Influence of Bos indicus crossbreeding and cattle age on apparent utilization of a high-grain diet

Ten Bos indicus x MARC III (initial BW = 303 +/- 25 kg) and 10 MARC III (initial BW = 322 +/- 16 kg) steers were used in a 2 x 2 factorial design to determine whether cattle age or Bos indicus crossbreeding influence site of digestion of a high-grain diet. Initially, five Bos indicus x MARC III and five MARC III steers were fitted with duodenal cannulas and adapted to a 95% concentrate diet that was offered for ad libitum consumption for a 237-d feeding period (calves). During the feeding period, duodenal and fecal samples were collected during 4-d periods beginning on d 14, 67, 137, and 228. The remaining 10 steers were fed a forage-based diet for a targeted daily gain of .6 to .7 kg for 210 d (yearlings). Following this period, yearling steers were duodenally cannulated and adapted to the 95% concentrate diet. Yearling steers had ad libitum access to feed for 165 d, and samples were collected during 4-d periods beginning on d 13, 42, 102, and 159. Dry matter intake was 9.8 and 7.6 kg/d and daily gain was 1.35 and 1.16 kg in yearlings and calves, respectively. Apparent OM digestion in the stomach was greater (P < .01) in yearlings than in calves. In contrast, postruminal disappearance as a percentage of OM intake was greater (P = .05) in calves than in yearlings. Duodenal flows of total N, microbial N, nonmicrobial N, and total amino acids and total tract N digestibility were not affected (P > .05) by age or Bos indicus crossbreeding. Fecal N excretion was greater (P < .01) in yearlings than in calves. Results of this experiment suggest little effect of Bos indicus influence on utilization of a high-grain diet. However, more feed is digested in the rumen of yearlings than of calves consuming a high-grain diet.     

Butorphanol and azaperone as a safe alternative for repeated chemical restraint in captive white rhinoceros (Ceratotherium simum).

Anesthesia in the white rhinoceros (Ceratotherium simum) has routinely involved potent narcotic anesthetic agents such as etorphine or carfentanil with their associated adverse side effects. In captive rhinoceroses conditioned to routine handling, a combination of butorphanol and azaperone at mean (+/- SD) doses of 69.3 +/- 18.0 mg and 103.1 +/- 20.9 mg, respectively, was used to produce levels of neuroleptanalgesia ranging from light "standing" sedation to deeper planes of anesthesia producing sternal and lateral recumbency. This combination was used for repeated (minimum repeat frequency of 3 days between events) anesthetic episodes (n = 26) in two animals, with the remaining episode performed in a white rhinoceros with chronic renal disease. The action of butorphanol was satisfactorily reversed with naltrexone (125 mg i.v. and 125 mg i.m.). Results (mean +/- SD) include sternal recumbency achieved in 14.1 +/- 8.1 min after i.m. dosing, standing and ambulation occurred in 1.7 +/- 0.6 min after reversal, heart rate was 62.0 +/- 10.1 beats/min, respiratory rate was 14.7 +/- 5.6 breaths/min, and percentage of oxygen saturation of hemoglobin (Spo2) was 89.2 +/- 3.0%. Without supplementation, the total elapsed time ranged from 44.9 min to 103.0 min, whereas elapsed times up to 214.3 min were achieved with supplementation (mean time to supplementation was 28.0 +/- 13.9 min after initial dosing). Butorphanol and azaperone produced adequate muscle relaxation and apparently adequate analgesia for minor surgical interferences, including abdominal laparoscopy. Respiratory rates and Spo2 measurements were improved compared with reports of using more potent opioids in this species.     

Intralesional cisplatin chemotherapy and topical cryotherapy for the control of choanal squamous cell carcinoma in an African penguin (Spheniscus demersus).

A 3.5-yr-old, 2.5-kg female African penguin (Spheniscus demersus) was diagnosed with a choanal squamous cell carcinoma on the basis of biopsy after a history of choanal ulceration and anorexia with weight loss. Therapeutic modalities included the use of intralesional cisplatin followed by localized, topical cryotherapy with liquid nitrogen. The penguin remained free of clinical disease for a period of 9 mo, at which time a second cryotreatment was performed. The patient has remained free of all signs of choanal carcinoma for a period of 13 mo since the second cryotreatment.     

Determination of Feeder Cell‐Based Cellular Niches Supporting the Colonization and Maintenance of Spermatogonial Stem Cells from Prepubertal Domestic Cat Testes

Recently, isolation and in vitro culture of putative spermatogonial stem cells (SSCs) in the domestic cat have been conducted. However, the cellular niche conditions that facilitate the establishment and long‐term maintenance of feline SSCs (FSSCs) have not been described. Therefore, we investigated the type of feeder cells used to stimulate colony formation and growth of FSSCs among the various factors in the FSSC niche. Spermatogonial stem cells isolated from feline testes were cultured on mitotically inactivated testicular stromal cells (TSCs) derived from cats, dogs and mice, and mouse embryonic fibroblasts (MEFs). The formation and growth of colonies derived from SSCs cultured on each type of feeder cell were identified at passage 0, and the morphology, alkaline phosphatase (AP) activity and expression of SSC‐specific genes in surviving colonies were investigated at passage 4. Among these diverse feeder cells, TSCs from cat showed the greatest colony formation, growth and maintenance of FSSCs, and SSC colonies cultured by passage 4 showed a typical dome‐shaped morphology, AP activity and expression of SSC‐specific genes (NANOG, OCT4, SOX2 and CD9). Accordingly, these results demonstrate that feline TSCs could be used as feeder cells to support the establishment and maintenance of SSCs from domestic cats.     

Genetic divergence of kingfish from Japan, Australia and New Zealand inferred by microsatellite DNA and mitochondrial DNA control region markers

ABSTRACT: Genetic polymorphism in kingfish, collected from coastal waters of Japan, Australia and New Zealand, were examined using microsatellite (MS) DNA and mitochondrial DNA (mtDNA) control region markers. Sixteen to 25.7 alleles per locus were observed in three MS markers, while the average observed (and expected) heterozygosities were 0.782 (0.918), 0.750 (0.809) and 0.650 (0.888) for Australian, Japanese and New Zealand kingfish, respectively. Twelve mtDNA haplotypes were detected by the digestion of control region sequences with five endonucleases: Hae III, Hinf I Mbo I, Rsa I and Taq I. Significant genetic divergence was observed between the kingfish population from Japan and those from Australia–New Zealand. There was no significant differentiation among the Australian and New Zealand population samples.     

Level of nutrition and splanchnic metabolite flux in young lambs

Splanchnic metabolite flux was measured in young lambs given access to a high-concentrate diet either ad libitum (ADLIB) or at a maintenance level (MAINT) for 21 d. Net fluxes of urea N (UN), ammonia N (NH3 N), alpha-amino N (AAN), amino acids, glucose (G), and lactate (L) across the liver and portal-drained viscera (PDV) were measured in 11 crossbred ram lambs (35 kg) surgically fitted with indwelling catheters in the portal, hepatic, and mesenteric veins and mesenteric artery. During the 21-d period, daily N and ME intakes were 24.6 and 10.7 g N/d and 3.02 and 1.28 Mcal/d, respectively, for ADLIB and MAINT lambs. Intakes, thus, were 42% lower for MAINT than for ADLIB lambs. Net portal fluxes of UN, NH3 N, AAN, and L in MAINT lambs were 46%, 84%, 50%, and 74%, respectively, of that in ADLIB lambs. Expressed as a percentage of N intake, the proportion of AAN absorbed by the PDV was higher in MAINT lambs (P less than .05) than in ADLIB lambs. There was no net portal glucose absorption in either group of lambs; however, net hepatic glucose production in MAINT lambs was 48% of that in ADLIB lambs. There was net utilization of glutamine by the PDV; net glutamine flux in MAINT lambs was 49% of that in ADLIB lambs. The liver utilized AAN and NH3 N and produced UN. Splanchnic tissues modulate metabolite flux following changes in feed intake in young ruminants.     

Differences among breed crosses of cattle in the conversion of food energy to calf weight during the preweaning interval

The objective of this study was to determine whether F1 cows that differ in genetic potential for weight at maturity and milk yield vary in the conversion of food energy to calf weight gain. Food intakes and weight change data were recorded by pen for cows and calves from approximately 45 d postpartum. Cows assigned to the study were 7- to 9-yr-old F1s produced by top-crossing Angus, Hereford, Brown Swiss, Chianina, Gelbvieh; Maine Anjou, and Red Poll sires to either Angus or Hereford dams. Calves were sired by Simmentals. Experimental units were pens (10 to 12 cow/calf pairs); pen was replicated within breed of sire in each of 2 yr (n = 24). Calf weight gain and energy consumed by the dams differed among the F1s, as did the ratio of calf weight gain to energy consumed by the calf and cow. Angus or Hereford (35.8), Red Poll (35.7), or Maine Anjou (35.6) F1s produced more calf weight per unit of energy consumed (g/Mcal) by the cow and calf than Chianina (33.1) or Gelbvieh (33.7) F1 females; Brown Swiss cows were intermediate (34.3). Differences in food conversion efficiency exist among breed crosses. These differences seem to be associated with breed cross differences in genetic potential for milk yield and mature weight; an exception to this trend was the Maine Anjou.     

Compensatory growth following metabolizable protein or energy restrictions in beef steers

One hundred sixty crossbred steers were used to compare the effects of metabolizable protein and energy restrictions on subsequent compensatory growth. Diets were formulated to impose severe or mild growth restrictions for periods of 77 to 154 d. Steers were realimented on a high-concentrate diet and fed to achieve approximately 1 cm s.c. fat thickness. Finishing performance and carcass characteristics were evaluated relative to unrestricted control animals. All restricted animals, with the exception of those on the mild, brief energy restriction, exhibited compensatory growth relative to controls. A single direct comparison of energy and protein restriction treatments indicated that finishing performance during realimentation was similar for these two groups. Evaluation of the relative effects of protein and energy restriction by multiple linear regression indicated that compensatory growth was influenced by differences in duration or severity of nutrient deprivation to a greater extent for energy-restricted than for protein-restricted steers. Linear contrasts and regression estimates indicated that compensatory growth was influenced more by differences in severity of restriction than by duration of the restriction period.