed to the blastocyst stage than did PB− embryos (P < 0.05, 34.6 ± 2.4% and 20.7 ± 2.8%, respectively). However, when the GV oocytes of the PB− group were not included in recalculations, there was no difference in blastocyst rates between M-I arrested and M-II oocytes (35.3 and 34.6%, respectively). The number of blastomere nuclei in embryos obtained from the PB+ group (52.0 ± 2.5) was greater than that from the PB− group (P < 0.05, 29.1 ± 2.8). The proportion of degenerated parts in the blastocysts, as determined by morphological appearance, was the same in the PB+ and PB− groups. Although the quality of PB+ embryos was enhanced as compared with that of the PB− group, the proportion of inner cell mass and trophectoderm cells in PB+ and PB− blastocysts did not differ (1:1.9 and 1:2.2, respectively). Chromosome analysis revealed that PB+ blastocysts had more diploidy (P < 0.05, 69.7%) than did PB− blastocysts (44.0%), whereas PB− blastocysts had more triploid cells (P < 0.05, 34.0%) than did PB+ oocytes (8.4%). These results indicate that pig oocytes arrested before the M-II stage (M-I oocytes) undergo cytoplasmic maturation during maturation culture and have the same ability to develop to blastocysts after IVF as M-II oocytes, but some of them resulted in degeneration or delayed development with poor embryo quality.     

Different effects of ATP on the contractile activity of mice diaphragmatic and skeletal muscles

Apart from acetyl-choline (Ach), adenosine-5′-trisphosphate (ATP) is thought to play a role in neuromuscular function, however little information is available on its cellular physiology. As such, effects of ATP and adenosine on contractility of mice diaphragmatic and skeletal muscles (m. extensor digitorum longa—MEDL) have been investigated in in vitro experiments. Application of carbacholine (CCh) in vitro in different concentrations led to pronounced muscle contractions, varying from 9.15 ± 4.76 to 513.13 ± 15.4 mg and from 44.65 ± 5.01 to 101.46 ± 9.11 mg for diaphragm and MEDL, respectively. Two hundred micromolars of CCh in both muscles caused the contraction with the 65% (diaphragm) to 75% (MEDL) of maximal contraction force—this concentration was thus used in further experiments. It was found that application of ATP (100 μM) increased the force of diaphragmatic contraction caused by CCh (200 μM) from 335.2 ± 51.4 mg (n = 21) in controls to 426.5 ± 47.8 mg (n = 10; P < 0.05), but decreased the contractions of MEDL of CCh from 76.6 ± 6.5 mg (n = 26) in control to 40.2 ± 9.0 mg (n = 8; P < 0.05). Application of adenosine (100 μM) had no effect on CCh-induced contractions of these muscles.

Resting membrane potential (MP) measurements using sharp electrodes were done at 10, 20 and 30 min after the application of ATP and adenosine. Diaphragm showed depolarization from 75 ± 0.6 down to 63.2 ± 1.05, 57.2 ± 0.96 and 53.6 ± 1.1 mV after 10, 20 and 30 min of exposition, respectively (20 fibers from 4 muscles each, P < 0.05 in all three cases). Adenosine showed no effect on diaphragmatic MP. Both agents were ineffective in case of MEDL.

The effects of ATP in both tissues were abolished by suramin (100 μM), a P2-receptor antagonist, and chelerythrin (50 μM), a specific protein-kinase C (PKC) inhibitor, but were not affected by 1H-[1,2,4]-oxadiazolo-[4,3-]-quinoxalin-1-one (ODQ, 1 μM), a guanylyl-cyclase inhibitor, or by adenosine-3,5-monophosphothioate (Rp-cAMP, 1 μM), a protein-kinase A (PKA) inhibitor.

Besides the action on contractile activity, ATP (100 μM) led to a significant (P < 0.001) depolarization of diaphragm muscle fibers from 74.5 ± 2.3 down to 64 ± 2.1, 58.2 ± 2.2 and 54.3 ± 2.4 mV after 10, 20 and 30 min of incubation, respectively. Incubation of MEDL with the same ATP concentration showed no significant change of MP.

Denervation of the muscles for 28 days led to a decrease of CCh-induced contractions of diaphragm down to 171.1 ± 34.5 mg (n = 11, P < 0.05), but increased the contractile force of MEDL up to 723.9 ± 82.3 mg (n = 9, P < 0.01). Application of ATP elevated the contractility of denervated diaphragm caused by CCh up to normal values (311.1 ± 79.7 mg, n = 6, P > 0.05 versus control), but did not significantly affect of contractility of MEDL, which became 848.1 ± 62.7 mg (n = 6).

These results show that the effects of ATP on both diaphragmatic and skeletal muscles are mediated through P2Y receptors coupled to chelerytrin-sensitive protein-kinase C.