Effect of Previous Experience on Grazing Patterns and Diet Selection of Brangus Cows in the Chihuahuan Desert

The ability to adapt to different environments is critical when livestock are moved because of drought or other management considerations. The impact of previous experience on grazing patterns and diet selection of Brangus cows in desert conditions was evaluated. Cows originating from a humid-subtropical environment (Leona, Texas) were brought to the Chihuahuan Desert (naïve) and evaluated against cows that spent their life in the Chihuahuan Desert (native) and cows that were born and raised in the Chihuahuan Desert but were moved to Leona, Texas during the preceding 3 yr (tourist). In addition, native cows with recent experience in desert conditions were compared with naïve cows and tourist cows that had not been in the Chihuahuan Desert for at least 3 yr. All cows were mature and had similar pedigrees (n = 21). Cows from the three groups were tracked in three extensive pastures (> 1 000 ha) for three 8–10-d periods during winter, early summer, and later summer. Cows never grazed in the experimental pastures before the study, but native and tourist cows had grazed adjacent pastures. Fecal near-infrared spectroscopy was used to estimate diet quality. Naïve cows used 335 ha ± 83 standard error (SE) less area (P = 0.06) and were 479 m ± 105 SE closer to water (P = 0.03) than cows born and raised in the Chihuahuan Desert (native and tourist cows pooled) when first evaluated in winter. After pooling all data, native cows were farther (P = 0.06) from water (730 m ± 283 SE) and spent less time at water (10.53% ± 3.93 SE) than cows that did not spend their entire life in the desert (naïve and tourist pooled). During winter and early summer (drought conditions), naïve cows selected diets with lower (P < 0.05) crude protein (CP) than cows born in the desert, but during late summer after abundant precipitation naïve cows selected a diet with higher (P = 0.07) CP. Although Brangus cows are highly adaptable, animals raised in nearby pastures appear to have advantages over naïve animals when grazing Chihuahuan Desert rangeland.     

Age and Body Condition of Goats Influence Consumption of Juniper and Monoterpene-Treated Feed

Redberry juniper (Juniperus pinchotii Sudworth) is an invasive, evergreen tree that is rapidly expanding throughout western and central Texas. Goats will consume some juniper on rangelands; however, intake is limited. The objective of our research was to determine how the age and body condition of goats influence their consumption of juniper and an artificial feed containing 4 monoterpenes. Two separate experiments were conducted. Experiment 1 examined the intake of redberry juniper foliage and used 39 goats either young (2 yr) or mature (> 6 yr). One-half of each age group was fed appropriate basal rations to reach either a high (HBC) or low body condition (LBC). Goats in LBC ate more (P < 0.01, 8.6 g · kg⁻¹ body weight [BW] ± 0.7 SE) juniper than those in HBC (2.3 g · kg⁻¹ BW ± 0.3 SE), and young animals consumed more (P < 0.05, 7.2 g · kg⁻¹ BW ± 0.7 SE) juniper than mature goats (3.9 g · kg⁻¹ BW ± 0.5 SE) across body condition treatments. In experiment 2, 36 goats, either young (2 yr) or mature (> 6 yr) and in either HBC or LBC, were offered a synthetic ration treated with 20.8 g · kg⁻¹ of 4 monoterpenes found in redberry juniper. Goats in LBC ate more (P < 0.01, 25.3 g · kg⁻¹ BW ± 1.0 SE) of the terpene-treated feed than those in HBC (17.5 g · kg⁻¹ BW ± 0.7 SE), and young animals ate more (P < 0.05, 22.5 g · kg⁻¹ BW ± 0.8 SE) than mature goats (20.3 g · kg⁻¹ BW ± 0.8 SE) across body condition treatments. Total intake as a proportion of body weight was also affected by body condition. Age and body condition are important factors that influence intake of chemically defended plants. A better understanding of how these attributes affect diet selection will aid livestock producers in improving grazing management.     

Production potentials of native chickens (Gallus gallus domesticus L.) of Western Visayas, Philippines

Poultry genetic resources diversity serves as a reservoir of genes adaptable to local conditions, production, resource utilization, and production that are compatible with consumer preferences for meat and egg products. This study was, therefore, conducted to determine the production potentials of native chickens in Western Visayas, Philippines. A total of 270 raisers were interviewed and 810 chickens were characterized. These numbers were divided equally among the provinces of Aklan, Antique, Capiz, Guimaras, Iloilo, and Negros Occidental. The data collected were analyzed using one-way analysis of variance and significant differences were determined using the Duncan’s Multiple Range Test. Results show that native chickens from Aklan had the highest (P?<?0.01) hatching percentage (93.10?±?1.67 %) and oldest (P?<?0.01) slaughter/marketing age (23.56?±?1.03 weeks). Those from Guimaras had the biggest (P?<?0.01) egg (42.69?±?0.87 g) and heaviest slaughter/marketing weight (920.00?±?22.72 to 924.44?±?23.01 g); the shortest (P?<?0.01) clutch interval (77.87?±?4.14 days) was observed from those in Iloilo. Those from Antique had the highest (P?<?0.01) survival rate from 1 day old to a slaughter/marketing age of 52.48?±?1.83 %. The adult live weight ranged from 1.27?±?0.04 to 1.62?±?0.04 kg with those from Aklan as the lowest (P?<?0.01) while those from Guimaras were the highest. Thus, the observed variations in reproductive and growth performances of native chickens from this region expressed their potentials for genetic improvement toward production.     

Brangus Cow–Calf Performance Under Two Stocking Levels on Chihuahuan Desert Rangeland

Cow–calf productivity on 2 lightly (25%–30% use) and 2 conservatively grazed pastures (35%–40% use) were evaluated over a 5-year-period (1997 to 2001) in the Chihuahuan Desert of south-central New Mexico. Spring calving Brangus cows were randomly assigned to study pastures in January of each year. Experimental pastures were similar in area (1 098 ± 69 ha, mean ± SE) with similar terrain and distance to water. Use of primary forage species averaged 28.8% ± 4.3% in lightly stocked pastures and 41.8% ± 4.4% on conservatively grazed pastures. Perennial grass standing crop (168.8 ± 86 vs. 173.6 ±  kg·ha^-1) and adjusted 205-day calf weaning weights (279.1 ±  vs. 270.7 ±  kg) did not differ among lightly and conservatively grazed pastures. Cow body condition scores in autumn, winter, and spring were similar among grazing levels as were autumn and winter body weights. However, cow body weights tended to be heavier (P < 0.10) in lightly grazed pastures relative to conservatively grazed pastures (524 vs. 502 ± 9.7 kg) in spring. Lightly grazed pastures yielded greater (P < 0.05) kg of calf weaned·ha^-1 and calf crop percent than conservatively grazed pastures in 1998 due to destocking of conservatively grazed pastures during that year's drought. Conversely, pregnancy percent tended to be greater (P < 0.1) in conservatively relative to lightly grazed pastures (92.6% vs. 87.7%); however, this advantage is explained by herd management as cows in the conservatively grazed pastures were removed during drought of 1998, avoiding exposure to the drought stress experienced by cows in the lightly grazed pastures. Nonetheless, pregnancy percents from both grazing treatments would be acceptable for most range beef production systems. Results suggest that consistently applying light grazing use of forage is a practical approach for Chihuahuan Desert cow–calf operations to avoid herd liquidation during short term drought.     

Cortisol release and heart rate variability in sport horses participating in equestrian competitions

Equestrian competitions require both physical activity and mental adaptation in horses. Cortisol, heart rate, and heart rate variability (HRV) are accepted stress parameters and, in this study, have been determined in horses (n = 13) participating in equestrian competitions for up to 3 consecutive days. Participation in competitions caused an increase in salivary cortisol concentrations (e.g., on day 1 from 1.0 ± 0.2 before to 2.2 ± 0.4 ng/mL after the competition, days 1 and 2: P < 0.001, day 3: P < 0.05) and an increase in heart rate (days 1 and 2: P < 0.001, day 3: P = 0.01). A consistent decrease in HRV occurred only in response to the final competition on day 3 (P < 0.01). When horses competing in dressage and show jumping were compared, cortisol release and HRV did not differ between groups, but after the competition, heart rate was lower in dressage than in show jumping horses (P < 0.05). Heart rate increased not only during the actual competition but already when horses were prepared in their stables (e.g., day 1: ?60 minutes, 38.6 ± 2; ?5 minutes, 77 ± 7; competition, 81 ± 10 beats per minute; P < 0.01). In conclusion, participation in equestrian competitions caused an increase in cortisol release and heart rate and a decrease in HRV variables. However, competitions were not a major stressor compared with other anthropogenic challenges such as transport, to which horses are exposed regularly.     

Effects of Long-Term Livestock Grazing on Fuel Characteristics in Rangelands: An Example From the Sagebrush Steppe

Livestock grazing potentially has substantial influence on fuel characteristics in rangelands around the globe. However, information quantifying the impacts of grazing on rangeland fuel characteristics is limited, and the effects of grazing on fuels are important because fuel characteristics are one of the primary factors determining risk, severity, continuity, and size of wildfires. We investigated the effects of long-term (70+ yr) livestock grazing exclusion (nongrazed) and moderate levels of livestock grazing (grazed) on fuel accumulations, continuity, gaps, and heights in shrub-grassland rangelands. Livestock used the grazed treatment through 2008 and sampling occurred in mid- to late summer in 2009. Nongrazed rangelands had over twofold more herbaceous standing crop than grazed rangelands (P < 0.01). Fuel accumulations on perennial bunchgrasses were approximately threefold greater in nongrazed than grazed treatments. Continuity of fuels in nongrazed compared to grazed treatments was also greater (P < 0.05). The heights of perennial grass current year’s and previous years’ growth were 1.3-fold and 2.2-fold taller in nongrazed compared to grazed treatments (P < 0.01). The results of this study suggest that moderate livestock grazing decreases the risk of wildfires in sagebrush steppe plant communities and potentially other semi-arid and arid rangelands. These results also suggest wildfires in moderately grazed sagebrush rangelands have decreased severity, continuity, and size of the burn compared to long-term nongrazed sagebrush rangelands. Because of the impacts fuels have on fire characteristics, moderate levels of grazing probably increase the efficiency of fire suppression activities. Because of the large difference between fuel characteristics in grazed and nongrazed sagebrush rangelands, we suggest that additional management impacts on fuels and subsequently fires need to be investigated in nonforested rangelands to protect native plant communities and prioritize management needs.     

Long-Term Vegetation Trends on Grazed and Ungrazed Chihuahuan Desert Rangelands

Long-term information on the effects of managed grazing versus excluded grazing effects on vegetation composition of desert rangelands is limited. Our study objectives were to evaluate changes in frequency of vegetation components and ecological condition scores under managed livestock grazing and excluded livestock grazing over a 38-yr period at various locations in the Chihuahuan Desert of southwestern New Mexico. Sampling occurred in 1962, 1981, 1992, 1998, 1999, and 2000. Range sites of loamy (1), gravelly (2), sandy (2), and shallow sandy (2) soils were used as replications. Black grama (Bouteloua eriopoda Torr.) was the primary vegetation component at the seven locations. Dyksterhuis quantitative climax procedures were used to determine trends in plant frequency based on a 1.91-cm loop and rangeland ecological condition scores. Frequency measures of total perennial grass, black grama, tobosa (Hilaria mutica Buckley), total shrubs, honey mesquite (Prosopis glandulosa Torr.), and other vegetation components were similar on both grazed and ungrazed treatments (P > 0.1) at the beginning and end of the study. The amount of change in rangeland ecological condition scores was the same positive increase (14%) for both grazed and ungrazed treatments. Major changes (P < 0.1) occurred within this 38-yr study period in ecological condition scores and frequency of total perennial grasses and black grama in response to annual fluctuations in precipitation. Based on this research, managed livestock grazing and excluded livestock grazing had the same long-term effects on change in plant frequency and rangeland ecological condition; thus, it appears that managed livestock grazing is sustainable on Chihuahuan desert rangelands receiving over 25 cm annual precipitation.     

Comparative performance of dairy cows in low-input smallholder and high-input production systems in South Africa

The aim of this study was to benchmark the performance of dairy cows in the low-input smallholder system against their counterparts in the high-input system, in South Africa. Data comprised of cow performance records from the national dairy recording scheme. Performance measures included production (305-day yields of milk, fat, and protein), lactation length, somatic cell count (SCC), and reproductive traits, represented by age at first calving (AFC) and calving interval (CI). Least squares means of each trait were compared between the two systems, and lactation curves for production traits and SCC were plotted for each production system. Mean yields of milk, fat, and protein were significantly (P?<?0.05) lower in the smallholder (4097?±?165, 174?±?5.1, and 141?±?4.5 respectively) compared to the high-input system (6921?±?141, 298?±?4.7, and 245?±?4.1 respectively). Mean lactation length was significantly (P?<?0.05) shorter for the smallholder (308?±?15.1) than the high-input system (346?±?12.8). Log-transformed somatic cell count (SCS) was, however, significantly (P?<?0.05) higher in the smallholder (2.41?±?0.01) relative to the high-input system (2.27?±?0.01). Cows in high-input herds showed typical lactation curves, in contrast to the flat and low peaking curves obtained for the smallholder system. Cows on smallholder herds had their first calving significantly (P?<?0.05) older (30?±?0.5) than those in the high-input system (27?±?0.5). There was, however, no significant difference (P?<?0.05) in CI between the two systems. These results highlight large room for improvement of dairy cow performance in the smallholder system and could assist in decision-making aimed at improving the productivity of the South African dairy industry.     

Ovarian evaluation of Girolando (Holstein × Gir) heifers submitted to a GnRH–PGF2α–GnRH protocol in the dry or rainy seasons in the tropical savannah

The Girolando breed is used in pasture-based dairy production systems in Brazil to associate the high production of Bos taurus to the rusticity and thermal adaptation of Bos indicus. This study was designed to evaluate the physiological response to a gonadotropin-releasing hormone (GnRH)–prostaglandin F_2α (PGF_2α)–GnRH protocol to synchronize the ovulation in 40 Girolando heifers of a pasture-based dairy production system and its relationships with the temperature and humidity index (THI) during the dry (DS) and rainy season (RS) in the tropical savannah—Brazil's cerrado biome. Responses were characterized by follicular and corpus luteum number and diameter, ovulation (D9), and pregnancy rates after first AI. Total follicle number (8.1?±?0.3?×?8.8?±?0.3), D9 ovulatory follicle diameter (11.9?±?0.4?×?10.1?±?0.4 mm), corpus luteum diameter (8.6?±?1.3?×?3.9?±?1.5 mm), corpus luteum score (3.7?±?0.8?×?1.8?±?1.0), corpus luteum diameter after AI (9.6?±?1.6?×?3.9?±?1.5 mm), and corpus luteum score after AI (3.2?±?0.4?×?0.9?±?0.6) in DS and RS differed (P?<?0.01). D9 ovulation rate was 40 % (DS) and 20 % (RS), without differences (P?>?0.05). Pregnancy rate was 45 % (DS) and 11 % (RS), with differences (P?<?0.01). THI differed between DS and RS (P?<?0.01). THI may interfere in the follicular and luteal dynamics and in the response of Girolando heifers to the GnRH–PGF_2α protocol in the tropical savannah, thus reducing the chances of pregnancy at the first artificial insemination.     

Physiological and haematological indices suggest superior heat tolerance of white-coloured West African Dwarf sheep in the hot humid tropics

Coat colour contributes to physiological adaptation in mammals and mediates response to thermal stress. Twenty-four adult West African Dwarf sheep of both sexes and with different coat colour types were used in this study. We measured rectal temperature (RT), respiratory rate (RR) and pulse rate (PR) before sunrise and sunset during the late dry season (January–March) and early rainy season (April–June) as well as packed cell volume (PCV), red blood cell (RBC) count, white blood cell (WBC) count, plasma sodium (Na⁺) and potassium (K⁺). Animals with black coat colour had the highest (P?<?0.05) mean values of 38.92?±?0.03 °C, 65.09?±?1.06 breaths/min, 81.35?±?0.78 beats/min, 1.70?±?0.01 for RT, RR, PR and heat stress index (HSI), respectively, followed by brown mouflon and brown with extensive white, while the Badger Face coloured sheep had the least mean values. There were significant (P?<?0.05) differences between male and female sheep for RT, RR, PR and HSI. Season had a significant (P?<?0.05) effect on RT, RR, PR and HSI. Coat colour and sex also significantly (P?<?0.01) affected RBC, WBC, Na⁺ and K⁺. Seasonal variation (P?<?0.05) in all the blood parameters was observed, with the exception of PCV. Interaction effect of coat colour and sex was significant (P?<?0.05) on RT and HSI. Correlation coefficients among the measured traits ranged from positive to negative values. These results indicate that selection of white-coloured sheep to attenuate heat stress is desirable in the hot humid tropics.     

Effects of Wildlife on Cattle Diets in Laikipia Rangeland,Kenya

The impacts of wild herbivores on cattle diet selection were investigated in an East African rangeland during August 2001 and February 2002. The study compared cattle diets in plots exclusively accessible to cattle (C) and those accessible to megaherbivores (elephants and giraffes), non-megaherbivore wild herbivores > 15 kg (zebras, hartebeests, Grant's gazelles, oryx, elands, and buffaloes) and cattle (MWC); or non-megaherbivore wild herbivores and cattle (WC). There were no treatment differences in selection of most grass species in either sampling period (P > 0.05). However, selection of forbs differed among treatments during February when conditions were relatively dry and percent of bites taken by cattle on this forage class increased (P < 0.005) from 1.8% ± 0.3 to 7.7% ± 1.6 (mean ± SE). During this period, cattle took a lower percent of bites on forbs in MWC (4.3% ± 1.7; P = 0.01) and WC (5.9% ± 2.2; P = 0.03) than in C (12.9% ± 0.9). These patterns were generally driven by Commelina spp., which comprised 65% ± 9.4 of total bites on forbs. Notably, these differences were associated with differences in cover of forbs, which was positively correlated with percent of bites on forbs (r² = 0.86, P < 0.01). Because forbs may be critical components of cattle diets in such rangelands during relatively dry periods, these dietary changes may indicate potential seasonal costs of wildlife to cattle production. Looking for ways to offset such costs may be worthwhile for livestock properties that accommodate wildlife.     

Forb Cover Increases After Solarization and Winter Fire in a Grassland Invaded by Yellow Bluestem

Solarization (covering soil and vegetation with plastic) has long been used in agriculture to control undesirable plants, but solarization of invasive plants in rangelands has shown mixed and species-specific results. Yellow bluestem (Bothriochloa ischaemum (L.) Keng var. songarica (Rupr. ex Fisch & C.A. Mey) Celarier & Harlan), an invasive perennial C₄ grass, is common throughout the southern Great Plains and is not controlled by winter prescribed fire. We tested whether solarization (tarping) with black plastic, combined with winter prescribed fire, could control yellow bluestem. We applied three treatments (with four replicates): solarization (August to November 2017) + fire (January 2018), trimming + fire, and fire only. Results after two growing seasons show that total yellow bluestem cover in solarized + fire plots was reduced to 54% ± 10% (mean ± standard error), lower than trimmed + fire (82% ± 5%, p < 0.01) and fire only plots (78% ± 6%, p = 0.01). Forb cover in solarized + fire plots (15% ± 4%) was much higher than trimmed + fire (4% ± 1%, p < 0.01) and fire only plots (3% ± 1%, p < 0.01). Native forb richness was only slightly higher in solarized + fire plots (16 ± 2 species) compared to fire only (10 ± 2 species, p = 0.08) and trimmed + fire plots (10 ± 1 species, p = 0.08). Interestingly, native forb richness in all plots increased compared to pre-treatment values (2 ± 1 species for all treatments, p < 0.01). Solarization + winter fire can slightly decrease yellow bluestem cover and greatly increase native forb cover, creating islands of diversity in otherwise low-diversity grasslands. However, repeated treatments or alternative techniques will be needed for full control of yellow bluestem.     

Behavior of artificially suckled foals

Artificial feeding of foals is rarely practiced other than for raising orphans. This study investigated the effects of an artificial feeding system on the growth and welfare of a group of “Cavallo Agricolo Italiano da Tiro Pesante Rapido” foals (n = 12). A viable artificial rearing method could allow for the commercial supply of mare’s milk for cosmetic or pediatric purposes. Six foals were maintained on an artificial suckling (AS) regimen using a modified bovine milk replacer, and 6 remained with their dams (control group, naturally suckled [NS]).Housing and management was identical for both groups. During the 6-month trial, the foals were weighed every 3 weeks from 4 days of age, and their daily weight gains were calculated. Foals were directly observed for 6 separate 24-hour periods at 4, 10, 47, 114, 142, and 176 days of age, and an ethogram was compiled from the observed behaviors (resting, social, alimentary, and eliminative).All data were analyzed using a repeated measures analysis.At 4 days of age, the behavior of the AS foals was significantly different from that of the control group foals in that they stood up for longer duration (530 vs. 174 minutes, P < 0.01), performed fewer suckling bouts (P < 0.01), and did not play (P < 0.01) or lick (P < 0.05). AS foals were more aggressive and cross-suckled more (P < 0.01) at 10 days of age than at the first observation period.After weaning, AS foals ate more concentrate and less hay than the control group foals (P < 0.01). However, at the end of the trial, there were no significant differences between the groups in terms of weight (AS vs. NS [mean ± standard deviation]: 350 ± 15 vs. 360 ± 20 kg, P = 0.34) and daily weight gains (1630 ± 370 vs. 1600 ± 310 g/d, P = 0.88).Artificial suckling techniques could be applied to Cavallo Agricolo Italiano da Tiro Pesante Rapido foals, without negative effects on growth and welfare during the first 6 months of life. In fact, after an initial adaptation period, the AS foals did not exhibit any abnormal behavior or behavioral differences compared with NS foals. Further studies are required to improve this rearing technique, which could facilitate the efficient raising of orphan foals and/or marketing equine milk. Additional research would enable the effects of this rearing technique on the long-term growth, behavior, and health of the foals.     

Relationships Among Plasma Proteins,Hematological Values,and Gender in Thoroughbred and Miniature Horses

Our objective was to investigate the relationships among plasma proteins, hematological values, and gender in Thoroughbred (nine females and 16 males) and miniature (30 females and four males) horses. Twenty-two protein bands, ranging from 8 to 264 kDa, were detected in horse plasma. Red blood cells, hemoglobin, and hematocrit were negatively correlated (r ≤ −0.29; P < .05) with bands 13 and 17 but positively correlated (r ≥ 0.40; P < .01) with band 3. A negative correlation (r ≤ −0.27; P < .05) was detected between bands 1, 8, and lymphocytes. Neutrophils were positively correlated with bands 1 and 8. Basophils had a positive correlation (r = 0.36) with band 12 and negative correlation with bands 11 (r = −0.30) and 13 (r = −0.48). Platelets had positive correlations (r ≥ 0.24; P < .10) with bands 3, 4, 5, 10, 14, 19, and 22. The relative intensities of protein bands 4, 16, and 22 were affected (P < .05) by an interaction of breed and gender. Gender effects (P < .05) were detected for plasma protein bands 1 (1.6 vs. 2.4 ± 0.23), 5 (2.6 vs. 3.6 ± 0.25), and 11 (8.7 vs. 13.2 ± 1.1), respectively, for females and males. Breed effects (P < .05) were detected for plasma protein bands 5 (2.5 vs. 3.8 ± 0.25) and 11 (9.0 vs. 12.9 ± 1.1), respectively, for Thoroughbreds and miniatures. When developing new pathophysiological tools for equine disease diagnosis and therapy, breed and gender effects should be considered.     

Practice on improving fattening local cattle production in Vietnam by increasing crude protein level in concentrate and concentrate level

Two experiments were conducted to determine the effects of crude protein (CP) level in concentrate (experiment 1) and concentrate level (experiment 2) on feed intake, nutrient digestibility, nitrogen (N) retention, ruminal pH and NH₃-N concentration and average daily gain (ADG) of Vietnamese local fattening cattle. Animals (24 cattle, initial live weight (LW) 150.3?±?11.8 kg in experiment 1 and 145.1?±?9.8 kg in experiment 2) were allotted based on LW to one of four treatments in a randomised complete block design. In experiment 1, concentrate with four levels of CP (10, 13, 16 and 19 %) was fed at 1.5 % of LW. In experiment 2, concentrate was fed at 1.0, 1.4, 1.8 and 2.2 % of LW. In both experiments, roughage was 5 kg/day native grass and ad libitum rice straw (fresh basis). Results showed that the CP level in concentrate significantly affected dry matter (DM) intake (P?<?0.05), N retention, ADG and ruminal NH₃-N concentration (P?<?0.01), but it had no significant effect on DM, organic matter (OM) and neutral detergent fibre (NDF) digestibility (P?>?0.05), whereas CP digestibility increased (P?<?0.001) along with the CP level. DM intake, N retention and ADG increased (P?<?0.001) linearly with concentrate intake. DM and CP digestibility were not significantly affected by concentrate intake (P?>?0.05). OM digestibility and NH₃-N concentration increased linearly (P?<?0.05), whereas NDF digestibility and ruminal pH declined linearly with increased concentrate consumption (P?<?0.01). These results indicate that 16 % CP in concentrate and feeding concentrate at the rate of 2.2 % of LW are recommendable for fattening local cattle in Vietnam.     

Leucaena and dried poultry waste improve the performance of West African Dwarf sheep on a grass diet

This study investigated the effects on digestibility and growth when West African Dwarf (WAD) sheep were fed a basal diet of Tripsacum laxum with Leucaena leucocephala or dried poultry waste as supplement. Fifteen WAD sheep (12 rams and 3 ewes) were randomly allocated to three dietary treatments of 5 animals each, namely T1—basal diet of chopped T. laxum (control), T2—basal diet plus dried poultry waste, and T3—basal diet plus L. leucocephala. Animals had access to drinking water and a mineral mix ad libitum. They were weighed weekly after a 2-week adaptation period, for a duration of 12 weeks. At the end of the feeding trial, three rams randomly selected from each treatment group were used for the digestibility study. Results revealed that average daily intake of L. leucocephala (350.0?±?0.3 g/animal) was higher than that of dried poultry waste (260.0?±?0.1 g/animal). The supplemented groups, T2 and T3, gained 21.4 and 31.0 g daily respectively, while animals of the control group (T1) lost 6.0 g daily. There was a significant difference (P?<?0.01) in dry matter intake between the control and supplemented groups, with T2 recording the highest intake. Organic matter intake of treatment 3 was significantly (P?<?0.01) higher than that of T1 and T2. The differences in crude fibre (CF) ingestion between T2 and T1 as well as T3 and T1 were significant (P?<?0.01), with the highest ingestion of CF occurring in T1. The dry matter digestibility of the supplemented groups was significantly higher (P?<?0.05) than that of the control. The organic matter digestibility of T2 and T3, as well as T1 and T3 were significantly different (P?<?0.05), being highest in T3 (77.0?±?2.1 %) and lowest in T2 (58.1?±?1.0 %) It was concluded from the study that T. laxum can be better utilized in West African Dwarf sheep when supplemented with dried poultry waste or L. leucocephala.     

Effect of scrotal bifurcation on breeding soundness traits in Beetal bucks during summer season

Relationship of scrotal bifurcation or splitness with breeding soundness traits was investigated in 15 Beetal bucks (17–20 months of age and 48.72?±?1.57 kg mean BW). Breeding soundness traits of conjoined/unsplit (n?=?6) scrotal bucks was compared with split (n?=?9) scrotal bucks having lengthwise >?1 in. bifurcation. Two consecutive semen ejaculations per buck were collected at monthly interval during summer season (April to June 2018) using intact buck as teaser and sexual behavior was simultaneously recorded. Scrotal morphometry parameters, i.e., scrotal circumference, scrotal volume, scrotal skin thickness, testis length, width, and thickness were also recorded. Bucks with split scrotum had relatively more scrotal dimensions (scrotal circumference (P?<?0.01), scrotal volume (P?<?0.01), testis length (P?<?0.01)) than conjoined scrotal bucks. Among various semen attributes, semen volume of first ejaculate (P?<?0.01), second ejaculate (P?<?0.05), mean semen volume (P?<?0.01), total sperm count of first ejaculate, and mean sperm count of both ejaculates were more (P?<?0.01) in split scrotal bucks. However, scrotal bifurcation had no influence on sexual behavior of bucks. It is concluded that Beetal bucks with split scrotum had relatively better breeding efficiency traits than conjoined scrotal bucks.

     

Effect of Brazilian red propolis administration on hematological, biochemical variables and parasitic response of Santa Inês ewes during and after flushing period

Brazilian red propolis was administered orally to Santa Inês ewes, and evaluation was made of general health and hematological, biochemical, and parasitic responses during and after flushing. Thirty mature, nonlactating, nonpregnant Santa Inês ewes (40?±?2 kg and 2.5 years old) were grazing tropical pasture (Brachiaria decumbens and Pennisetum purpureum) and, as flushing after synchronization, were supplemented with a concentrate–roughage mixture at a rate of 4 % body weight (BW). Ewes were divided according to BW and fecal egg count (FEC) into two groups (n?=?15 each): control and propolis that received propolis ethanolic extract at rates of, respectively, 0 and 3 g/ewe/day. The treatments lasted 21 days until the end of flushing period. BW and body condition score (BCS) were recorded, and blood and fecal samples were taken weekly for 8 weeks. Mean values of BW and BCS were not (P?>?0.05) affected by propolis administration. Propolis increased (P?<?0.01) total leukocytes (WBC), but no significant differences were observed for other hematological parameters. Propolis increased (P?<?0.01) total protein and globulin concentrations and decreased (P?<?0.01) triglycerides, glutamate oxaloacetate transaminase, and glutamate pyruvate transaminase. Propolis decreased (P?<?0.05) FEC. Propolis administration had good impact on ewe health and may be a promising feed additive during critical periods such as flushing.     

Higher feeding diets effects on age and liveweight gain at puberty in crossbred Nelore × Hereford heifers

This study was conducted to determine the age and liveweight at puberty of 120 crossbred beef heifers submitted to four diets to achieve predetermined weight gains (kg/day): 0.5 (G500; n?=?32), 0.75 (G750; n?=?32), 1.0 (G1000; n?=?29), and 1.25 (G1250; n?=?27). Animals were classified depending on their level of crossing between Nelore (N) and Hereford (H): 25%N-75%H, 37.5%N-63.5%H, 43.7%N-56.7%H, 50%N-50%H, and 75%N-25%H. Reproductive evaluation was performed at the beginning and at the end of the experimental period by ultrasonography and hormone analysis. The average age and liveweight at puberty were 388.0?±?1.9 days and 331.4?±?1.3 kg, respectively. Animals from the 25%N-75%H group reached puberty earlier than heifers from other genetic groups supplemented with G1250 diet (P?<?0.05). Heifers with higher degree of Nelore (75%N-25%H) fed with G1000 diet showed estrus 42 days prior to mating, but only 57 % reached puberty at mating (P?<?0.05). Heifers with follicles of higher diameter reached puberty (P?<?0.05) earlier. Higher average daily weight gain showed a positive effect on follicular diameter and IGF-I level at puberty (P?<?0.01). Concentrations of GH were lower in heifers fed G1250 compared to G1000 diet (P?<?0.05). There was a significant interaction between nutritional level and insulin levels at puberty (P?<?0.01). We demonstrated the relationship between IGF-I and average daily gain on the onset of puberty in heifers. In conclusion, heifers submitted to the higher feeding level showed a higher follicular diameter and were younger at puberty.     

Effect of peripheral concentrations of progesterone on follicular growth and fertility in ewes

The effects of progesterone (P₄) on follicular growth and fertility in ewes were examined. In Experiment 1, 22 ewes received either one or three packets of P₄ (5 g/packed) or an empty packet subcutaneously (sc) from Days 5 to 15 of the estrous cycle (estrus = Day 0). On Day 6, P₄-treated ewes received 12.5 mg of prostaglandin F₂α. Follicles ⩾3 mm in diameter were observed via transrectal ultrasonography daily from Day 4 through estrus, corpora lutea (CL) were observed 5 to 7 d after estrus. Ewes with low (LOW; ⩽1 ng/ml; n = 5), intermediate (MED; > 1 and <2 ng/ml; n = 10), or normal (NOR; ⩾2 ng/ml; n = 7) P₄ in jugular plasma on Days 7 through 15 differed in follicular development. The largest follicle at estrus was larger in ewes with LOW vs. MED and NOR P₄ (7.8 ± 0.3 vs. 6.9 ± 0.2 mm; P < 0.05). Treatments differed in proportions of multiple-ovulating ewes, in which the oldest ovulatory follicle was first observed before Day 10 (LOW: 3 of 3, MED: 6 of 10, NOR: 0 of 5, respectively; P < 0.05). Estradiol was higher early in the treatment period in LOW ewes than in MED and NOR ewes (day × treatment; P < 0.05). In Experiment 2, ewes received 5 mg of P₄ in corn oil (low progesterone [LP]; n = 51) or 2 ml of corn oil (CON; n = 49) sc every 12 hr on Days 6 through 14 of the estrous cycle before mating. LP ewes received 15 mg of prostaglandin F₂α on Day 6. Mean serum P₄ on Days 7 through 15 was 0.6 ± 0.1 ng/ml in LP and 1.9 ± 0.1 ng/ml in CON ewes. Eleven LP and 12 CON ewes were scanned daily from Day 4 through mating, and in all ewes (n = 93), CL were counted 10 d after mating and embryos were counted at 25, 40, and 60 d of gestation. In multiple-ovulating ewes, day of cycle of appearance was earlier for the oldest (Day 6.1 ± 0.8 vs. 10.4 ± 0.8) but not second oldest (Day 11.7 ± 1.0 vs. 12.2 ± 0.9) ovulatory follicles in LP compared with CON ewes. The conception rate was lower in LP (72%) than in CON ewes (98%; P < 0.01). However, numbers of CL 10 d after mating, and in pregnant ewes, numbers of embryos 25 d after mating and lambs born, did not differ with treatment. In summary, low P₄ increased the size of the largest follicles and the age of the oldest ovulatory follicles. Embryos resulting from the ovulation of older and younger follicles in the same ewe did not differ in their ability to survive.